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Sample records for production target irradiation

  1. Soluble irradiation targets and methods for the production of radiorhenium

    SciTech Connect

    Vanderhevden, J.L.E.; Su, F.M.; Ehrhardt, G.J.

    1992-09-08

    This patent describes a method of producing a rhenium-188 radionuclide generator. It comprises irradiating a water soluble irradiation target selected from the group consisting of sodium tungstate and lithium tungstate, reacting the irradiated target with an aqueous zirconium solution to obtain an insoluble zirconium tungstate gel, and disposing the zirconium tungstate in an elutable container to obtain the rhenium-188 radionuclide generator.

  2. Development of a Ne gas target for {sup 22}Na production by proton irradiation

    SciTech Connect

    Mandal, Bidhan Ch. Pal, Gautam; Barua, Luna; Das, Sujata Saha

    2016-03-15

    The article presents the design and development of a neon gas target for the production of {sup 22}Na using a proton beam from the room temperature cyclotron in Variable Energy Cyclotron Centre, Kolkata. The target design is made to handle a beam power of 85 W (17 MeV, 5 μA). The design is based on simulation using the computer code FLUKA for the beam dump and CFD-CFX for target cooling. The target has been successfully used for the production of {sup 22}Na in a 6 day long 17 MeV, 5 μA proton irradiation run.

  3. Isotope production target irradiation experience at the annular core research reactor

    SciTech Connect

    Talley, D.G.

    1997-02-01

    As a result of an Environmental Impact Statement (EIS) recently issued by the Department of Energy, Sandia National Laboratories (SNL) has been selected as the {open_quotes}most appropriate facility{close_quotes} for the production of {sup 99}Mo. The daughter product of {sup 99}Mo is {sup 99m}Tc, a radioisotope used in 36,000 medical procedures per day in the U.S.{close_quote} At SNL, the {sup 99}Mo would be created by the fission process in UO{sub 2} coated {open_quotes}targets{close_quotes} and chemically separated in the SNL Hot Cell Facility (HCF). SNL has recently completed the irradiation of five production targets at its Annular Core Research Reactor (ACRR). Following irradiation, four of the targets were chemically processed in the HCF using the Cintichem process.

  4. Post-Irradiation Examination of 237Np Targets for 238Pu Production

    SciTech Connect

    Morris, Robert Noel; Baldwin, Charles A; Hobbs, Randy W; Schmidlin, Joshua E

    2015-01-01

    Oak Ridge National Laboratory is recovering the US 238Pu production capability and the first step in the process has been to evaluate the performance of a 237Np target cermet pellet encased in an aluminum clad. The process proceeded in 3 steps; the first step was to irradiate capsules of single pellets composed of NpO2 and aluminum power to examine their shrinkage and gas release. These pellets were formed by compressing sintered NpO2 and aluminum powder in a die at high pressure followed by sintering in a vacuum furnace. Three temperatures were chosen for sintering the solution precipitated NpO2 power used for pellet fabrication. The second step was to irradiate partial targets composed of 8 pellets in a semi-prototypical arrangement at the two best performing sintering temperatures to determine which temperature gave a pellet that performed the best under the actual planned irradiation conditions. The third step was to irradiate ~50 pellets in an actual target configuration at design irradiation conditions to assess pellet shrinkage and gas release, target heat transfer, and dimensional stability. The higher sintering temperature appeared to offer the best performance after one cycle of irradiation by having the least shrinkage, thus keeping the heat transfer gap between the pellets and clad small minimizing the pellet operating temperature. The final result of the testing was a target that can meet the initial production goals, satisfy the reactor safety requirements, and can be fabricated in production quantities. The current focus of the program is to verify that the target can be remotely dissembled, the pellets dissolved, and the 238Pu recovered. Tests are being conducted to examine these concerns and to compare results to code predictions. Once the performance of the full length targets has been quantified, the pellet 237Np loading will be revisited to determine if it can be

  5. Production of 230U/226Th for targeted alpha therapy via proton irradiation of 231Pa.

    PubMed

    Morgenstern, Alfred; Lebeda, Ondrej; Stursa, Jan; Bruchertseifer, Frank; Capote, Roberto; McGinley, John; Rasmussen, Gert; Sin, Mihaela; Zielinska, Barbara; Apostolidis, Christos

    2008-11-15

    (230)U and its daughter nuclide (226)Th are novel therapeutic nuclides for application in targeted alpha-therapy of cancer. We have investigated the feasibility of producing (230)U/(226)Th via proton irradiation of (231)Pa according to the reaction (231)Pa(p,2n)(230)U. The experimental excitation function for this reaction is reported for the first time. Cross sections were measured using thin targets of (231)Pa prepared by electrodeposition and (230)U yields were analyzed using alpha-spectrometry. Beam parameters (energy and intensity) were determined both by calculation using a mathematical model based on measured beam orbits and beam current integrator and by parallel monitor reactions on copper foils using high-resolution gamma-spectrometry and IAEA recommended cross-section data. The measured cross sections are in good agreement with model calculations using the EMPIRE-II code and are sufficiently high for the production of (230)U/(226)Th in clinically relevant amounts. A highly effective separation process was developed to isolate clinical grade (230)U from irradiated protactinium oxide targets. Product purity was assessed using alpha- and gamma-spectrometry as well as ICPMS.

  6. Hot electron production using the Texas Petawatt Laser irradiating thick gold targets

    NASA Astrophysics Data System (ADS)

    Taylor, Devin; Liang, Edison; Clarke, Taylor; Henderson, Alexander; Chaguine, Petr; Wang, Xin; Dyer, Gilliss; Serratto, Kristina; Riley, Nathan; Donovan, Michael; Ditmire, Todd

    2013-06-01

    We present data for relativistic hot electron production by the Texas Petawatt Laser irradiating solid Au targets with thickness between 1 and 4 mm. The experiment was performed at the short focus target chamber TC1 in July 2011, with intensities on the order of several ×1019 W/cm2 and laser energies around 50 J. We discuss the design of an electron-positron magnetic spectrometer to record the lepton energy spectra ejected from the Au targets and present a deconvolution algorithm to extract the lepton energy spectra. We measured hot electron spectra out to ˜50 MeV, which show a narrow peak around 10-20 MeV, plus high energy exponential tail. The hot electron spectral shapes appear significantly different from those reported for other PW lasers.

  7. Neutron production by a 13C thick target irradiated by 20 90 MeV protons

    NASA Astrophysics Data System (ADS)

    Lhersonneau, G.; Malkiewicz, T.; Vakhtin, D.; Plokhoi, V.; Alyakrinskiy, O.; Barbui, M.; Brandenburg, S.; Dendooven, P.; Cinausero, M.; Kandiev, Ya.; Kettunen, H.; Khlebnikov, S.; Lyapin, V.; Penttilä, H.; Prete, G.; Rizzi, V.; Samarin, S.; Tecchio, L. B.; Trzaska, W. H.; Tyurin, G.

    2008-10-01

    Neutron production using an enriched 13C carbon converter has been measured during the design study of the italian RIB facility SPES. Energy and angular distributions of neutrons emitted by bombarding a 13C target of stopping length with protons in the range of 20 to 90 MeV have been measured by time-of-flight and activation and compared with the prediction of a Monte Carlo code developed at Snezhinsk. At the proton energy of 100 MeV, firstly envisaged for SPES, the gain with respect to a natural C target is less than a factor of two, while yields still compare well with those for 40 MeV deuterons on natural carbon adopted by SPIRAL-II. At energies near 30 MeV the 13C thick target is definitely more prolific than the target of natural carbon, but both yields with protons are clearly lower than the one with deuterons. At the energy of 20 MeV envisaged for a first stage of SPES it might be more efficient to irradiate the uranium target with protons rather than using the two-stage method with converter.

  8. Enhanced electron-positron pair production by ultra intense laser irradiating a compound target

    NASA Astrophysics Data System (ADS)

    Liu, Jian-Xun; Ma, Yan-Yun; Yu, Tong-Pu; Zhao, Jun; Yang, Xiao-Hu; Gan, Long-Fei; Zhang, Guo-Bo; Zhao, Yuan; Zhang, Shi-Jie; Liu, Jin-Jin; Zhuo, Hong-Bin; Shao, Fu-Qiu; Kawata, Shigeo

    2016-12-01

    High-energy-density electron-positron pairs play an increasingly important role in many potential applications. Here, we propose a scheme for enhanced positron production by an ultra intense laser irradiating a gas-Al compound target via the multi-photon Breit-Wheeler (BW) process. The laser pulse first ionizes the gas and interacts with a near-critical-density plasma, forming an electron bubble behind the laser pulse. A great deal of electrons are trapped and accelerated in the bubble, while the laser front hole-bores the Al target and deforms its front surface. A part of the laser wave is thus reflected by the inner curved target surface and collides with the accelerated electron bunch. Finally, a large number of γ photons are emitted in the forward direction via the Compton back-scattering process and the BW process is initiated. Dense electron-positron pairs are produced with a maximum density of 6.02× {{10}27} m-3. Simulation results show that the positron generation is greatly enhanced in the compound target, where the positron yield is two orders of magnitude greater than that in only the solid slab case. The influences of the laser intensity, gas density and length on the positron beam quality are also discussed, which demonstrates the feasibility of the scheme in practice.

  9. Long-lived isotopes production in Pb-Bi target irradiated by high energy protons

    SciTech Connect

    Korovin, Y.A.; Konobeyev, A.Y.; Pereslavtsev, P.E.

    1995-10-01

    Concentration of long-lived isotopes has been calculated for lead and lead-bismuth targets irradiated by protons with energy 0.4, 0.8, 1.0 and 1.6 GeV. The time of irradiation is equal from 1 month up to 2 years. The data libraries BROND, ADL and MENDL have been used to obtain the rate of nuclide transmutation. All calculations have been performed using the SNT code.

  10. Long-lived isotopes production in Pb-Bi target irradiated by high energy protons

    NASA Astrophysics Data System (ADS)

    Korovin, Yu. A.; Konobeyev, A. Yu.; Pereslavtsev, P. E.

    1995-09-01

    Concentration of long-lived isotopes has been calculated for lead and lead-bismuth targets irradiated by protons with energy 0.4, 0.8, 1.0 and 1.6 GeV. The time of irradiation is equal from 1 month up to 2 years. The data libraries BROND, ADL and MENDL have been used to obtain the rate of nuclider transmutation. All calculations have been performed using the SNT code [1].

  11. Long-lived isotopes production in Pb-Bi target irradiated by high energy protons

    SciTech Connect

    Korovin, Yu. A.; Konobeyev, A. Yu.; Pereslavtsev, P. E.

    1995-09-15

    Concentration of long-lived isotopes has been calculated for lead and lead-bismuth targets irradiated by protons with energy 0.4, 0.8, 1.0 and 1.6 GeV. The time of irradiation is equal from 1 month up to 2 years. The data libraries BROND, ADL and MENDL have been used to obtain the rate of nuclider transmutation. All calculations have been performed using the SNT code.

  12. Proton-induced polonium production in massive lead bismuth target irradiated by 660 MeV protons

    NASA Astrophysics Data System (ADS)

    Polanski, Aleksander; Petrochenkov, Sergey; Pohorecki, Wladyslaw

    2006-06-01

    The paper presents study of polonium production in bismuth foils placed in lead target. Proton-induced production of residual nuclei 206Po, 207Po, 208Po, 209Po, 210Po in 209Bi foils placed in lead target irradiated by 660 MeV protons was calculated. A comparison with calculated spatial distribution of polonium production using an MCNPX code and experimental results has been performed. The results of calculation will be useful for design of target of Subcritical Assembly in Dubna (SAD).

  13. High energy irradiations simulating cosmic-ray-induced planetary gamma ray production. I - Fe target

    NASA Technical Reports Server (NTRS)

    Metzger, A. E.; Parker, R. H.; Yellin, J.

    1986-01-01

    Two thick Fe targets were bombarded by a series of 6 GeV proton irradiations for the purpose of simulating the cosmic ray bombardment of planetary objects in space. Gamma ray energy spectra were obtained with a germanium solid state detector during the bombardment, and 46 of the gamma ray lines were ascribed to the Fe targets. A comparison between observed and predicted values showed good agreement for Fe lines from neutron inelastic scattering and spallation reactions, and less satisfactory agreement for neutron capture reactions, the latter attributed to the difference in composition between the Fe target and the mean lunar abundance used in the modeling. Through an analysis of the irradiation results together with continuum data obtained in lunar orbit, it was found that 100 hours of measurement with a current instrument should generate a spectrum containing approximately 20 lines due to Fe alone, with a 2-sigma sensitivity for detection of about 0.2 percent.

  14. Production of medical isotopes from a thorium target irradiated by light charged particles up to 70 MeV

    NASA Astrophysics Data System (ADS)

    Duchemin, C.; Guertin, A.; Haddad, F.; Michel, N.; Métivier, V.

    2015-02-01

    The irradiation of a thorium target by light charged particles (protons and deuterons) leads to the production of several isotopes of medical interest. Direct nuclear reaction allows the production of Protactinium-230 which decays to Uranium-230 the mother nucleus of Thorium-226, a promising isotope for alpha radionuclide therapy. The fission of Thorium-232 produces fragments of interest like Molybdenum-99, Iodine-131 and Cadmium-115g. We focus our study on the production of these isotopes, performing new cross section measurements and calculating production yields. Our new sets of data are compared with the literature and the last version of the TALYS code.

  15. Production of medical isotopes from a thorium target irradiated by light charged particles up to 70 MeV.

    PubMed

    Duchemin, C; Guertin, A; Haddad, F; Michel, N; Métivier, V

    2015-02-07

    The irradiation of a thorium target by light charged particles (protons and deuterons) leads to the production of several isotopes of medical interest. Direct nuclear reaction allows the production of Protactinium-230 which decays to Uranium-230 the mother nucleus of Thorium-226, a promising isotope for alpha radionuclide therapy. The fission of Thorium-232 produces fragments of interest like Molybdenum-99, Iodine-131 and Cadmium-115g. We focus our study on the production of these isotopes, performing new cross section measurements and calculating production yields. Our new sets of data are compared with the literature and the last version of the TALYS code.

  16. Parallel computation safety analysis irradiation targets fission product molybdenum in neutronic aspect using the successive over-relaxation algorithm

    NASA Astrophysics Data System (ADS)

    Susmikanti, Mike; Dewayatna, Winter; Sulistyo, Yos

    2014-09-01

    One of the research activities in support of commercial radioisotope production program is a safety research on target FPM (Fission Product Molybdenum) irradiation. FPM targets form a tube made of stainless steel which contains nuclear-grade high-enrichment uranium. The FPM irradiation tube is intended to obtain fission products. Fission materials such as Mo99 used widely the form of kits in the medical world. The neutronics problem is solved using first-order perturbation theory derived from the diffusion equation for four groups. In contrast, Mo isotopes have longer half-lives, about 3 days (66 hours), so the delivery of radioisotopes to consumer centers and storage is possible though still limited. The production of this isotope potentially gives significant economic value. The criticality and flux in multigroup diffusion model was calculated for various irradiation positions and uranium contents. This model involves complex computation, with large and sparse matrix system. Several parallel algorithms have been developed for the sparse and large matrix solution. In this paper, a successive over-relaxation (SOR) algorithm was implemented for the calculation of reactivity coefficients which can be done in parallel. Previous works performed reactivity calculations serially with Gauss-Seidel iteratives. The parallel method can be used to solve multigroup diffusion equation system and calculate the criticality and reactivity coefficients. In this research a computer code was developed to exploit parallel processing to perform reactivity calculations which were to be used in safety analysis. The parallel processing in the multicore computer system allows the calculation to be performed more quickly. This code was applied for the safety limits calculation of irradiated FPM targets containing highly enriched uranium. The results of calculations neutron show that for uranium contents of 1.7676 g and 6.1866 g (× 106 cm-1) in a tube, their delta reactivities are the still

  17. Measurement and modelling of radionuclide production in thick spherical targets irradiated isotropically with 1600 MeV protons

    SciTech Connect

    Michel, R.; Lange, H.J.; Leya, I.; Luepke, M.; Herpers, U.; Meltzow, B.; Roesel, R.; Filges, D.; Cloth, P.; Dragovitsch, P.

    1994-12-31

    Two thick spherical targets made of gabbro and of steel with radii of 25 and 10 cm, respectively, were isotropically irradiated with 1.6 GeV protons at the Saturne accelerator at Laboratoire National Saturne/Saclay in order to simulate the interactions of galactic cosmic ray (GCR) protons with stony and iron meteoroids. The artificial meteoroids contained large numbers of individual small targets of up to 27 elements, in which the depth-dependent production of residual nuclides was measured by {gamma}-, accelerator and conventional mass spectrometry. Theoretical production depth profiles were derived by folding depth-dependent spectra of primary and secondary particles calculated by the HERMES code system with experimental and theoretical production rates shortcomings of the cross section data base can be distinguished and medium-energy neutron cross sections can be improved.

  18. Waste Treatment of Acidic Solutions from the Dissolution of Irradiated LEU Targets for 99-Mo Production

    SciTech Connect

    Bakel, Allen J.; Conner, Cliff; Quigley, Kevin; Vandegrift, George F.

    2016-10-01

    One of the missions of the Reduced Enrichment for Research and Test Reactors (RERTR) program (and now the National Nuclear Security Administrations Material Management and Minimization program) is to facilitate the use of low enriched uranium (LEU) targets for 99Mo production. The conversion from highly enriched uranium (HEU) to LEU targets will require five to six times more uranium to produce an equivalent amount of 99Mo. The work discussed here addresses the technical challenges encountered in the treatment of uranyl nitrate hexahydrate (UNH)/nitric acid solutions remaining after the dissolution of LEU targets. Specifically, the focus of this work is the calcination of the uranium waste from 99Mo production using LEU foil targets and the Modified Cintichem Process. Work with our calciner system showed that high furnace temperature, a large vent tube, and a mechanical shield are beneficial for calciner operation. One- and two-step direct calcination processes were evaluated. The high-temperature one-step process led to contamination of the calciner system. The two-step direct calcination process operated stably and resulted in a relatively large amount of material in the calciner cup. Chemically assisted calcination using peroxide was rejected for further work due to the difficulty in handling the products. Chemically assisted calcination using formic acid was rejected due to unstable operation. Chemically assisted calcination using oxalic acid was recommended, although a better understanding of its chemistry is needed. Overall, this work showed that the two-step direct calcination and the in-cup oxalic acid processes are the best approaches for the treatment of the UNH/nitric acid waste solutions remaining from dissolution of LEU targets for 99Mo production.

  19. Prediction of production of 22Na in a gas-cell target irradiated by protons using Monte Carlo tracking

    NASA Astrophysics Data System (ADS)

    Eslami, M.; Kakavand, T.; Mirzaii, M.; Rajabifar, S.

    2015-01-01

    The 22Ne(p,n)22Na is an optimal reaction for the cyclotron production of 22Na. This work tends to monitor the proton induced production of 22Na in a gas-cell target, containing natural and enriched neon gas, using Monte Carlo method. The excitation functions of reactions are calculated by both TALYS-1.6 and ALICE/ASH codes and then the optimum energy range of projectile for the high yield production is selected. A free gaseous environment of neon at a particular pressure and temperature is prearranged and the proton beam is transported within it using Monte Carlo codes MCNPX and SRIM. The beam monitoring performed by each of these codes indicates that the gas-cell has to be designed as conical frustum to reach desired interactions. The MCNPX is also employed to calculate the energy distribution of proton in the designed target and estimation of the residual nuclei during irradiation. The production yield of 22Na in 22Ne(p,n)22Na and natNe(p,x)22Na reactions are estimated and it shows a good agreement with the experimental results. The results demonstrate that Monte Carlo makes available a beneficial manner to design and optimize the gas targets as well as calibration of detectors, which can be used for the radionuclide production purposes.

  20. Parallel computation safety analysis irradiation targets fission product molybdenum in neutronic aspect using the successive over-relaxation algorithm

    SciTech Connect

    Susmikanti, Mike; Dewayatna, Winter; Sulistyo, Yos

    2014-09-30

    One of the research activities in support of commercial radioisotope production program is a safety research on target FPM (Fission Product Molybdenum) irradiation. FPM targets form a tube made of stainless steel which contains nuclear-grade high-enrichment uranium. The FPM irradiation tube is intended to obtain fission products. Fission materials such as Mo{sup 99} used widely the form of kits in the medical world. The neutronics problem is solved using first-order perturbation theory derived from the diffusion equation for four groups. In contrast, Mo isotopes have longer half-lives, about 3 days (66 hours), so the delivery of radioisotopes to consumer centers and storage is possible though still limited. The production of this isotope potentially gives significant economic value. The criticality and flux in multigroup diffusion model was calculated for various irradiation positions and uranium contents. This model involves complex computation, with large and sparse matrix system. Several parallel algorithms have been developed for the sparse and large matrix solution. In this paper, a successive over-relaxation (SOR) algorithm was implemented for the calculation of reactivity coefficients which can be done in parallel. Previous works performed reactivity calculations serially with Gauss-Seidel iteratives. The parallel method can be used to solve multigroup diffusion equation system and calculate the criticality and reactivity coefficients. In this research a computer code was developed to exploit parallel processing to perform reactivity calculations which were to be used in safety analysis. The parallel processing in the multicore computer system allows the calculation to be performed more quickly. This code was applied for the safety limits calculation of irradiated FPM targets containing highly enriched uranium. The results of calculations neutron show that for uranium contents of 1.7676 g and 6.1866 g (× 10{sup 6} cm{sup −1}) in a tube, their delta

  1. Production of isotopes and isomers with irradiation of Z = 47–50 targets by 23-MeV bremsstrahlung

    SciTech Connect

    Karamian, S. A.; Carroll, J. J.; Aksenov, N. V.; Albin, Yu. A.; Belov, A. G.; Bozhikov, G. A.; Dmitriev, S. N.; Starodub, G. Ya.

    2015-09-15

    The irradiations of Ag to Sn targets by bremsstrahlung generated with 23-MeV electron beams are performed at the MT-25 microtron. Gamma spectra of the induced activities have been measured and the yields of all detected radionuclides and isomers are carefully measured and analyzed. A regular dependence of yields versus changed reaction threshold is confirmed. Many isomers are detected and the suppression of the production probability is observed with growing product spin. Special peculiarities for the isomer-to-ground state ratios were deduced for the {sup 106m}Ag, {sup 108m}Ag, {sup 113m}In, {sup 115m}In, and {sup 123m}Sn isomers. The production of such nuclides as {sup 108m}Ag, {sup 115m}In, {sup 117g}In, and {sup 113m}Cd is of interest for applications, especially when economic methods are available.

  2. Production of 64Cu and 67Cu radiopharmaceuticals using zinc target irradiated with accelerator neutrons

    NASA Astrophysics Data System (ADS)

    Kawabata, Masako; Hashimoto, Kazuyuki; Saeki, Hideya; Sato, Nozomi; Motoishi, Shoji; Nagai, Yasuki

    2014-09-01

    Copper radioisotopes have gained a lot of attention in radiopharmaceuticals owing to their unique decay characteristics. The longest half-life β emitter, 67Cu, is thought to be suitable for targeted radio-immunotherapy. Adequate production of 67Cu to meet the demands of clinical studies has not been fully established. Another attractive copper isotope, 64Cu has possible applications as a diagnostic imaging tracer combined with a therapeutic effect. This work proposes a production method using accelerator neutrons in which two copper radioisotopes can be produced: 1) 68Zn(n,x)67Cu and 2) 64Zn(n,p)64Cu using ~14 MeV neutrons generated by natC(d, n) reaction, both from natural or enriched zinc oxides. The generated 64,67Cu were separated from the target zinc oxide using a chelating and an anion exchange columns and were labelled with two widely studied chelators where the labelling efficiency was found to be acceptably good. The major advantage of this method is that a significant amount of 64,67Cu with a very few impurity radionuclides are produced which also makes the separation procedure simple. Provided an accelerator supplying an Ed = ~ 40 MeV, a wide application of 64,67Cu based drugs in nuclear medicine is feasible in the near future. We will present the characteristics of this production method using accelerator neutrons including the chemical separation processes.

  3. Neutron Productions from thin Be target irradiated by 50 MeV/u 238U beam

    NASA Astrophysics Data System (ADS)

    Lee, Hee-Seock; Oh, Joo-Hee; Jung, Nam-Suk; Oranj, Leila Mokhtari; Nakao, Noriaki; Uwamino, Yoshitomo

    2017-09-01

    Neutrons generated from thin beryllium target by 50 MeV/u 238U beam were measured using activation analysis at 15, 30, 45, and 90 degrees from the beam direction. A 0.085 mm-thick Be stripper of RIBF was used as the neutron generating target. Activation detectors of bismuth, cobalt, and aluminum were placed out of the stripper chamber. The threshold reactions of 209Bi(n, xn)210-xBi(x=4 8), 59Co(n, xn)60-xCO(x=2 5), 59Co(n, 2nα)54Mn, 27Al(n, α)24Na, and 27Al(n,2nα)22Na were applied to measure the production rates of radionuclides. The neutron spectra were obtained using an unfolding method with the SAND-II code. All of production rates and neutron spectra were compared with the calculated results using Monte Carlo codes, the PHITS and the FLUKA. The FLUKA results showed better agreement with the measurements than the PHITS. The discrepancy between the measurements and the calculations were discussed.

  4. Targeted cytoplasmic irradiation and autophagy.

    PubMed

    Wu, Jinhua; Zhang, Bo; Wuu, Yen-Ruh; Davidson, Mercy M; Hei, Tom K

    2017-03-01

    The effect of ionizing irradiation on cytoplasmic organelles is often underestimated because the general dogma considers direct DNA damage in the nuclei to be the primary cause of radiation induced toxicity. Using a precision microbeam irradiator, we examined the changes in mitochondrial dynamics and functions triggered by targeted cytoplasmic irradiation with α-particles. Mitochondrial dysfunction induced by targeted cytoplasmic irradiation led to activation of autophagy, which degraded dysfunctional mitochondria in order to maintain cellular energy homeostasis. The activation of autophagy was cytoplasmic irradiation-specific and was not detected in nuclear irradiated cells. This autophagic process was oxyradical-dependent and required the activity of the mitochondrial fission protein dynamin related protein 1 (DRP1). The resultant mitochondrial fission induced phosphorylation of AMP activated protein kinase (AMPK) which leads to further activation of the extracellular signal-related kinase (ERK) 1/2 with concomitant inhibition of the mammalian target of rapamycin (mTOR) to initiate autophagy. Inhibition of autophagy resulted in delayed DNA damage repair and decreased cell viability, which supports the cytoprotective function of autophagy. Our results reveal a novel mechanism in which dysfunctional mitochondria are degraded by autophagy in an attempt to protect cells from toxic effects of targeted cytoplasmic radiation.

  5. Deuteron irradiation of W and WO3 for production of high specific activity 186Re: Challenges associated with thick target preparation

    SciTech Connect

    Balkin, Ethan R.; Gagnon, Katherine; Strong, Kevin T.; Smith, Bennett E.; Dorman, Eric F.; Emery, Robert C.; Pauzauskie, Peter J.; Fassbender, Michael E.; Cutler, Cathy S.; Ketring, Alan R.; Jurisson, Silvia S.; Wilbur, D. Scott

    2016-06-28

    This investigation evaluated target fabrication and beam parameters for scale-up production of high specific activity 186Re using deuteron irradiation of enriched 186W via the 186W(d,2n)186Re reaction. Thick W and WO3 targets were prepared, characterized and evaluated in deuteron irradiations. Full-thickness targets, as determined using SRIM, were prepared by uniaxi-ally pressing powdered natural abundance W and WO3, or 96.86% enriched 186W, into Al target supports. Alternatively, thick targets were prepared by pressing 186W between two layers of graphite powder or by placing pre-sintered (1105°C, 12 hours) natural abundance WO3 pellets into an Al target support. Assessments of structural integrity were made on each target pre-pared. Prior to irradiation, material composition analyses were conducted using SEM, XRD, and Raman spectroscopy. With-in a minimum of 24 hours post irradiation, gamma-ray spectroscopy was performed on all targets to assess production yields and radionuclidic byproducts. Problems were encountered with the structural integrity of some pressed W and WO3 pellets before and during irradiation, and target material characterization results could be correlated with the structural integrity of the pressed target pellets. Under the conditions studied, the findings suggest that all WO3 targets prepared and studied were unacceptable. By contrast, 186W metal was found to be a viable target material for 186Re production. Lastly, thick targets prepared with powdered 186W pressed between layers of graphite provided a particularly robust target configuration.

  6. Deuteron irradiation of W and WO3 for production of high specific activity 186Re: Challenges associated with thick target preparation

    SciTech Connect

    Balkin, Ethan R.; Gagnon, Katherine; Strong, Kevin T.; Smith, Bennett E.; Dorman, Eric F.; Emery, Robert C.; Pauzauskie, Peter J.; Fassbender, Michael E.; Cutler, Cathy S.; Ketring, Alan R.; Jurisson, Silvia S.; Wilbur, D. Scott

    2016-06-28

    This investigation evaluated target fabrication and beam parameters for scale-up production of high specific activity 186Re using deuteron irradiation of enriched 186W via the 186W(d,2n)186Re reaction. Thick W and WO3 targets were prepared, characterized and evaluated in deuteron irradiations. Full-thickness targets, as determined using SRIM, were prepared by uniaxi-ally pressing powdered natural abundance W and WO3, or 96.86% enriched 186W, into Al target supports. Alternatively, thick targets were prepared by pressing 186W between two layers of graphite powder or by placing pre-sintered (1105°C, 12 hours) natural abundance WO3 pellets into an Al target support. Assessments of structural integrity were made on each target pre-pared. Prior to irradiation, material composition analyses were conducted using SEM, XRD, and Raman spectroscopy. With-in a minimum of 24 hours post irradiation, gamma-ray spectroscopy was performed on all targets to assess production yields and radionuclidic byproducts. Problems were encountered with the structural integrity of some pressed W and WO3 pellets before and during irradiation, and target material characterization results could be correlated with the structural integrity of the pressed target pellets. Under the conditions studied, the findings suggest that all WO3 targets prepared and studied were unacceptable. By contrast, 186W metal was found to be a viable target material for 186Re production. Lastly, thick targets prepared with powdered 186W pressed between layers of graphite provided a particularly robust target configuration.

  7. Deuteron irradiation of W and WO3 for production of high specific activity 186Re: Challenges associated with thick target preparation

    DOE PAGES

    Balkin, Ethan R.; Gagnon, Katherine; Strong, Kevin T.; ...

    2016-06-28

    This investigation evaluated target fabrication and beam parameters for scale-up production of high specific activity 186Re using deuteron irradiation of enriched 186W via the 186W(d,2n)186Re reaction. Thick W and WO3 targets were prepared, characterized and evaluated in deuteron irradiations. Full-thickness targets, as determined using SRIM, were prepared by uniaxi-ally pressing powdered natural abundance W and WO3, or 96.86% enriched 186W, into Al target supports. Alternatively, thick targets were prepared by pressing 186W between two layers of graphite powder or by placing pre-sintered (1105°C, 12 hours) natural abundance WO3 pellets into an Al target support. Assessments of structural integrity were mademore » on each target pre-pared. Prior to irradiation, material composition analyses were conducted using SEM, XRD, and Raman spectroscopy. With-in a minimum of 24 hours post irradiation, gamma-ray spectroscopy was performed on all targets to assess production yields and radionuclidic byproducts. Problems were encountered with the structural integrity of some pressed W and WO3 pellets before and during irradiation, and target material characterization results could be correlated with the structural integrity of the pressed target pellets. Under the conditions studied, the findings suggest that all WO3 targets prepared and studied were unacceptable. By contrast, 186W metal was found to be a viable target material for 186Re production. Lastly, thick targets prepared with powdered 186W pressed between layers of graphite provided a particularly robust target configuration.« less

  8. Efficient plasma production by intense laser irradiation of low density foam targets

    SciTech Connect

    Tripathi, S.; Chaurasia, S.; Munda, D. S.; Gupta, N. K.; Dhareshwar, L. J.; Nataliya, B.

    2010-12-01

    Experimental investigations conducted on low density structured materials, such as foams have been presented in this paper. These low density foam targets having a density greater than the critical density of the laser produced plasma ({rho}{sub cr{approx_equal}}3 mg{center_dot}cm{sup -3} at laser wavelength 1.06 {mu}m) have been envisaged to have enhanced laser absorption. Experiments were done with an indigenously developed, focused 15 Joule/500 ps Nd: Glass laser at {lambda} = 1064 nm. The focused laser intensity on the target was in the range of I{approx_equal}10{sup 13}-2x10{sup 14} W/cm{sup 2}. Laser absorption was determined by energy balance experiments. Laser energy absorption was observed to be higher than 85%. In another set of experiments, low density carbon foam targets of density 150 mg/cc were compared with the solid carbon targets. The x-ray emission in the soft x-ray region was observed to increase in foam target by about 1.8 times and 2.3 times in carbon foam and Pt doped foam as compared to solid carbon. Further, investigations were also carried out to measure the energy transmitted through the sub-critical density TAC foam targets having a density less than 3 mg/cc. Such targets have been proposed to be used for smoothening of intensity ripples in a high power laser beam profile. Transmission exceeding 1.87% has been observed and consistent with results from other laboratories.

  9. Measurement of Volatile Radionuclides Production and Release Yields followed by a Post-Irradiation Analysis of a Pb/Bi Filled Ta Target at ISOLDE

    NASA Astrophysics Data System (ADS)

    Zanini, L.; Köster, U.; David, J. C.; Tall, Y.; Andersson, M.; Berg, K.; Cormon, S.; Fallot, M.; Foucher, Y.; Frånberg, H.; Gröschel, F.; Guertin, A.; Kirchner, T.; Leray, S.; Manfrin, E.; Noah, E.; Ravn, H.; Stora, T.; Thiollière, N.; Wohlmuther, M.

    2014-05-01

    A crucial requirement in the development of liquid-metal spallation neutron target is knowledge of the composition and amount of volatile radionuclides that are released from the target during operation. It is also important to know the total amount produced, which could be released if there was an accident. One type is the lead-bismuth eutectic (LBE) target where different radionuclides can be produced following interaction with a high-energy proton beam, notably noble gases (Ar, Kr, Xe isotopes) and other relative volatile isotopes such as Hg and At. The results of an irradiation experiment performed at ISOLDE on a LBE target are compared with predictions from the MCNPX code using the latest developments on the Liège Intranuclear Cascade model (INCL4.6) and the CEM03 model. The calculations are able to reproduce the mass distribution of the radioisotopes produced, including the At production, where there is a significant contribution from secondary reactions. Subsequently, a post-irradiation examination of the irradiated target was performed. Investigations of both the tantalum target structure, in particular the beam window, and the lead-bismuth eutectic were performed using several experimental techniques. No sign of severe irradiation damage, previously observed in other ISOLDE targets, was found.

  10. Niobium-based sputtered thin films for corrosion protection of proton-irradiated liquid water targets for [18F] production

    NASA Astrophysics Data System (ADS)

    Skliarova, H.; Azzolini, O.; Cherenkova-Dousset, O.; Johnson, R. R.; Palmieri, V.

    2014-01-01

    Chemically inert coatings on Havar® entrance foils of the targets for [18F] production via proton irradiation of enriched water at pressurized conditions are needed to decrease the amount of ionic contaminants released from Havar®. In order to find the most effective protective coatings, the Nb-based coating microstructure and barrier properties have been correlated with deposition parameters such as substrate temperature, applied bias, deposition rate and sputtering gas pressure. Aluminated quartz used as a substrate allowed us to verify the protection efficiency of the desirable coatings as diffusion barriers. Two modelling corrosion tests based on the extreme susceptibility of aluminum to liquid gallium and acid corrosion were applied. Pure niobium coatings have been found to be less effective barriers than niobium-titanium coatings. But niobium oxide films, according to the corrosion tests performed, showed superior barrier properties. Therefore multi-layered niobium-niobium oxide films have been suggested, since they combine the high thermal conductivity of niobium with the good barrier properties of niobium oxide.

  11. Conversion of Molybdenum-99 production process to low enriched uranium: Neutronic and thermal hydraulic analyses of HEU and LEU target plates for irradiation in Pakistan Research Reactor-1

    NASA Astrophysics Data System (ADS)

    Mushtaq, Ahmad; Iqbal, Masood; Bokhari, Ishtiaq Hussain; Mahmood, Tayyab; Muhammad, Atta

    2012-09-01

    Technetium-99m, the daughter product of Molybdenum-99 is the most widely needed radionuclide for diagnostic studies in Pakistan. Molybdenum-99 Production Facility has been established at PINSTECH. Highly enriched uranium (93% 235U) U/Al alloy targets have been irradiated in Pakistan Research Reactor-1 (PARR-1) for the generation of fission Mo-99, while basic dissolution technique is used for separation of Mo-99 from target matrix activity. In line with the international objective of minimizing and eventually eliminating the use of HEU in civil commerce, national and international efforts have been underway to shift the production of medical isotopes from HEU to LEU (LEU; <20% 235U enrichment) targets. To achieve the equivalent amount of 99Mo with LEU targets, approximately 5 times uranium is needed. LEU aluminum uranium dispersion target has been developed, which may replace existing HEU aluminum/uranium alloy targets for production of 99Mo using basic dissolution technique. Neutronic and thermal hydraulic calculations were performed for safe irradiation of targets in the core of PARR-1.

  12. Thorium silicate compound as a solid-state target for production of isomeric thorium-229 nuclei by electron beam irradiation

    NASA Astrophysics Data System (ADS)

    Borisyuk, P. V.; Vasilyev, O. S.; Lebedinskii, Y. Y.; Krasavin, A. V.; Tkalya, E. V.; Troyan, V. I.; Habibulina, R. F.; Chubunova, E. V.; Yakovlev, V. P.

    2016-09-01

    In this paper, we discuss an idea of the experiment for excitation of the isomeric transition in thorium-229 nuclei by irradiating with electron beam targets with necessary physical characteristics. The chemical composition and bandgap of ThSi10O22 were determined by X-ray photoelectron spectroscopy and reflection electron energy loss spectroscopy. It was found that the energy gap is equal to 7.7 eV and does not change when the target is exposed to a medium energy electron beam for a long time. This indicates that the compound possesses high electron-beam resistance. A quantitative estimation of the output function of isomeric thorium-229 nuclei generated by interaction of nuclei with the secondary electron flow formed by irradiating the solid-state ThSi10O22-based target is given. The estimation shows that ThSi10O22 is a promising thorium-containing target for investigating excitation of the nuclear low-lying isomeric transition in the thorium-229 isotope using medium-energy electrons.

  13. Irradiation of northwest agricultural products

    NASA Astrophysics Data System (ADS)

    Eakin, D. E.; Tingey, G. I.

    1985-02-01

    Irradiation of food for disinfestation and preservation is increasing in importance because of increasing restrictions on various chemical treatments. Irradiation treatment is of particular interest in the Northwest because of a growing supply of agricultural products and the need to develop new export markets. Several products have, or could potentially have, significant export markets if stringent insect ocntrol procedures are developed and followed. Due to the recognized potential benefits of irradiation, this program was conducted to evaluate the benefits of using irradiation on Northwest agricultural products. Commodities currently included in the program are cherries, apples, asparagus, spices, hay, and hides.

  14. Extension of excitation functions up to 50 MeV for activation products in deuteron irradiations of Pr and Tm targets

    NASA Astrophysics Data System (ADS)

    Hermanne, A.; Tárkányi, F.; Takács, S.; Ditrói, F.

    2016-09-01

    Extension up to 50 MeV incident deuteron energy is presented for excitation functions of activation products formed in monoisotopic Tm (169Tm) and Pr (141Pr). By stacked foil irradiations direct and/or cumulative production of 140,139m,138Nd, 138mPr, 141,139,137m,135Ce on Pr and 166,169Yb, 166,167,168Tm on Tm targets were measured. Confirmation of earlier experimental results for all investigated radionuclides is found and the influence of the higher energy on thick target yields and batch production of medically relevant radionuclides (140Nd, 139Pr (as decay product of 139mNd), 166,169Yb, 167Tm) is discussed. A comparison of experimental values with TALYS1.6 code results (predicted values from TENDL-2015 on-line library) shows a better description of the (d,pxn) reactions than older ones.

  15. Separation of transuranium elements from irradiated targets

    SciTech Connect

    Wham, R.M.; Benker, D.E.; Felker, L.K.; Chattin, F.R.

    1993-12-31

    Aluminum targets containing curium/americium oxide are irradiated to produce the transcurium actinides einsteinium, fermium, berkelium, and californium. Recovery of recycle curium/americium and the transcurium elements involves several chemical processing steps to selectively recover those elements and remove fission products. Chemical processing steps developed at the Radiochemical Engineering Development Center (REDC) include aluminum dejacketing, solvent extraction to remove bulk impurities, solvent extraction to remove plutonium, anion exchange to partition curium and transcurium elements from the rare earths, and a second anion exchange cycle to separate americium/curium from the transcurium elements.

  16. Suprathermal electron production in laser-irradiated Cu targets characterized by combined methods of x-ray imaging and spectroscopy

    NASA Astrophysics Data System (ADS)

    Renner, O.; Šmíd, M.; Batani, D.; Antonelli, L.

    2016-07-01

    In a series of experiments performed with laser-irradiated planar targets at the PALS laser facility, the generation of suprathermal electrons has been studied at conditions relevant for the development of a shock ignition approach to inertial confinement fusion. A simultaneous application of high-collection-efficiency K-shell imaging with high resolution x-ray spectroscopy offers a novel approach to hot electron diagnosis at non-coated or moderately coated, medium-atomic-number targets, where the contribution of suprathermal-electron-generated, frequency-shifted Kα emission from highly ionized atoms cannot be neglected. Based on experimental data provided by these combined techniques and their interpretation via collisional-radiative atomic codes and Monte Carlo modeling of hot electron energy deposition in heated Cu targets, the fraction of the energy converted to hot electrons at laser intensities  ≈1016 W cm-2 was measured to be at the level of 0.1-0.8%. The higher values of conversion efficiency found for frequency tripled radiation support a theoretical conjecture of enhanced laser energy absorption by a resonance mechanism and its transport to a flow of fast electrons.

  17. 225Ac and 223Ra production via 800 MeV proton irradiation of natural thorium targets.

    PubMed

    Weidner, J W; Mashnik, S G; John, K D; Ballard, B; Birnbaum, E R; Bitteker, L J; Couture, A; Fassbender, M E; Goff, G S; Gritzo, R; Hemez, F M; Runde, W; Ullmann, J L; Wolfsberg, L E; Nortier, F M

    2012-11-01

    Cross sections for the formation of (225,227)Ac, (223,225)Ra, and (227)Th via the proton bombardment of natural thorium targets were measured at a nominal proton energy of 800 MeV. No earlier experimental cross section data for the production of (223,225)Ra, (227)Ac and (227)Th by this method were found in the literature. A comparison of theoretical predictions with the experimental data shows agreement within a factor of two. Results indicate that accelerator-based production of (225)Ac and (223)Ra is a viable production method. Published by Elsevier Ltd.

  18. Results of the six-and-a-half day electron-accelerator irradiation of enriched Mo-100 targets for the production of Mo-99

    SciTech Connect

    Chemerisov, S.; Bailey, J.; Heltemes, T.; Jonah, C.; Makarashvili, V.; Tkac, P.; Rotsch, D.; Virgo, M.; Vandegrift, G. F.

    2016-10-01

    A six-and-a-half day irradiation of enriched Mo-100 target disks was performed by Argonne’s electron linac. This report describes the irradiation conditions and the means used to process the targets for shipment to NorthStar Medical Isotopes, LLC, for feed to their RadioGenixTM technetium generator.

  19. Production and separation of no-carrier-added radioactive tracers of yttrium, strontium and rubidium from heavy-ion irradiated germanium target: applicability to the standardization of a separation technique for production of positron-emitting radionuclide 86Y.

    PubMed

    Pal, Sujit; Chattopadhyay, Sankha; Das, M K; Sudersanan, M

    2006-12-01

    Among various positron-emitting radionuclides, certain radioisotopes of Y, Sr and Rb have important applications in diagnostic and therapeutic nuclear medicine. In the present work, an attempt has been made to produce some of those radioisotopes by irradiating a natural Ge-target material with heavy-ion oxygen ((16)O(+6)) projectiles. An effective radiochemical separation scheme was developed to isolate Y, Sr and Rb radiotracers from the irradiated Ge-matrix in no-carrier-added form with a view to applying those radiotracers for standardization of a technique for the radiochemical separation of Y from natural Sr target. The standardized separation technique could be utilized for the production of the positron-emitting (86)Y from an enriched (86)Sr target irradiated at a medical cyclotron.

  20. Irradiation of Northwest agricultural products

    SciTech Connect

    Eakin, D.E.; Tingey, G.L.

    1985-02-01

    Irradiation of food for disinfestation and preservation is increasing in importance because of increasing restrictions on various chemical treatments. Irradiation treatment is of particular interest in the Northwest because of a growing supply of agricultural products and the need to develop new export markets. Several products have, or could potentially have, significant export markets if stringent insect control procedures are developed and followed. Due to the recognized potential benefits of irradiation, Pacific Northwest Laboratory (PNL) is conducting this program to evaluate the benefits of using irradiation on Northwest agricultural products under the US Department of Energy (DOE) Defense Byproducts Production and Utilization Program. Commodities currently included in the program are cherries, apples, asparagus, spices, hay, and hides.

  1. Production Target Design Report

    SciTech Connect

    Woloshun, Keith Albert; Dale, Gregory E.; Olivas, Eric Richard

    2015-07-28

    The Northstar 99Mo production target, a cylindrical length of 100Mo rod, has evolved considerably since its first conception.  The cylinder was very early sliced into disks to increase the heat transfer area, first to 1 mm thick disks then to the current 0.5 mm thick.  The coolant was changed early in the target development from water to helium to eliminate corrosion and dissolution.  The diameter has increased from initially 6 mm to 12 mm, the current diameter of the test target now at ANL, to nominally 28 mm (26-30.6 mm, depending upon optimal beam spot size and shape).  The length has also changed to improve the production to cost ratio, so now the target is nominally 41 mm long (excluding coolant gaps between disks), and irradiated on both ends.  This report summarizes the current status of the plant target design.

  2. PLUTONIUM-238 PRODUCTION TARGET DESIGN STUDIES

    SciTech Connect

    Hurt, Christopher J; Wham, Robert M; Hobbs, Randall W; Owens, R Steven; Chandler, David; Freels, James D; Maldonado, G Ivan

    2014-01-01

    A new supply chain is planned for plutonium-238 using existing reactors at the Oak Ridge National Laboratory (ORNL) and Idaho National Laboratory (INL) and existing chemical recovery facilities at ORNL. Validation and testing activities for new irradiation target designs have been conducted in three phases over a 2 year period to provide data for scale-up to production. Target design, qualification, target fabrication, and irradiation of fully-loaded targets have been accomplished. Data from post-irradiation examination (PIE) supports safety analysis and irradiation of future target designs.

  3. Niobium sputtered Havar foils for the high-power production of reactive [18F]fluoride by proton irradiation of [18O]H2O targets.

    PubMed

    Wilson, J S; Avila-Rodriguez, M A; Johnson, R R; Zyuzin, A; McQuarrie, S A

    2008-05-01

    Niobium sputtered Havar entrance foils were used for the production of reactive [(18)F]fluoride by proton irradiation of [(18)O]H(2)O targets under pressurized conditions. The synthesis yield in the routine production of 2-[(18)F]fluoro-2-deoxy-glucose (FDG) was used as an indicative parameter of the reactivity of (18)F. The yield of FDG obtained with (18)F produced in a target with Havar foil was used as a baseline. No statistically significant difference was found in the saturated yields of (18)F when using Havar or Havar-Nb sputtered entrance foils. However, the amount of long-lived radionuclidic impurities decreased more than 10-fold using the Havar-Nb entrance foil. The average decay corrected synthesis yield of FDG, evaluated over a period of more than 2 years, was found to be approximately 5% higher when using a Havar-Nb entrance foil and a marked improvement on the FDG yield consistency was noted. In addition, the frequency of target rebuilding was greatly diminished when using the Nb sputtered entrance foil.

  4. Separation of sodium-22 from irradiated targets

    DOEpatents

    Taylor, Wayne A.; Jamriska, David

    1996-01-01

    A process for selective separation of sodium-22 from an irradiated target including dissolving an irradiated target to form a first solution, contacting the first solution with hydrated antimony pentoxide to selectively separate sodium-22 from the first solution, separating the hydrated antimony pentoxide including the separated sodium-22 from the first solution, dissolving the hydrated antimony pentoxide including the separated sodium-22 in a mineral acid to form a second solution, and, separating the antimony from the sodium-22 in the second solution.

  5. Post-Irradiation Examination of Array Targets - Part I

    SciTech Connect

    Icenhour, A.S.

    2004-01-23

    During FY 2001, two arrays, each containing seven neptunium-loaded targets, were irradiated at the Advanced Test Reactor in Idaho to examine the influence of multi-target self-shielding on {sup 236}Pu content and to evaluate fission product release data. One array consisted of seven targets that contained 10 vol% NpO{sub 2} pellets, while the other array consisted of seven targets that contained 20 vol % NpO{sub 2} pellets. The arrays were located in the same irradiation facility but were axially separated to minimize the influence of one array on the other. Each target also contained a dosimeter package, which consisted of a small NpO{sub 2} wire that was inside a vanadium container. After completion of irradiation and shipment back to the Oak Ridge National Laboratory, nine of the targets (four from the 10 vol% array and five from the 20 vol% array) were punctured for pressure measurement and measurement of {sup 85}Kr. These nine targets and the associated dosimeters were then chemically processed to measure the residual neptunium, total plutonium production, {sup 238}Pu production, and {sup 236}Pu concentration at discharge. The amount and isotopic composition of fission products were also measured. This report provides the results of the processing and analysis of the nine targets.

  6. Results of four one-day electron-accelerator irradiations of enriched Mo-100 targets for the production of Mo-99

    SciTech Connect

    Chemerisov, S.; Bailey, J.; Heltemes, T.; Jonah, C.; Gromov, R.; Makarashvili, V.; Tkac, P.; Rotsch, D.; Virgo, M.; Vandegrift, G. F.

    2016-10-01

    A series of four one-day irradiations was conducted with 100Mo-enriched disk targets. After irradiation, the enriched disks were removed from the target and dissolved. The resulting solution was processed using a NorthStar RadioGenix 99mTc generator either at Argonne National Laboratory or at the NorthStar Medical Radioisotopes facility. Runs on the RadioGenix system produced inconsistent analytical results for 99mTc in the Tc/Mo solution. These inconsistencies were attributed to the impurities in the solution or improper column packing. During the irradiations, the performance of the optic transitional radiation (OTR) and infrared cameras was tested in high radiation field. The OTR cameras survived all irradiations, while the IR cameras failed every time. The addition of X-ray and neutron shielding improved camera survivability and decreased the number of upsets.

  7. Microjet formation and hard x-ray production from a liquid metal target irradiated by intense femtosecond laser pulses

    SciTech Connect

    Lar'kin, A. Uryupina, D.; Ivanov, K.; Savel'ev, A.; Bonnet, T.; Gobet, F.; Hannachi, F.; Tarisien, M.; Versteegen, M.; Spohr, K.; Breil, J.; Chimier, B.; Dorchies, F.; Fourment, C.; Leguay, P.-M.; Tikhonchuk, V. T.

    2014-09-15

    By using a liquid metal as a target one may significantly enhance the yield of hard x-rays with a sequence of two intense femtosecond laser pulses. The influence of the time delay between the two pulses is studied experimentally and interpreted with numerical simulations. It was suggested that the first arbitrary weak pulse produces microjets from the target surface, while the second intense pulse provides an efficient electron heating and acceleration along the jet surface. These energetic electrons are the source of x-ray emission while striking the target surface. The microjet formation is explained based on the results given by both optical diagnostics and hydrodynamic modeling by a collision of shocks originated from two distinct zones of laser energy deposition.

  8. A target design for irradiation of NaI at high beam current

    NASA Technical Reports Server (NTRS)

    Blue, J. W.; Sodd, V. J.

    1972-01-01

    A solution to the targetry problems encountered when the iodine nucleus is a target for cyclotron irradiation is given as a target design. A target based on this design was used in 30 microampere irradiations of 46 MeV alpha particles for one-half hour without significant damage. Such an irradiation produces 6 to 7 mCi of Cs-129. This target should also be considered for cyclotron production of the radioisotopes Cs-127, I-123, and Xe-127.

  9. Note: Proton irradiation at kilowatt-power and neutron production from a free-surface liquid-lithium target

    SciTech Connect

    Halfon, S.; Feinberg, G.; Arenshtam, A.; Kijel, D.; Weissman, L.; Aviv, O.; Berkovits, D.; Dudovitch, O.; Eisen, Y.; Eliyahu, I.; Haquin, G.; Hazenshprung, N.; Kreisel, A.; Mardor, I.; Shimel, G.; Shor, A.; Silverman, I.; Yungrais, Z.; Paul, M. Tessler, M.

    2014-05-15

    The free-surface Liquid-Lithium Target, recently developed at Soreq Applied Research Accelerator Facility (SARAF), was successfully used with a 1.9 MeV, 1.2 mA (2.3 kW) continuous-wave proton beam. Neutrons (∼2 × 10{sup 10} n/s having a peak energy of ∼27 keV) from the {sup 7}Li(p,n){sup 7}Be reaction were detected with a fission-chamber detector and by gold activation targets positioned in the forward direction. The setup is being used for nuclear astrophysics experiments to study neutron-induced reactions at stellar energies and to demonstrate the feasibility of accelerator-based boron neutron capture therapy.

  10. A solid target system with remote handling of irradiated targets for PET cyclotrons.

    PubMed

    Siikanen, J; Tran, T A; Olsson, T G; Strand, S-E; Sandell, A

    2014-12-01

    A solid target system was developed for a PET cyclotron. The system is compatible with many different target materials in the form of foils and electroplated/sputtered targets which makes it useful for production of a wide variety of different PET radionuclides. The target material is manually loaded into the system. Remote handling of irradiated target material is managed with a pneumatic piston and a vacuum technique which allows the targets to be dropped into a shielded transport container. To test the target performance, proton irradiations (12.8 MeV, 45 μA) of monoisotopic yttrium foils (0.64 mm, direct water cooling) were performed to produce 89Zr. The yields were 2200±200 MBq (1 h, n=13) and 6300±65 MBq (3 h, n=3).

  11. Simulation of cosmic irradiation conditions in thick target arrangements

    NASA Technical Reports Server (NTRS)

    Theis, S.; Englert, P.; Reedy, R. C.; Arnold, J. R.

    1986-01-01

    One approach to simulate 2-pi irradiation conditions of planetary surfaces which has been widely applied in the past are bombardments of so called thick targets. A very large thick target was exposed recently to 2.1 GeV protons at the Bevatron-Bevalac in Berkeley. In a 100x100x180 cm steel-surrounded granodiorite target radioactive medium and high energy spallation products of the incident primary and of secondary particles were analyzed along the beam axis down to depths of 140 g/cm(2) in targets such as Cu, Ni, Co, Fe, T, Si, SiO2 and Al. Activities of these nuclides were exclusively determined via instrumental gamma-ray spectroscopy. Relative yields of neutron capture and spallation products induced in Co and Cu targets during the thick target bombardment are shown as a function of depth. The majority of the medium energy products such as Co-58 from Co targets exhibit a maximum at shallow depths of 40-60 g/cm(2) and then decrease exponentially. In a comparable 600 MeV proton bombarded thick target such a slight maximum for medium energy products was not observed. Rather, Co-58 activities in Co decreased steadily with the highest activity at the surface. The activities of the n-capture product Co-60 increase steadily starting at the surface. This indicates the rapidly growing flux of low energy neutrons within the target.

  12. Recovery of niobium from irradiated targets

    DOEpatents

    Phillips, Dennis R.; Jamriska, Sr., David J.; Hamilton, Virginia T.

    1994-01-01

    A process for selective separation of niobium from proton irradiated molybdenum targets is provided and includes dissolving the molybdenum target in a hydrogen peroxide solution to form a first ion-containing solution, contacting the first ion-containing solution with a cationic resin whereby ions selected form the group consisting of molybdenum, biobium, technetium, selenium, vanadium, arsenic, germanium, zirconium and rubidium remain in a second ion-containing solution while ions selected from the group consisting of rubidium, zinc, beryllium, cobalt, iron, manganese, chromium, strontium, yttrium and zirconium are selectively adsorbed by the cationic resin; adjusting the pH of the second ion-containing solution to within a range of from about 5.0 to about 6.0; contacting the pH adjusting second ion-containing solution with a dextran-based material for a time to selectively separate niobium from the solution and recovering the niobium from the dextran-based material.

  13. Separation of americium, curium, and plutonium from irradiated targets

    SciTech Connect

    Felker, L.K.; Benker, D.E.; Chattin, F.R.

    1995-04-01

    The Radiochemical Engineering Development Center (REDC) at Oak Ridge National Laboratory (ORNL) processes highly irradiated targets for the Mark 42 program to separate Am, Cm, and Pu. The target feed material for each assembly was 3.3 kg of plutonium (78% {sup 239}Pu) that was irradiated at the Savannah River Site to yield approximately 100 g each of {sup 243}Am and {sup 244}Cm, and 100-g quantities of {sup 242}Pu for special DOE projects. The REDC has plans to process ten of these target assemblies over the next few years. The first assembly has been dissolved, and approximately 1/4 of this material has been used to test the processing flowsheet. Various aqueous processes developed at the REDC over the past years were utilized to dissolve the target segments, separate the bulk of the impurities from the transuranics, separate the plutonium from the transplutonium actinides, and separate the rare earth fission products from the Am-Cm. The separation of the Am-Cm products to the desired purity levels presented new processing challenges for REDC operations. Through a combination of precipitation and cation-exchange operations, an Am product containing part-per-million levels of Cm was obtained. Standard REDC processing techniques were used to prepare the products as oxides for shipment. Future processing will focus on the reduction of waste solutions, improvement of yields, and application of new technologies for improved processing.

  14. Development of Water Target for Radioisotope Production

    NASA Astrophysics Data System (ADS)

    Tripp, Nathan

    2011-10-01

    Ongoing studies of plant physiology at TUNL require a supply of nitrogen-13 for use as a radiotracer. Production of nitrogen-13 using a water target and a proton beam follows the nuclear reaction 16-O(p,a)13-N. Unfortunately the irradiation of trace amounts of oxygen-18 within a natural water target produces fluorine-18 by the reaction 18-O(p, n)18-F. The presence of this second radioisotope reduces the efficacy of nitrogen-13 as a radiotracer. Designing a natural water target for nitrogen-13 production at TUNL required the design of several new systems to address the problems inherent in nitrogen-13 production. A heat exchanger cools the target water after irradiation within the target cell. The resulting improved thermal regulation of the target water prevents the system from overheating and minimizes the effect of the cavitations occurring within the target. Alumina pellets within a scrubbing unit remove the fluorine-18 contamination from the irradiated water. The modular design of the water target apparatus makes the system highly adaptable, allowing for easy reuse and adaptation of the different components into future projects. The newly designed and constructed water target should meet the current and future needs of TUNL researchers in the production of nitrogen-13. This TUNL REU project was funded in part by a grant from the National Science Foundation (NSF) NSF-PHY-08-51813.

  15. Recovery of germanium-68 from irradiated targets

    DOEpatents

    Phillips, Dennis R.; Jamriska, Sr., David J.; Hamilton, Virginia T.

    1993-01-01

    A process for selective separation of germanium-68 from proton irradiated molybdenum targets is provided and includes dissolving the molybdenum target in a hydrogen peroxide solution to form a first ion-containing solution, contacting the first ion-containing solution with a cationic resin whereby ions selected from the group consisting of molybdenum, niobium, technetium, selenium, vanadium, arsenic, germanium, zirconium and rubidium remain in a second ion-containing solution while ions selected from the group consisting of rubidium, zinc, beryllium, cobalt, iron, manganese, chromium, strontium, yttrium and zirconium are selectively adsorbed by the first resin, adjusting the pH of the second ion-containing solution to within a range of from about 0.7 to about 3.0, adjusting the soluble metal halide concentration in the second ion-containing solution to a level adapted for subsequent separation of germanium, contacting the pH-adjusted, soluble metal halide-containing second ion-containing solution with a dextran-based material whereby germanium ions are separated by the dextran-based material, and recovering the germanium from the dextran-based material, preferably by distillation.

  16. Thermal Convection on an Irradiated Target

    NASA Astrophysics Data System (ADS)

    Mehmedagic, Igbal; Thangam, Siva

    2016-11-01

    The present work involves the computational modeling of metallic targets subject to steady and high intensity heat flux. The ablation and associated fluid dynamics when metallic surfaces are exposed to high intensity laser fluence at normal atmospheric conditions is modelled. The incident energy from the laser is partly absorbed and partly reflected by the surface during ablation and subsequent vaporization of the melt. Computational findings based on effective representation and prediction of the heat transfer, melting and vaporization of the targeting material as well as plume formation and expansion are presented and discussed in the context of various ablation mechanisms, variable thermo-physical and optical properties, plume expansion and surface geometry. The energy distribution during the process between the bulk and vapor phase strongly depends on optical and thermodynamic properties of the irradiated material, radiation wavelength, and laser intensity. The relevance of the findings to various manufacturing processes as well as for the development of protective shields is discussed. Funded in part by U. S. Army ARDEC, Picatinny Arsenal, NJ.

  17. Electron irradiation of dry food products

    NASA Astrophysics Data System (ADS)

    Grünewald, Th.

    The interest of the industrial food producer is increasing in having the irradiation facility installed in the food processing chain. The throughput of the irradiator should be high and the residence time of the product in the facility should be short. These conditions can be accomplished by electron irradiators. To clarify the irradiation conditions spices taken out of the industrial process, food grade salt, sugar, and gums as models of dry food products were irradiated. With a radiation dose of 10 kGy microbial load can be reduced on 10∗∗4 microorganisms/g. The sensory properties of the spices were not changed in an atypical way. For food grade salt and sugar changes of colour were observed which are due to lattice defects or initiated browning. The irradiation of several gums led only in some cases to an improvement of the thickness properties in the application below 50°C, in most cases the thickness effect was reduced. The products were packaged before irradiation. But it would be possible also to irradiate the products without packaging moving the product through the iradiation field in a closed conveyor system.

  18. A target design for irradiation of NaI at high beam current.

    NASA Technical Reports Server (NTRS)

    Blue, J. W.; Sodd, V. J.

    1972-01-01

    A solution to the targetry problems encountered when the iodine nucleus is a target for cyclotron irradiation is given as a new target design. A target based on this design has been used in 30 microampere irradiations of 46 MeV alpha particles for one-half hour without significant damage. Such an irradiation produces 6 to 7 mCi of Cs-129, an isotope useful in nuclear medicine. This target should also be considered for cyclotron production of the radioisotopes Cs-127, I-123, and Xe-127.

  19. Final Report on MEGAPIE Target Irradiation and Post-Irradiation Examination

    SciTech Connect

    Yong, Dai

    2015-06-30

    Megawatt pilot experiment (MEGAPIE) was successfully performed in 2006. One of the important goals of MEGAPIE is to understand the behaviour of structural materials of the target components exposed to high fluxes of high-energy protons and spallation neutrons in flowing LBE (liquid lead-bismuth eutectic) environment by conducting post-irradiation examination (PIE). The PIE includes four major parts: non-destructive test, radiochemical analysis of production and distribution of radionuclides produced by spallation reaction in LBE, analysis of LBE corrosion effects on structural materials, T91 and SS 316L steels, and mechanical testing of the T91 and SS 316L steels irradiated in the lower part of the target. The non-destructive test (NDT) including visual inspection and ultrasonic measurement was performed in the proton beam window area of the T91 calotte of the LBE container, the most intensively irradiated part of the MEGAPIE target. The visual inspection showed no visible failure and the ultrasonic measurement demonstrated no detectable change in thickness in the beam window area. Gamma mapping was also performed in the proton beam window area of the AlMg3 safety-container. The gamma mapping results were used to evaluate the accumulated proton fluence distribution profile, the input data for determining irradiation parameters. Radiochemical analysis of radionuclides produced by spallation reaction in LBE is to improve the understanding of the production and distribution of radionuclides in the target. The results demonstrate that the radionuclides of noble metals, 207Bi, 194Hg/Au are rather homogeneously distributed within the target, while radionuclides of electropositive elements are found to be deposited on the steel-LBE interface. The corrosion effect of LBE on the structural components under intensive irradiation was investigated by metallography. The results show that no evident corrosion damages. However, unexpected deep

  20. Method for mounting laser fusion targets for irradiation

    DOEpatents

    Fries, R. Jay; Farnum, Eugene H.; McCall, Gene H.

    1977-07-26

    Methods for preparing laser fusion targets of the ball-and-disk type are disclosed. Such targets are suitable for irradiation with one or two laser beams to produce the requisite uniform compression of the fuel material.

  1. Production of modified starches by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Kang, Il-Jun; Byun, Myung-Woo; Yook, Hong-Sun; Bae, Chun-Ho; Lee, Hyun-Soo; Kwon, Joong-Ho; Chung, Cha-Kwon

    1999-04-01

    As a new processing method for the production of modified starch, gamma irradiation and four kinds of inorganic peroxides were applied to commercial corn starch. The addition of inorganic peroxides without gamma irradiation or gamma irradiation without the addition of inorganic peroxides effectively decreased initial viscosity, but did not sufficiently keep viscosity stable. The combination of adding ammonium persulfate (APS) and gamma irradiation showed the lowest initial viscosity and the best stability out of the tested four kinds of inorganic peroxides. Among the tested mixing methods of APS, soaking was found to be more effective than dry blending or spraying. Therefore, the production of modified starch with low viscosity as well as with sufficient viscosity stability became feasible by the control of gamma irradiation dose levels and the amount of added APS to starch.

  2. Radionuclide production calculations: A GUI to determine irradiation conditions

    NASA Astrophysics Data System (ADS)

    Ferguson, S.; Riauka, T.; Jans, H.; Gagnon, K.

    2017-05-01

    There is a wide diversity of production methods for radionuclides. With these, intensive calculations are often required to characterize the different radionuclide production strategies and to determine optimal irradiation parameters. These calculations are essential for predicting the yield and radionuclidic purity of the resulting product. In this work, a graphical user interface (GUI) has been built in Matlab® to facilitate these production calculations and compare production methods. The user is able to import cross-sections, define target compositions and outline irradiation conditions for calculating yields. This GUI facilitates the process of varying irradiation parameters and allows the user to determine the yield of radionuclides as a function of energy and time.

  3. The BLAIRR Irradiation Facility Hybrid Spallation Target Optimization

    SciTech Connect

    Simos N.; Hanson A.; Brown, D.; Elbakhshawn, M.

    2016-04-11

    BLAIRR STUDY STATUS OVERVIEW Beamline Complex Evaluation/Assessment and Adaptation to the Goals Facility Radiological Constraints ? Large scale analyses of conventional facility and integrated shield (concrete, soil)Target Optimization and Design: Beam-target interaction optimization Hadronic interaction and energy deposition limitations Single phase and Hybrid target concepts Irradiation Damage Thermo-mechanical considerations Spallation neutron fluence optimization for (a) fast neutron irradiation damage (b) moderator/reflector studies, (c) NTOF potential and optimization (d) mono-energetic neutron beam

  4. Monitoring pathogens from irradiated agriculture products

    NASA Astrophysics Data System (ADS)

    Butterweck, Joseph S.

    The final food and environmental safety assessment of agriculture product irradiation can only be determined by product history. Product history will be used for future research and development, regulations, commercial practices and implementation of agriculture and food irradiation on a regional basis. The commercial irradiator treats large varieties and amounts of products that are used in various environments. It, in time, will generate a large data base of product history. Field product monitoring begins when food irradiation progresses from the pilot/demonstration phase to the commercial phase. At that time, it is important that there be in place a monitoring system to collect and analyze field data. The systems managers, public health authorities and exotic disease specialists will use this information to assess the reduction of food pathogens on the populace and the environment. The common sources of monitoring data are as follows: 1) Host Monitoring a) Medical Diagnosis b) Autopsy c) Serology Surveys 2) Environmental Monitoring a) Sentinel b) Pest Surveys/Microbial Counts c) Sanitary Inspections 3) Food Industries Quality Assurance Monitoring a) End Product Inspection b) Complaints c) Continual Use of the Product

  5. Gas generation during waste treatment of acidic solutions from the dissolution of irradiated LEU targets for 99Mo production

    SciTech Connect

    Bakel, Allen J.; Conner, Cliff; Quigley, Kevin; Vandegrift, George F.

    2017-01-01

    The goal of the Reduced Enrichment for Research and Test Reactors Program is to limit the use of high-enriched uranium (HEU) in research and test reactors by substituting low-enriched uranium (LEU) wherever possible. The work reported here documents our work to develop the calcining technologies and processes that will be needed for 99Mo production using LEU foil targets and the Modified Cintichem Process. The primary concern with the conversion to LEU from HEU targets is that it would result in a five- to six-fold increase in the total uranium. This increase results in more liquid waste from the process. We have been working to minimize the increase in liquid waste and to minimize the impact of any change in liquid waste. Direct calcination of uranium-rich nitric acid solutions generates NO2 gas and UO3 solid. We have proposed two processes for treating the liquid waste from a Modified Cintichem Process with a LEU foil. One is an optimized direct calcination process that is similar to the process currently in use. The other is a uranyl oxalate precipitation process. The specific goal of the work reported here was to characterize and compare the chemical reactions that occur during these two processes. In particular, the amounts and compositions of the gaseous and solid products were of interest. A series of experiments was carried out to show the effects of temperature and the redox potential of the reaction atmosphere. The primary products of the direct calcination process were mixtures of U3O8 and UO3 solids and NO2 gas. The primary products of the oxalate precipitation process were mixtures of U3O8 and UO2 solid and CO2 gas. Higher temperature and a reducing atmosphere tended to favor quadrivalent over hexavalent uranium in the solid product. These data will help producers to decide between the two processes. In addition, the data can be used

  6. Preservation of food products by irradiation

    SciTech Connect

    McGivney, W.T.

    1988-01-01

    The use of irradiation to preserve food has the potential to significantly enhance our capacity to maximize the quality and quantity of the food we consume. In a world in which distribution of food occurs across continents and in which malnourished populations are in dire need of basic food products, any safe, effective, and efficient means of preserving food is more than welcome. Irradiation, as a method for food preservation, has been studied for more than 30 years. This discussion focuses on this most recent method for the preservation of food with particular emphasis on its effects on the safety, nutritive, and aesthetic values of the food preserved by irradiation. The use of ionizing radiation as a method to preserve foods is one that has been demonstrated to be effective for a variety of food classes. Irradiation offers a means to decontaminate, disinfest, and retard the spoilage of the food supply. At the same time, it appears that the wholesomeness of these food products is maintained. Nutritive value can be sustained by use of effective doses of radiation. Concerns over the safety of irradiated food are rooted in questions regarding the potential induction of radioactivity, harmful radiolytic products, and pathogenic radiation-resistant or mutant strains of microorganisms. Research findings have allayed concerns over safety. However, more research is necessary to conclusively resolve these safety issues. Food irradiation is a promising technology that has and will contribute to our ability to feed the people of this world. This technology is but one of many available ways to preserve our greatest natural resource, the food supply. Enhancement of the ability to preserve food by irradiation will facilitate the distribution of food from fertile developed regions to the malnourished peoples of underdeveloped countries. 21 references.

  7. Development of annular targets for {sup 99}MO production.

    SciTech Connect

    Conner, C.; Lewandowski, E. F.; Snelgrove, J. L.; Liberatore, M. W.; Walker, D. E.; Wiencek, T. C.; McGann, D. J.; Hofman, G. L.; Vandegrift, G. F.

    1999-09-30

    The new annular target performed well during irradiation. The target is inexpensive and provides good heat transfer during irradiation. Based on these and previous tests, we conclude that targets with zirconium tubes and either nickel-plated or zinc-plated foils work well. We proved that we could use aluminum target tubes, which are much cheaper and easier to work with than the zirconium tubes. In aluminum target tubes nickel-plated fission-recoil barriers work well and prevent bonding of the foil to the new target tubes during irradiation. Also, zinc-plated and aluminum-foil barriers appear promising in anodized aluminum tubes. Additional tests are anticipated to address such issues as fission-recoil barrier thickness and uranium foil composition. Overall, however, the target was successful and will provide an inexpensive, efficient way to irradiate LEU metal foil for the production of {sup 99}Mo.

  8. Vacuum aperture isolator for retroreflection from laser-irradiated target

    DOEpatents

    Benjamin, Robert F.; Mitchell, Kenneth B.

    1980-01-01

    The disclosure is directed to a vacuum aperture isolator for retroreflection of a laser-irradiated target. Within a vacuum chamber are disposed a beam focusing element, a disc having an aperture and a recollimating element. The edge of the focused beam impinges on the edge of the aperture to produce a plasma which refracts any retroreflected light from the laser's target.

  9. Evaluation of CERES surface irradiance products

    NASA Astrophysics Data System (ADS)

    Kato, S.; Loeb, N. G.; Rose, F. G.; Rutan, D. A.; Doelling, D.; Radkevich, A.; Ham, S. H.

    2014-12-01

    Understanding the surface radiation budget is important for several reasons. At the global and large temporal scales, it should balance with the sum of surface latent and sensible heat fluxes and ocean heating. At regional scales, it is an indispensable boundary condition for ocean or snow models or any other models that need energy input to the surface. NASA's Clouds and the Earth's Radiant Energy System (CERES) project provides surface irradiance data products for a range of temporal and spatial scales computed using a radiative transfer model initialized using satellite-derived cloud and aerosol properties. Other inputs to the radiative transfer model include temperature and humidity profiles from NASA Global Modeling and Assimilation Office's (GMAO) reanalysis. The CERES team uses more than 80 surface observation sites located over land and ocean to evaluate computed irradiances. When computed monthly 1° by 1° gridded mean downward irradiances are compared with 10 years of observed irradiances, the bias averaged over all land and ocean sites are, respectively, -1.7 Wm-2 and 4.7 Wm-2 for shortwave and -1.0 Wm-2 and -2.0 Wm-2 for longwave. The shortwave agreement is significantly better than other satellite-based surface irradiance products. One of reasons for the better agreement is careful treatment of diurnal cycle of clouds by merging 3-hourly geostationary satellite-derived cloud properties. In addition, computed surface irradiance variability shows a remarkable agreement with observed variability. However, these data sets have their shortcomings. The uncertainty in nighttime surface longwave irradiance over polar regions is larger than that of other regions primarily due to the difficulty of cloud detection and large uncertainties in skin temperature and near-surface temperature and humidity. The large uncertainty in polar region surface irradiances hampers, for example, investigation of surface radiation budget changes in response to changes in sea ice

  10. Disinfestation of different cereal products by irradiation

    NASA Astrophysics Data System (ADS)

    Kovács, E.; Kiss, I.; Boros, A.; Horváth, Ny.; Tóth, J.; Gyulai, P.; Szalma, Á.

    The sensitivity of overlineTribolium confusum - small flour beetle - to radiation was studied in a dose range of 0-0.8 kGy. We found that the insect egg was the most sensitive to radiation, then larvae and pupae followed it. 0.2 kGy dose of irradiation kills these forms or their further development is inhibited. Imagoes do not immediately die after 0.8 kGy dose of irradiation; the young imagoes are more sensitive to radiation than the aged ones. 0.4 kGy average dose of irradiation is a suitable protection against overlineTribolium confusum. Disinfestation experiments were performed with wheat-germ and wheat-bran and parallelly the most important ingredients of the two products were analysed. The vitamin E content and the rate of lipid-oxidation of wheat germ were determined. The vitamin E content decreased after radiation treatment, however, during storage of at least 6 months, it remained at a level specified by food quality standards (higher than 10 mg%). Carbohydrate content of wheat-bran (water soluble carbohydrate content, crude-fibre and dietary fibre content) did not change at all. Storability of radiation disinfested wheat-germ was 8 months, wheat-bran 3-4 months. On the base of the results 2-2 tons of wheat-germ and wheat-bran were irradiated and trial marked in 1985. In 1986 the irradiation of 10 tons of wheat-germ is planned.

  11. Prospects for Irradiation in Cellulosic Ethanol Production

    PubMed Central

    Saini, Anita; Aggarwal, Neeraj K.; Sharma, Anuja; Yadav, Anita

    2015-01-01

    Second generation bioethanol production technology relies on lignocellulosic biomass composed of hemicelluloses, celluloses, and lignin components. Cellulose and hemicellulose are sources of fermentable sugars. But the structural characteristics of lignocelluloses pose hindrance to the conversion of these sugar polysaccharides into ethanol. The process of ethanol production, therefore, involves an expensive and energy intensive step of pretreatment, which reduces the recalcitrance of lignocellulose and makes feedstock more susceptible to saccharification. Various physical, chemical, biological, or combined methods are employed to pretreat lignocelluloses. Irradiation is one of the common and promising physical methods of pretreatment, which involves ultrasonic waves, microwaves, γ-rays, and electron beam. Irradiation is also known to enhance the effect of saccharification. This review explains the role of different radiations in the production of cellulosic ethanol. PMID:26839707

  12. Target Material Irradiation Studies for High-Intensity Accelerator Beams

    SciTech Connect

    Simos, N.; Kirk, H.; Ludewig, H.; Thieberger, P.; Weng, W.T.; McDonald, K.; Sheppard, J.; Evangelakis, G.; Yoshimura, K.; /KEK, Tsukuba

    2005-08-16

    This paper presents results of recent experimental studies focusing on the behavior of special materials and composites under irradiation conditions and their potential use as accelerator targets. The paper also discusses the approach and goals of on-going investigations on an expanded material matrix geared toward the neutrino superbeam and muon collider initiatives.

  13. Irradiation Products On Dwarf Planet Makemake

    NASA Astrophysics Data System (ADS)

    Brown, M. E.; Schaller, E. L.; Blake, G. A.

    2015-03-01

    The dark, reddish tinged surfaces of icy bodies in the outer solar system are usually attributed to the long term irradiation of simple hydrocarbons leading to the breaking of C-H bonds, loss of hydrogen, and the production of long carbon chains. While the simple hydrocarbon methane is stable and detected on the most massive bodies in the Kuiper Belt, evidence of active irradiation chemistry is scant except for the presence of ethane on methane-rich Makemake and the possible detections of ethane on more methane-poor Pluto and Quaoar. We have obtained deep high signal-to-noise spectra of Makemake from 1.4 to 2.5 μm in an attempt to trace the radiation chemistry in the outer solar system beyond the initial ethane formation. We present the first astrophysical detection of solid ethylene and evidence for acetylene and high-mass alkanes—all expected products of the continued irradiation of methane, and use these species to map the chemical pathway from methane to long-chain hydrocarbons.

  14. NOTE: Validation of blood product irradiation doses

    NASA Astrophysics Data System (ADS)

    Cheung, T.; Butson, M.; Yu, P. K. N.

    2001-10-01

    Dosimetry of blood irradiation using x-ray beams on a medical linear accelerator has been studied to evaluate the accuracy of a diode detector and the delivery achievable. Variations in applied doses for a standard dual field 6 MV x-ray are measured with a commercial diode detector. Results show that the diode detector measured applied in vitro doses to within 5.4% (2 standard deviations (2 SD)) of those calculated with a collapsed-cone convolution treatment-planning computer for a sample of 100 blood irradiations. Experiments involving the packing procedure of the blood products in the blood box were performed. It was found that a large proportion of the variation in the predicted and measured dose was due to the compacting of the scatter material at the base of the blood box (over a 6 month period) producing a higher density below the blood than originally scanned; hence an overall reduction of delivered dose was observed. The diode measurements (which provide an immediate printout) are recommended in conjunction with a film dosimeter such as radiochromic film, which still provides a back-up dose monitor and a visual reminder that the blood has been irradiated. It is also recommended that the blood box be completely evacuated of all scatter material every month and the base be carefully repacked to provide uniform scatter material.

  15. Validation of blood product irradiation doses.

    PubMed

    Cheung, T; Butson, M; Yu, P K

    2001-10-01

    Dosimetry of blood irradiation using x-ray beams on a medical linear accelerator has been studied to evaluate the accuracy of a diode detector and the delivery achievable. Variations in applied doses for a standard dual field 6 MV x-ray are measured with a commercial diode detector. Results show that the diode detector measured applied in vitro doses to within 5.4% (2 standard deviations (2 SD)) of those calculated with a collapsed-cone convolution treatment-planning computer for a sample of 100 blood irradiations. Experiments involving the packing procedure of the blood products in the blood box were performed. It was found that a large proportion of the variation in the predicted and measured dose was due to the compacting of the scatter material at the base of the blood box (over a 6 month period) producing a higher density below the blood than originally scanned; hence an overall reduction of delivered dose was observed. The diode measurements (which provide an immediate printout) are recommended in conjunction with a film dosimeter such as radiochromic film, which still provides a back-up dose monitor and a visual reminder that the blood has been irradiated. It is also recommended that the blood box be completely evacuated of all scatter material every month and the base be carefully repacked to provide uniform scatter material.

  16. Optimization of direct drive irradiation uniformity of cylindrical target

    NASA Astrophysics Data System (ADS)

    Tian, Chao; Shan, Lianqiang; Zhou, Weimin; Liu, Dongxiao; Bi, Bi; Zhang, Feng; Wang, Weiwu; Yuan, Zongqiang; Yang, Lei; Gu, Yuqiu; Zhang, Baohan

    2017-07-01

    The irradiation uniformity of a cylindrical target directly driven by laser beams has been considered, which is relevant for fast ignition electron-transport experiments. The laser intensity distribution on the cylindrical target surface is analyzed and optimized by applying the polar direct drive technique and adjusting the laser beam parameters. Moreover, the rotation of laser spot around its propagation axis is taken into consideration. A case study based on the SG-III prototype laser configuration is presented to demonstrate the optimization approach. The irradiation uniformity is reduced from 10% to 1.6% for perfectly balanced beams, and the effects of uncertainties in beam errors (power imbalance and pointing error) are also studied. Furthermore, differences in laser absorption with different incident angles are taken into account and the results show that highly uniform energy deposition can be achieved.

  17. Sample Targeting During Single-Particle Single-Cell Irradiation

    NASA Astrophysics Data System (ADS)

    Bigelow, A. W.; Randers-Pehrson, G.; Michel, K. A.; Brenner, D. J.; Dymnikov, A. D.

    2003-08-01

    An apertured microbeam is used for single-particle single-cell irradiation to study radiobiological effects at the Radiological Research Accelerator Facility (RARAF), Center for Radiological Research, Columbia University. The present sample targeting system involves imaging techniques and a stepping motor stage to sequentially position a cell nucleus above a vertical ion beam. An interest expressed by the biology research community in targeting subnuclear components has spurred the development of microbeam II, a next-generation facility to include a focused ion beam and a more precise sample manipulator, a voice coil stage. Sample positioning precision will rely on a feedback circuit incorporating linear variable differential transformer (LVDT) position measurements. In addition, post-lens electrostatic deflection is a contender for a point-and-shoot system that could speed up the cell irradiation process for cells within an image frame. Crucial to this development is that ion beam blow up must be minimal during deflection.

  18. High power neutron production targets

    SciTech Connect

    Wender, S.

    1996-06-01

    The author describes issues of concern in the design of targets and associated systems for high power neutron production facilities. The facilities include uses for neutron scattering, accelerator driven transmutation, accelerator production of tritium, short pulse spallation sources, and long pulse spallation sources. Each of these applications requires a source with different design needs and consequently different implementation in practise.

  19. Post irradiation examination of the Spallation Neutron Source target vessels

    SciTech Connect

    McClintock, David A; Ferguson, Phillip D; Mansur, Louis K

    2010-01-01

    The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory is an accelerator-based pulsed neutron source that produces high-energy spallation neutrons by bombarding liquid mercury flowing through a stainless steel target vessel. During operation the proton beam and spallation neutrons produce radiation damage in the AISI 316L austenitic stainless steel target vessel and water-cooled shroud. The beam pulses also cause rapid heating of the liquid mercury, which may produce cavitation erosion damage on the inner surface of the target vessel. The cavitation erosion rate is thought to be highly sensitive to beam power and predicted to be the primary life-limiting factor of target vessel. Though mitigation of cavitation erosion and radiation damage to the target vessel will be a critical for successful high-power operation of the SNS facility, the effects of radiation damage and cavitation erosion to target vessels in liquid metal spallation systems are not well known. Therefore preparations are being undertaken to perform post irradiation examination (PIE) of the liquid mercury target vessel and water-cooled shroud after end-of-life occurs. An overview of the planned PIE for the SNS target vessel is presented here, including proposed techniques for specimen acquisition and subsequent material properties characterization.

  20. Proton driven acceleration by intense laser pulses irradiating thin hydrogenated targets

    NASA Astrophysics Data System (ADS)

    Torrisi, L.; Cutroneo, M.; Cavallaro, S.; Giuffrida, L.; Andò, L.; Cirrone, P.; Bertuccio, G.; Puglisi, D.; Calcagno, L.; Verona, C.; Picciotto, A.; Krasa, J.; Margarone, D.; Velyhan, A.; Laska, L.; Krousky, E.; Pfeiffer, M.; Skala, J.; Ullschmied, J.; Wolowski, J.; Badziak, J.; Rosinski, M.; Ryc, L.; Szydlowski, A.

    2013-05-01

    The Asterix iodine laser of the PALS laboratory in Prague, operating at 1315 nm fundamental frequency, 300 ps pulse duration, 600 J maximum pulse energy and 1016 W/cm2 intensity, is employed to irradiate thin hydrogenated targets placed in high vacuum. Different metallic and polymeric targets allow to generate multi-energetic and multi-specie ion beams showing peculiar properties. The plasma obtained by the laser irradiation is monitored, in terms of properties of the emitted charge particles, by using time-of-flight techniques and Thomson parabola spectrometer (TPS). A particular attention is given to the proton beam production in terms of the maximum energy, emission yield and angular distribution as a function of the laser energy, focal position (FP), target thickness and composition.

  1. Application of the TRUEX process to highly irradiated targets

    SciTech Connect

    Felker, L.K.; Benker, D.E.

    1995-03-01

    The Radiochemical Engineering Development Center (REDC) at Oak Ridge National Laboratory processes highly irradiated targets for the Mark 42 program to separate americium, curium, and plutonium. Argonne National Laboratory (ANL) has developed the TRUEX process for the removal of transuranic elements from aqueous waste streams and a computer model that aids in the design of potential flowsheets. Because the TRUEX process is attractive for application to the large volumes of high-activity tank wastes stored at various Department of Energy sites, a test of the process on the highly irradiated Mark 42 target material would yield useful information on the performance of the process under {open_quotes}real{close_quotes} conditions. Researchers at ANL used the Generic TRUEX Model (GTM) to design a TRUEX flowsheet to process Mark 42 target material. Researchers at the REDC refurbished the Solvent Extraction Test Facility mixer-settler contactors and conducted three test runs using the TRUEX process. The results from the three demonstration tests are presented along with the predicted results from the GTM.

  2. Ion-exchange chromatographic separation of einsteinium from irradiated californium targets

    SciTech Connect

    Elesin, A.A.; Nikolaev, V.M.; Shalimov, V.V.; Popov, Yu.S.; Kovantsev, V.N.; Tselishchev, I.V.; Filimonov, V.T.; Mishenev, V.B.; Yadovin, A.A.; Golosovskii, L.S.; Chetverikov, A.P.

    1987-07-01

    Einsteinium was obtained by preparing two experimental californium targets and subjecting them to neutron irradiation in a high-flux reactor. The einsteinium was separated from the bombarded targets on a column packed with KU-2U sulfonated cation-exchange resin (20-50 ..mu..m) and eluted at room temperature with an ammonium ..cap alpha..-hydroxyisobutyrate solution. Three successive separation cycles removed californium to produce einsteinium in 68% yield with a decontamination factor of 5.3 x 10/sup 6/. About 20% of the einsteinium was used up by analysis and 11% remained in intermediate fractions. The method developed yielded pure einsteinium with little fission products present. The contribution of the fission products to the total einsteinium gamma-irradiation dose rate was no greater than 81%, due primarily to the radioisotope terbium-160.

  3. Practical dosimetric aspects of blood and blood product irradiation

    SciTech Connect

    Fearon, T.C.; Luban, N.L.

    1986-09-01

    The method of choice to reduce susceptibility to transfusion-transmitted graft-versus-host disease is irradiation of allogenic blood and blood products for transfusion to immunosuppressed recipients. Optimal irradiation requires delivery of a known and homogeneous absorbed dose. The use of absorbed dose in air measured at the center of the irradiation volume without proper compensation for sample absorption can lead to approximately 20 percent underexposure. A lucite cylinder was used to provide the delivery of a homogeneous irradiation dose to blood products of different volumes by allowing rotation of the product.

  4. Rationale and recommendations for the irradiation of blood products

    SciTech Connect

    Pritchard, S.L.; Rogers, P.C.

    1987-01-01

    Blood products are often irradiated to prevent proliferation of lymphocytes which could cause graft-vs.-host disease in immunocompromised recipients. The effects of irradiation on the function of blood components is discussed. It is concluded that 1500 rad is sufficient to prevent lymphocyte proliferation and production of graft-vs.-host disease in vivo, although 10 to 20% of lymphocytes are still capable of proliferation in vitro after 1500 rad. Neutrophils and erythrocytes are extremely radioresistant and their function is unaffected by 1500 rad. There are limited data to suggest that platelet yields may be slightly reduced following irradiation. Guidelines for the use of irradiated blood products are suggested.61 references.

  5. Separation of no-carrier-added astatine radionuclides from α-particle irradiated lead bismuth eutectic target: A classical method.

    PubMed

    Maiti, Moumita; Lahiri, Susanta; Kumar, Deepak; Choudhury, Dibyasree

    2017-09-01

    Possibility of separation of no-carrier-added (NCA) astatine radionuclides from the bulk lead-bismuth-eutectic (LBE) target was explored in a simple way in the laboratory scale. A LBE target was irradiated by 40MeV α-particles delivered from a cyclotron facility, India. Quantitative analysis of the irradiated target indicated the production of (210,209)At, (207)Po radionuclides in the target matrix. The (210,209)At radionuclides were separated by precipitation of bulk Pb, Bi and NCA radiotoxic Po radionuclides. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Mitochondrial-targeted human catalase affords neuroprotection from proton irradiation.

    PubMed

    Liao, Alicia C; Craver, Brianna M; Tseng, Bertrand P; Tran, Katherine K; Parihar, Vipan K; Acharya, Munjal M; Limoli, Charles L

    2013-07-01

    Significant past work has linked radiation exposure of the CNS to elevated levels of oxidative stress and inflammation. These secondary reactive processes are both dynamic and persistent and are believed to compromise the functionality of the CNS, in part, by disrupting endogenous neurogenesis in the hippocampus. While evidence has shown neurogenesis to be sensitive to irradiation and redox state, the mechanistic basis underlying these effects is incompletely understood. To clarify the role of reactive oxygen species (ROS) in mediating radiation-induced changes in neurogenesis we have analyzed transgenic mice that overexpress human catalase localized to the mitochondria. With this model, we investigated the consequences of low dose and clinically relevant proton irradiation on neurogenesis, and how that process is modified in response to genetic disruption of mitochondrial ROS levels. In unirradiated animals, basal neurogenesis was improved significantly by reductions in mitochondrial ROS. In animals subjected to proton exposure, hippocampal progenitor cell proliferation was attenuated significantly by overexpression of human catalase in the mitochondria. Furthermore, expression of the MCAT transgene significantly improved neurogenesis in WT animals after low-dose proton exposure (0.5 Gy), with similar trends observed at higher dose (2 Gy). Our report documents for the first time the impact of proton irradiation on hippocampal neurogenesis, and the neuroprotective properties of reducing mitochondrial ROS through the targeted overexpression of catalase. © 2013 by Radiation Research Society

  7. Targets and methods for target preparation for radionuclide production

    SciTech Connect

    Zhuikov, Boris L; Konyakhin, Nicolai A; Kokhanyuk, Vladimir M; Srivastava, Suresh C

    2012-10-16

    The invention relates to nuclear technology, and to irradiation targets and their preparation. One embodiment of the present invention includes a method for preparation of a target containing intermetallic composition of antimony Ti--Sb, Al--Sb, Cu--Sb, or Ni--Sb in order to produce radionuclides (e.g., tin-117 m) with a beam of accelerated particles. The intermetallic compounds of antimony can be welded by means of diffusion welding to a copper backing cooled during irradiation on the beam of accelerated particles. Another target can be encapsulated into a shell made of metallic niobium, stainless steel, nickel or titanium cooled outside by water during irradiation. Titanium shell can be plated outside by nickel to avoid interaction with the cooling water.

  8. Craniospinal Irradiation With Spinal IMRT to Improve Target Homogeneity

    SciTech Connect

    Panandiker, Atmaram Pai; Ning, Holly; Likhacheva, Anna; Ullman, Karen; Arora, Barbara; Ondos, John C.; Karimpour, Shervin; Packer, Roger; Miller, Robert; Citrin, Deborah . E-mail: citrind@mail.nih.gov

    2007-08-01

    Purpose: To report a new technique for the spinal component of craniospinal irradiation (CSI) in the supine position, to describe a verification procedure for this method, and to compare this technique with conventional plans. Methods and Materials: Twelve patients were treated between 1998 and 2006 with CSI using a novel technique. Sixteen children were treated with a conventional field arrangement. All patients were followed for outcomes and toxicity. CSI was delivered using a posteroanterior (PA) intensity-modulated radiation therapy (IMRT) spinal field matched to conventional, opposed lateral cranial fields. Treatment plans were generated for each patient using the IMRT technique and a standard PA field technique. The resulting dosimetry was compared to determine target homogeneity, maximum dose to normal tissues, and total monitor units delivered. Results: Evaluation of the spinal IMRT technique compared with a standard PA technique reveals a 7% reduction in the target volume receiving {>=}110% of the prescribed dose and an 8% increase in the target volume receiving {>=}95% of the prescribed dose. Although target homogeneity was improved, the maximum dose delivered in the paraspinal muscles was increased by approximately 8.5% with spinal IMRT compared to the PA technique. Follow-up evaluations revealed no unexpected toxicity associated with the IMRT technique. Conclusions: A new technique of spine IMRT is presented in combination with a quality assurance method. This method improves target dose uniformity compared to the conventional CSI technique. Longer follow-up will be required to determine any benefit with regard to toxicity and disease control.

  9. Cyclotron production of Ac-225 for targeted alpha therapy.

    PubMed

    Apostolidis, C; Molinet, R; McGinley, J; Abbas, K; Möllenbeck, J; Morgenstern, A

    2005-03-01

    The feasibility of producing Ac-225 by proton irradiation of Ra-226 in a cyclotron through the reaction Ra-226(p,2n)Ac-225 has been experimentally demonstrated for the first time. Proton energies were varied from 8.8 to 24.8 MeV and cross-sections were determined by radiochemical analysis of reaction yields. Maximum yields were reached at incident proton energies of 16.8 MeV. Radiochemical separation of Ac-225 from the irradiated target yielded a product suitable for targeted alpha therapy of cancer.

  10. Particle therapy of moving targets-the strategies for tumour motion monitoring and moving targets irradiation.

    PubMed

    Kubiak, Tomasz

    2016-10-01

    Particle therapy of moving targets is still a great challenge. The motion of organs situated in the thorax and abdomen strongly affects the precision of proton and carbon ion radiotherapy. The motion is responsible for not only the dislocation of the tumour but also the alterations in the internal density along the beam path, which influence the range of particle beams. Furthermore, in case of pencil beam scanning, there is an interference between the target movement and dynamic beam delivery. This review presents the strategies for tumour motion monitoring and moving target irradiation in the context of hadron therapy. Methods enabling the direct determination of tumour position (fluoroscopic imaging of implanted radio-opaque fiducial markers, electromagnetic detection of inserted transponders and ultrasonic tumour localization systems) are presented. Attention is also drawn to the techniques which use external surrogate motion for an indirect estimation of target displacement during irradiation. The role of respiratory-correlated CT [four-dimensional CT (4DCT)] in the determination of motion pattern prior to the particle treatment is also considered. An essential part of the article is the review of the main approaches to moving target irradiation in hadron therapy: gating, rescanning (repainting), gated rescanning and tumour tracking. The advantages, drawbacks and development trends of these methods are discussed. The new accelerators, called "cyclinacs", are presented, because their application to particle therapy will allow making a breakthrough in the 4D spot scanning treatment of moving organs.

  11. Experiments With Recirculating Target for F-18 Production

    NASA Astrophysics Data System (ADS)

    Kiselev, M. Y.

    2003-08-01

    Approximately 10 ml of O-18 water was loaded in an apparatus containing a 5 ml storage vessel, pump, silver target attached to a cyclotron, filter, backpressure regulator, conductivity meter, several valves and ion exchange cartridges. The water was continuously pumped through the target during proton bombardment at a rate 5 ml/min. Continuous irradiation with beam current ranging from 10 to 50 uA was conducted while pressure, temperature and conductivity were continuously monitored. The results indicate that recirculating of the target water can increase production of F-18 in relation to consumed O-18 water material. It can also increase productivity by eliminating idle periods for re-filling the target. A backpressure regulator can precisely control target pressure. This method also allows for continuous monitoring of the target material temperature, pressure, conductivity and accumulated radioactivity. Results of these observations provide important information about target performance and physical processes taking place inside the target.

  12. Charpy impact tests on martensitic/ferritic steels after irradiation in SINQ target-3

    NASA Astrophysics Data System (ADS)

    Dai, Yong; Marmy, Pierre

    2005-08-01

    Charpy impact tests were performed on martensitic/ferritic (MF) steels T91, F82H, Optifer-V and Optimax-A/-C irradiated in SINQ Target-3 up to 7.5 dpa and 500 appm He in a temperature range of 120-195 °C. Results demonstrate that for all the four kinds of steels, the ductile-to-brittle transition temperature (DBTT) increases with irradiation dose. The difference in the DBTT shifts (ΔDBTT) of the different steels is not significant after irradiation in the SINQ target. The ΔDBTT data from the previous small punch (Δ DBTT SP) and the present Charpy impact (ΔDBTT CVN) tests can be correlated with the expression: Δ DBTT SP = 0.4ΔDBTT CVN. All the ΔDBTT data fall into a linear band when they are plotted versus helium concentration. The results indicate that helium effects on the embrittlement of MF steels are significant, particularly at higher concentrations. It suggests that MF steels may not be very suitable for applications at low temperatures in spallation irradiation environments where helium production is high.

  13. Materials characterization of irradiated spectralon from the NIF target chamber

    NASA Astrophysics Data System (ADS)

    Chow, Robert; Frieders, Gene; Jensen, Wayne; Pearson, Mark; Datte, Phil

    2015-08-01

    The Near Backscatter Imager (NBI) participates in nearly every kind of experiment conducted at NIF and measures backscatter, the result of the interaction between incident laser light and plasma waves at a target. Large Spectralon plates, on the order of a hundreds of mm per side, are used as Lambertian scatter components for the NBI diagnostics. The plates were deployed in 2009 and replaced in April of 2014. All NBI assemblies suffered reflectivity degradation, and some of these changes were spatially localized defects observed after irradiation to a cumulative combined neutron and Υ dose of 0.038 Gy. The growth of a defect was correlated to the combined cumulative neutron and Υ radiation dose from NIF fusion shots. Spectralon plates that were irradiated to cumulative combined neutron and Υ dose of 0.74 Gy were characterized for materials and mechanical changes with the following techniques: RBS, FTIR, XPS, SEM, EDX and tensile tests. These tests indicate that the bulk Spectralon did not measurably degrade but there are discolorations that affect the reflectivity. Surface analysis indicates that the surface CF2 species re-forms to make various organic and CFx species.

  14. Optical emission from Al target irradiated by FLASH

    NASA Astrophysics Data System (ADS)

    Stránský, M.; Rohlena, K.

    2014-04-01

    The following text touches on some peculiarities in optical emission spectroscopy results from experiments on the free-electron laser FLASH [1, 2]. Aluminum targets were irradiated with 13.5 nm ~ 25 fs pulses at intensities of 1013 and 1016 W/cm2 (20 and 1 μm foci). Surprisingly, only neutral atom lines for the case with wider focus and traces of ion lines in the tighter focus case were observed with the optical emission spectroscopy (200-600 nm range), [2]. The motivating idea behind this work is the suggestion in [1] by Zastrau that the optical spectrometer sees only emissions from a cold expanding lower-density (< 1022 cm-3) plasma plume. In this contribution the notion of UV range screening is analyzed in detail.

  15. Craniospinal Irradiation with Spinal IMRT to Improve Target Homogeneity

    PubMed Central

    Panandiker, Atmaram Pai; Ning, Holly; Likhacheva, Anna; Ullman, Karen; Arora, Barbara; Ondos, John; Karimpour, Shervin; Packer, Roger; Miller, Robert; Citrin, Deborah

    2007-01-01

    Purpose To report a new technique for the spinal component of craniospinal irradiation (CSI) in the supine position, to describe a verification procedure for this method, and to compare this technique to conventional plans. Methods and Materials Twelve patients were treated between 1998 and 2006 with CSI using a novel technique. Sixteen children were treated with a conventional field arrangement. All patients were followed for outcomes and toxicity. CSI was delivered using a posterior-to-anterior (PA) intensity-modulated radiation therapy (IMRT) spinal field matched to conventional, opposed lateral cranial fields. Treatment plans were generated for each patient using the IMRT technique and a standard PA field technique. The resulting dosimetry was compared to determine target homogeneity, maximum dose to normal tissues, and total monitor units delivered. Results Evaluation of the spinal IMRT technique compared to a standard PA technique reveals a 7% reduction in the target volume receiving ≥110% of the prescribed dose and an 8 % increase in the target volume receiving ≥ 95% of the prescribed dose. While target homogeneity was improved, the maximum dose delivered in the paraspinal muscles was increased by approximately 8.5 % with spinal IMRT compared to the PA technique. Follow-up evaluations revealed no unexpected toxicity associated with the IMRT technique. Conclusions A new technique of spine IMRT is presented in combination with a quality assurance method. This method improves target dose uniformity compared to the conventional CSI technique. Longer follow-up will be required to determine any benefit with regard to toxicity and disease control. PMID:17467921

  16. Irradiation of meat products, chicken and use of irradiated spices for sausages

    NASA Astrophysics Data System (ADS)

    Kiss, I. F.; Beczner, J.; Zachariev, Gy.; Kovács, S.

    The shelf-life of packed minced meat has been increased at least threefold at 4°C by applying a 2 kGy dose. Results have been confirmed by detailed quatitative microbiological examinations. Sensory evaluations show no significant difference between the unirradiated samples. The optimal average dose was 4 kGy for packed-frosen chicken. The number of mesophilic aerobic microbes was reduced by 2, that of psychrotolerant by 2-3 and that of Enterbacteriaceae by 3-4 orders of magnitude by 4 kGy. S. aureus and Salmonella could not be detected in the irradiated samples. In sensory evaluations there was no significant difference between untreated and irradiated samples. In 1984-1985 5100 kg irradiated chickens were marketed labelled as radiation treated. Irradiated spices (5 kGy) were used in the production of sausages (heat-treated and non-heat-treated) under industrial conditions. The microbiological contamination of irradiated spices was lower than that of ethylene oxide treated ones. The cell count in products made with irradiated spices was lower than in those made with unirradiated spices. The sausages proved to be of very good quality. In accordance with the permission, products were marketed and because of the low ratio of spices there was no need to declare them as using irradiated spices.

  17. Recovery and purification of nickel-63 from HFIR-irradiated targets

    SciTech Connect

    Williams, D.F.; O'Kelley, G.D.; Knauer, J.B.; Porter, C.E.; Wiggins, J.T.

    1993-06-01

    The production of large quantities of high-specific-activity [sup 63]Ni (>10 Ci/g) requires both a highly enriched [sup 62]Ni target and a long irradiation period at high neutron flux. Trace impurities in the nickel and associated target materials are also activated and account for a significant fraction of the discharged activity and essentially all of the gamma activity. While most of these undesirable activation products can be removed as chloride complexes during anion exchange, chromium, present at [sup 51]Cr, and scandium, present as [sup 46]Sc, are exceptions and require additional processing to achieve the desired purity. Optimized flowsheets are discussed based upon the current development and production experience.

  18. Recovery and purification of nickel-63 from HFIR-irradiated targets

    SciTech Connect

    Williams, D.F.; O`Kelley, G.D.; Knauer, J.B.; Porter, C.E.; Wiggins, J.T.

    1993-06-01

    The production of large quantities of high-specific-activity {sup 63}Ni (>10 Ci/g) requires both a highly enriched {sup 62}Ni target and a long irradiation period at high neutron flux. Trace impurities in the nickel and associated target materials are also activated and account for a significant fraction of the discharged activity and essentially all of the gamma activity. While most of these undesirable activation products can be removed as chloride complexes during anion exchange, chromium, present at {sup 51}Cr, and scandium, present as {sup 46}Sc, are exceptions and require additional processing to achieve the desired purity. Optimized flowsheets are discussed based upon the current development and production experience.

  19. Effect of. gamma. -ray irradiation on alcohol production from corn

    SciTech Connect

    Han, Y.W.; Cho, Y.K.; Ciegler, A.

    1983-11-01

    Cracked corn was irradiated with ..gamma.. rays at 0-100 Mrad and the effects of the irradiation on sugar yield, susceptibility to enzymatic hydrolysis of starch, yeast growth, and alcohol production were studied. Gamma irradiation at 50 Mrad or greater produced a considerable amount of reducing sugar but little glucose. At lower dosages, ..gamma.. irradiation significantly increased the susceptibility of corn starch to enzymatic hydrolysis, but dosages of 50 Mrad or greater decomposed the starch molecules as indicated by the reduction in iodine uptake. About 12.5% reducing sugar was produced by amylase treatment of uncooked, irradiated corn. This amount exceeded the level of sugar produced from cooked (gelatinized) corn by the same enzyme treatment. The yeast numbers in submerged cultivation were lower on a corn substrate that was irradiated at 50 Mrad or greater compared to that on an unirradiated control. About the same level of alcohol was produced on uncooked, irradiated (10/sup 5/ - 10/sup 6/ rad) corn as from cooked (121 degrees C for 30 min) corn. Therefore, the conventional cooking process for gelatinization of starch prior to its saccharification can be eliminated by irradiation. Irradiation also eliminated the necessity of sterilization of the medium and reduced the viscosity of high levels of substrate in the fermentation broth. (Refs. 10).

  20. Using wet microalgae for direct biodiesel production via microwave irradiation.

    PubMed

    Cheng, Jun; Yu, Tao; Li, Tao; Zhou, Junhu; Cen, Kefa

    2013-03-01

    To address the large energy consumption of microalgae dewatering and to simplify the conventional two-step method (cellular lipid extraction and lipid transesterification) for biodiesel production, a novel process for the direct conversion of wet microalgae biomass into biodiesel by microwave irradiation is proposed. The influences of conventional thermal heating and microwave irradiation on biodiesel production from wet microalgae biomass were investigated. The effects of using the one-step (simultaneous lipid extraction and transesterification) and two-step methods were also studied. Approximately 77.5% of the wet microalgal cell walls were disrupted under microwave irradiation. The biodiesel production rate and yield from wet microalgae biomass obtained through the one-step process using microwave irradiation were 6-fold and 1.3-fold higher than those from wet microalgae obtained through the two-step process using conventional heating.

  1. Cleaning with water decomposed products obtained by laser irradiation

    NASA Astrophysics Data System (ADS)

    Hidai, Hirofumi; Tokura, Hitoshi

    2006-11-01

    ArF excimer laser irradiation can decompose water, and decomposed products contain highly reactive substrates, such as radicals. We propose cleaning using pure water with the aid of water decomposed products obtained by ArF excimer laser irradiation. In this study, the oxidation potential of decomposed products was estimated in metal etching. Then, cleaning of cutting oil was examined. The focal point of the lens used was set at the water surface. Specimens were aligned parallel to the laser beam, so that only decomposed products affected contaminants. As a result, decomposed products could not etch nickel and copper plates, but only zinc plates. Cutting oil was cleaned after 18 000 irradiation pulses. The range of the region cleaned was 5 mm around the focal point.

  2. Separation of Plutonium from Irradiated Fuels and Targets

    SciTech Connect

    Gray, Leonard W.; Holliday, Kiel S.; Murray, Alice; Thompson, Major; Thorp, Donald T.; Yarbro, Stephen; Venetz, Theodore J.

    2015-09-30

    Spent nuclear fuel from power production reactors contains moderate amounts of transuranium (TRU) actinides and fission products in addition to the still slightly enriched uranium. Originally, nuclear technology was developed to chemically separate and recover fissionable plutonium from irradiated nuclear fuel for military purposes. Military plutonium separations had essentially ceased by the mid-1990s. Reprocessing, however, can serve multiple purposes, and the relative importance has changed over time. In the 1960’s the vision of the introduction of plutonium-fueled fast-neutron breeder reactors drove the civilian separation of plutonium. More recently, reprocessing has been regarded as a means to facilitate the disposal of high-level nuclear waste, and thus requires development of radically different technical approaches. In the last decade or so, the principal reason for reprocessing has shifted to spent power reactor fuel being reprocessed (1) so that unused uranium and plutonium being recycled reduce the volume, gaining some 25% to 30% more energy from the original uranium in the process and thus contributing to energy security and (2) to reduce the volume and radioactivity of the waste by recovering all long-lived actinides and fission products followed by recycling them in fast reactors where they are transmuted to short-lived fission products; this reduces the volume to about 20%, reduces the long-term radioactivity level in the high-level waste, and complicates the possibility of the plutonium being diverted from civil use – thereby increasing the proliferation resistance of the fuel cycle. In general, reprocessing schemes can be divided into two large categories: aqueous/hydrometallurgical systems, and pyrochemical/pyrometallurgical systems. Worldwide processing schemes are dominated by the aqueous (hydrometallurgical) systems. This document provides a historical review of both categories of reprocessing.

  3. Physics of Double Pulse Irradiation of Targets For Proton Acceleration

    NASA Astrophysics Data System (ADS)

    Kerr, S.; Mo, M.; Masud, R.; Manzoor, L.; Tiedje, H.; Tsui, Y.; Fedosejevs, R.; Link, A.; Patel, P.; McLean, H.; Hazi, A.; Chen, H.; Ceurvorst, L.; Norreys, P.

    2016-10-01

    Experiments have been carried out on double-pulse irradiation of um-scale foil targets with varying preplasma conditions. Our experiment at the Titan Laser facility utilized two 700 fs, 1054 nm pulses, separated by 1 to 5 ps with a total energy of 100 J, and with 5-20% of the total energy contained within the first pulse. The proton spectra were measured with radiochromic film stacks and magnetic spectrometers. The prepulse energy was on the order of 10 mJ, which appears to have a moderating effect on the double pulse enhancement of proton beam. We have performed LSP PIC simulations to understand the double pulse enhancement mechanism, as well as the role of preplasma in modifying the interaction. A 1D parameter study was done to isolate various aspects of the interaction, while 2D simulations provide more detailed physical insight and a better comparison with experimental data. Work by the Univ. of Alberta was supported by the Natural Sciences and Engineering Research Council of Canada. Work by LLNL was performed under the auspices of U.S. DOE under contract DE-AC52-07NA27344.

  4. Fabrication of neptunium oxide targets for irradiation in FFTF

    SciTech Connect

    Blair, H.T.; Chidester, K.M.

    1993-07-01

    The feasibility of.fabdcating neptunium oxide into various target configurations for irradiation in FFTF to produce plutonium-238 was demonstrated by the Nuclear Fuels Technology group at Los Alamos. The configurations included cold-pressed and sintered pellets and wafers and powder encapsulated in 0.0025-cm thick molybdenum foil envelopes. NpO{sub 2} Pellets with a density of 86.5%TD and wafers that were approximately 2-cm diameter by 0.0229-cm thick were produced. Uranium dioxide wafers were fabricated without cracking and warping by assuring uniform distribution of powder in the die before pressing and by setting the pressed wafers on ceramic microspheres for sintering. Forming the powder into microspheres before pressing enabled uniform die filling. Radiation exposure measurements made during the NPO{sub 2} processing showed a maximum of 500 g/mo could be handled in the shielded gloveboxes at Los Alamos and still comply with the exposure limits set by DOE Radiological Control Manual, DOE-EH-0256T.

  5. Correlation between irradiation conditions and nanoparticles obtained in case of laser ablation of aluminum targets in liquids

    NASA Astrophysics Data System (ADS)

    Damian, V.; Apostol, I.; Apostol, D.; Bojan, M.; Iordache, I.; Manoiu, S.; Militaru, A.; Udrea, C.

    2014-07-01

    The process of nanoparticles production by nanosecond pulsed laser ablation of aluminum targets situated in deionized water was studied from the point of view of laser-target interaction and incident laser fluence domain selection as a preliminary stage in the process of nanoparticles production. We have analyzed the irradiated surface morphology and crater profiles as a function of irradiation conditions (incident fluence and irradiation pulses number) by optical microscopy and white light interferometry in order to determine the most efficient coupling between the irradiation conditions and the irradiated surface immersed in liquid. The obtained nanoparticles were studied "in situ", as obtained in suspension in water and "ex situ", using TEM. TEM analyses have demonstrated that we have obtained nanoparticles with the lowest dimensions of 3-5 nm organized in clouds with dimensions between 40 and 80 nm. Typically the obtained nanoparticles presented two clear distributions, one corresponding to low diameters in the 6-10 or 20-40 nm regions, and another with a distribution around a maximum situated at hundreds of nanometers (250-290 nm). The obtained nanoparticles distribution was correlated with the irradiation conditions.

  6. Production of organic molecules by proton irradiation

    NASA Technical Reports Server (NTRS)

    Scattergood, T.; Lesser, P.; Owen, T.

    1974-01-01

    Preliminary experiments were carried out to investigate the effectiveness of proton irradiation for producing organic chromophores. The source of the 2 MeV protons used in the experiments was a model Van de Graaff accelerator. The gas cells used were hollow aluminum cylinders. The test results show that energetic protons can be an effective energy source for the formation of complex molecules from simple ones. With the exception of sulfide compounds none of the molecules that were identified are colored. However, coloring agents could be contained in unresolvable fractions.

  7. Chemical state of fission products in irradiated uranium carbide fuel

    NASA Astrophysics Data System (ADS)

    Arai, Yasuo; Iwai, Takashi; Ohmichi, Toshihiko

    1987-12-01

    The chemical state of fission products in irradiated uranium carbide fuel has been estimated by equilibrium calculation using the SOLGASMIX-PV program. Solid state fission products are distributed to the fuel matrix, ternary compounds, carbides of fission products and intermetallic compounds among the condensed phases appearing in the irradiated uranium carbide fuel. The chemical forms are influenced by burnup as well as stoichiometry of the fuel. The results of the present study almost agree with the experimental ones reported for burnup simulated carbides.

  8. Production of LEU Fully Ceramic Microencapsulated Fuel for Irradiation Testing

    SciTech Connect

    Terrani, Kurt A; Kiggans Jr, James O; McMurray, Jake W; Jolly, Brian C; Hunt, Rodney Dale; Trammell, Michael P; Snead, Lance Lewis

    2016-01-01

    Fully Ceramic Microencapsulated (FCM) fuel consists of tristructural isotropic (TRISO) fuel particles embedded inside a SiC matrix. This fuel inherently possesses multiple barriers to fission product release, namely the various coating layers in the TRISO fuel particle as well as the dense SiC matrix that hosts these particles. This coupled with the excellent oxidation resistance of the SiC matrix and the SiC coating layer in the TRISO particle designate this concept as an accident tolerant fuel (ATF). The FCM fuel takes advantage of uranium nitride kernels instead of oxide or oxide-carbide kernels used in high temperature gas reactors to enhance heavy metal loading in the highly moderated LWRs. Production of these kernels with appropriate density, coating layer development to produce UN TRISO particles, and consolidation of these particles inside a SiC matrix have been codified thanks to significant R&D supported by US DOE Fuel Cycle R&D program. Also, surrogate FCM pellets (pellets with zirconia instead of uranium-bearing kernels) have been neutron irradiated and the stability of the matrix and coating layer under LWR irradiation conditions have been established. Currently the focus is on production of LEU (7.3% U-235 enrichment) FCM pellets to be utilized for irradiation testing. The irradiation is planned at INL s Advanced Test Reactor (ATR). This is a critical step in development of this fuel concept to establish the ability of this fuel to retain fission products under prototypical irradiation conditions.

  9. Oxidative product formation in irradiated neutrophils. A flow cytometric analysis

    SciTech Connect

    Wolber, R.A.; Duque, R.E.; Robinson, J.P.; Oberman, H.A.

    1987-03-01

    The effect of irradiation on neutrophil oxidative function was evaluated using a flow cytometric assay of intracellular hydrogen peroxide (H/sub 2/O/sub 2/) production. This assay quantitates the H/sub 2/O/sub 2/-dependent conversion of the nonfluorescent compound, 2'-7'-dichlorofluorescein (DCFH), into fluorescent 2'-7'-dichlorofluorescein (DCF) on a single-cell basis. Intracellular H/sub 2/O/sub 2/ production in response to stimulation with phorbol myristate acetate was not affected by neutrophil irradiation at doses up to 2500 rad. In addition, irradiation of intracellular DCFH and aqueous 2'-7'-dichlorofluorescein diacetate (DCFH-DA) resulted in DCF production, which suggested that oxidative molecules produced by aqueous radiolysis were detected by this assay. This study indicates that radiation doses of 1500 to 2500 rad, which are sufficient to prevent induction of graft-versus-host disease by transfused blood components, are not deleterious to neutrophil oxidative metabolism.

  10. Production of No-Carrier Added Lutetium-177 by Irradiation of Enriched Ytterbium-176.

    PubMed

    Tarasov, Valery A; Andreev, Oleg I; Romanov, Evgeny G; Kuznetsov, Rostislav A; Kupriyanov, Vladimir V; Tselishchev, Ivan V

    2015-01-01

    Two methods of Lu-177 production are reviewed: irradiation of isotopically enriched Lu- 176 (direct way) and irradiation of ytterbium enriched with Yb-176 (indirect way). Based on neutronphysical calculations Lu-177 yield and specific activity were estimated for both methods. Lu-177 specific activity strongly depends on neutron flux density in the direct way, that is 75,000 Ci/g for 10- days irradiation in a neutron flux of 2.10(15) cm(-2) s(-1), and only 13,000 Ci/g after 30 days irradiation at neutron flux 1.10(14) cm(-2) s(-1). Irradiation of Yb-176 provides Lu-177 specific activity close to theoretical value (110,000 Ci/g). Neutron flux density effect Lu-177 yield, that is 530 Ci/g for 2.1015 cm(-2) s(-1) neutron flux density after 30 days irradiation. A procedure of isolation and purification of Lu-177 from irradiated targets is described based on combination of galvanostatic extraction of ytterbium followed by cation-exchange chromatography from alfa-hydroxyisobutirate solutions on BioRad AG(®)50W-X8 resin.

  11. Light irradiance and spectral distribution effects on cyanobacterial hydrogen production

    NASA Astrophysics Data System (ADS)

    Fatihah Salleh, Siti; Kamaruddin, Azlina; Hekarl Uzir, Mohamad; Rahman Mohamed, Abdul; Halim Shamsuddin, Abdul

    2016-03-01

    Light is an essential energy source for photosynthetic cyanobacteria. Changes in both light irradiance and spectral distribution will affect their photosynthetic productivity. Compared to the light irradiance, little investigations have been carried out on the effect of light spectra towards cyanobacterial hydrogen production. Hence, this work aims to investigate the effects of both light quantity and quality on biohydrogen productivity of heterocystous cyanobacterium, A.variabilis. Under white light condition, the highest hydrogen production rate of 31 µmol H2 mg chl a -1 h-1 was achieved at 70 µE m-2 s-1. When the experiment was repeated at the same light irradiance but different light spectra of blue, red and green, the accumulations of hydrogen were significantly lower than the white light except for blue light. As the light irradiance was increased to 350 µE m-2 s-1, the accumulated hydrogen under the blue light doubled that of the white light. Besides that, an unusual prolongation of the hydrogen production up to 120 h was observed. The results obtained suggest that blue light could be the most desirable light spectrum for cyanobacterial hydrogen production.

  12. Ozone Production by Irradiation of Intense, Pulsed Relativistic Electron Beam

    NASA Astrophysics Data System (ADS)

    Imada, Go; Morishima, Nobuyuki; Yatsui, Kiyoshi

    Characteristics of ozone production have been investigated by irradiation of intense, pulsed relativistic electron beam (IREB). The 1.8-m-long gas-treatment chamber is filled up with dry-N2-balanced O2 gas mixture with the pressure of 98 kPa and is irradiated by IREB. The kinetic energy, current and pulse width of the IREB are - 2 MeV, - 2.9 kA, and - 80 ns (FWHM), respectively. It is found that - 340 ppm of ozone is produced by firing 10 shots of the IREB. We have also obtained the production yield of ozone of 9 - 21 g/kWh.

  13. Hydrogen production by Rhodobacter sphaeroides DSM 158 under intense irradiation.

    PubMed

    Krujatz, Felix; Härtel, Paul; Helbig, Karsten; Haufe, Nora; Thierfelder, Simone; Bley, Thomas; Weber, Jost

    2015-01-01

    To identify optimal hydrogen production conditions using growing cultures of Rhodobacter sphaeroides DSM 158 the effects of varying the reactor's volumetric power input (0.01-1.4kWm(-3)) and irradiation intensity (5-2500Wm(-2)) were investigated in batch and continuous production modes. Irradiation intensity had a greater effect on hydrogen production than volumetric power input. Hydrogen production and photofermentative biomass formation were maximized by irradiation at 2250Wm(-2) with a volumetric power input of 0.55kWm(-3). The bacterial dry weight (2.64gL(-1)) and rate of hydrogen production (195mLL(-1)h(-1)) achieved under these conditions were greater than any that have previously been reported for batch-mode hydrogen production by R. sphaeroides. Continuous mode experiments (D=0.1h(-1)) yielded a bacterial dry weight, hydrogen production rate, productivity and hydrogen yield of 2.35±0.18gL(-1), 165±6.2mLL(-1)h(-1), 3.96LL(-1)d(-1) and 36.6%, respectively.

  14. Application of AnaLig resin for (99m)Tc separation from (100)Mo target irradiated in cyclotron.

    PubMed

    Pawlak, D W; Wojdowska, W; Parus, L J; Mikołajczak, R

    2016-07-01

    The purpose of this study was the development of procedure for molybdenum metallic target processing after its irradiation in a cyclotron. As a first step the dissolution of molybdenum in various physical forms was investigated. The concentrations of NaOH and (NH4)2CO3 allowing the highest sorption of Tc on AnaLig Tc-02 resin had been found. Based on these results the sintered irradiated Mo pellet was processed. The radionuclidic and radiochemical purities of separated Tc product were evaluated.

  15. Analyzing UV-B narrowband solar irradiance: comparison with erythemal and vitamin D production irradiances.

    PubMed

    Sola, Yolanda; Lorente, Jerónimo; Ossó, Albert

    2012-12-05

    The heliotherapy and the phototherapy are mainly focused on taking benefit of the therapeutic effects of the ultraviolet (UV) irradiance on different skin diseases. The use of UV-B narrowband lamps, with emissions centered at 311 nm, has spread out among the dermatologist community because of its high therapeutic effect in comparison with its low erythema dose. For cloudless sun exposure, the balance of solar erythemal and solar narrowband (NB)-equivalent irradiances depends on several factors such as the solar zenith angle (SZA), the total ozone column (TOC) and the altitude. For SZA below 55°, the ratio of solar UV-B narrowband and erythemal irradiances increases with the SZA whereas the ratio of vitamin D production and erythemal irradiances decreases with the SZA with the maximum around midday. Furthermore, the solar NB ratio also increases with the TOC because the shorter wavelengths of the erythemal action spectrum are more affected by the ozone absorption processes. Considering the daily variations of the ratio between narrowband and erythemal irradiance, sun exposures avoiding midday hours are recommended in order to prevent negative side-effects. However to accumulate great NB doses and sufficient vitamin D in winter months is difficult because the time exposures may be longer than the day duration. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Accuracy of positioning and irradiation targeting for multiple targets in intracranial image-guided radiation therapy: a phantom study.

    PubMed

    Tominaga, Hirofumi; Araki, Fujio; Shimohigashi, Yoshinobu; Ishihara, Terunobu; Kawasaki, Keiichi; Kanetake, Nagisa; Sakata, Junichi; Iwashita, Yuki

    2014-12-21

    This study investigated the accuracy of positioning and irradiation targeting for multiple off-isocenter targets in intracranial image-guided radiation therapy (IGRT). A phantom with nine circular targets was created to evaluate both accuracies. First, the central point of the isocenter target was positioned with a combination of an ExacTrac x-ray (ETX) and a 6D couch. The positioning accuracy was determined from the deviations of coordinates of the central point in each target obtained from the kV-cone beam computed tomography (kV-CBCT) for IGRT and the planning CT. Similarly, the irradiation targeting accuracy was evaluated from the deviations of the coordinates between the central point of each target and the central point of each multi-leaf collimator (MLC) field for multiple targets. Secondly, the 6D couch was intentionally rotated together with both roll and pitch angles of 0.5° and 1° at the isocenter and similarly the deviations were evaluated. The positioning accuracy for all targets was less than 1 mm after 6D positioning corrections. The irradiation targeting accuracy was up to 1.3 mm in the anteroposterior (AP) direction for a target 87 mm away from isocenter. For the 6D couch rotations with both roll and pitch angles of 0.5° and 1°, the positioning accuracy was up to 1.0 mm and 2.3 mm in the AP direction for the target 87 mm away from the isocenter, respectively. The irradiation targeting accuracy was up to 2.1 mm and 2.6 mm in the AP direction for the target 87 mm away from the isocenter, respectively. The off-isocenter irradiation targeting accuracy became worse than the positioning accuracy. Both off-isocenter accuracies worsened in proportion to rotation angles and the distance from the isocenter to the targets. It is necessary to examine the set-up margin for off-isocenter multiple targets at each institution because irradiation targeting accuracy is peculiar to the linac machine.

  17. Accuracy of positioning and irradiation targeting for multiple targets in intracranial image-guided radiation therapy: a phantom study

    NASA Astrophysics Data System (ADS)

    Tominaga, Hirofumi; Araki, Fujio; Shimohigashi, Yoshinobu; Ishihara, Terunobu; Kawasaki, Keiichi; Kanetake, Nagisa; Sakata, Junichi; Iwashita, Yuki

    2014-12-01

    This study investigated the accuracy of positioning and irradiation targeting for multiple off-isocenter targets in intracranial image-guided radiation therapy (IGRT). A phantom with nine circular targets was created to evaluate both accuracies. First, the central point of the isocenter target was positioned with a combination of an ExacTrac x-ray (ETX) and a 6D couch. The positioning accuracy was determined from the deviations of coordinates of the central point in each target obtained from the kV-cone beam computed tomography (kV-CBCT) for IGRT and the planning CT. Similarly, the irradiation targeting accuracy was evaluated from the deviations of the coordinates between the central point of each target and the central point of each multi-leaf collimator (MLC) field for multiple targets. Secondly, the 6D couch was intentionally rotated together with both roll and pitch angles of 0.5° and 1° at the isocenter and similarly the deviations were evaluated. The positioning accuracy for all targets was less than 1 mm after 6D positioning corrections. The irradiation targeting accuracy was up to 1.3 mm in the anteroposterior (AP) direction for a target 87 mm away from isocenter. For the 6D couch rotations with both roll and pitch angles of 0.5° and 1°, the positioning accuracy was up to 1.0 mm and 2.3 mm in the AP direction for the target 87 mm away from the isocenter, respectively. The irradiation targeting accuracy was up to 2.1 mm and 2.6 mm in the AP direction for the target 87 mm away from the isocenter, respectively. The off-isocenter irradiation targeting accuracy became worse than the positioning accuracy. Both off-isocenter accuracies worsened in proportion to rotation angles and the distance from the isocenter to the targets. It is necessary to examine the set-up margin for off-isocenter multiple targets at each institution because irradiation targeting accuracy is peculiar to the linac machine.

  18. Process and targets for production of no-carrier-added radiotin

    DOEpatents

    Srivastava, Suresh C; Zhuikov, Boris Leonidovich; Ermolaev, Stanislav Victorovich; Konyakhin, Nikolay Alexandrovich; Kokhanyuk, Vladimir Mikhailovich; Khamyanov, Stepan Vladimirovich; Togaeva, Natalya Roaldovna

    2014-04-22

    One embodiment of the present invention includes a process for production and recovery of no-carrier-added radioactive tin (NCA radiotin). An antimony target can be irradiated with a beam of accelerated particles forming NCA radiotin, followed by separation of the NCA radiotin from the irradiated target. The target is metallic Sb in a hermetically sealed shell. The shell can be graphite, molybdenum, or stainless steel. The irradiated target can be removed from the shell by chemical or mechanical means, and dissolved in an acidic solution. Sb can be removed from the dissolved irradiated target by extraction. NCA radiotin can be separated from the remaining Sb and other impurities using chromatography on silica gel sorbent. NCA tin-117m can be obtained from this process. NCA tin-117m can be used for labeling organic compounds and biological objects to be applied in medicine for imaging and therapy of various diseases.

  19. Determination of the accuracy for targeted irradiations of cellular substructures at SNAKE

    NASA Astrophysics Data System (ADS)

    Siebenwirth, C.; Greubel, C.; Drexler, S. E.; Girst, S.; Reindl, J.; Walsh, D. W. M.; Dollinger, G.; Friedl, A. A.; Schmid, T. E.; Drexler, G. A.

    2015-04-01

    In the last 10 years the ion microbeam SNAKE, installed at the Munich 14 MV tandem accelerator, has been successfully used for radiobiological experiments by utilizing pattern irradiation without targeting single cells. Now for targeted irradiation of cellular substructures a precise irradiation device was added to the live cell irradiation setup at SNAKE. It combines a sub-micrometer single ion irradiation facility with a high resolution optical fluorescence microscope. Most systematic errors can be reduced or avoided by using the same light path in the microscope for beam spot verification as well as for and target recognition. In addition online observation of the induced cellular responses is possible. The optical microscope and the beam delivering system are controlled by an in-house developed software which integrates the open-source image analysis software, CellProfiler, for semi-automatic target recognition. In this work the targeting accuracy was determined by irradiation of a cross pattern with 55 MeV carbon ions on nucleoli in U2OS and HeLa cells stably expressing a GFP-tagged repair protein MDC1. For target recognition, nuclei were stained with Draq5 and nucleoli were stained with Syto80 or Syto83. The damage response was determined by live-cell imaging of MDC1-GFP accumulation directly after irradiation. No systematic displacement and a random distribution of about 0.7 μm (SD) in x-direction and 0.8 μm (SD) in y-direction were observed. An independent analysis after immunofluorescence staining of the DNA damage marker yH2AX yielded similar results. With this performance a target with a size similar to that of nucleoli (i.e. a diameter of about 3 μm) is hit with a probability of more than 80%, which enables the investigation of the radiation response of cellular subcompartments after targeted ion irradiation in the future.

  20. Solar Irradiance Data Products at the LASP Interactive Solar IRradiance Datacenter (LISIRD)

    NASA Astrophysics Data System (ADS)

    Lindholm, D. M.; Ware DeWolfe, A.; Wilson, A.; Pankratz, C. K.; Snow, M. A.; Woods, T. N.

    2011-12-01

    The Laboratory for Atmospheric and Space Physics (LASP) has developed the LASP Interactive Solar IRradiance Datacenter (LISIRD, http://lasp.colorado.edu/lisird/) web site to provide access to a comprehensive set of solar irradiance measurements and related datasets. Current data holdings include products from NASA missions SORCE, UARS, SME, and TIMED-SEE. The data provided covers a wavelength range from soft X-ray (XUV) at 0.1 nm up to the near infrared (NIR) at 2400 nm, as well as Total Solar Irradiance (TSI). Other datasets include solar indices, spectral and flare models, solar images, and more. The LISIRD web site features updated plotting, browsing, and download capabilities enabled by dygraphs, JavaScript, and Ajax calls to the LASP Time Series Server (LaTiS). In addition to the web browser interface, most of the LISIRD datasets can be accessed via the LaTiS web service interface that supports the OPeNDAP standard. OPeNDAP clients and other programming APIs are available for making requests that subset, aggregate, or filter data on the server before it is transported to the user. This poster provides an overview of the LISIRD system, summarizes the datasets currently available, and provides details on how to access solar irradiance data products through LISIRD's interfaces.

  1. Contamination of Optical Surfaces Under Irradiation by Outgassed Volatile Products

    SciTech Connect

    Khasanshin, R. H.; Grigorevskiy, A. V.; Galygin, A. N.; Alexandrov, N. G.

    2009-01-05

    Deposition of outgassed products of a polymeric composite on model material surfaces being irradiated by electrons and protons with initial energies of E{sub e} = 40 keV and E{sub p} = 30 keV respectively was studied. It was shown that deposition of volatile products on model material surfaces being under ionizing radiations results in increase of organic film growth rate.

  2. Production of sodium-22 from proton irradiated aluminum

    DOEpatents

    Taylor, Wayne A.; Heaton, Richard C.; Jamriska, David J.

    1996-01-01

    A process for selective separation of sodium-22 from a proton irradiated minum target including dissolving a proton irradiated aluminum target in hydrochloric acid to form a first solution including aluminum ions and sodium ions, separating a portion of the aluminum ions from the first solution by crystallization of an aluminum salt, contacting the remaining first solution with an anion exchange resin whereby ions selected from the group consisting of iron and copper are selectively absorbed by the anion exchange resin while aluminum ions and sodium ions remain in solution, contacting the solution with an cation exchange resin whereby aluminum ions and sodium ions are adsorbed by the cation exchange resin, and, contacting the cation exchange resin with an acid solution capable of selectively separating the adsorbed sodium ions from the cation exchange resin while aluminum ions remain adsorbed on the cation exchange resin is disclosed.

  3. Low-Dose Irradiation Enhances Gene Targeting in Human Pluripotent Stem Cells

    PubMed Central

    Hatada, Seigo; Subramanian, Aparna; Mandefro, Berhan; Ren, Songyang; Kim, Ho Won; Tang, Jie; Funari, Vincent; Baloh, Robert H.; Sareen, Dhruv

    2015-01-01

    Human pluripotent stem cells (hPSCs) are now being used for both disease modeling and cell therapy; however, efficient homologous recombination (HR) is often crucial to develop isogenic control or reporter lines. We showed that limited low-dose irradiation (LDI) using either γ-ray or x-ray exposure (0.4 Gy) significantly enhanced HR frequency, possibly through induction of DNA repair/recombination machinery including ataxia-telangiectasia mutated, histone H2A.X and RAD51 proteins. LDI could also increase HR efficiency by more than 30-fold when combined with the targeting tools zinc finger nucleases, transcription activator-like effector nucleases, and clustered regularly interspaced short palindromic repeats. Whole-exome sequencing confirmed that the LDI administered to hPSCs did not induce gross genomic alterations or affect cellular viability. Irradiated and targeted lines were karyotypically normal and made all differentiated lineages that continued to express green fluorescent protein targeted at the AAVS1 locus. This simple method allows higher throughput of new, targeted hPSC lines that are crucial to expand the use of disease modeling and to develop novel avenues of cell therapy. Significance The simple and relevant technique described in this report uses a low level of radiation to increase desired gene modifications in human pluripotent stem cells by an order of magnitude. This higher efficiency permits greater throughput with reduced time and cost. The low level of radiation also greatly increased the recombination frequency when combined with developed engineered nucleases. Critically, the radiation did not lead to increases in DNA mutations or to reductions in overall cellular viability. This novel technique enables not only the rapid production of disease models using human stem cells but also the possibility of treating genetically based diseases by correcting patient-derived cells. PMID:26185257

  4. Target production for inertial fusion energy

    SciTech Connect

    Woodworth, J.G.; Meier, W.

    1995-03-01

    Inertial fusion energy (IFE) power plants will require the ignition and burn of 5-10 fusion fuel targets every second. The technology to economically mass produce high-quality, precision targets at this rate is beyond the current state of the art. Techniques that are scalable to high production rates, however, have been identified for all the necessary process steps, and many have been tested in laboratory experiments or are similar to current commercial manufacturing processes. In this paper, we describe a baseline target factory conceptual design and estimate its capital and operating costs. The result is a total production cost of {approximately}16{cents} per target. At this level, target production represents about 6% of the estimated cost of electricity from a 1-GW{sub e} IFE power plant. Cost scaling relationships are presented and used to show the variation in target cost with production rate and plant power level.

  5. Optimization of irradiation conditions for {sup 177}Lu production at the LVR-15 research reactor

    SciTech Connect

    Lahodova, Z.; Viererbl, L.; Klupak, V.; Srank, J.

    2012-07-01

    The use of lutetium in medicine has been increasing over the last few years. The {sup 177}Lu radionuclide is commercially available for research and test purposes as a diagnostic and radiotherapy agent in the treatment of several malignant tumours. The yield of {sup 177}Lu from the {sup 176}Lu(n,{gamma}){sup 177}Lu nuclear reaction depends significantly on the thermal neutron fluence rate. The capture cross-sections of both reaction {sup 176}Lu(n,{gamma}){sup 177}Lu and reaction {sup 177}Lu(n,{gamma}){sup 178}Lu are very high. Therefore a burn-up of target and product nuclides should be taken into account when calculating {sup 177}Lu activity. The maximum irradiation time, when the activity of the {sup 177}Lu radionuclide begins to decline, was found for different fluence rates. Two vertical irradiation channels at the LVR-15 nuclear research reactor were compared in order to choose the channel with better irradiation conditions, such as a higher thermal neutron fluence rate in the irradiation volume. In this experiment, lutetium was irradiated in a titanium capsule. The influence of the Ti capsule on the neutron spectrum was monitored using activation detectors. The choice of detectors was based on requirements for irradiation time and accurate determination of thermal neutrons. The following activation detectors were selected for measurement of the neutron spectrum: Ti, Fe, Ni, Co, Ag and W. (authors)

  6. Effect of gamma irradiation on microbiological, chemical and sensory characteristics of licorice root product

    NASA Astrophysics Data System (ADS)

    Al-Bachir, M.; Al-Adawi, M. A.; Al-Kaid, A.

    2004-03-01

    Licorice root products were irradiated at doses of 0, 5, 10, 15 and 20 kGy in a 60Co package irradiator. Irradiated and unirradiated samples were stored at room temperatures. Microbial population on product, chemical changes and sensory properties of produced solution of licorice root products were evaluated after 0 and 12 months of storage. The results indicated that gamma irradiation reduced the counts of microorganisms on licorice root products. D10 of total count and klebsiella spp. were about 1.4 and 0.7 kGy, respectively. The mineral ions (Na, Ca and K) concentration in solution produced from irradiated products were lower than non-irradiated ones. Glycyrrhezinic acid and maltose concentration in solution produced from irradiated products were higher than non-irradiated ones. Sensory evaluation indicated that no significant differences ( P<0.05) were found between solution produced from irradiated and unirradiated products in color, flavor, texture, or taste.

  7. Heavy-Ion Irradiation of Thulium(III) Oxide Targets Prepared by Polymer-Assisted Deposition

    SciTech Connect

    Garcia, Mitch A.; Ali, Mazhar N.; Chang, Noel N.; Parsons-Moss, Tashi; Ashby, Paul D.; Gates, Jacklyn M.; Stavsetra, Liv; Gregorich, Kenneth E.; Nitsche, Heino

    2008-09-15

    Thulium(III) oxide (Tm{sub 2}O{sub 3}) targets prepared by the polymer-assisted deposition (PAD) method were irradiated by heavy-ion beams to test the method's feasibility for nuclear science applications. Targets were prepared on silicon nitride backings (thickness of 1000 nm, 344 {micro}g/cm{sup 2}) and were irradiated with an {sup 40}Ar beam at laboratory frame energy of {approx}210 MeV (50 particle nA). The root mean squared (RMS) roughness prior to irradiation is 1.1 nm for a {approx}250 nm ({approx}220 {micro}g/cm{sup 2}) Tm{sub 2}O{sub 3} target, and an RMS roughness of 2.0 nm after irradiation was measured by atomic force microscopy (AFM). Scanning electron microscopy of the irradiated target reveals no significant differences in surface homogeneity when compared to imaging prior to irradiation. Target flaking was not observed from monitoring Rutherford scattered particles as a function of time.

  8. Post-irradiation Examination and Fission Product Inventory Analysis of AGR-1 Irradiation Capsules

    SciTech Connect

    J M Harp; P D Demkowicz; S A Ploger

    2012-10-01

    The AGR-1 experiment was the first in a series of Advanced Gas Reactor (AGR) experiments designed to test TRISO fuel under High Temperature Gas Reactor irradiation conditions. This experiment was irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) and is currently undergoing post-irradiation examination (PIE) at INL’s Materials and Fuels Complex (MFC). The inventory and distribution of fission products, especially Ag-110m, was assessed and analyzed for all the components of the AGR-1 capsules. This data should help inform the study of fission product migration in coated particle fuel. Gamma spectrometry was used to measure the activity of various different fission products in the different components of the AGR-1 test train. Each capsule contained: 12 fuel compacts, a graphite holder that kept the fuel compacts in place, graphite spacers that were above and below the graphite holders and fuel compacts, gas lines through which a helium neon gas mixture flowed in and out of each capsule, and the stainless steel shell that contained the experiment. Gamma spectrometry results and the experimental techniques used to capture these results will be presented for all the capsule components. The components were assayed to determine the total activity of different fission products present in or on them. These totals are compared to the total expected activity of a particular fission product in the capsule based on predictions from physics simulation. Based on this metric, a significant fraction of the Ag-110m was detected outside the fuel compacts, but the amount varied highly between the 6 capsules. Very small fractions of Cs-137 (<2E-5), Cs-134 (<1e-5), and Eu-154 (<4e-4) were detected outside of the fuel compacts. Additionally, the distribution of select fission products in some of the components including the fuel compacts and the graphite holders were measured and will be discussed.

  9. Improving the survivability of Nb-encapsulated Ga targets for the production of 68Ge

    NASA Astrophysics Data System (ADS)

    Bach, H. T.; Claytor, T. N.; Hunter, J. F.; Olivas, E. R.; Kelsey, C. T., IV; Engle, J. W.; Connors, M. A.; Nortier, F. M.; Runde, W. H.; Moddrell, C.; Lenz, J. W.; John, K. D.

    2013-03-01

    At the Los Alamos Neutron Science Center (LANSCE) Isotope Production Facility (IPF), radioisotopes are produced for medical, scientific, and industrial applications by irradiating various targets with a 100 MeV, 230 μA proton beam. The medical isotope germanium-68 is produced by irradiating Nb capsules containing molten Ga target material. During irradiation, the Nb is subjected to intense radiation damage, corrosive attack by Ga, and mechanical and thermally-induced stresses for an extended period. Maintaining the structural integrity of the Nb target capsules during irradiation is crucial to contain the molten Ga target and the radioisotope product. In the present work, we focus on potential material related factors and assess the effect of the Nb stock material on target durability. We do so by comparing post-irradiation target mortality information to data collected during pre-irradiation ultrasound testing and X-ray imaging. We also explore possible failure mechanisms by using MCNP6 simulations and ANSYS codes to predict the induced atom displacement levels, hydrogen gas built-up, temperature distribution, and mechanical stresses. Our analysis, performed entirely in the context of an aggressive production program that allows for only limited diagnostic interference, suggests that using Nb stock with reasonably large and uniform grains is the most important factor in reducing early target failure at integrated beam current values <18 mAh and random failure at the face of the rear window at <60 mAh. We discuss possible failure mechanisms of failed targets that were fabricated using the same stock material and grain structure and then irradiated to integrated beam current values of up to 60 mAh and more. Based on these observations, we have enacted new specifications for Nb stock material quality, target design, and limits on integrated beam current. These changes have resulted in improved Nb capsule survivability.

  10. Chemical state of fission products in irradiated UO 2

    NASA Astrophysics Data System (ADS)

    Imoto, S.

    1986-08-01

    The chemical state of fission products in irradiated UO 2 fuel has been estimated for FBR as well as LWR on the basis of equilibrium calculation with the SOLGASMIX-PV code. The system considered for the calculation is composed of a gas phase, a CaF 2 type oxide phase, three grey phases, a noble metal alloy, a mixed telluride phase and several other phases each consisting of single compound. The distribution of elements into these phases and the amount of chemical species in each phase at different temperatures are obtained as a function of oxygen potential for LWR and FBR. Changes of the chemical potential of the fuel-fission products system during burnup are also evaluated with particular attention to the difference between LWR and FBR. Some informations obtained by the calculation are compared with the results of post irradiation examination of UO 2 fuels.

  11. Production of high melt strength polypropylene by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Lugão, A. B.; Artel, B. W. H.; Yoshiga, A.; Lima, L. F. C. P.; Parra, D. F.; Bueno, J. R.; Liberman, S.; Farrah, M.; Terçariol, W. R.; Otaguro, H.

    2007-11-01

    High melt strength polypropylene (HMS-PP) has been recently developed and introduced in the market by the major international producers of polypropylene. Therefore, BRASKEM, the leading Brazilian PP producer, together with EMBRARAD, the leading Brazilian gamma irradiator, and the IPEN (Institute of Nuclear Energy and Research) worked to develop a national technology for the production of HMS-PP. One of the effective approaches to improve melt strength and extensibility is to add chain branches onto polypropylene backbone using gamma radiation. Branching and grafting result from the radical combinations during irradiation process. Crosslinking and main chain scission in the polymer structure are also obtained during this process. In this work, gamma irradiation technique was used to induce chemical changes in commercial polypropylene with two different monomers, Tri-allyl-isocyanurate (TAIC) and Tri-methylolpropane-trimethacrylate (TMPTMA), with concentration ranging from 1.5 to 5.0 mmol/100 g of polypropylene. These samples were irradiated with a 60Co source at dose of 20 kGy. It used two different methods of HMS-PP processing. The crosslinking of modified polymers was studied by measuring gel content melt flow rate and rheological properties like melt strength and drawability. It was observed that the reaction method and the monomer type have influenced the properties. However, the concentration variation of monomer has no effect.

  12. Measurement of preheating due to radiation and nonlocal electron heat transport in laser-irradiated targets

    SciTech Connect

    Otani, K.; Shigemori, K.; Kadono, T.; Hironaka, Y.; Nakai, M.; Shiraga, H.; Azechi, H.; Mima, K.; Ozaki, N.; Kimura, T.; Miyanishi, K.; Kodama, R.; Sakaiya, T.; Sunahara, A.

    2010-03-15

    This paper reports an experimental study on preheating of laser-irradiated targets. We performed temperature measurements at the rear surface of laser-irradiated targets under conditions of two different laser wavelengths (0.35 or 0.53 mum) and several intensities (2x10{sup 13}-1x10{sup 14} W/cm{sup 2}) in order to verify an effect of radiation and nonlocal electron heat transport. The preheating temperature was evaluated by observing self-emission, reflectivity, and expansion velocity at the rear surface of planar polyimide foils. The experimental results show that the x-ray radiation is dominant for preheating for 0.35-mum laser irradiation, but contribution of nonlocal electron heat transport is not negligible for 0.53-mum laser irradiation conditions.

  13. Proton emission from thin hydrogenated targets irradiated by laser pulses at 1016 W/cm2a)

    NASA Astrophysics Data System (ADS)

    Torrisi, L.; Giuffrida, L.; Cutroneo, M.; Cirrone, P.; Picciotto, A.; Krasa, J.; Margarone, D.; Velyhan, A.; Laska, L.; Ullschmied, J.; Wolowski, J.; Badziak, J.; Rosinski, M.

    2012-02-01

    The iodine laser at PALS Laboratory in Prague, operating at 1315 nm fundamental harmonics and at 300 ps FWHM pulse length, is employed to irradiate thin hydrogenated targets placed in vacuum at intensities on the order of 1016 W/cm2. The laser-generated plasma is investigated in terms of proton and ion emission in the forward and backward directions. The time-of-flight technique, using ion collectors and semiconductor detectors, is used to measure the ion currents and the corresponding velocities and energies. Thomson parabola spectrometer is employed to separate the contribution of the ion emission from single laser shots. A particular attention is given to the proton production in terms of the maximum energy, emission yield, and angular distribution as a function of the laser energy, focal position, target thickness, and composition. Metallic and polymeric targets allow to generate protons with large energy range and different yield, depending on the laser, target composition, and target geometry properties.

  14. Magnetized plasma structures in laser-irradiated curved targets

    NASA Astrophysics Data System (ADS)

    Korneev, Philipp

    2017-01-01

    This work presents an extensive theoretical study of magnetic field generation effect in hollow targets with curved internal surface, known as “snail” or “escargot” targets [1]. They were recently proposed as a robust setup for generating intense spontaneous quasi-stationary magnetic fields frozen in laser-produced plasmas. The results of such studies are indispensable for planing experimental investigations and for possible applications of the curved targets, including, but not limited to, laboratory astrophysics, fast ignition, and particle acceleration.

  15. Production of (211)At by a vertical beam irradiation method.

    PubMed

    Nagatsu, Kotaro; Minegishi, Katsuyuki; Fukada, Masami; Suzuki, Hisashi; Hasegawa, Sumitaka; Zhang, Ming-Rong

    2014-12-01

    We produced (211)At by irradiating the semi-sealed encapsulated Bi target with an external vertical beam. At 28.5MeV, the yield of (211)At was 22MBq/μAh (600μCi/μAh). (211)At was recovered by dry distillation, and 80% of the produced (211)At was successfully obtained in dry Na(211)At form within 2h from the end of bombardment (EOB). The radionuclidic purity of (211)At was >99% at 5h from EOB. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Direct irradiation of long-lived fission products in an ATW system

    SciTech Connect

    Carter, T.F.; Henderson, D.; Sailor, W.C.

    1995-10-01

    The feasibility of directly irradiating five long-lived fission products (LLFPs: {sup 79}Se, {sup 93}Zr, {sup 107}Pd, {sup 126}Sn, and {sup 135}Cs, each with a half-life greater than 10,000 years), by incorporating them into the target of an Accelerator Transmutation of Waste (ATW) system is discussed. The important parameters used to judge the feasibility of a direct irradiation system were the target`s neutron spallation yield (given in neutrons produced per incident proton), and the removal rate of the LLFP, with the baseline incineration rate set at two light water reactors (LWRs) worth of the LLFP waste per year. A target was constructed which consisted of a LLFP cylindrical {open_quotes}plug{close_quotes} inserted into the top (where the proton beam strikes) of a 30 cm radius, 100 cm length lead target. {sup 126}Sn and {sup 79}Se were each found to have high enough removal rates to support two LWR`s production of the LLFP per year of ATW operation. For the baseline plug geometry (5 cm radius, 30 cm length) containing {sup 126}Sn, 3.5 LWRs could be supported per year (at 75% beam availability). Furthermore, the addition of a {sup 126}Sn plus had a slightly positive effect on the target`s neutron yield. The neutron production was 36.83 {plus_minus}.0039 neutrons per proton with a pure lead target having a yield of 36.29 {plus_minus}.0038. It was also found that a plug composed of a tin-selenide compound (SnSe) had high enough removal rates to burn two or more reactor years of both LLFPs simultaneously.

  17. Development of two-band infrared radiometer for irradiance calibration of target simulators

    SciTech Connect

    Yang, Sen; Li, Chengwei

    2015-07-15

    A detector-based spectral radiometer has been developed for the calibration of target simulator. Unlike the conventional spectral irradiance calibration method based on radiance and irradiance, the new radiometer is calibrated using image-space temperature based method. The image-space temperature based method improves the reproducibility in the calibration of radiometer and reduces the uncertainties existing in the conventional calibration methods. The calibrated radiometer is then used to establish the irradiance transfer standard for the target simulator. With the designed radiometer in this paper, a highly accurate irradiance calibration for target simulators of wavelength from 2.05 to 2.55 μm and from 3.7 to 4.8 μm can be performed with an expanded uncertainty (k = 2) of calibration of 2.18%. Last but not least, the infrared radiation of the target simulator was measured by the infrared radiometer, the effectiveness and capability of which are verified through measurement of temperature and irradiance and a comparison with the thermal imaging camera.

  18. Development of two-band infrared radiometer for irradiance calibration of target simulators.

    PubMed

    Yang, Sen; Li, Chengwei

    2015-07-01

    A detector-based spectral radiometer has been developed for the calibration of target simulator. Unlike the conventional spectral irradiance calibration method based on radiance and irradiance, the new radiometer is calibrated using image-space temperature based method. The image-space temperature based method improves the reproducibility in the calibration of radiometer and reduces the uncertainties existing in the conventional calibration methods. The calibrated radiometer is then used to establish the irradiance transfer standard for the target simulator. With the designed radiometer in this paper, a highly accurate irradiance calibration for target simulators of wavelength from 2.05 to 2.55 μm and from 3.7 to 4.8 μm can be performed with an expanded uncertainty (k = 2) of calibration of 2.18%. Last but not least, the infrared radiation of the target simulator was measured by the infrared radiometer, the effectiveness and capability of which are verified through measurement of temperature and irradiance and a comparison with the thermal imaging camera.

  19. Mitochondria-Targeted Vitamin E Protects Skin from UVB-Irradiation.

    PubMed

    Kim, Won-Serk; Kim, Ikyon; Kim, Wang-Kyun; Choi, Ju-Yeon; Kim, Doo Yeong; Moon, Sung-Guk; Min, Hyung-Keun; Song, Min-Kyu; Sung, Jong-Hyuk

    2016-05-01

    Mitochondria-targeted vitamin E (MVE) is designed to accumulate within mitochondria and is applied to decrease mitochondrial oxidative damage. However, the protective effects of MVE in skin cells have not been identified. We investigated the protective effect of MVE against UVB in dermal fibroblasts and immortalized human keratinocyte cell line (HaCaT). In addition, we studied the wound-healing effect of MVE in animal models. We found that MVE increased the proliferation and survival of fibroblasts at low concentration (i.e., nM ranges). In addition, MVE increased collagen production and downregulated matrix metalloproteinase1. MVE also increased the proliferation and survival of HaCaT cells. UVB increased reactive oxygen species (ROS) production in fibroblasts and HaCaT cells, while MVE decreased ROS production at low concentration. In an animal experiment, MVE accelerated wound healing from laser-induced skin damage. These results collectively suggest that low dose MVE protects skin from UVB irradiation. Therefore, MVE can be developed as a cosmetic raw material.

  20. Mitochondria-Targeted Vitamin E Protects Skin from UVB-Irradiation

    PubMed Central

    Kim, Won-Serk; Kim, Ikyon; Kim, Wang-Kyun; Choi, Ju-Yeon; Kim, Doo Yeong; Moon, Sung-Guk; Min, Hyung-Keun; Song, Min-Kyu; Sung, Jong-Hyuk

    2016-01-01

    Mitochondria-targeted vitamin E (MVE) is designed to accumulate within mitochondria and is applied to decrease mitochondrial oxidative damage. However, the protective effects of MVE in skin cells have not been identified. We investigated the protective effect of MVE against UVB in dermal fibroblasts and immortalized human keratinocyte cell line (HaCaT). In addition, we studied the wound-healing effect of MVE in animal models. We found that MVE increased the proliferation and survival of fibroblasts at low concentration (i.e., nM ranges). In addition, MVE increased collagen production and downregulated matrix metalloproteinase1. MVE also increased the proliferation and survival of HaCaT cells. UVB increased reactive oxygen species (ROS) production in fibroblasts and HaCaT cells, while MVE decreased ROS production at low concentration. In an animal experiment, MVE accelerated wound healing from laser-induced skin damage. These results collectively suggest that low dose MVE protects skin from UVB irradiation. Therefore, MVE can be developed as a cosmetic raw material. PMID:26869457

  1. Electrophilic natural products and their biological targets.

    PubMed

    Gersch, Malte; Kreuzer, Johannes; Sieber, Stephan A

    2012-06-01

    The study of biologically active natural products has resulted in seminal contributions to our understanding of living systems. In the case of electrophilic natural products, the covalent nature of their interaction has largely facilitated the identification of their biological binding partners. In this review, we provide a comprehensive compilation of electrophilic natural products from all major chemical classes together with their biological targets. Covering Michael acceptor systems, ring-strained compounds and other electrophiles, such as esters or carbamates, we highlight representative and instructive examples for over 20 electrophilic moieties. The fruitful cooperation of natural product chemistry, medicinal chemistry and chemical biology has produced a collection of well-studied examples for how electrophilic natural products exert their biological functions that range from antibiotic to antitumor effects. Special emphasis is put on the elucidation of their respective biological targets via activity-based protein profiling, which together with the recent advancements in mass spectrometry has been crucial to the success of the field. The wealth of naturally occurring electrophilic moieties and their chemical complexity enables binding of a large variety of biological targets, such as enzymes of all classes, nonenzymatic proteins, DNA and other cellular compounds. With approximately 30,000 genes in the human genome but only 266 confirmed protein drug targets, the study of biologically active, electrophilic natural products has the potential to provide insights into fundamental biological processes and to greatly aid the discovery of new drug targets.

  2. Systems and methods for processing irradiation targets through a nuclear reactor

    DOEpatents

    Dayal, Yogeshwar; Saito, Earl F.; Berger, John F.; Brittingham, Martin W.; Morales, Stephen K.; Hare, Jeffrey M.

    2016-05-03

    Apparatuses and methods produce radioisotopes in instrumentation tubes of operating commercial nuclear reactors. Irradiation targets may be inserted and removed from instrumentation tubes during operation and converted to radioisotopes otherwise unavailable during operation of commercial nuclear reactors. Example apparatuses may continuously insert, remove, and store irradiation targets to be converted to useable radioisotopes or other desired materials at several different origin and termination points accessible outside an access barrier such as a containment building, drywell wall, or other access restriction preventing access to instrumentation tubes during operation of the nuclear plant.

  3. Reaction products and mass balances from irradiated TCE vapor

    SciTech Connect

    Matthews, S.M.; Wang, F.T.; Mill, T.

    1995-12-31

    Trichloroethylene (TCE) vapor, at a concentration of 3000 ppmv in synthetic air, was sealed in Tedlar bags and irradiated with a 3.7 MeV electron beam. Bags of dry vapor and vapor at 90% relative humidity were irradiated. Doses up to 11 megarads (11 MR) were applied. Each bag was chemically analyzed for reaction products and a mass balance of the chlorine and carbon was obtained within the 11 MR dose range. The results of these radiolysis experiments and chemical analysis show that, given the proper treatment, the TCE concentration is reduced to below detection limit and the reaction products of the organic carbon and chlorine are carbon monoxide (CO), carbon dioxide (CO{sub 2}), chlorine gas (Cl{sub 2}) and hydrochloric acid (140). No detectable amounts of dichloroacetyl chloride (DCAC) or phosgene (PG) remained in the sample after proper treatment. DCAC and PG were found only as intermediary oxidation products of the TCE. High energy ionizing radiation, as electron beams and bremsstrahlung, is a new treatment technology for destroying toxic compounds and hazardous Wastes. A demonstration of complete destruction of organic products, using this treatment at standard temperature and pressure, is expected to help implement the use of this technology.

  4. Production of freely-migrating defects during irradiation

    SciTech Connect

    Rehn, L.E.; Okamoto, P.R.

    1986-09-01

    During irradiation at elevated temperatures, vacancy and interstitial defects that escape can produce several different types of microstructural changes. Hence the production rate of freely-migrating defects must be known as a function of irradiating particle species and energy before quantitative correlations can be made between microstructural changes. Our fundamental knowledge of freely-migrating defect production has increased substantially in recent years. Critical experimental findings that led to the improved understanding are reviewed in this paper. A strong similarity is found for the dependence of freely-migrating defect production on primary recoil energy as measured in a variety of metals and alloys by different authors. The efficiency for producing freely-migrating defects decreases much more strongly with increasing primary recoil energy than does the efficiency for creating stable defects at liquid helium temperatures. The stronger decrease can be understood in terms of additional intracascade recombination that results from the nonrandom distribution of defects existing in the primary damage state for high primary recoil energies. Although the existing data base is limited to fcc materials, the strong similarity in the reported investigations suggests that the same dependence of freely-migrating defect production on primary recoil energy may be characteristic of a wide variety of other alloy systems as well. 52 refs., 4 figs.

  5. Self-Irradiation Effects on 99Mo Reagents and Products

    SciTech Connect

    Carson, S.D.; Garcia, M.J.; McDonald, M.J.; Simpson, R.L.; Tallant, D.R.

    1998-10-07

    produced in 1996 and shipped to pharmaceutical houses for evaluation of compatibility with oxime solution used to precipitate `?vfo as the oxime complex is both air and light-sensitive, and containing a black precipitate that forms during shipment, presumably as a result of self- irradiation. Addition of sodium hypochlorite to the product solution prior to shipment prevents precipitate formation, indicating the precipitate is a reduced form of `%lo. to remove any precipitate. Duplicate aliquots of the filtered samples were titrated to a phenolphthalein irradiation and afler standing at room temperature for 86.4 hours. Precipitates were washed to a FTIR analysis of the white precipitate showed it to be alpha benzoin oxime. Since the basic After 86.4 hours, no precipitate had formed in bottles containing sodium hypochlorite. Black precipitate had formed in all bottles that did not contain sodium hypochlorite after 14.4 hours. The precipitate appeared to initially form on the surface of the HDPE sample bottles and Black precipitate was first noticed in sample set 1 after 28.8 hrs' irradiation. No visible sample containing precipitate was kept at room temperature in the original bottle. Precipitate in sample sets 2 and 3. Since no precipitate formed in these bottles, this was equivalent to duplicate samples. Once the precipitate in the 20-mL aliquots that had been set aside had returned to sample sets 1 through 3 and the samples with redissolved precipitate all experienced an average decrease in base strength of 0.013 meq mL-l. Sample 1-C had a decrease of 0.004 meq mL-l and sample 1-D had returned to the initial value of 0.198 meq mL-l. Raman spectra for the black precipitate from samples l-C, 1-D and supplemental sample set 1 Fig. 2. Raman spectra of the black precipitate formed in 9%40 product solutions after 28.8,43.2, 72 and 86.4 hours of `oCo irradiation in Sandia's Gamma Irradiation Facility. increase with time, as seen in the titration of 1-C and 1-D samples

  6. Production of {sup 99}Mo using LEU and molybdenum targets in a 1 MW Triga reactor

    SciTech Connect

    Mo, S.C.

    1993-12-31

    The production of {sup 99}Mo using Low Enriched Uranium (LEU) and natural molybdenum targets in a 1 MW Triga reactor is investigated. The successive linear programming technique is applied to minimize the target loadings for different yield constraints. The irradiation time is related to the kinetics of the growth and decay of {sup 99}Mo. The feasibility of a neutron generated based {sup 99}Mo production system is discussed.

  7. Bioethanol production from Ficus religiosa leaves using microwave irradiation.

    PubMed

    Klein, Miri; Griess, Ofir; Pulidindi, Indra Neel; Perkas, Nina; Gedanken, Aharon

    2016-07-15

    A microwave assisted feasible process for the production of bioethanol from Ficus religiosa leaves was developed. Under the process conditions (8 min. microwave irradiation, 1 M HCl), 10.1 wt% glucose yield was obtained from the leaves. Microwave based hydrolysis process yielded higher glucose content (10.1 wt%) compared to the conventional hydrothermal process (4.1 wt%). Upon fermentation of the hydrolysate using Baker's yeast, 3 wt% (dry wt. basis) of bioethanol was produced. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. On Cherenkov light production by irradiated nuclear fuel rods

    NASA Astrophysics Data System (ADS)

    Branger, E.; Grape, S.; Jacobsson Svärd, S.; Jansson, P.; Andersson Sundén, E.

    2017-06-01

    Safeguards verification of irradiated nuclear fuel assemblies in wet storage is frequently done by measuring the Cherenkov light in the surrounding water produced due to radioactive decays of fission products in the fuel. This paper accounts for the physical processes behind the Cherenkov light production caused by a single fuel rod in wet storage, and simulations are presented that investigate to what extent various properties of the rod affect the Cherenkov light production. The results show that the fuel properties have a noticeable effect on the Cherenkov light production, and thus that the prediction models for Cherenkov light production which are used in the safeguards verifications could potentially be improved by considering these properties. It is concluded that the dominating source of the Cherenkov light is gamma-ray interactions with electrons in the surrounding water. Electrons created from beta decay may also exit the fuel and produce Cherenkov light, and e.g. Y-90 was identified as a possible contributor to significant levels of the measurable Cherenkov light in long-cooled fuel. The results also show that the cylindrical, elongated fuel rod geometry results in a non-isotropic Cherenkov light production, and the light component parallel to the rod's axis exhibits a dependence on gamma-ray energy that differs from the total intensity, which is of importance since the typical safeguards measurement situation observes the vertical light component. It is also concluded that the radial distributions of the radiation sources in a fuel rod will affect the Cherenkov light production.

  9. Yeast cell metabolism investigated by CO{_2} production and soft X-ray irradiation

    NASA Astrophysics Data System (ADS)

    Masini, A.; Batani, D.; Previdi, F.; Milani, M.; Pozzi, A.; Turcu, E.; Huntington, S.; Takeyasu, H.

    1999-01-01

    Results obtained using a new technique for studying cell metabolism are presented. The technique, consisting in CO2 production monitoring, has been applied to Saccharomyces cerevisiae yeast cells. Also the cells were irradiated using the soft X-ray laser-plasma source at Rutherford Appleton Laboratory with the aim of producing a damage of metabolic processes at the wall level, responsible for fermentation, without great interference with respiration, taking place in mitochondria, and DNA activity. The source was calibrated with PIN diodes and X-ray spectrometers and used Teflon stripes as target, emitting X-rays at about 0.9 keV, with a very low penetration in biological material. X-ray doses delivered to the different cell compartments were calculated following a Lambert-Bouguet-Beer law. Immediately after irradiation, the damage to metabolic activity was measured again by monitoring CO2 production. Results showed a general reduction in gas production by irradiated samples, together with non-linear and non-monotone response to dose. There was also evidence of oscillations in cell metabolic activity and of X-ray induced changes in oscillation frequency.

  10. Ion irradiation effects on sooting flames by-products

    NASA Astrophysics Data System (ADS)

    Brunetto, R.; Pino, T.; Dartois, E.; Cao, A. T.; D'Hendecourt, L.; Strazzulla, G.; Bréchignac, Ph.

    2008-10-01

    Carbonaceous extraterrestrial matter is observed in a wide variety of astrophysical environments. Spectroscopic signatures reveal a large variety of chemical structure illustrating the rich carbon chemistry that occurs in space. In order to produce laboratory analogues of the carbonaceous cosmic dust, a new chemical reactor has been built in the Laboratoire de Photophysique Moléculaire. It is a low pressure flat burner providing flames of premixed hydrocarbon/oxygen gas mixtures, closely following the model system used by the combustion community. In such a device the flame is a one-dimensional chemical reactor offering a broad range of combustion conditions and sampling which allows production of many and various by-products. In the present work, we have studied the effect of ion irradiation (200-400 keV), at the Laboratorio di Astrofisica Sperimentale in Catania, on several samples, ranging from strongly aromatic to strongly aliphatic materials. Infrared and Raman spectra were monitored to follow the evolution of the films under study, and characterize the irradiation process-induced modifications.

  11. Enhanced hydrogen production of Enterobacter aerogenes mutated by nuclear irradiation.

    PubMed

    Cheng, Jun; Liu, Min; Song, Wenlu; Ding, Lingkan; Liu, Jianzhong; Zhang, Li; Cen, Kefa

    2017-03-01

    Nuclear irradiation was used for the first time to generate efficient mutants of hydrogen-producing bacteria Enterobacter aerogenes, which were screened with larger colour circles of more fermentative acid by-products. E. aerogenes cells were mutated by nuclear irradiation of (60)Co γ-rays. The screened E. aerogenes ZJU1 mutant with larger colour circles enhanced the hydrogenase activity from 89.8 of the wild strain to 157.4mLH2/(gDWh). The hereditary stability of the E. aerogenes ZJU1 mutant was certified after over ten generations of cultivation. The hydrogen yield of 301mLH2/gglucose with the mutant was higher by 81.8% than that of 166mL/gglucose with the wild strain. The peak hydrogen production rate of 27.2mL/(L·h) with the mutant was higher by 40.9% compared with that of 19.3mL/(L·h) with the wild strain. The mutant produced more acetate and butyrate but less ethanol compared with the wild strain during hydrogen fermentation.

  12. The SPES High Power ISOL production target

    NASA Astrophysics Data System (ADS)

    Andrighetto, A.; Corradetti, S.; Ballan, M.; Borgna, F.; Manzolaro, M.; Scarpa, D.; Monetti, A.; Rossignoli, M.; Silingardi, R.; Mozzi, A.; Vivian, G.; Boratto, E.; De Ruvo, L.; Sattin, N.; Meneghetti, G.; Oboe, R.; Guerzoni, M.; Margotti, A.; Ferrari, M.; Zenoni, A.; Prete, G.

    2016-11-01

    SPES (Selective Production of Exotic Species) is a facility under construction at INFN-LNL (Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Legnaro), aimed to produce intense neutron-rich radioactive ion beams (RIBs). These will be obtained using the ISOL (Isotope Separation On-Line) method, bombarding a uranium carbide target with a proton beam of 40MeV energy and currents up to 200μA. The target configuration was designed to obtain a high number of fissions, up to 1013 per second, low power deposition and fast release of the produced isotopes. The exotic isotopes generated in the target are ionized, mass separated and re-accelerated by the ALPI superconducting LINAC at energies of 10AMeV and higher, for masses in the region of A = 130 amu , with an expected rate on the secondary target up to 109 particles per second. In this work, recent results on the R&D activities regarding the SPES RIB production target-ion source system are reported.

  13. Fumonisin production on irradiated corn kernels: effect of inoculum size.

    PubMed

    Chulze, S N; Etcheverry, M G; Lecumberry, S E; Magnoli, C E; Dalcero, A M; Ramirez, M L; Pascale, M; Rodriguez, M I

    1999-07-01

    Production of fumonisins B1, B2, and B3 by Fusarium moniliforme was evaluated on irradiated corn kernels inoculated with different spore concentrations (10, 10(2), 10(3), 10(5), and 10(6)), a water activity of 0.97, and a temperature of 25 degrees C. There was a direct relationship between the level of toxin produced and inoculum size. The highest levels of total fumonisin produced after 35 days of incubation were 5,028 and 9,063 ng/g at 10(5) and 10(6) spores per ml, respectively. The pattern of fumonisin production (FB1 > FB2 > FB3) in cultures growing from different inocula was not affected during the 35 days of incubation. The ratio between FB2 and FB1 varied from 0.15 to 0.42, whereas the ratio between FB3 and FB1 varied from 0.34 to 0.87.

  14. A Semantically Enabled Metadata Repository for Solar Irradiance Data Products

    NASA Astrophysics Data System (ADS)

    Wilson, A.; Cox, M.; Lindholm, D. M.; Nadiadi, I.; Traver, T.

    2014-12-01

    The Laboratory for Atmospheric and Space Physics, LASP, has been conducting research in Atmospheric and Space science for over 60 years, and providing the associated data products to the public. LASP has a long history, in particular, of making space-based measurements of the solar irradiance, which serves as crucial input to several areas of scientific research, including solar-terrestrial interactions, atmospheric, and climate. LISIRD, the LASP Interactive Solar Irradiance Data Center, serves these datasets to the public, including solar spectral irradiance (SSI) and total solar irradiance (TSI) data. The LASP extended metadata repository, LEMR, is a database of information about the datasets served by LASP, such as parameters, uncertainties, temporal and spectral ranges, current version, alerts, etc. It serves as the definitive, single source of truth for that information. The database is populated with information garnered via web forms and automated processes. Dataset owners keep the information current and verified for datasets under their purview. This information can be pulled dynamically for many purposes. Web sites such as LISIRD can include this information in web page content as it is rendered, ensuring users get current, accurate information. It can also be pulled to create metadata records in various metadata formats, such as SPASE (for heliophysics) and ISO 19115. Once these records are be made available to the appropriate registries, our data will be discoverable by users coming in via those organizations. The database is implemented as a RDF triplestore, a collection of instances of subject-object-predicate data entities identifiable with a URI. This capability coupled with SPARQL over HTTP read access enables semantic queries over the repository contents. To create the repository we leveraged VIVO, an open source semantic web application, to manage and create new ontologies and populate repository content. A variety of ontologies were used in

  15. HTCAP-1: a program for calcuating operating temperatures in HFIR target irradiation experiments

    SciTech Connect

    Kania, M.J.; Howard A.M.

    1980-06-01

    The thermal modeling code, HTCAP-1, calculates in-reactor operating temperatures of fueled specimens contained in the High Flux Isotope Reactor (HFIR) target irradiation experiments (HT-series). Temperature calculations are made for loose particle and bonded fuel rod specimens. Maximum particle surface temperatures are calculated for the loose particles and centerline and surface temperatures for the fuel rods. Three computational models are employed to determine fission heat generation rates, capsule heat transfer analysis, and specimen temperatures. This report is also intended to be a users' manual, and the application of HTCAP-1 to the HT-34 irradiation capsule is presented.

  16. Targeted Cytoplasmic Irradiation with Alpha Particles Induces Mutations in Mammalian Cells

    NASA Astrophysics Data System (ADS)

    Wu, Li-Jun; Randers-Pehrson, Gerhard; Xu, An; Waldren, Charles A.; Geard, Charles R.; Yu, Zengliang; Hei, Tom K.

    1999-04-01

    Ever since x-rays were shown to induce mutation in Drosophila more than 70 years ago, prevailing dogma considered the genotoxic effects of ionizing radiation, such as mutations and carcinogenesis, as being due mostly to direct damage to the nucleus. Although there was indication that alpha particle traversal through cellular cytoplasm was innocuous, the full impact remained unknown. The availability of the microbeam at the Radiological Research Accelerator Facility of Columbia University made it possible to target and irradiate the cytoplasm of individual cells in a highly localized spatial region. By using dual fluorochrome dyes (Hoechst and Nile Red) to locate nucleus and cellular cytoplasm, respectively, thereby avoiding inadvertent traversal of nuclei, we show here that cytoplasmic irradiation is mutagenic at the CD59 (S1) locus of human-hamster hybrid (AL) cells, while inflicting minimal cytotoxicity. The principal class of mutations induced are similar to those of spontaneous origin and are entirely different from those of nuclear irradiation. Furthermore, experiments with radical scavenger and inhibitor of intracellular glutathione indicated that the mutagenicity of cytoplasmic irradiation depends on generation of reactive oxygen species. These findings suggest that cytoplasm is an important target for genotoxic effects of ionizing radiation, particularly radon, the second leading cause of lung cancer in the United States. In addition, cytoplasmic traversal by alpha particles may be more dangerous than nuclear traversal, because the mutagenicity is accomplished by little or no killing of the target cells.

  17. Particle therapy of moving targets—the strategies for tumour motion monitoring and moving targets irradiation

    PubMed Central

    2016-01-01

    Particle therapy of moving targets is still a great challenge. The motion of organs situated in the thorax and abdomen strongly affects the precision of proton and carbon ion radiotherapy. The motion is responsible for not only the dislocation of the tumour but also the alterations in the internal density along the beam path, which influence the range of particle beams. Furthermore, in case of pencil beam scanning, there is an interference between the target movement and dynamic beam delivery. This review presents the strategies for tumour motion monitoring and moving target irradiation in the context of hadron therapy. Methods enabling the direct determination of tumour position (fluoroscopic imaging of implanted radio-opaque fiducial markers, electromagnetic detection of inserted transponders and ultrasonic tumour localization systems) are presented. Attention is also drawn to the techniques which use external surrogate motion for an indirect estimation of target displacement during irradiation. The role of respiratory-correlated CT [four-dimensional CT (4DCT)] in the determination of motion pattern prior to the particle treatment is also considered. An essential part of the article is the review of the main approaches to moving target irradiation in hadron therapy: gating, rescanning (repainting), gated rescanning and tumour tracking. The advantages, drawbacks and development trends of these methods are discussed. The new accelerators, called “cyclinacs”, are presented, because their application to particle therapy will allow making a breakthrough in the 4D spot scanning treatment of moving organs. PMID:27376637

  18. Investigation on Soft X-Ray Lasers with a Picosecond-Laser-Irradiated Gas Puff Target

    SciTech Connect

    Fiedorowiez, H; Bartnik, A; Jarocki, R; Rakowski, R; Dunn, J; Smith, R F; Hunter, J; Hilsen, J; Shlyaptsev, V N

    2002-10-09

    We present results of experimental studies on transient gain soft x-ray lasers with a picosecond-laser-irradiated gas puff target. The target in a form of an elongated gas sheet is formed by pulsed injection of gas through a slit nozzle using a high-pressure electromagnetic valve developed and characterized at the Institute of Optoelectronics. The x-ray laser experiments were performed at the Lawrence Livermore National Laboratory using the tabletop Compact Multipulse Terawatt (COMET) laser to irradiate argon, krypton or xenon gas puff targets. Soft x-ray lasing in neon-like argon on the 3p-3s transition at 46.9 nm and the 3d-3p transition at 45.1 nm have been demonstrated, however, no amplification for nickel-like krypton or xenon was observed. Results of the experiments are presented and discussed.

  19. Effects of the irradiation of a finite number of laser beams on the implosion of a cone-guided target

    NASA Astrophysics Data System (ADS)

    Yanagawa, T.; Sakagami, H.; Nagatomo, H.; Sunahara, A.

    2016-03-01

    In direct drive laser fusion, the non-uniformity of the laser absorption on the target surface caused by the irradiation of a finite number of laser beams is a sever problem. GekkoXII laser at Osaka University has twelve laser beams and is irradiated to the target with a dodecahedron orientation, in which the distribution of the laser absorption on the target surface becomes non-uniform. Furthermore, in the case of a cone-guided target, the laser irradiation orientation is more limited. In this paper, we conducted implosion simulations of the cone- guided target based on GekkoXII irradiation orientation and compared the case of using the twelve beams and nine beams where the three beams irradiating the cone region are cut. The implosion simulations were conducted by a three-dimensional pure hydro code.

  20. Sensing device and method for measuring emission time delay during irradiation of targeted samples

    NASA Technical Reports Server (NTRS)

    Danielson, J. D. Sheldon (Inventor)

    2000-01-01

    An apparatus for measuring emission time delay during irradiation of targeted samples by utilizing digital signal processing to determine the emission phase shift caused by the sample is disclosed. The apparatus includes a source of electromagnetic radiation adapted to irradiate a target sample. A mechanism generates first and second digital input signals of known frequencies with a known phase relationship, and a device then converts the first and second digital input signals to analog sinusoidal signals. An element is provided to direct the first input signal to the electromagnetic radiation source to modulate the source by the frequency thereof to irradiate the target sample and generate a target sample emission. A device detects the target sample emission and produces a corresponding first output signal having a phase shift relative to the phase of the first input signal, the phase shift being caused by the irradiation time delay in the sample. A member produces a known phase shift in the second input signal to create a second output signal. A mechanism is then provided for converting each of the first and second analog output signals to digital signals. A mixer receives the first and second digital output signals and compares the signal phase relationship therebetween to produce a signal indicative of the change in phase relationship between the first and second output signals caused by the target sample emission. Finally, a feedback arrangement alters the phase of the second input signal based on the mixer signal to ultimately place the first and second output signals in quadrature. Mechanisms for enhancing this phase comparison and adjustment technique are also disclosed.

  1. Production of radionuclides in artificial meteorites irradiated isotropically with 600 MeV protons

    NASA Technical Reports Server (NTRS)

    Michel, R.; Dragovitsch, P.; Englert, P.; Herpers, U.

    1986-01-01

    The understanding of the production of cosmogenic nuclides in small meteorites (R is less than 40 cm) still is not satisfactory. The existing models for the calculation of depth dependent production rates do not distinguish between the different types of nucleons reacting in a meteorite. They rather use general depth dependent particle fluxes to which cross sections have to be adjusted to fit the measured radionuclide concentrations. Some of these models can not even be extended to zero meteorite sizes without logical contradictions. Therefore, a series of three thick target irradiations was started at the 600 MeV proton beam of the CERN isochronuous cyclotron in order to study the interactions of small stony meteorites with galactic protons. The homogeneous 4 pi irradiation technique used provides a realistic meteorite model which allows a direct comparison of the measured depth profiles with those in real meteorites. Moreover, by the simultaneous measurement of thin target production cross sections one can differentiate between the contributions of primary and secondary nucleons over the entire volume of the artificial meteorite.

  2. Optical imaging of irradiated cyclotron target window foils using Cerenkov and radioluminescence imaging

    NASA Astrophysics Data System (ADS)

    Spinelli, A. E.; Boschi, F.; Calandrino, R.

    2017-05-01

    Radioisotopes production for PET radiopharmaceuticals is performed using cyclotrons resulting in radio activation of different cyclotron components. It is thus necessary to measure the level of radiation exposure and, if possible, to image the areas where most of the radiations are emitted in particular during maintenance or decommissioning procedures. In this work we present a novel optical imaging approach using Cerenkov luminescence imaging (CLI) and radioluminescence imaging (RLI). CLI was performed by placing a glass Cerenkov radiator on a target window (Havar foils) and RLI data were obtained by covering the Havar foils with an intensifying screen. CLI or RLI were acquired using a small animal optical imaging system used in bioluminescence mode without the use of any optical filters. The analysis of the normalized radiance line profiles of both CLI and RLI images showed a similar pattern, however the absolute radiance of the RLI signal is several order of magnitude higher with respect to CLI. We conclude that optical imaging with CLI and RLI can be considered a novel method to detect and image activation areas in irradiated samples from a medical cyclotron.

  3. The influence of target preparation and mode of irradiation on PIXE analysis of biological samples

    NASA Astrophysics Data System (ADS)

    Galuszka, Janusz; Jarczyk, Lucjan; Rokita, Eugeniusz; Strzalkowski, Adam; Sych, Marek

    1984-04-01

    The following methods of target preparation were examined and compared: dry ashing at high temperature, low temperature ashing in plasma asher, wet ashing, lyophilization at a temperature of 35°C, cryofixation with drying in vacuum and dehydration in alcohol with drying in vacuum. All these techniques were applied to prepare targets from five different rat organs: liver, kidney, brain, lung and muscle tissue. The dried and powdered sample material was pressed into pellets or was distributed on formvar film. The evaporation of the thin carbon layer on the investigated target and placing of the thin carbon film in front of a target were also tested. The targets were irradiated in vacuum using an external beam in the air chamber. The influence of the method of target preparation on the detection limits, time requirements and escape of elements from the sample material is discussed.

  4. Improvement of saccharification process for bioethanol production from Undaria sp. by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Yoon, Minchul; Choi, Jong-il; Lee, Ju-Woon; Park, Don-Hee

    2012-08-01

    Recently, many research works have reported on improvements to the saccharification process that increase bioethanol production from cellulosic materials. Gamma irradiation has been studied as an effective method for the depolymerization of complex polysaccharides. In this study, the effect of gamma irradiation on saccharification of Undaria biomass for bioethanol production was investigated. The Undaria biomass was irradiated at doses of 0, 10, 50, 100, 200 and 500 kGy and then hydrolyzed using sulfuric acid. The effects of gamma irradiation were measured through microscopic analysis to determine morphological changes and concentration of the reducing sugar of hydrolysates. Microscopic images show that gamma irradiation causes structure breakage of the Undaria cell wall. The concentration of reducing sugar of hydrolysates significantly increased as a result of gamma irradiation, with or without acid hydrolysis. These results indicate that the combined method of gamma irradiation with acid hydrolysis can significantly improve the saccharification process for bioethanol production from marine algae materials.

  5. A Mitochondria-Targeted Nitroxide/Hemigramicidin S Conjugate Protects Mouse Embryonic Cells Against Gamma Irradiation

    SciTech Connect

    Jiang Jianfei; Belikova, Natalia A.; Hoye, Adam T.; Zhao Qing; Epperly, Michael W.; Greenberger, Joel S.; Wipf, Peter; Kagan, Valerian E.

    2008-03-01

    Purpose: To evaluate the in vitro radioprotective effect of the mitochondria-targeted hemigramicidin S-conjugated 4-amino-2,2,6,6-tetramethyl-piperidine-N-oxyl (hemi-GS-TEMPO) 5-125 in {gamma}-irradiated mouse embryonic cells and adenovirus-12 SV40 hybrid virus transformed human bronchial epithelial cells BEAS-2B and explore the mechanisms involved in its radioprotective effect. Methods and Materials: Cells were incubated with 5-125 before (10 minutes) or after (1 hour) {gamma}-irradiation. Superoxide generation was determined by using dihydroethidium assay, and lipid oxidation was quantitated by using a fluorescence high-performance liquid chromatography-based Amplex Red assay. Apoptosis was characterized by evaluating the accumulation of cytochrome c in the cytosol and externalization of phosphatidylserine on the cell surface. Cell survival was measured by means of a clonogenic assay. Results: Treatment (before and after irradiation) of cells with 5-125 at low concentrations (5, 10, and 20 {mu}M) effectively suppressed {gamma}-irradiation-induced superoxide generation, cardiolipin oxidation, and delayed irradiation-induced apoptosis, evaluated by using cytochrome c release and phosphatidylserine externalization. Importantly, treatment with 5-125 increased the clonogenic survival rate of {gamma}-irradiated cells. In addition, 5-125 enhanced and prolonged {gamma}-irradiation-induced G{sub 2}/M phase arrest. Conclusions: Radioprotection/mitigation by hemi-GS-TEMPO likely is caused by its ability to act as an electron scavenger and prevent superoxide generation, attenuate cardiolipin oxidation in mitochondria, and hence prevent the release of proapoptotic factors from mitochondria. Other mechanisms, including cell-cycle arrest at the G{sub 2}/M phase, may contribute to the protection.

  6. The cytoplasm as a radiation target: an in silico study of microbeam cell irradiation.

    PubMed

    Byrne, H L; Domanova, W; McNamara, A L; Incerti, S; Kuncic, Z

    2015-03-21

    We performed in silico microbeam cell irradiation modelling to quantitatively investigate ionisations resulting from soft x-ray and alpha particle microbeams targeting the cytoplasm of a realistic cell model. Our results on the spatial distribution of ionisations show that as x-rays are susceptible to scatter within a cell that can lead to ionisations in the nucleus, soft x-ray microbeams may not be suitable for investigating the DNA damage response to radiation targeting the cytoplasm alone. In contrast, ionisations from an ideal alpha microbeam are tightly confined to the cytoplasm, but a realistic alpha microbeam degrades upon interaction with components upstream of the cellular target. Thus it is difficult to completely rule out a contribution from alpha particle hits to the nucleus when investigating DNA damage response to cytoplasmic irradiation. We find that although the cytoplasm targeting efficiency of an alpha microbeam is better than that of a soft x-ray microbeam (the probability of stray alphas hitting the nucleus is 0.2% compared to 3.6% for x-rays), stray alphas produce more ionisations in the nucleus and thus have greater potential for initiating damage responses therein. Our results suggest that observed biological responses to cytoplasmic irradiation include a small component that can be attributed to stray ionisations in the nucleus resulting from the stochastic nature of particle interactions that cause out-of-beam scatter. This contribution is difficult to isolate experimentally, thus demonstrating the value of the in silico approach.

  7. Targeting nuclear receptors with marine natural products.

    PubMed

    Yang, Chunyan; Li, Qianrong; Li, Yong

    2014-01-27

    Nuclear receptors (NRs) are important pharmaceutical targets because they are key regulators of many metabolic and inflammatory diseases, including diabetes, dyslipidemia, cirrhosis, and fibrosis. As ligands play a pivotal role in modulating nuclear receptor activity, the discovery of novel ligands for nuclear receptors represents an interesting and promising therapeutic approach. The search for novel NR agonists and antagonists with enhanced selectivities prompted the exploration of the extraordinary chemical diversity associated with natural products. Recent studies involving nuclear receptors have disclosed a number of natural products as nuclear receptor ligands, serving to re-emphasize the translational possibilities of natural products in drug discovery. In this review, the natural ligands of nuclear receptors will be described with an emphasis on their mechanisms of action and their therapeutic potentials, as well as on strategies to determine potential marine natural products as nuclear receptor modulators.

  8. Targeting Nuclear Receptors with Marine Natural Products

    PubMed Central

    Yang, Chunyan; Li, Qianrong; Li, Yong

    2014-01-01

    Nuclear receptors (NRs) are important pharmaceutical targets because they are key regulators of many metabolic and inflammatory diseases, including diabetes, dyslipidemia, cirrhosis, and fibrosis. As ligands play a pivotal role in modulating nuclear receptor activity, the discovery of novel ligands for nuclear receptors represents an interesting and promising therapeutic approach. The search for novel NR agonists and antagonists with enhanced selectivities prompted the exploration of the extraordinary chemical diversity associated with natural products. Recent studies involving nuclear receptors have disclosed a number of natural products as nuclear receptor ligands, serving to re-emphasize the translational possibilities of natural products in drug discovery. In this review, the natural ligands of nuclear receptors will be described with an emphasis on their mechanisms of action and their therapeutic potentials, as well as on strategies to determine potential marine natural products as nuclear receptor modulators. PMID:24473166

  9. Blood vessel damage correlated with irradiance for in vivo vascular targeted photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Zhang, Jinde; Tan, Zou; Niu, Xiangyu; Lin, Linsheng; Lin, Huiyun; Li, Buhong

    2016-10-01

    Vascular targeted photodynamic therapy (V-PDT) has been widely utilized for the prevention or treatment of vascular-related diseases, including age-related macular degeneration, port-wine stains and prostate cancer. In order to quantitative assessment the blood vessel damage during V-PDT, nude mice were implanted with Titanium dorsal skin window chambers for in vivo V-PDT studies. For treatments, various irradiances including 50, 75, 100 and 200 mW/cm2 provided by a 532 nm semiconductor laser were performed with the same total light dose of 30 J/cm2 after the mice were intravenously injection of Rose Bengal for 25 mg/Kg body weight. Laser speckle imaging and microscope were used to monitor blood flow dynamics and vessel constriction during and after V-PDT, respectively. The V-PDT induced vessel damages between different groups were compared. The results show that significant difference in blood vessel damage was found between the lower irradiances (50, 75 and 100 mW/cm2) and higher irradiance (200 mW/cm2), and the blood vessel damage induced by V-PDT is positively correlated with irradiance. This study implies that the optimization of irradiance is required for enhancing V-PDT therapeutic efficiency.

  10. Mechanisms of DNA Damage Response to Targeted Irradiation in Organotypic 3D Skin Cultures

    PubMed Central

    Acheva, Anna; Ghita, Mihaela; Patel, Gaurang; Prise, Kevin M.; Schettino, Giuseppe

    2014-01-01

    DNA damage (caused by direct cellular exposure and bystander signaling) and the complex pathways involved in its repair are critical events underpinning cellular and tissue response following radiation exposures. There are limited data addressing the dynamics of DNA damage induction and repair in the skin particularly in areas not directly exposed. Here we investigate the mechanisms regulating DNA damage, repair, intracellular signalling and their impact on premature differentiation and development of inflammatory-like response in the irradiated and surrounding areas of a 3D organotypic skin model. Following localized low-LET irradiation (225 kVp X-rays), low levels of 53BP1 foci were observed in the 3D model (3.8±0.28 foci/Gy/cell) with foci persisting and increasing in size up to 48 h post irradiation. In contrast, in cell monolayers 14.2±0.6 foci/Gy/cell and biphasic repair kinetics with repair completed before 24 h was observed. These differences are linked to differences in cellular status with variable level of p21 driving apoptotic signalling in 2D and accelerated differentiation in both the directly irradiated and bystander areas of the 3D model. The signalling pathways utilized by irradiated keratinocytes to induce DNA damage in non-exposed areas of the skin involved the NF-κB transcription factor and its downstream target COX-2. PMID:24505255

  11. INTERACTION OF LASER RADIATION WITH MATTER. LASER PLASMA: Low-density absorber—converter in direct-irradiation laser thermonuclear targets

    NASA Astrophysics Data System (ADS)

    Gus'kov, Sergei Yu; Merkul'ev, Yu A.

    2001-04-01

    A version of a thermonuclear target for direct irradiation by a laser pulse is proposed, which ensures a virtually arbitrary laser-to-soft X-ray radiation conversion efficiency. The key target element is the external spherical layer of a low-density composite material with a density close to the critical plasma density. The layer material is a porous medium of light elements (porous beryllium, porous plastics) with clusters of heavy elements (gold, copper) distributed inside it. This layer fulfils the dual function of absorbing laser radiation and converting the laser radiation to X-rays. A theory is developed to describe the plasma production and the generation of intrinsic radiation in composite materials of this kind irradiated by a high-power laser pulse. The efficiency of X-ray energy deposition for targets with a low-density absorber-converter is shown to be higher than for direct-irradiation targets with a solid converter and indirect-irradiation targets. Also discussed are the technological possibilities of producing low-density composite media containing clusters of heavy elements and having parameters that provide efficient operation of the absorber—converter in laser thermonuclear targets.

  12. Monitoring and managing of cyclotron beam distribution on the surface of irradiated targets

    NASA Astrophysics Data System (ADS)

    Kirsanov, B. N.; Obleukhov, A. B.; Razbash, A. A.

    2016-12-01

    A system for monitoring and managing of the proton-beam distribution on the surface of the targets in the cyclotrons of the Cyclotron Co. is presented in this report. Parameters of proton beams, designs of the target and target devices, used for isotope production, and the system of the managing of the beam distribution on the target are given. The control is fulfilled via monitoring of the temperature distributions using infrared radiation from the target surface. The need in such system for increasing of the isotope productivity and reducing of the likelihood of the target damage is substantiated.

  13. Modeling astatine production in liquid lead-bismuth spallation targets

    NASA Astrophysics Data System (ADS)

    David, J. C.; Boudard, A.; Cugnon, J.; Ghali, S.; Leray, S.; Mancusi, D.; Zanini, L.

    2013-03-01

    Astatine isotopes can be produced in liquid lead-bismuth eutectic targets through proton-induced double charge exchange reactions on bismuth or in secondary helium-induced interactions. Models implemented into the most common high-energy transport codes generally have difficulties to correctly estimate their production yields as was shown recently by the ISOLDE Collaboration, which measured release rates from a lead-bismuth target irradiated by 1.4 and 1 GeV protons. In this paper, we first study the capability of the new version of the Liège intranuclear cascade model, INCL4.6, coupled to the deexcitation code ABLA07 to predict the different elementary reactions involved in the production of such isotopes through a detailed comparison of the model with the available experimental data from the literature. Although a few remaining deficiencies are identified, very satisfactory results are found, thanks in particular to improvements brought recently on the treatment of low-energy helium-induced reactions. The implementation of the models into MCNPX allows identifying the respective contributions of the different possible reaction channels in the ISOLDE case. Finally, the full simulation of the ISOLDE experiment is performed, taking into account the likely rather long diffusion time from the target, and compared with the measured diffusion rates for the different astatine isotopes, at the two studied energies, 1.4 and 1 GeV. The shape of the isotopic distribution is perfectly reproduced as well as the absolute release rates, assuming in the calculation a diffusion time between 5 and 10hours. This work finally shows that our model, thanks to the attention paid to the emission of high-energy clusters and to low-energy cluster induced reactions, can be safely used within MCNPX to predict isotopes with a charge larger than that of the target by two units in spallation targets, and, probably, more generally to isotopes created in secondary reactions induced by composite

  14. 800-MeV proton irradiation of thorium and depleted uranium targets

    SciTech Connect

    Russell, G.J.; Brun, T.O.; Pitcher, E.J.

    1995-10-01

    As part of the Los Alamos Fertile-to-Fissile-Conversion (FERFICON) program in the late 1980`s, thick targets of the fertile materials thorium and depleted uranium were bombarded by 800-MeV protons to produce the fissile materials {sup 233}U and {sup 239}Pu, respectively. The amount of {sup 233}U made was determined by measuring the {sup 233}Pa activity, and the yield of {sup 239}Pu was deduced by measuring the activity of {sup 239}Np. For the thorium target, 4 spallation products and 34 fission products were also measured. For the depleted uranium target, 3 spallation products and 16 fission products were also measured. The number of fissions in each target was deduced from fission product mass-yield curves. In actuality, axial distributions of the products were measured, and the distributions were then integrated over the target volume to obtain the total number of products for each reaction.

  15. Laser irradiations of advanced targets promoting absorption resonance for ion acceleration in TNSA regime

    NASA Astrophysics Data System (ADS)

    Torrisi, L.; Calcagno, L.; Giulietti, D.; Cutroneo, M.; Zimbone, M.; Skala, J.

    2015-07-01

    Advanced targets based on Au nanoparticles embedded in polymers films show high absorption coefficient in the UV-visible and infrared region. They can be employed to enhance the proton and ion acceleration from the laser-generated plasma in TNSA regime. In conditions of "p" polarized laser irradiations at 1015 W/cm2 intensity, in these films can be induced resonant absorption due to plasma wave excitation. Plasma on-line diagnostics is based on SiC detectors, Thomson spectrometry and X-ray streak camera imaging. Measurements of kinetic energy of accelerated ions indicate a significant increment using polymer targets containing gold nanoparticles and "p" polarized laser light with respect to pure polymers and unpolarized light irradiation.

  16. Modeling of thermal properties of a TeO 2 target for radioiodine production

    NASA Astrophysics Data System (ADS)

    Čomor, J. J.; Stevanović, Ž.; Rajčević, M.; Košutić, D.

    2004-03-01

    Three radionuclides of iodine ( 120I, 123I and 124I) are of great interest for modern nuclear medical diagnostics. They can be all produced by the (p,n) nuclear reaction using isotopically enriched solid TeO 2 targets. The produced radioiodine can be rapidly separated from the target material by dry-distillation from the melted target after the irradiation. Since TeO 2 has low thermal conductivity, the most critical issue in the design of a production target is the provision of its effective cooling in order to avoid melting of the oxide layer during the irradiation. A compact solid target irradiation system (COSTIS) has been designed for the irradiation of TeO 2 targets, suitable for routine production of radioiodine. The target is a circular Pt-disk that carries the TeO 2 melted into a circular grove in the center of the disk. The target coin is manually inserted into COSTIS, fixed pneumatically in the irradiation position, released remotely after irradiation and falls down driven by gravity into a transport container. The engineering design of the cavity for helium cooling of the front face of TeO 2 and the impinging water jet cooling the back face of the target disk was done based on a simulation of the thermal behavior of the target during the irradiation. A straightforward numerical method for the prediction of the thermal properties of the solid target has been developed. The approach is based on calculations without using the common practice of Prandtl and Nusselt empirical correlation. The fluid flow description in the boundary layer was refined in such a way, that the heat flux, exchanged between the solid and fluid, is obtained directly from Fourier law. The governing equations are based on the local thermodynamic equilibrium and conservation equation of mass, momentum and energy. In order to solve the set of governing equations, the finite-volume method is used. This procedure gives rapid answers whether the proposed geometry satisfies the design

  17. Probing Dense Plasmas Created from Intense Irradiation of Solid Target in the XUV Domain

    SciTech Connect

    Dobosz, S.; Doumy, G.; Stabile, H.; Monot, P.; Bougeard, M.; Reau, F.; Martin, Ph.

    2006-04-07

    In this paper, electronic density and temperature have been inferred from XUV transmission through hot solid-density plasma created by high temporal contrast femtosecond irradiation of thin plastic foil target in the 1018W/cm2 intensity range. High order harmonics generated in pulsed gas jet are used as a probe beam. The initial plasma parameters are determined with an accuracy better than 15% on the 100fs time scale, by comparison of the transmission of two consecutive harmonics.

  18. Behavior of structural and target materials irradiated in spallation neutron environments

    SciTech Connect

    Stubbins, J.F.; Wechsler, M.; Borden, M.

    1995-10-01

    This paper describes considerations for selection of structural and target materials for accelerator-driven neutron sources. Due to the operating constraints of proposed accelerator-driven neutron sources, the criteria for selection are different than those commonly applied to fission and fusion systems. Established irradiation performance of various alloy systems is taken into account in the selection criteria. Nevertheless, only limited materials performance data are available which specifically related to neutron energy spectra anticipated for spallation sources.

  19. Behavior of structural and target materials irradiated in spallation neutron environments

    SciTech Connect

    Stubbins, J.F.; Wechsler, M.; Borden, M.; Sommer, W.F.

    1995-05-01

    This paper describes considerations for selection of structural and target materials for accelerator-driven neutron sources. Due to the operating constraints of proposed accelerator-driven neutron sources, the criteria for selection are different than those commonly applied to fission and fusion systems. Established irradiation performance of various alloy systems is taken into account in the selection criteria. Nevertheless, only limited materials performance data are available which specifically related to neutron energy spectra anticipated for spallation sources.

  20. Abiotic production of iodine molecules in irradiated ice

    NASA Astrophysics Data System (ADS)

    Choi, Wonyong; Kim, Kitae; Yabushita, Akihiro

    2015-04-01

    Reactive halogen species play an important role in Earth's environmental systems. Iodine compounds are related to ozone depletion event (ODE) during Antarctic spring, formation of CCN (cloud condensation nuclei), and controlling the atmospheric oxidizing capacity. However, the processes and mechanisms for abiotic formation of iodine compounds in polar region are still unclear. Although the chemical reactions taking place in ice are greatly different from those in aquatic environment, reaction processes of halogens in frozen condition have rarely studied compared to those in water. In this study, we investigated iodide oxidation to form triiodide (I3-) in ice phase under UV irradiation ( λ > 300 nm) and dark condition. The production of I3- through iodide oxidation, which is negligible in aqueous solution, was significantly accelerated in ice phase even in the absence of UV irradiation. The following release of gaseous iodine molecule (I2) to the atmosphere was also monitored by cavity ring-down spectroscopy (CRDS). We speculate that the markedly enhanced iodide oxidation in polycrystalline ice is due to the freeze concentration of iodides, protons, and dissolved oxygen in the ice crystal grain boundaries. The experiments conducted under ambient solar radiation of the Antarctic region (King George Island, 62°13'S 58°47'W, sea level) also confirmed that the generation of I3- via iodide oxidation process is enhanced when iodide is trapped in ice. The observed intrinsic oxidative transformation of iodide to generate I3-(aq) and I2(g) in frozen environment suggests a previously unknown pathway for the substantial release of reactive iodine species to the atmosphere.

  1. Estimation of photoneutron yield from beryllium target irradiated by variable energy microtron-based bremsstrahlung radiation

    NASA Astrophysics Data System (ADS)

    Eshwarappa, K. M.; Ganesh; Siddappa, K.; Kashyap, Yogesh; Sinha, Amar; Sarkar, P. S.; Godwal, B. K.

    2005-03-01

    The possibility of setting up microtron-based photoneutron source by utilizing bremsstrahlung radiation interaction with beryllium targets is critically examined. The bremsstrahlung yield for tantalum (Ta) target is obtained by EGS4 simulation. The neutron yield is estimated theoretically by MCNP simulation. The yield was measured experimentally by neutron irradiation of calibrated SSNTD CR-39 films. The total neutron yield is found to be of the order 10 10 n/s for 250 Hz PRR and 10 9 n/s for 50 Hz PRR. A detailed comparison shows good agreement between theoretical and experimentally measured yields.

  2. UV-C irradiation of HSV-1 infected fibroblasts (HSV-FS) enhances human natural killer (NK) cell activity against these targets

    SciTech Connect

    Pettera, L.; Fitzgerald-Bocarsly, P. )

    1991-03-11

    Expression of Herpes Simplex Virus Type 1 (HSV-1) immediate early gene products has been bound to be sufficient for NK cell mediated lysis of HSV-1 infected FS. To block the targets at various stages in the infectious cycle, HSV-FS were irradiated with UV light for 1 min at 2, 6, and 20 hr post-infection. NK mediated lysis of 2 hr and 5 hr UV treated HSV-FS was 2-fold higher than non-UV treated HSV-FS despite a {gt}99% inhibition in virus yield. In contrast, 20 hr infected targets were lysed less well than 2 and 6 hr targets despite strong glycoprotein expression and induction of high levels of interferon-alpha (IFN-{alpha}) production by effector PBMC's; this lysis was not enhanced by UV treatment. Since NK lysis of HSV-FS has been found to be dependent on an HLA-DR{sup +} accessory cell (AC), lysis of irradiated HSV-FS by PBMC's depleted of AC was measured. Such depletion eradicated NK lysis of the UV treated HSV-FS indicating that irradiation does not overcome the AC requirement for NK lysis. UV irradiation of another HLA-DR{sup +} dependent target, Vesicular Stomatitis Virus (VSV) infected FS led to a dramatic reduction in both NK lysis and IFN-{alpha} induction. HSV-1 is a DNA virus whose genes are expressed in a cascade fashion whereas VSV is an RNA virus. The authors hypothesize that the enhancement in AC dependent NK activity observed for UV irradiated HSV-FS, but not VSV-FS, targets is due to overproduction of either a cellular or viral gene product which specifically occurs early in the HSV-1 infectious cycle and is downregulated by 20 hr post-infection.

  3. Preliminary investigations on the use of uranium silicide targets for fission Mo-99 production

    SciTech Connect

    Cols, H.; Cristini, P.; Marques, R.

    1997-08-01

    The National Atomic Energy Commission (CNEA) of Argentine Republic owns and operates an installation for production of molybdenum-99 from fission products since 1985, and, since 1991, covers the whole national demand of this nuclide, carrying out a program of weekly productions, achieving an average activity of 13 terabecquerel per week. At present they are finishing an enlargement of the production plant that will allow an increase in the volume of production to about one hundred of terabecquerel. Irradiation targets are uranium/aluminium alloy with 90% enriched uranium with aluminium cladding. In view of international trends held at present for replacing high enrichment uranium (HEU) for enrichment values lower than 20 % (LEU), since 1990 the authors are in contact with the RERTR program, beginning with tests to adapt their separation process to new irradiation target conditions. Uranium silicide (U{sub 3}Si{sub 2}) was chosen as the testing material, because it has an uranium mass per volume unit, so that it allows to reduce enrichment to a value of 20%. CNEA has the technology for manufacturing miniplates of uranium silicide for their purposes. In this way, equivalent amounts of Molybdenum-99 could be obtained with no substantial changes in target parameters and irradiation conditions established for the current process with Al/U alloy. This paper shows results achieved on the use of this new target.

  4. Treatment of effluents from petroleum production by electron beam irradiation

    NASA Astrophysics Data System (ADS)

    Duarte, Celina Lopes; Geraldo, Lucia Limoeiro; Junior, Oswaldo de Aquino P.; Borrely, Sueli Ivone; Sato, Ivone Mulako; Sampa, Maria Helena de Oliveira

    2004-09-01

    During the offshore oil production large volumes of aqueous waste with high salinity are produced. The produced water originates mainly from the oil-bearing formation but may also include seawater, which has been injected to maintain reservoir pressure. This water is normally separated from oil on the platform generating aqueous effluent with metals, sulfite, ammonium and organic compounds. The conventional treatment used includes filtration, flotation, ionic change and adsorption in activated charcoal, but the high salinity of this water decreases the treatment efficiency. The high efficiency of electron beam irradiation on removing organic compound in industrial effluent has been shown, and the primary aim of this study is to evaluate the efficiency of this new technology to treat the oil water production. Experiments were conducted using samples from two platforms processed in the radiation dynamics electron beam accelerator with 1.5 MeV energy and 37 kW power. The results showed that the electron beam technology has high efficiency in destroying organic compounds even in the presence of high salinity and complex effluent.

  5. Thin-film preparation by back-surface irradiation pulsed laser deposition using metal powder targets

    NASA Astrophysics Data System (ADS)

    Kawasaki, Hiroharu; Ohshima, Tamiko; Yagyu, Yoshihito; Ihara, Takeshi; Yamauchi, Makiko; Suda, Yoshiaki

    2017-01-01

    Several kinds of functional thin films were deposited using a new thin-film preparation method named the back-surface irradiation pulsed laser deposition (BIPLD) method. In this BIPLD method, powder targets were used as the film source placed on a transparent target holder, and then a visible-wavelength pulsed laser was irradiated from the holder side to the substrate. Using this new method, titanium oxide and boron nitride thin films were deposited on the silicon substrate. Surface scanning electron microscopy (SEM) images suggest that all of the thin films were deposited on the substrate with some large droplets irrespective of the kind of target used. The deposition rate of the films prepared by using this method was calculated from film thickness and deposition time to be much lower than that of the films prepared by conventional PLD. X-ray diffraction (XRD) measurement results suggest that rutile and anatase TiO2 crystal peaks were formed for the films prepared using the TiO2 rutile powder target. Crystal peaks of hexagonal boron nitride were observed for the films prepared using the boron nitride powder target. The crystallinity of the prepared films was changed by annealing after deposition.

  6. Current and potential trade in horticultural products irradiated for phytosanitary purposes

    USDA-ARS?s Scientific Manuscript database

    The current status of trade in horticultural products irradiated for phytosanitary purposes is examined, including trends, strengths and weaknesses. A strategy is proposed to take advantage of the best future opportunities for increasing trade in irradiated horticultural products. This will be do...

  7. Quasimonoenergetic proton bunches generation from doped foil targets irradiated by intense lasers

    SciTech Connect

    Cui Yunqian; Wang Weimin; Li Yutong; Sheng Zhengming; Zhang Jie

    2013-02-15

    We propose a scheme to generate 10 MeV-level quasimonoenergetic proton bunches using proton-doped heavy-ion targets irradiated by intense lasers via target normal sheath acceleration. The heavy substrate ions provide a long-life quasi-stable sheath field to accelerate the doped protons at the target rear and consequently a quasimonoenergetic proton bunch is produced. The scheme is demonstrated by two-dimensional particle-in-cell simulations. An exemplificative simulation with parameters of targets made by ion-implant technique, a kind of modern doping process, gives a quasimonoenergetic bunch with peak energy {approx}13MeV, energy spread {approx}24%, and {approx}nC charge at the focused laser intensity 10{sup 20}W/cm{sup 2}.

  8. Single freeform surface design for prescribed input wavefront and target irradiance

    NASA Astrophysics Data System (ADS)

    Bösel, Christoph; Gross, Herbert

    2017-09-01

    In beam shaping applications, the minimization of the number of necessary optical elements for the beam shaping process can benefit the compactness of the optical system and reduce its cost. The single freeform surface design for input wavefronts, which are neither planar nor spherical, is therefore of interest. In this work, the design of single freeform surfaces for a given zero-\\'etendue source and complex target irradiances is investigated. Hence, not only collimated input beams or point sources are assumed. Instead, a predefined input ray direction vector field and irradiance distribution on a source plane, which has to be redistributed by a single freeform surface to give the predefined target irradiance, is considered. To solve this design problem, a partial differential equation (PDE) or PDE system, respectively, for the unknown surface and its corresponding ray mapping is derived from energy conservation and the ray-tracing equations. In contrast to former PDE formulations of the single freeform design problem, the derived PDE of Monge-Amp\\`ere type is formulated for general zero-\\'etendue sources in cartesian coordinates. The PDE system is discretized with finite differences and the resulting nonlinear equation system solved by a root-finding algorithm. The basis of the efficient solution of the PDE system builds the introduction of an initial iterate constuction approach for a given input direction vector field, which uses optimal mass transport with a quadratic cost function. After a detailed description of the numerical algorithm, the efficiency of the design method is demonstrated by applying it to several design examples. This includes the redistribution of a collimated input beam beyond the paraxial approximation, the shaping of point source radiation and the shaping of an astigmatic input wavefront into a complex target irradiance distribution.

  9. Post-irradiation examination of the Spallation Neutron Source target module

    NASA Astrophysics Data System (ADS)

    McClintock, D. A.; Ferguson, P. D.; Mansur, L. K.

    2010-03-01

    The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory is an accelerator-based pulsed neutron source that produces high-energy spallation neutrons by bombarding liquid mercury flowing through a stainless steel target vessel. During operation the proton beam and spallation neutrons produce radiation damage in the AISI 316L austenitic stainless steel target vessel and water-cooled shroud. The beam pulses also cause rapid heating of the liquid mercury, which may produce cavitation erosion damage on the inner surface of the target vessel. The cavitation erosion rate is thought to be highly sensitive to beam power and predicted to be the primary life-limiting factor of the target module. Though cavitation erosion and radiation damage to the target vessel are expected to dictate its lifetime, the effects of radiation damage and cavitation erosion to target vessels in liquid metal spallation systems are not well known. Therefore preparations are being undertaken to perform post-irradiation examination (PIE) of the liquid mercury target vessel and water-cooled shroud after end-of-life occurs. An overview of the planned PIE for the SNS target vessel is presented here, including proposed techniques for specimen acquisition and subsequent material properties characterization.

  10. Analysis of Beam-Induced Damage to the SLC Positron Production Target

    SciTech Connect

    Bharadwaj, Vinod

    2002-08-20

    The nominal Next Linear Collider (NLC) positron production design is based on extrapolation of the existing SLAC Linear Collider (SLC) positron production system. Given that the SLC positron production target failed during a run, it is necessary to analyze the beam-induced damage to the target in order to validate the extrapolations on which the NLC target is based. The failed SLC target and its associated housing were sent to existing ''hot-cell'' facilities at LANL for analysis. The target material, a tungsten-rhenium ''puck'', was removed from the housing and photographed and x-rayed. Leak-checking on the cooling system was performed. Sections were then removed from the target to determine the extent of internal damage to the material. High resolution photographs were taken and extensive hardness tests were performed on the irradiated and non-irradiated areas of the target material. The results of these analyses and conclusions applicable to the NLC target design are presented in this paper.

  11. PROCESS FOR CONTINUOUSLY SEPARATING IRRADIATION PRODUCTS OF THORIUM

    DOEpatents

    Hatch, L.P.; Miles, F.T.; Sheehan, T.V.; Wiswall, R.H.; Heus, R.J.

    1959-07-01

    A method is presented for separating uranium-233 and protactinium from thorium-232 containing compositions which comprises irradiating finely divided particles of said thorium with a neutron flux to form uranium-233 and protactinium, heating the neutron-irradiated composition in a fluorine and hydrogen atmosphere to form volatile fluorides of uranium and protactinium and thereafter separating said volatile fluorides from the thorium.

  12. Negative pressure and spallation in graphite targets under nano- and picosecond laser irradiation

    SciTech Connect

    Belikov, R S; Khishchenko, K V; Krasyuk, I K; Semenov, A Yu; Stuchebryukhov, I A; Rinecker, T; Schoenlein, A; Rosmej, O N; Tomut, M

    2015-05-31

    We present the results of experiments on the spallation phenomena in graphite targets under shock-wave nano- and picosecond irradiation, which have been performed on Kamerton-T (GPI, Moscow, Russia) and PHELIX (GSI, Darmstadt, Germany) laser facilities. In the range of the strain rates of 10{sup 6} – 10{sup 7} s{sup -1}, the data on the dynamic mechanical strength of the material at rapure (spallation) have been for the first time obtained. With a maximal strain rate of 1.4 × 10{sup 7} s{sup -1}, the spall strength of 2.1 GPa is obtained, which constitutes 64% of the theoretical ultimate tensile strength of graphite. The effect of spallation is observed not only on the rear side of the target, but also on its irradiated (front) surface. With the use of optical and scanning electron microscopes, the morphology of the front and rear surfaces of the targets is studied. By means of Raman scattering of light, the graphite structure both on the target front surface under laser exposure and on its rear side in the spall zone is investigated. A comparison of the dynamic strength of graphite and synthetic diamond is performed. (extreme light fields and their applications)

  13. Investigation of laser ion acceleration inside irradiated solid targets by neutron spectroscopy

    SciTech Connect

    Youssef, A.; Kodama, R.; Tampo, M.

    2006-03-15

    Origins and acceleration directions of accelerated ions inside solid LiF, CH-LiF, and LiF-CH targets irradiated by a 450 fs, 20 J, 1053 nm laser at an intensity of 3x10{sup 18} W/cm{sup 2} have been investigated by neutron spectroscopy. The irradiated targets generate neutrons through the reaction {sup 7}Li (p,n){sup 7}Be between accelerated protons and background {sup 7}Li ions inside the target. The produced neutron spectra observed from two different observation angles 20 deg. and 120 deg. to the target rear-side normal. From the measured and calculated spectra, by three-dimensional Monte Carlo code, the maximum energy, the total number, and the slope temperature of the accelerated ions are investigated. The results indicate that ions are not only accelerated from the front surface toward the rear surface, but also from the rear surface toward the front surface with comparable maximum energy and higher number.

  14. Proton emission from thin hydrogenated targets irradiated by laser pulses at 10(16) W∕cm2.

    PubMed

    Torrisi, L; Giuffrida, L; Cutroneo, M; Cirrone, P; Picciotto, A; Krasa, J; Margarone, D; Velyhan, A; Laska, L; Ullschmied, J; Wolowski, J; Badziak, J; Rosinski, M

    2012-02-01

    The iodine laser at PALS Laboratory in Prague, operating at 1315 nm fundamental harmonics and at 300 ps FWHM pulse length, is employed to irradiate thin hydrogenated targets placed in vacuum at intensities on the order of 10(16) W∕cm(2). The laser-generated plasma is investigated in terms of proton and ion emission in the forward and backward directions. The time-of-flight technique, using ion collectors and semiconductor detectors, is used to measure the ion currents and the corresponding velocities and energies. Thomson parabola spectrometer is employed to separate the contribution of the ion emission from single laser shots. A particular attention is given to the proton production in terms of the maximum energy, emission yield, and angular distribution as a function of the laser energy, focal position, target thickness, and composition. Metallic and polymeric targets allow to generate protons with large energy range and different yield, depending on the laser, target composition, and target geometry properties.

  15. Gamma Knife irradiation method based on dosimetric controls to target small areas in rat brains

    SciTech Connect

    Constanzo, Julie; Paquette, Benoit; Charest, Gabriel; Masson-Côté, Laurence; Guillot, Mathieu

    2015-05-15

    Purpose: Targeted and whole-brain irradiation in humans can result in significant side effects causing decreased patient quality of life. To adequately investigate structural and functional alterations after stereotactic radiosurgery, preclinical studies are needed. The purpose of this work is to establish a robust standardized method of targeted irradiation on small regions of the rat brain. Methods: Euthanized male Fischer rats were imaged in a stereotactic bed, by computed tomography (CT), to estimate positioning variations relative to the bregma skull reference point. Using a rat brain atlas and the stereotactic bregma coordinates obtained from CT images, different regions of the brain were delimited and a treatment plan was generated. A single isocenter treatment plan delivering ≥100 Gy in 100% of the target volume was produced by Leksell GammaPlan using the 4 mm diameter collimator of sectors 4, 5, 7, and 8 of the Gamma Knife unit. Impact of positioning deviations of the rat brain on dose deposition was simulated by GammaPlan and validated with dosimetric measurements. Results: The authors’ results showed that 90% of the target volume received 100 ± 8 Gy and the maximum of deposited dose was 125 ± 0.7 Gy, which corresponds to an excellent relative standard deviation of 0.6%. This dose deposition calculated with GammaPlan was validated with dosimetric films resulting in a dose-profile agreement within 5%, both in X- and Z-axes. Conclusions: The authors’ results demonstrate the feasibility of standardizing the irradiation procedure of a small volume in the rat brain using a Gamma Knife.

  16. Gamma Knife irradiation method based on dosimetric controls to target small areas in rat brains.

    PubMed

    Constanzo, Julie; Paquette, Benoit; Charest, Gabriel; Masson-Côté, Laurence; Guillot, Mathieu

    2015-05-01

    Targeted and whole-brain irradiation in humans can result in significant side effects causing decreased patient quality of life. To adequately investigate structural and functional alterations after stereotactic radiosurgery, preclinical studies are needed. The purpose of this work is to establish a robust standardized method of targeted irradiation on small regions of the rat brain. Euthanized male Fischer rats were imaged in a stereotactic bed, by computed tomography (CT), to estimate positioning variations relative to the bregma skull reference point. Using a rat brain atlas and the stereotactic bregma coordinates obtained from CT images, different regions of the brain were delimited and a treatment plan was generated. A single isocenter treatment plan delivering ≥ 100 Gy in 100% of the target volume was produced by Leksell GammaPlan using the 4 mm diameter collimator of sectors 4, 5, 7, and 8 of the Gamma Knife unit. Impact of positioning deviations of the rat brain on dose deposition was simulated by GammaPlan and validated with dosimetric measurements. The authors' results showed that 90% of the target volume received 100 ± 8 Gy and the maximum of deposited dose was 125 ± 0.7 Gy, which corresponds to an excellent relative standard deviation of 0.6%. This dose deposition calculated with GammaPlan was validated with dosimetric films resulting in a dose-profile agreement within 5%, both in X- and Z-axes. The authors' results demonstrate the feasibility of standardizing the irradiation procedure of a small volume in the rat brain using a Gamma Knife.

  17. 4D particle therapy PET simulation for moving targets irradiated with scanned ion beams.

    PubMed

    Laube, K; Menkel, S; Bert, C; Enghardt, W; Helmbrecht, S; Saito, N; Fiedler, F

    2013-02-07

    Particle therapy positron emission tomography (PT-PET) allows for an in vivo and in situ verification of applied dose distributions in ion beam therapy. Since the dose distribution cannot be extracted directly from the β(+)-activity distribution gained from the PET scan the validation is done by means of a comparison between the reconstructed β(+)-activity distributions from a PT-PET measurement and from a PT-PET simulation. Thus, the simulation software for generating PET data predicted from the treatment planning is an essential part of the dose verification routine. For the dose monitoring of intra-fractionally moving target volumes the PET data simulation needs to be upgraded by using time resolved (4D) algorithms to account correctly for the motion dependent displacement of the positron emitters. Moreover, it has to consider the time dependent relative movement between target volume and scanned beam to simulate the accurate positron emitter distribution generated during irradiation. Such a simulation program is presented which properly proceeds with motion compensated dose delivery by scanned ion beams to intra-fractionally moving targets. By means of a preclinical phantom study it is demonstrated that even the sophisticated motion-mitigated beam delivery technique of range compensated target tracking can be handled correctly by this simulation code. The new program is widely based on the 3D PT-PET simulation program which had been developed at the Helmholtz-Zentrum Dresden-Rossendorf, Germany (HZDR) for application within a pilot project to simulate in-beam PET data for about 440 patients with static tumor entities irradiated at the former treatment facility of the GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany (GSI). A simulation example for a phantom geometry irradiated with a tracked (12)C-ion beam is presented for demonstrating the proper functionality of the program.

  18. Post-Irradiation Properties of Candidate Materials for High-Power Targets

    SciTech Connect

    Kirk, H.G.; Ludewig, H.; Mausner, L.F.; Simos, N.; Thieberger, P.; Hayato, Y.; Yoshimura, K.; McDonald, K.T.; Sheppard, J.; Trung, L.P.; /SUNY, Stony Brook

    2006-03-15

    The desire of the high-energy-physics community for more intense secondary particle beams motivates the development of multi-megawatt, pulsed proton sources. The targets needed to produce these secondary particle beams must be sufficiently robust to withstand the intense pressure waves arising from the high peak-energy deposition which an intense pulsed beam will deliver. In addition, the materials used for the targets must continue to perform in a severe radiation environment. The effect of the beam induced pressure waves can be mitigated by use of target materials with high-yield strength and/or low coefficient of thermal expansion (CTE). We report here first results of an expanded study of the effects of irradiation on several additional candidate materials with high strength (AlBeMet, beryllium, Ti-V6-Al4) or low CTE (a carbon-carbon composite, a new Toyota ''gum'' metal alloy, Super-Invar).

  19. Identification and dose determination using ESR measurements in the flesh of irradiated vegetable products

    PubMed

    de Jesus EF; Rossi; Lopes

    2000-05-01

    The international commerce of vegetable products is often dependent on the quarantine protections that are imposed by the importing countries because of the fear of contamination by fruit flies. The use of ionizing radiation as a treatment for these products can be used to remove this problem and a real proof of irradiation can contribute to the implementation of the international commerce. ESR measurement on the pulp of vegetable products can be used as a proof of irradiation using the species introduced in cellulose that are found uniquely in irradiated products. The stability of these species are compatible with the life of the products analyzed. The pulp signal intensity is sufficient to identify products irradiated with doses as low as 100 Gy for some fruits.

  20. Myanmar production meets first-gas targets

    SciTech Connect

    Lepage, A.

    1998-09-07

    Despite scheduling complications caused by annual monsoons, the Yadana project to bring offshore Myanmar gas ashore and into neighboring Thailand has met it first-gas target of July 1, 1998. The Yadana field is a dry-gas reservoir in the reef upper Birman limestone formation t 1,260 m and a pressure of 174 bara (approximately 2,500 psi). It extends nearly 7 km (west to east) and 10 km (south to north). The water-saturated reservoir gas contains mostly methane mixed with CO{sub 2} and N{sub 2}. No production of condensate is anticipated. The Yadana field contains certified gas reserves of 5.7 tcf, calculated on the basis of 2D and 3D seismic data-acquisition campaigns and of seven appraisal wells. The paper discusses early interest, development sequences, offshore platforms, the gas-export pipeline, safety, environmental steps, and schedule constraints.

  1. Fixed-target hadron production experiments

    NASA Astrophysics Data System (ADS)

    Popov, Boris A.

    2015-08-01

    Results from fixed-target hadroproduction experiments (HARP, MIPP, NA49 and NA61/SHINE) as well as their implications for cosmic ray and neutrino physics are reviewed. HARP measurements have been used for predictions of neutrino beams in K2K and MiniBooNE/SciBooNE experiments and are also being used to improve predictions of the muon yields in EAS and of the atmospheric neutrino fluxes as well as to help in the optimization of neutrino factory and super-beam designs. Recent measurements released by the NA61/SHINE experiment are of significant importance for a precise prediction of the J-PARC neutrino beam used for the T2K experiment and for interpretation of EAS data. These hadroproduction experiments provide also a large amount of input for validation and tuning of hadron production models in Monte-Carlo generators.

  2. Effects of irradiation source and dose level on quality characteristics of processed meat products

    NASA Astrophysics Data System (ADS)

    Ham, Youn-Kyung; Kim, Hyun-Wook; Hwang, Ko-Eun; Song, Dong-Heon; Kim, Yong-Jae; Choi, Yun-Sang; Song, Beom-Seok; Park, Jong-Heum; Kim, Cheon-Jei

    2017-01-01

    The effect of irradiation source (gamma-ray, electron-beam, and X-ray) and dose levels on the physicochemical, organoleptic and microbial properties of cooked beef patties and pork sausages was studied, during 10 days of storage at 30±1 °C. The processed meat products were irradiated at 0, 2.5, 5, 7.5, and 10 kGy by three different irradiation sources. The pH of cooked beef patties and pork sausages was unaffected by irradiation sources or their doses. The redness of beef patties linearly decreased with increasing dose level (P<0.05), obviously by e-beam irradiation compared to gamma-ray and X-ray (P<0.05). The redness of pork sausages was increased by gamma-ray irradiation, whereas it decreased by e-beam irradiation depending on absorbed dose level. No significant changes in overall acceptability were observed for pork sausages regardless of irradiation source (P>0.05), while gamma-ray irradiated beef patties showed significantly decreased overall acceptability in a dose-dependent manner (P<0.05). Lipid oxidation of samples was accelerated by irradiation depending on irradiation sources and dose levels during storage at 30 °C. E-beam reduced total aerobic bacteria of beef patties more effectively, while gamma-ray considerably decreased microbes in pork sausages as irradiation dose increased. The results of this study indicate that quality attributes of meat products, in particular color, lipid oxidation, and microbial properties are significantly influenced by the irradiation sources.

  3. Analysis of the (148)Gd and (154)Dy Content in Proton-Irradiated Lead Targets.

    PubMed

    Talip, Z; Pfister, S; Dressler, R; David, J C; Vögele, A; Vontobel, P; Michel, R; Schumann, D

    2017-06-20

    This work presents the determination of the (148)Gd and (154)Dy content in Pb targets irradiated by 220-2600 MeV protons. It includes the chemical separation of lanthanides, followed by the preparation of proper samples, by molecular plating technique, for α-spectrometry measurements. The experimental cross section results were compared with theoretical predictions, calculated with the INCL++-ABLA07 code. The comparisons showed a satisfactory agreement for (148)Gd (less than within a factor two), while measured (154)Dy cross sections are higher than the theoretical values.

  4. Impact of irradiation on the safety and quality of poultry and meat products: a review.

    PubMed

    O'Bryan, Corliss A; Crandall, Philip G; Ricke, Steven C; Olson, Dennis G

    2008-05-01

    For more than 100 years research on food irradiation has demonstrated that radiation will make food safer and improve the shelf life of irradiated foods. Using the current food safety technology, we may have reached the point of diminishing returns even though recent figures from the CDC show a significant drop in the number of foodborne illnesses. However, too many people continue to get sick and die from eating contaminated food. New and under utilized technologies such as food irradiation need to be re-examined to achieve new levels of safety for the food supply. Effects of irradiation on the safety and quality of meat and poultry are discussed. Irradiation control of the principle microbial pathogens including viruses, the differences among at-risk sub-populations, factors affecting the diminished rate of improvement in food safety and published D values for irradiating raw meat and poultry are presented. Currently permitted levels of irradiation are probably not sufficient to control pathogenic viruses. Typical gram-negative spoilage organisms are very sensitive to irradiation. Their destruction leads to a significant increase in the acceptable shelf life. In addition, the destruction of these normal spoilage organisms did not provide a competitive growth advantage for irradiation injured food pathogens. Another of the main focuses of this review is a detailed compilation of the effects of most of the food additives that have been proposed to minimize the negative quality effect of irradiation. Most of the antimicrobials and antioxidants used singly or in combination produced an increased lethality of irradiation and a decrease in oxidation by-products. Combinations of dosage, temperature, dietary and direct additives, storage temperature and packaging atmosphere can produce meats that the average consumer will find indistinguishable from non-irradiated meats. A discussion of the production of unique radiological by-products is also included.

  5. Transportation risk assessment for the shipment of irradiated FFTF tritium target assemblies from the Hanford Site to the Savannah River Site

    SciTech Connect

    Nielsen, D. L.

    1997-11-19

    A Draft Technical Information Document (HNF-1855) is being prepared to evaluate proposed interim tritium and medical isotope production at the Fast Flux Test Facility (FFTF). This report examines the potential health and safety impacts associated with transportation of irradiated tritium targets from FFTF to the Savannah River Site for processing at the Tritium Extraction Facility. Potential risks to workers and members of the public during normal transportation and accident conditions are assessed.

  6. Use of gamma irradiation to prevent aflatoxin B 1 production in smoked dried fish

    NASA Astrophysics Data System (ADS)

    Ogbadu, G. H.

    Smoked dried fish bought from the Nigerian market was inoculated with spores of barAspergillus flavus (U.I. 81) and irradiated with doses of 0.625, 1.25, 2.50 and 5.00 KGy gamma irradiation. The effect of aflatoxin B 1 production on subsequent incubation for 8 days as stationary cultures was measured. The amount of aflatoxin B 1 produced was found to decrease with increased gamma irradiation dose levels. While the non-irradiated control produced significantly (at 1% level) greater amounts of aflatoxin B 1 as compared to the treated cultures.

  7. Accessing Solar Irradiance Data Products From the LASP Interactive Solar IRradiance Datacenter (LISIRD)

    NASA Astrophysics Data System (ADS)

    Ware Dewolfe, A.; Wilson, A.; Lindholm, D. M.; Pankratz, C. K.; Snow, M.; Woods, T. N.

    2009-12-01

    The Laboratory for Atmospheric and Space Physics (LASP) is enhancing the LASP Interactive Solar IRradiance Datacenter (LISIRD) to provide access to a comprehensive set of solar spectral irradiance measurements. LISIRD has recently been updated to serve many new datasets and models, including sunspot index, photometric sunspot index, Lyman-alpha, and magnesium-II core-to-wing ratio. A new user interface emphasizes web-based interactive visualizations, allowing users to explore and compare this data before downloading it for analysis. The data provided covers a wavelength range from soft X-ray (XUV) at 0.1 nm up to the near infrared (NIR) at 2400 nm, as well as wavelength-independent Total Solar Irradiance (TSI). Combined data from the SORCE, TIMED-SEE, UARS-SOLSTICE, and SME instruments provide almost continuous coverage from 1981 to the present, while Hydrogen Lyman-alpha (121.6 nm) measurements / models date from 1947 to the present. This poster provides an overview of the LISIRD system, summarizes the data sets currently available, describes future plans and capabilities, and provides details on how to access solar irradiance data through LISIRD interfaces at http://lasp.colorado.edu/lisird/.

  8. Production scale purification of Ge-68 and Zn-65 from irradiated gallium metal.

    PubMed

    Fitzsimmons, Jonathan M; Mausner, Leonard

    2015-07-01

    Germanium-68 (Ge-68) is produced by proton irradiation of a gallium metal target, purified by organic extraction and used in a medical isotope generator to produce Gallium-68 PET imaging agents. The purpose of this work was to implement a production scale separation of Ge-68 and Zn-65 that does not use organic solvents and uses a limited number of columns. The current separation approach was modified to use AG1 resin and/or Sephadex(©) G25 with zinc spikes to purify Ge-68 with near quantitative recovery. The purified Ge-68 meets DOE specifications. Methods utilizing zinc spikes resulted in the purist Ge-68 produced at Brookhaven National Lab with no other impurities by ICP-OES. During process optimization approximately 2.5 Ci of Ge-68 was purified utilizing the different processing methods, and the material was sold to the Nuclear Medicine community between 2012-2013. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Hollow Atom Production Due to High Intensity X-ray Sources Irradiating Clusters And Its Applications

    SciTech Connect

    Moribayashi, Kengo

    2009-07-25

    This paper shows the production of hollow atoms and the proposal of the measurement by using x-ray flux irradiating clusters by continuing work from our previous papers left braceK. Moribayashi, J.Phys.B, 41 085602 (2008)right brace. The x-ray emissions from hollow atoms produced by high intensity x-ray sources are employed for this measurement. This measurement is useful for the application of laser-driven x-ray sources and x-ray free electron lasers to the measurement of diffraction patterns of bio-molecules, which is indispensable for the study of their three-dimensional structure. This paper develops the methods and discussions of our previous paper. Namely, the electron impact ionization processes are added to our calculation model. Further, the size effects of the targets are shown.

  10. Demonstration of {sup 99}MO production using LEU metal-foil targets in the cintichem process.

    SciTech Connect

    Vandegrift, G. F.; Conner, C.; Hofman, G. L.; Snelgrove, J. L.; Mutalib, A.; Purwadi, B.; Adang, H. G.; Hotman, L.; Kadarisman, Sukmana, A.; Dicky, T. J.; Sriyono, Suripto, A.; Lutfi, D.; Amin; Basiran, A.; Gogo, A.; Sarwani; Taryo, T.

    1999-09-30

    In March and September 1999, demonstrations of the irradiation, disassembly, and processing of LEU metal foil targets were performed in the Indonesian BATAN PUSPIPTEK Facilities. These demonstrations showed that (1) irradiation and disassembly can be performed so that the uranium foil can be easily removed from the target body, and (2) with only minor changes to the current process, the LEU foil can produce yield and purity of the {sup 99}Mo product at least as great as that obtained with the HEU target. Further, because of these modifications, two hours are cut from the processing time, and the liquid waste volume is reduced. Results of these demonstrations will be presented along with conclusions and plans for future work.

  11. Production of Y-86 and other radiometals for research purposes using a solution target system.

    PubMed

    Oehlke, Elisabeth; Hoehr, Cornelia; Hou, Xinchi; Hanemaayer, Victoire; Zeisler, Stefan; Adam, Michael J; Ruth, Thomas J; Celler, Anna; Buckley, Ken; Benard, Francois; Schaffer, Paul

    2015-11-01

    Diagnostic radiometals are typically obtained from cyclotrons by irradiating solid targets or from radioisotope generators. These methods have the advantage of high production yields, but require additional solid target handling infrastructure that is not readily available to many cyclotron facilities. Herein, we provide an overview of our results regarding the production of various positron-emitting radiometals using a liquid target system installed on a 13 MeV cyclotron at TRIUMF. Details about the production, purification and quality control of (89)Zr, (68)Ga and for the first time (86)Y are discussed. Aqueous solutions containing 1.35-1.65 g/mL of natural-abundance zinc nitrate, yttrium nitrate, and strontium nitrate were irradiated on a 13 MeV cyclotron using a standard liquid target. Different target body and foil materials were investigated for corrosion. Production yields were calculated using theoretical cross-sections from the EMPIRE code and compared with experimental results. The radioisotopes were extracted from irradiated target material using solid phase extraction methods adapted from previously reported methods, and used for radiolabelling experiments. We demonstrated production quantities that are sufficient for chemical and biological studies for three separate radiometals, (89)Zr (Asat = 360 MBq/μA and yield = 3.17 MBq/μA), (86)Y (Asat = 31 MBq/μA and yield = 1.44 MBq/μA), and (68)Ga (Asat = 141 MBq/μA and yield = 64 MBq/μA) from one hour long irradiations on a typical medical cyclotron. (68)Ga yields were sufficient for potential clinical applications. In order to avoid corrosion of the target body and target foil, nitrate solutions were chosen as well as niobium as target-body material. An automatic loading system enabled up to three production runs per day. The separation efficiency ranged from 82 to 99%. Subsequently, (68)Ga and (86)Y were successfully used to radiolabel DOTA-based chelators while deferoxamine was used to coordinate

  12. Effect of a target size on the recoil momentum upon laser irradiation of absorbing materials

    SciTech Connect

    Chumakou, A N; Petrenko, A M; Bosak, N A

    2004-10-31

    The dependence of a recoil momentum on the radius of a target irradiated by a single-pulse Nd{sup 3+}:YAG laser ({lambda}=1.064 {mu}m, {tau}=20 ns, E{<=}300 mJ) in the air is studied. The recoil momentum decreases three-fold with increasing the relative target radius from 0.3 to 5 and tends to saturation for r>3. The calculation of the recoil momentum on the basis of the Euler and Navier-Stokes equations gave understated values for r>1, which lowered to negative values. The reasons for the qualitative discrepancy between the experimental and calculated data is discussed. (interaction of laser radiation with matter)

  13. Nanostructured targets irradiation by ns-laser for nuclear astrophysics applications: first results

    NASA Astrophysics Data System (ADS)

    Muoio, A.; Altana, C.; Frassetto, M.; Lanzalone, G.; Malferrari, L.; Mascali, D.; Odorici, F.; Tudisco, S.

    2017-03-01

    The studies discussed in this work are related to a scientific program that aims to reproduce astrophysical-plasmas in laboratory in order to better understand the nuclear processes involved in the stellar burning. An experimental campaign aiming to investigate the effects of innovative nanostructured targets based on Ni, Fe and Co nanowires on laser energy absorption in the ns time domain has been carried out at the LENS (Laser Energy for Nuclear Science) laboratory of INFN-LNS, Catania. Nanowires structures are tuned to increase the light absorption in the visible and infrared range due possibly to plasmonic excitation driven by the incoming photons. Different diagnostics techniques permit to monitor the plasma and to determine its reproducibility. Targets were then irradiated by Nd:YAG 2J, 6 ns infrared laser (λ = 1064 nm) at different pumping energies. Some preliminary results will be illustrated.

  14. Directed fast electron beams in ultraintense picosecond laser irradiated solid targets

    SciTech Connect

    Ge, X. L.; Lin, X. X.; Yuan, X. H. E-mail: ytli@iphy.ac.cn; Sheng, Z. M.; Carroll, D. C.; Neely, D.; Gray, R. J.; Tresca, O.; McKenna, P.; Yu, T. P.; Chen, M.; Liu, F.; Zhuo, H. B.; Zielbauer, B.; and others

    2015-08-31

    We report on fast electron transport and emission patterns from solid targets irradiated by s-polarized, relativistically intense, picosecond laser pulses. A beam of multi-MeV electrons is found to be transported along the target surface in the laser polarization direction. The spatial-intensity and energy distributions of this beam are compared with the beam produced along the laser propagation axis. It is shown that even for peak laser intensities an order of magnitude higher than the relativistic threshold, laser polarization still plays an important role in electron energy transport. Results from 3D particle-in-cell simulations confirm the findings. The characterization of directional beam emission is important for applications requiring efficient energy transfer, including secondary photon and ion source development.

  15. Application of EPR spectroscopy to identify irradiated Indian medicinal plant products.

    PubMed

    Sanyal, Bhaskar; Chatterjee, S; Variyar, Prasad S; Sharma, Arun

    2012-06-01

    A study of gamma-irradiated Indian medicinal plant products was carried out using electron paramagnetic resonance (EPR) spectroscopy. Improved approaches like high-power measurement, microwave saturation, and thermal behavior of the radicals were explored for detection of irradiation. Aswagandha (Withania somnifera), vairi (Salacia reticulata), amla (Emblica officinalis), haldi (Curcumin longa), and guduchi (Tinospora cordifolia) exhibited a weak singlet at g = 2.005 before irradiation. Aswagandha, immediately after radiation treatment, revealed a complex EPR spectrum characterized by EPR spectrum simulation technique as superposition of 3 paramagnetic centers. One group of signal with organic origin was carbohydrate and cellulose radical and the other was isotropic signal of inorganic origin (g⟂ =2.0044 and g|| = 1.9980). However, other products did not exhibit any radiation-specific signal after irradiation. Power saturation and thermal behavior techniques were not suitable for these products. However, amongst all the 3 approaches, high-power measurement of EPR spectra emerged as a suitable technique in identification of the irradiated aswagandha. Gamma-irradiation confirms hygienic quality and improves shelf life of food and other products. However, there is a lack of international consensus over considering this as a general application and different regulations are being enforced. EPR is one of the most promising techniques to identify irradiated foodstuffs for regulatory requirements but it has many limitations. Improved approaches based on the EPR technique explained in this study may be useful to identify irradiated products and become beneficial to food regulators and food irradiation enterprises to enhance confidence in irradiation technology. © 2012 Institute of Food Technologists®

  16. FGF1-gold nanoparticle conjugates targeting FGFR efficiently decrease cell viability upon NIR irradiation

    PubMed Central

    Szlachcic, Anna; Pala, Katarzyna; Zakrzewska, Malgorzata; Jakimowicz, Piotr; Wiedlocha, Antoni; Otlewski, Jacek

    2012-01-01

    Fibroblast growth factor receptors (FGFRs) are overexpressed in a wide variety of tumors, such as breast, bladder, and prostate cancer, and therefore they are attractive targets for different types of anticancer therapies. In this study, we designed, constructed, and characterized FGFR-targeted gold nanoconjugates suitable for infrared-induced thermal ablation (localized heating leading to cancer cell death) based on gold nanoparticles (AuNPs). We showed that a recombinant ligand of all FGFRs, human fibroblast growth factor 1 (FGF1), can be used as an agent targeting covalently bound AuNPs to cancer cells overexpressing FGFRs. To assure thermal stability, protease resistance, and prolonged half-life of the targeting protein, we employed highly stable FGF1 variant that retains the biological activities of the wild type FGF1. Novel FGF1 variant, AuNP conjugates are specifically internalized only by the cells expressing FGFRs, and they significantly reduce their viability after irradiation with near-infrared light (down to 40% of control cell viability), whereas the proliferation potential of cells lacking FGFRs is not affected. These results demonstrate the feasibility of FGF1-coated AuNPs for targeted cancer therapy. PMID:23226697

  17. Generation of soft x-ray radiation by laser irradiation of a gas puff xenon target

    SciTech Connect

    Fiedorowicz, H.; Bartnik, A.; Szczurek, M.

    1995-12-31

    Plasmas produced from laser-irradiated gas puff xenon targets, created by pulsed injection of xenon with high-pressure solenoid valve, offer the possibility of realizing a debrisless x-ray point source for the x-ray lithography applications. In this paper the authors present results of the experimental investigations on the x-ray generation from a gas puff xenon target irradiated with nanosecond high-power laser pulses produced using two different laser facilities: a Nd:glass laser operating at 1.06 {micro}m, which generated 10--15 J pulses in 1 ns FWHM, and Nd:glass slab laser, producing pulses of 10 ns duration with energy reaching 12 J for a 0.53 {micro}m wavelength or 20 J for 1.05 {micro}m. To study the x-ray emission different x-ray diagnostic methods have been used. X-ray spectra were registered using a flat CsAP crystal spectrograph with an x-ray film or a curved KAP crystal spectrograph with a convex curvature to an x-ray CCD readout detector. X-ray images have been taken using pinhole cameras with an x-ray film or a CCD array. X-ray yield was measured with the use of semiconductor detectors (silicon photodiodes or diamond photoconductors).

  18. Improvement of foaming ability of egg white product by irradiation and its application

    NASA Astrophysics Data System (ADS)

    Song, Hyun-Pa; Kim, Binna; Choe, Jun-Ho; Jung, Samooel; Kim, Kyong-Su; Kim, Dong-Ho; Jo, Cheorun

    2009-03-01

    To investigate the enhancement of foaming abilities of liquid egg white (LEW) and egg white powder (EWP) by irradiation and its application for bakery product, LEW and EWP were irradiated at 0, 1, 2, and 5 kGy by Co-60 gamma ray. There was no pH change found among treatments in both LEW and EWP. The viscosity of LEW decreased significantly by irradiation ( P<0.05), whereas that of EWP was not affected by irradiation. The foaming ability of LEW and EWP was significantly increased by irradiation as a dose-dependent manner ( P<0.05). The volume and the height of angel cake baked with irradiated LEW were significantly higher than those of unirradiated control ( P<0.05). For EWP, the volume and the height of angel cake were greater at 2 kGy only than those of control. A significant decrease in hardness, chewiness, and gumminess values and an increase in Hunter L* value were observed in the angel cakes prepared from irradiated egg white products ( P<0.05). Results indicated that irradiation of egg white could offer advantages in increasing foaming ability and improving quality of final bakery products.

  19. Improvement of shelf stability and processing properties of meat products by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Byun, Myung-Woo; Lee, Ju-Woon; Yook, Hong-Sun; Lee, Kyong-Haeng; Kim, Hee-Yun

    2002-03-01

    To evaluate the effects of gamma irradiation on the processing properties of meat products, emulsion-type sausage, beef patties and pork loin ham were manufactured. Most contaminated bacteria were killed by 3 kGy-irradiation to raw ground beef, and sausage can be manufactured with desirable flavor, a reduction of NaCl and phosphate, and extension of shelf life using gamma irradiation on the raw meat. The beef patties were manufactured with the addition of antioxidants (200 ppm), BHA, ascorbyl palmitate, α-tocopherol, or β-carotene, and gamma-irradiation. Retardation of lipid oxidation appeared at the patties with an antioxidant. A dose of 5 kGy was observed to be as effective as the use of 200 ppm NaNO 2 to provide and maintain the desired color of the product during storage. After curing, irradiation, heating and smoking could extensively prolong the shelf life of the hams.

  20. Industrial production of 131I by neutron irradiation and melting of sintered TeO2

    NASA Astrophysics Data System (ADS)

    Alanis, Jose; Navarrete, Manuel

    2001-07-01

    Optimal conditions of temperature and reaction rate have been settled to produce high purity TeO2 by the chemical reaction between Te and HNO3. Also, heating and time conditions for sintering this product have been found, in order to create cavities in the crystal inside, where a gaseous element such as iodine can be adsorbed with minimal leaking. In this way it is fabricated a suitable target to be irradiated with thermal neutrons for obtaining 131Te(t1/2=24.8 m) and 131mTe(t1/2=30 h) by (n, γ) nuclear reactions. Irradiation time has been chosen to get 131Te saturation activity (ti=150 m) because much longer irradiation times do not increase significantly total activity. Since parents 131Te and 131mTe have shorter half life than daughter 131I(t1/2=8.05 d) optimal cooling time must permit daughter activity to grow up till a maximum (tc=4d). Then, sintered cylinder shaped radioactive sample is manipulated in a hot cell, transported and put on a quartz tray, keeping Health Physics regulations. The quartz tray is inside a small electric oven enclosed in an airtight box with negative pressure (water 0.5 cm). There, it is gradually heated till melting point (733 °C). From 400 °C on, vapors are pumped out and bubbled in two solutions: one is 0.1 M NaOH, which retains nearly 99.9% of pumped 131I. Other is 0.02 M Na2CO3 (60%) plus 0.0025 M NaHCO3 (40%), which retains the remaining sample residue. Air filtering is accomplished by activated carbon and alumina filters in the inflow, glass wool fiber before bubbling, and activated carbon again in the outflow.

  1. 76 FR 20509 - Irradiation in the Production, Processing, and Handling of Food

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-13

    ... radiolytic products derived from proteins have the same chemical composition but are altered in their... toxicology studies of irradiated foods, including red meat, chicken, fish and eggs, which are available in...

  2. Progress report on the accelerator production of tritium materials irradiation program

    SciTech Connect

    Maloy, S.A.; Sommer, W.F.; Brown, R.D.; Roberts, J.E.

    1997-05-01

    The Accelerator Production of Tritium (APT) project is developing an accelerator and a spoliation neutron source capable of producing tritium through neutron capture on He-3. A high atomic weight target is used to produce neutrons that are then multiplied and moderated in a blanket prior to capture. Materials used in the target and blanket region of an APT facility will be subjected to several different and mixed particle radiation environments; high energy protons (1-2 GeV), protons in the 20 MeV range, high energy neutrons, and low energy neutrons, depending on position in the target and blanket. Flux levels exceed 10{sup 14}/cm{sup 2}s in some areas. The APT project is sponsoring an irradiation damage effects program that will generate the first data-base for materials exposed to high energy particles typical of spallation neutron sources. The program includes a number of candidate materials in small specimen and model component form and uses the Los Alamos Spallation Radiation Effects Facility (LASREF) at the 800 MeV, Los Alamos Neutron Science Center (LANSCE) accelerator.

  3. Using gamma spectrometry indicators to detect and quantify fission products changes in irradiated fuel

    SciTech Connect

    Loubet, L.; Martella, Th.

    2015-07-01

    A new analysis method based on gamma scanning of fission products on irradiated rods is presented. Indicators calculated from this method can be used for the qualitative treatment and comparison of irradiated rods from PWR, SFR or and MTR. Differences in the behavior of fission products (FP) can thus be quantified. Phenomena such as migration or geometrical changes in pellets should thus benefit from these accurate, yet quickly and easily achievable results. (authors)

  4. Improved hydrogen production in the microbial electrolysis cell by inhibiting methanogenesis using ultraviolet irradiation.

    PubMed

    Hou, Yanping; Luo, Haiping; Liu, Guangli; Zhang, Renduo; Li, Jiayi; Fu, Shiyu

    2014-09-02

    Methanogenesis inhibition is essential for the improvement of hydrogen (H2) yield and energy recovery in the microbial electrolysis cell (MEC). In this study, ultraviolet (UV) irradiation was proposed as an efficient method for methanogenesis control in a single chamber MEC. With 30 cycles of operation with UV irradiation in the MEC, high H2 concentrations (>91%) were maintained, while without UV irradiation, CH4 concentrations increased significantly and reached up to 94%. In the MEC, H2 yields ranged from 2.87 ± 0.03 to 3.70 ± 0.11 mol H2/mol acetate with UV irradiation and from 3.78 ± 0.12 to 0.03 ± 0.004 mol H2/mol acetate without UV irradiation. Average energy efficiencies from the UV-irradiated MEC were 1.5 times of those without UV irradiation. Energy production from the MEC without UV irradiation was a negative energy yield process because of large amount of CH4 produced over time, which was mainly attributable to cathodic hydrogenotrophic methanogenesis. Our results clearly showed that UV irradiation could effectively inhibit methanogenesis and improve MEC performance to produce H2.

  5. Reactive oxygen species production in mitochondria of human gingival fibroblast induced by blue light irradiation.

    PubMed

    Yoshida, Ayaka; Yoshino, Fumihiko; Makita, Tetsuya; Maehata, Yojiro; Higashi, Kazuyoshi; Miyamoto, Chihiro; Wada-Takahashi, Satoko; Takahashi, Shun-suke; Takahashi, Osamu; Lee, Masaichi Chang-il

    2013-12-05

    In recent years, it has become well known that the production of reactive oxygen species (ROS) induced by blue-light irradiation causes adverse effects of photo-aging, such as age-related macular degeneration of the retina. Thus, orange-tinted glasses are used to protect the retina during dental treatment involving blue-light irradiation (e.g., dental resin restorations or tooth bleaching treatments). However, there are few studies examining the effects of blue-light irradiation on oral tissue. For the first time, we report that blue-light irradiation by quartz tungsten halogen lamp (QTH) or light-emitting diode (LED) decreased cell proliferation activity of human gingival fibroblasts (HGFs) in a time-dependent manner (<5 min). Additionally, in a morphological study, the cytotoxic effect was observed in the cell organelles, especially the mitochondria. Furthermore, ROS generation induced by the blue-light irradiation was detected in mitochondria of HGFs using fluorimetry. In all analyses, the cytotoxicity was significantly higher after LED irradiation compared with cytotoxicity after QTH irradiation. These results suggest that blue light irradiation, especially by LED light sources used in dental aesthetic treatment, might have adverse effects on human gingival tissue. Hence, this necessitates the development of new dental aesthetic treatment methods and/or techniques to protect HGFs from blue light irradiation during dental therapy. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Global surface solar irradiance product derived from SCIAMACHY FRESCO cloud fraction

    NASA Astrophysics Data System (ADS)

    Wang, Ping; Stammes, Piet; Müller, Richard

    The FRESCO cloud retrieval algorithm has been developed as a simple but fast and efficient algorithm for GOME and SCIAMACHY (Koelemeijer et al., 2001; Fournier et al., 2006; Wang et al., 2008). FRESCO employs the O2 A band at 760 nm to retrieve the effective cloud fraction and cloud pressure using a simple Lambertian cloud model. The effective cloud fraction is a combination of geometric cloud fraction and cloud optical thickness, which yield the same reflectance at the top of the atmosphere as the cloud in the scene. It is well-known that clouds reduce the surface solar irradiance. Therefore the all-sky irradiance can be derived from the clear-sky irradiance with a scaling factor related to the cloud index. The cloud index is very similar to the effective cloud fraction by definition. The MAGIC (Mesoscale Atmospheric Global Irradiance Code) software converts the cloud index to the surface solar irradiance using the Heliosat method (Mueller et al. 2009). The MAGIC algorithm is also used by the CM-SAF surface solar irradiance product for clear sky cases. We applied the MAGIC software to FRESCO effective cloud fraction with slight modifications. In this presentation we will show the FRESCO-SSI monthly mean product and the comparison with the BSRN global irradiance data at Cabauw, the Netherlands and surface solar irradiance measurement at Tibetan plateau in China.

  7. Cyclotron production of Ga-68 for human use from liquid targets: From theory to practice

    NASA Astrophysics Data System (ADS)

    Alves, F.; Alves, V. H.; Neves, A. C. B.; do Carmo, S. J. C.; Nactergal, B.; Hellas, V.; Kral, E.; Gonçalves-Gameiro, C.; Abrunhosa, A. J.

    2017-05-01

    A fully automated system for the production of 68Ga based on commercially available cyclotron liquid target and synthesis modules is described. A solution containing enriched 68Zn dissolved in a nitric solution is irradiated in a Cyclone 18/9 IBA cyclotron leading to the production of up to about 25 GBq of 68Ga. The irradiated solution is transferred to a Synthera synthesis module in which 68Ga is separated and purified with a yield superior to 85 % and where further labelling is achieved with yields no inferior to 70 %. The developed and implemented method presents an improved approach for the production of 68Ga-radiopharmaceuticals suitable for human use, in a process that takes less than 2 hours. This technique represents an economically viable alternative to 68Ge/68Ga generators with improved characteristics.

  8. Forecasting Plant Productivity and Health Using Diffuse-to-Global Irradiance Ratios Extracted from the OMI Aerosol Product

    NASA Technical Reports Server (NTRS)

    Knowlton, Kelly; Andrews, Jane C.; Ryan, Robert E.

    2007-01-01

    Atmospheric aerosols are a major contributor to diffuse irradiance. This Candidate Solution suggests using the OMI (Ozone Monitoring Instrument) aerosol product as input into a radiative transfer model, which would calculate the ratio of diffuse to global irradiance at the Earth s surface. This ratio can significantly influence the rate of photosynthesis in plants; increasing the ratio of diffuse to global irradiance can accelerate photosynthesis, resulting in greater plant productivity. Accurate values of this ratio could be useful in predicting crop productivity, thereby improving forecasts of regional food resources. However, disagreements exist between diffuse-to-global irradiance values measured by different satellites and ground sensors. OMI, with its unique combination of spectral bands, high resolution, and daily global coverage, may be able to provide more accurate aerosol measurements than other comparable sensors.

  9. Feasibility study Part I - Thermal hydraulic analysis of LEU target for {sup 99}Mo production in Tajoura reactor

    SciTech Connect

    Bsebsu, F.M.; Abotweirat, F. E-mail: abutweirat@yahoo.com; Elwaer, S.

    2008-07-15

    The Renewable Energies and Water Desalination Research Center (REWDRC), Libya, will implement the technology for {sup 99}Mo isotope production using LEU foil target, to obtain new revenue streams for the Tajoura nuclear research reactor and desiring to serve the Libyan hospitals by providing the medical radioisotopes. Design information is presented for LEU target with irradiation device and irradiation Beryllium (Be) unit in the Tajoura reactor core. Calculated results for the reactor core with LEU target at different level of power are presented for steady state and several reactivity induced accident situations. This paper will present the steady state thermal hydraulic design and transient analysis of Tajoura reactor was loaded with LEU foil target for {sup 99}Mo production. The results of these calculations show that the reactor with LEU target during the several cases of transient are in safe and no problems will occur. (author)

  10. Gamma irradiation induced disintegration of waste activated sludge for biological hydrogen production

    NASA Astrophysics Data System (ADS)

    Yin, Yanan; Wang, Jianlong

    2016-04-01

    In this paper, gamma irradiation was applied for the disintegration and dissolution of waste activated sludge produced during the biological wastewater treatment, and the solubilized sludge was used as substrate for bio-hydrogen production. The experimental results showed that the solubilization of waste activated sludge was 53.7% at 20 kGy and pH=12, and the SCOD, polysaccharides, protein, TN and TP contents in the irradiated sludge solutions was 3789.6 mg/L, 268.3 mg/L, 1881.5 mg/L, 132.3 mg/L and 80.4 mg/L, respectively. The irradiated sludge was used for fermentative hydrogen production, and the hydrogen yield was 10.5±0.7 mL/g SCODconsumed. It can be concluded that the irradiated waste activated sludge could be used as a low-cost substrate for fermentative hydrogen production.

  11. Design and Demonstration of a Material-Plasma Exposure Target Station for Neutron Irradiated Samples

    SciTech Connect

    Rapp, Juergen; Aaron, A. M.; Bell, Gary L.; Burgess, Thomas W.; Ellis, Ronald James; Giuliano, D.; Howard, R.; Kiggans, James O.; Lessard, Timothy L.; Ohriner, Evan Keith; Perkins, Dale E.; Varma, Venugopal Koikal

    2015-10-20

    Fusion energy is the most promising energy source for the future, and one of the most important problems to be solved progressing to a commercial fusion reactor is the identification of plasma-facing materials compatible with the extreme conditions in the fusion reactor environment. The development of plasma–material interaction (PMI) science and the technology of plasma-facing components are key elements in the development of the next step fusion device in the United States, the so-called Fusion Nuclear Science Facility (FNSF). All of these PMI issues and the uncertain impact of the 14-MeV neutron irradiation have been identified in numerous expert panel reports to the fusion community. The 2007 Greenwald report classifies reactor plasma-facing materials (PFCs) and materials as the only Tier 1 issues, requiring a “. . . major extrapolation from the current state of knowledge, need for qualitative improvements and substantial development for both the short and long term.” The Greenwald report goes on to list 19 gaps in understanding and performance related to the plasma–material interface for the technology facilities needed for DEMO-oriented R&D and DEMO itself. Of the 15 major gaps, six (G7, G9, G10, G12, G13) can possibly be addressed with ORNL’s proposal of an advanced Material Plasma Exposure eXperiment. Establishing this mid-scale plasma materials test facility at ORNL is a key element in ORNL’s strategy to secure a leadership role for decades of fusion R&D. That is to say, our end goal is to bring the “signature facility” FNSF home to ORNL. This project is related to the pre-conceptual design of an innovative target station for a future Material–Plasma Exposure eXperiment (MPEX). The target station will be designed to expose candidate fusion reactor plasma-facing materials and components (PFMs and PFCs) to conditions anticipated in fusion reactors, where PFCs will be exposed to dense high-temperature hydrogen plasmas providing steady

  12. Chemical isolation of .sup.82 Sr from proton-irradiated Mo targets

    DOEpatents

    Grant, Patrick M.; Kahn, Milton; O'Brien, Jr., Harold A.

    1976-01-01

    Spallation reactions are induced in Mo targets with 200-800 MeV protons to produce microcurie to millicurie amounts of a variety of radionuclides. A six-step radiochemical procedure, incorporating precipitation, solvent extractions, and ion exchange techniques, has been developed for the separation and purification of Sr radioactivities from other spallation products and the bulk target material. Radiostrontium can be quantitatively recovered in a sufficiently decontaminated state for use in biomedical generator development.

  13. Neutron-rich isotope production using a uranium carbide - carbon nanotubes SPES target prototype

    NASA Astrophysics Data System (ADS)

    Corradetti, S.; Biasetto, L.; Manzolaro, M.; Scarpa, D.; Carturan, S.; Andrighetto, A.; Prete, G.; Vasquez, J.; Zanonato, P.; Colombo, P.; Jost, C. U.; Stracener, D. W.

    2013-05-01

    The SPES (Selective Production of Exotic Species) project, under development at the Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Legnaro (INFN-LNL), is a new-generation Isotope Separation On-Line (ISOL) facility for the production of radioactive ion beams by means of the proton-induced fission of uranium. In the framework of the research on the SPES target, seven uranium carbide discs, obtained by reacting uranium oxide with graphite and carbon nanotubes, were irradiated with protons at the Holifield Radioactive Ion Beam Facility (HRIBF) of Oak Ridge National Laboratory (ORNL). In the following, the yields of several fission products obtained during the experiment are presented and discussed. The experimental results are then compared to those obtained using a standard uranium carbide target. The reported data highlights the capability of the new type of SPES target to produce and release isotopes of interest for the nuclear physics community.

  14. Laser irradiation of disk targets at 0. 53. mu. m wavelength

    SciTech Connect

    Mead, W.C.; Campbell, E.M.; Estabrook, K.G.

    1981-01-26

    We present results and analysis for laser-irradiations of Be, CH, Ti, and Au disk targets with 0.53 ..mu..m light in 3 to 35 J, 600 ps pulses, at nominal intensities from 3 x 10/sup 13/ to approx. 4 x 10/sup 15/ W/cm/sup 2/. The measured absorptions are higher than observed in similar 1.06 ..mu..m irradiations, and are largely consistent with modeling which shows the importance of inverse bremsstrahlung and Brillouin scattering. Observed red-shifted back-reflected light shows that Brillouin is operating at low to moderate levels. The measured fluxes of multi-keV x-rays indicate low hot-electron fractions, with temperatures which are consistent with resonance absorption. Measurements show efficient conversion of absorbed light into sub-keV x-rays, with time-, angular-, and spatial-emission distributions which are generally consistent with non-LTE modeling using inhibited thermal electron transport.

  15. High levels of reactive oxygen species in gold nanoparticle-targeted cancer cells following femtosecond pulse irradiation

    NASA Astrophysics Data System (ADS)

    Minai, Limor; Yeheskely-Hayon, Daniella; Yelin, Dvir

    2013-07-01

    Cancer cells could be locally damaged using specifically targeted gold nanoparticles and laser pulse irradiation, while maintaining minimum damage to nearby, particle-free tissue. Here, we show that in addition to the immediate photothermal cell damage, high concentrations of reactive oxygen species (ROS) are formed within the irradiated cells. Burkitt lymphoma B cells and epithelial breast cancer cells were targeted by antibody-coated gold nanospheres and irradiated by a few resonant femtosecond pulses, resulting in significant elevation of intracellular ROS which was characterized and quantified using time-lapse microscopy of different fluorescent markers. The results suggest that techniques that involve targeting of various malignancies using gold nanoparticles and ultrashort pulses may be more effective and versatile than previously anticipated, allowing diverse, highly specific set of tools for local cancer therapy.

  16. Durability of targets and foils irradiated by intense heavy ion beams in experiments on synthesis of superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Sagaidak, R. N.

    2017-09-01

    Durability of targets and window foils irradiated by intense heavy ion (HI) beams in the experiments on synthesis of superheavy nuclei, which are carried out in Dubna with Gas-Filled Recoil Separator (DGFRS), has been viewed in various ways. High fluxes of HI and heat generations, which are realized within relatively small areas and thicknesses of these elements of DGFRS, are inherent in such experiments. The lifetimes of the targets and window foils are estimated as the result of HI beam actions such as radiation damages, sputtering and evaporation of atoms. The most critical processes determining the durability of the targets and window foils are discussed. The processes of heat transfer due to thermal conductivity, convection and radiation are also considered from the point of view of possible ways of cooling of the elements irradiated by an intense HI beam. Temperatures of the targets and window foils as functions of time are calculated in the conditions of their pulse heating by the beam followed by radiative cooling of their surfaces. Such pulsing mode is realized in the DGFRS operation with the rotation of target and window foils irradiated by a continuous HI beam. Estimates show that radiative cooling in such conditions can be the most effective way of heat removal at the temperature of several hundred degrees. Such temperature can be reached on the surfaces of the target and window foils irradiated by HI beams at the intensity 1013 s-1.

  17. Targeting Pro-Apoptotic TRAIL Receptors Sensitizes HeLa Cervical Cancer Cells to Irradiation-Induced Apoptosis

    SciTech Connect

    Maduro, John H.; Vries, Elisabeth de; Meersma, Gert-Jan; Hougardy, Brigitte; Zee, Ate G.J. van der; Jong, Steven de

    2008-10-01

    Purpose: To investigate the potential of irradiation in combination with drugs targeting the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) death receptor (DR)4 and DR5 and their mechanism of action in a cervical cancer cell line. Methods and Materials: Recombinant human TRAIL (rhTRAIL) and the agonistic antibodies against DR4 and DR5 were added to irradiated HeLa cells. The effect was evaluated with apoptosis and cytotoxicity assays and at the protein level. Membrane receptor expression was measured with flow cytometry. Small-interfering RNA against p53, DR4, and DR5 was used to investigate their function on the combined effect. Results: rhTRAIL and the agonistic DR4 and DR5 antibodies strongly enhanced 10-Gy-induced apoptosis. This extra effect was 22%, 23%, and 29% for rhTRAIL, DR4, and DR5, respectively. Irradiation increased p53 expression and increased the membrane expression of DR5 and DR4. p53 suppression, as well as small-interfering RNA against DR5, resulted in a significant downregulation of DR5 membrane expression but did not affect apoptosis induced by irradiation and rhTRAIL. After small-interfering RNA against DR4, rhTRAIL-induced apoptosis and the additive effect of irradiation on rhTRAIL-induced apoptosis were abrogated, implicating an important role for DR4 in apoptosis induced through irradiation in combination with rhTRAIL. Conclusion: Irradiation-induced apoptosis is strongly enhanced by targeting the pro-apoptotic TRAIL receptors DR4 or DR5. Irradiation results in a p53-dependent increase in DR5 membrane expression. The sensitizing effect of rhTRAIL on irradiation in the HeLa cell line is, however especially mediated through the DR4 receptor.

  18. Positron generation via two sequent laser pulses irradiating a solid aluminum target

    NASA Astrophysics Data System (ADS)

    Liu, Jian-Xun; Gan, Long-Fei; Ma, Yan-Yun; Zhao, Jun; Yang, Xiao-Hu; Yu, Tong-Pu; Zhuo, Hong-Bin; Shao, Fu-Qiu

    2017-08-01

    A scheme of two sequent laser pulses irradiating a thin solid aluminum target to generate electron-positron pairs via the multi-photon Breit-Wheeler (BW) process is proposed, in order to ease the usual requirement of the laser intensity. 2D and 3D particle-in-cell simulations show that the peak intensity of the laser pulses used in our scheme is only half of that in the case of one laser pulse with a peak intensity of 2 × 1023 W/cm2, but the positron yield is one order higher than that of the latter, which is around 3.7894 × 107 and has a maximal density of 3.134 × 1022 cm-3 when the time interval between the two pulses is set to Δt ≈ 2T0. Therefore, our scheme provides a helpful suggestion for the observation of the BW process in laboratories.

  19. Present status of the liquid lithium target facility in the international fusion materials irradiation facility (IFMIF)

    NASA Astrophysics Data System (ADS)

    Nakamura, Hiroo; Riccardi, B.; Loginov, N.; Ara, K.; Burgazzi, L.; Cevolani, S.; Dell'Orco, G.; Fazio, C.; Giusti, D.; Horiike, H.; Ida, M.; Ise, H.; Kakui, H.; Matsui, H.; Micciche, G.; Muroga, T.; Nakamura, Hideo; Shimizu, K.; Sugimoto, M.; Suzuki, A.; Takeuchi, H.; Tanaka, S.; Yoneoka, T.

    2004-08-01

    During the three year key element technology phase of the International Fusion Materials Irradiation Facility (IFMIF) project, completed at the end of 2002, key technologies have been validated. In this paper, these results are summarized. A water jet experiment simulating Li flow validated stable flow up to 20 m/s with a double reducer nozzle. In addition, a small Li loop experiment validated stable Li flow up to 14 m/s. To control the nitrogen content in Li below 10 wppm will require surface area of a V-Ti alloy getter of 135 m 2. Conceptual designs of diagnostics have been carried out. Moreover, the concept of a remote handling system to replace the back wall based on `cut and reweld' and `bayonet' options has been established. Analysis by FMEA showed safe operation of the target system. Recent activities in the transition phase, started in 2003, and plan for the next phase are also described.

  20. Systems and methods for managing shared-path instrumentation and irradiation targets in a nuclear reactor

    DOEpatents

    Heinold, Mark R.; Berger, John F.; Loper, Milton H.; Runkle, Gary A.

    2015-12-29

    Systems and methods permit discriminate access to nuclear reactors. Systems provide penetration pathways to irradiation target loading and offloading systems, instrumentation systems, and other external systems at desired times, while limiting such access during undesired times. Systems use selection mechanisms that can be strategically positioned for space sharing to connect only desired systems to a reactor. Selection mechanisms include distinct paths, forks, diverters, turntables, and other types of selectors. Management methods with such systems permits use of the nuclear reactor and penetration pathways between different systems and functions, simultaneously and at only distinct desired times. Existing TIP drives and other known instrumentation and plant systems are useable with access management systems and methods, which can be used in any nuclear plant with access restrictions.

  1. Measurements of the divergence of fast electrons in laser-irradiated spherical targets

    NASA Astrophysics Data System (ADS)

    Yaakobi, B.; Solodov, A. A.; Myatt, J. F.; Delettrez, J. A.; Stoeckl, C.; Froula, D. H.

    2013-09-01

    In recent experiments using directly driven spherical targets on the OMEGA laser system, the energy in fast electrons was found to reach ˜1% of the laser energy at an irradiance of ˜1.1 × 1015 W/cm2. The fraction of these fast electrons absorbed in the compressed fuel shell depends on their angular divergence. This paper describes measurements of this divergence deduced from a series of shots where Mo-coated shells of increasing diameter (D) were suspended within an outer CH shell. The intensity of the Mo-Kα line and the hard x-ray radiation were found to increase approximately as ˜D2, indicating wide divergence of the fast electrons. Alternative interpretations of these results (electron scattering, radiation excitation of Kα, and an electric field due to return current) are shown to be unimportant.

  2. Systems and methods for retaining and removing irradiation targets in a nuclear reactor

    SciTech Connect

    Runkle, Gary A.; Matsumoto, Jack T.; Dayal, Yogeshwar; Heinold, Mark R.

    2015-12-08

    A retainer is placed on a conduit to control movement of objects within the conduit in access-restricted areas. Retainers can prevent or allow movement in the conduit in a discriminatory fashion. A fork with variable-spacing between prongs can be a retainer and be extended or collapsed with respect to the conduit to change the size of the conduit. Different objects of different sizes may thus react to the fork differently, some passing and some being blocked. Retainers can be installed in inaccessible areas and allow selective movement in remote portions of conduit where users cannot directly interface, including below nuclear reactors. Position detectors can monitor the movement of objects through the conduit remotely as well, permitting engagement of a desired level of restriction and object movement. Retainers are useable in a variety of nuclear power plants and with irradiation target delivery, harvesting, driving, and other remote handling or robotic systems.

  3. Mechanisms of volatile production from sulfur-containing amino acids by irradiation

    NASA Astrophysics Data System (ADS)

    Uk Ahn, Dong; Joo Lee, Eun; Feng, Xi; Zhang, Wangang; Lee, Ji Hwan; Jo, Cheorun; Nam, Kichang

    2016-02-01

    Sulfur-containing amino acids were used to study the mechanisms of off-odor production in meat by irradiation. Irradiation not only increased the amounts of volatiles but also produced many new volatiles from sulfur-containing amino acid monomers. We speculate that the majority of the volatiles were the direct radiolytic products of the side chains, but Strecker degradation as well as deamination and decarboxylation of radiolytic products were also involved in the production of volatile compounds from sulfur amino acids. The volatile compounds produced in amino acids were not only the primary products of irradiation, but also the products of secondary chemical reactions after the primary compounds were produced. Cysteine and methionine produced odor characteristics similar to that of the irradiated meat, but the amounts of sulfur volatiles from methionine were far greater than that of cysteine. Although the present study was carried out using an amino acid model system, the information can be applied to the quality indexes of irradiated meats as well as other food products.

  4. Processing of LEU targets for {sup 99}Mo production -- Demonstration of a modified Cintichem process

    SciTech Connect

    Aliludin, Z.; Mutalib, A.; Sukmana, A.; Kadarisman; Gunawan, A.H.; Vandegrift, G.F.; Wu, D.; Srinivasan, B.; Snelgrove, J.L.

    1995-09-01

    Two demonstrations of the use of the Cintichem process on simulated low enriched uranium (LEU, < 20% {sup 235}U) targets were run by personnel in the BATAN Isotope Production Facilities at PUSPIPTEK (Serpong, Indonesia). These demonstrations were done using a solution of either natural or depleted uranium spiked with irradiated high enriched uranium (HEU). The activity levels were low enough to perform the process in a fume hood. The volumes, equipment, and procedures used were the same as those used in the actual processing of irradiated HEU targets in a shielded cell. These results, when combined with data obtained at the University of Illinois and Argonne National Laboratory, show that substitution of LEU for HEU is possible for the Cintichem process, perhaps, with no modification.

  5. Beauty and charm production at fixed-target experiments

    SciTech Connect

    Erik E. Gottschalk

    2003-12-10

    Fixed-target experiments continue to provide insights into the physics of particle production in strong interactions. The experiments are performed with different types of beam particles of varying energies, and many different target materials. Studies of beauty and charm production are of particular interest, since experimental results can be compared to perturbative QCD calculations. It is in this context that recent results from fixed-target experiments on beauty and charm production will be reviewed.

  6. Improvement of color and physiological properties of tuna-processing by-product by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Choi, Jong-il; Kim, Hyun-Joo; Kim, Jae-Hun; Song, Beom-Seok; Chun, Byeong-Soo; Ahn, Dong-Hyun; Byun, Myung-Woo; Lee, Ju-Woon

    2009-07-01

    Although the by-products from fishery industry had many nutrients, it is being wasted or only used as bacteria media. In this study, the effect of a gamma irradiation on the cooking drips of Thunnus thynnus (CDT) was investigated to examine the possible use of the cooking drips as a functional material for food and cosmetic composition. Total aerobic bacteria, and yeasts/molds from CDT were detected at the level of 2.79 and 2.58 Log CFU/mL, respectively. But, CDT was efficiently sterilized by a gamma irradiation at a low dose of 1 kGy. The Hunter L* value of the gamma-irradiated ethanol extract of CDT was increased, and the a* and b* values were decreased compared to the non-irradiated extract, showing color improvement. Antioxidant activity of the ethanol extract of CDT was increased by a gamma irradiation depending on the irradiation dose. The increased contents of polyphenolic compounds and proteins in CDT extract by gamma irradiation may be the reason of the increased biological activity. These results suggested that the wasted cooking drips can be successfully used as functional components with gamma irradiation treatment.

  7. Infectivity and egg production of Nematospiroides dubius as affected by space flight and ultraviolet irradiation

    NASA Technical Reports Server (NTRS)

    Long, R. A.; Ellis, W. L.; Taylor, G. R.

    1973-01-01

    Nematospiroides dubius was tested to determine the infective potential of the third stage larvae and the egg-production and egg-viability rates of the resulting adults after they are exposed to space flight and solar ultraviolet irradiation. The results are indicative that space-flown larvae exposed to solar ultraviolet irradiation were rendered noninfective in C57 mice, whereas flight control larvae that received no solar ultraviolet irradiation matured at the same rate as the ground control larvae. However, depressed egg viability was evident in the flight control larvae.

  8. Irradiation and fumigation effects on flavor, aroma and composition of grapefruit products

    SciTech Connect

    Moshonas, M.G.; Shaw, P.E.

    1982-05-01

    Effects were evaluated on grapefruit treated to meet quarantine restrictions against Caribbean fruit fly infestation. Differences were found in flavor of fresh sections, fresh juice, and aroma of peel oil when obtained from fruit irradiated with x-rays, as compared with products from nonirradiated fruit. Flavor differences were found in all pasteurized juices from fruit irradiated at 50-60 krad. Vitamin C levels were significantly lower in juice from most irradiated fruit. Flavor differences were found in fresh and pasteurized juice from fruit treated with methyl bromide, and in pasteurized juice from fruit treated with ethylene dibromide. Aroma differences were found in peel oil from fruit treated with phosphine.

  9. Infectivity and egg production of Nematospiroides dubius as affected by space flight and ultraviolet irradiation

    NASA Technical Reports Server (NTRS)

    Long, R. A.; Ellis, W. L.; Taylor, G. R.

    1973-01-01

    Nematospiroides dubius was tested to determine the infective potential of the third stage larvae and the egg-production and egg-viability rates of the resulting adults after they are exposed to space flight and solar ultraviolet irradiation. The results are indicative that space-flown larvae exposed to solar ultraviolet irradiation were rendered noninfective in C57 mice, whereas flight control larvae that received no solar ultraviolet irradiation matured at the same rate as the ground control larvae. However, depressed egg viability was evident in the flight control larvae.

  10. High-flux low-divergence positron beam generation from ultra-intense laser irradiated a tapered hollow target

    SciTech Connect

    Liu, Jian-Xun; Ma, Yan-Yun; Zhao, Jun; Yu, Tong-Pu Yang, Xiao-Hu; Gan, Long-Fei; Zhang, Guo-Bo; Yan, Jian-Feng; Zhuo, Hong-Bin; Liu, Jin-Jin; Zhao, Yuan; Kawata, Shigeo

    2015-10-15

    By using two-dimensional particle-in-cell simulations, we demonstrate high-flux dense positrons generation by irradiating an ultra-intense laser pulse onto a tapered hollow target. By using a laser with an intensity of 4 × 10{sup 23 }W/cm{sup 2}, it is shown that the Breit-Wheeler process dominates the positron production during the laser-target interaction and a positron beam with a total number >10{sup 15} is obtained, which is increased by five orders of magnitude than in the previous work at the same laser intensity. Due to the focusing effect of the transverse electric fields formed in the hollow cone wall, the divergence angle of the positron beam effectively decreases to ∼15° with an effective temperature of ∼674 MeV. When the laser intensity is doubled, both the positron flux (>10{sup 16}) and temperature (963 MeV) increase, while the divergence angle gets smaller (∼13°). The obtained high-flux low-divergence positron beam may have diverse applications in science, medicine, and engineering.

  11. Primordial comet mantle - Irradiation production of a stable, organic crust

    SciTech Connect

    Strazzulla, G.; Baratta, G.A.; Johnson, R.E.; Donn, B. Osservatorio Astrofisico, Catania Virginia, University, Charlottesville )

    1991-05-01

    The thickness and survivability of a cosmic ray-generated primordial comet refractory mantle, or 'crust', are presently predicted by laboratory data and corrected estimates of cosmic ray dose to be capable of surviving a new comet's entry into the inner solar system over numerous revolutions. It is suggested that, since this mantle may be as much as several meters deep, the probe apparatus of the projected CRAF and Rosetta spacecraft will have to be extended in order to reach the desired, unprocessed cometary material. As things stand, there is a high probability that these missions will sample cometary matter than has been heavily irradiated and reprocessed in the Oort cloud. 28 refs.

  12. Primordial comet mantle - Irradiation production of a stable, organic crust

    NASA Technical Reports Server (NTRS)

    Strazzulla, G.; Baratta, G. A.; Johnson, R. E.; Donn, B.

    1991-01-01

    The thickness and survivability of a cosmic ray-generated primordial comet refractory mantle, or 'crust', are presently predicted by laboratory data and corrected estimates of cosmic ray dose to be capable of surviving a new comet's entry into the inner solar system over numerous revolutions. It is suggested that, since this mantle may be as much as several meters deep, the probe apparatus of the projected CRAF and Rosetta spacecraft will have to be extended in order to reach the desired, unprocessed cometary material. As things stand, there is a high probability that these missions will sample cometary matter than has been heavily irradiated and reprocessed in the Oort cloud.

  13. Biohydrogen production by purple non-sulfur bacteria Rhodobacter sphaeroides: Effect of low-intensity electromagnetic irradiation.

    PubMed

    Gabrielyan, Lilit; Sargsyan, Harutyun; Trchounian, Armen

    2016-09-01

    The present work was focused on the effects of low-intensity (the flux capacity was of 0.06mWcm(-2)) electromagnetic irradiation (EMI) of extremely high frequencies or millimeter waves on the growth and hydrogen (H2) photoproduction by purple non-sulfur bacteria Rhodobacter sphaeroides MDC6521 (from Armenian mineral springs). After exposure of R. sphaeroides, grown under anaerobic conditions upon illumination, to EMI (51.8GHz and 53.0GHz) for 15min an increase of specific growth rate by ~1.2-fold, in comparison with control (non-irradiated cells), was obtained. However, the effect of EMI depends on the duration of irradiation: the exposure elongation up to 60min caused the delay of the growth lag phase and the decrease specific growth rate by ~1.3-fold, indicating the bactericidal effect of EMI. H2 yield of the culture, irradiated by EMI for 15min, determined during 72h growth, was ~1.2-fold higher than H2 yield of control cells, whereas H2 production by cultures, irradiated by EMI for 60min was not observed during 72h growth. This difference in the effects of extremely high frequency EMI indicates a direct effect of radiation on the membrane transfer and the enzymes of these bacteria. Moreover, EMI increased DCCD-inhibited H(+) fluxes across the bacterial membrane and DCCD-sensitive ATPase activity of membrane vesicles, indicating that the proton FoF1-ATPase is presumably a basic target for extremely high frequency EMI related to H2 production by cultures. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Visualization experiment of 30 MeV proton beam irradiated water target

    NASA Astrophysics Data System (ADS)

    Hwan Hong, Bong; Gun Yang, Tea; Su Jung, In; Soo Park, Yeun; Hee Cho, Hyung

    2011-11-01

    The nucleate boiling phenomena in a water target irradiated by 30 MeV proton beam were visualized experimentally. The beam size was 10 mm in diameter and beam current of 10, 15 and 20 μA were used, respectively. A target cavity of 4.5 cc in volume was filled with distilled water without atmosphere. A CMOS camera is used to record the phenomena through a side window. The temperature and pressure were measured during experiments. The depth of the Bragg peak was indicated by the blue light emission of the proton beam in the water target. In the case of 10 μA beam intensity, there was no visible phase change but fluxes by convection was observed at the Bragg peak and near the foil surface region. At 15 μA beam intensity, steam bubbles were generated by homogenous nuclear boiling at the Bragg peak and corrupted by cavitation at the upper region. The steam bubble generation point can be indicated by the blue light emission, which can show us the position of the Bragg peak. At 20 μΑ beam intensity, the steam bubbles were generated at Bragg peak and near the foil surface. The homogenous nucleate boiling at the Bragg peak was dominant and the heterogeneous nucleate boiling near the foil surface took place, occasionally. The cavitation of the steam bubble was also observed in the upper region within the target. The penetration depth of the proton beam was change along with the steam bubble formation. The blue light emission of the proton beam in water shows that the penetration depth of the proton beam becomes deeper when vapor bubbles are generated.

  15. Efficiency of gamma irradiation to inactivate growth and fumonisin production of Fusarium moniliforme on corn grains.

    PubMed

    Mansur, Ahmad Rois; Yu, Chun-Cheol; Oh, Deog-Hwan

    2014-02-28

    The efficiency of gamma irradiation (0, 1, 5, 10, 15, 20, and 30 kGy) as a sterilization method of corn samples (30 g) artificially contaminated with Fusarium moniliforme stored at normal condition (25ºC with approximate relative humidity (RH) of 55%) and optimal condition (25ºC with a controlled RH of 97%) was studied. The results showed that the fungal growth and the amount of fumonisin were decreased as the dose of gamma irradiation increased. Gamma irradiation at 1-5 kGy treatment significantly inhibited the growth of F. moniliforme by 1-2 log reduction on corn samples (P < 0.05). Sublethal effect of gamma irradiation was observed at 10-20 kGy doses after storage, and a complete inactivation required 30 kGy. Fungal growth and fumonisin production increased with higher humidity and longer storage time in all corn samples. This study also demonstrated that there was no strict correlation between fungal growth and fumonisin production. Storage at normal condition significantly resulted in lower growth and fumonisin production of F. moniliforme as compared with those stored at optimal condition (P < 0.05). Gamma irradiation with the dose of ≥ 5 kGy followed by storage at normal condition successfully prolonged the shelf life of irradiated corns, intended for human and animal consumptions, up to 7 weeks.

  16. Characterization of MeV proton acceleration from double pulse irradiation of foil targets

    NASA Astrophysics Data System (ADS)

    Kerr, S.; Mo, M. Z.; Masud, R.; Tiedje, H. F.; Tsui, Y.; Fedosejevs, R.; Link, A.; Patel, P.; McLean, H. S.; Hazi, A.; Chen, H.; Ceurvorst, L.; Norreys, P.

    2014-10-01

    We report on the experimental characterization of proton acceleration from double-pulse irradiation of um-scale foil targets. Temporally separated sub-picosecond pulses have been shown to increase the conversion efficiency of laser energy to MeV protons. Here, two 700 fs, 1 ω pulses were separated by 1 to 5 ps; total beam energy was 100 J, with 5-20% of the total energy contained within the first pulse. In contrast to the ultraclean beams used in previous experiments, prepulse energies on the order of 10 mJ were present in the current experiments which appear to have a moderating effect on the enhancement. Proton beam measurements were made with radiochromic film stacks, as well as magnetic spectrometers. The effect on electron generation was measured using Kα emission from buried Cu tracer layers, while specular light diagnostics (FROG, reflection spectralon) indicated the laser coupling efficiency into the target. The results obtained will be presented and compared to PIC simulations. Work by LLNL was performed under the auspices of U.S. DOE under contract DE-AC52-07NA27344.

  17. Productive steps toward an antimicrobial targeting virulence

    PubMed Central

    Barczak, Amy K.; Hung, Deborah T.

    2009-01-01

    Summary Targeting virulence factors has gained increasing attention as a potential approach to new antibiotics. Small molecule inhibitors of virulence have been shown to change the course of disease in whole organism infection models. Recently, key advances in the field include the identification of novel targets within cell signaling pathways, a new class of anti-virulence compounds that target bacterial defenses against host immunity, and a growing body of in vivo data to support the general approach of anti-virulence therapies. Additionally, there has been a distinct trend toward developing broader spectrum anti-virulence compounds, in particular agents with activity against diverse Gram-negative organisms. Herein we provide an update on the status of the field with a focus on recent advancements. PMID:19631578

  18. Effect of gamma irradiation on physical characteristics of Jordanian durum wheat and quality of semolina and lasagna products

    NASA Astrophysics Data System (ADS)

    Azzeh, F. S.; Amr, A. S.

    2009-09-01

    This study was conducted to determine the effect of using varying gamma irradiation doses on the physiochemical and rheological properties of semolina and its products. Ash, protein and water content were not influenced with gamma irradiation, while falling number and fungi counts decreased with increasing irradiation dose. Irradiation adversely affected wet gluten at 5 kGy dose. Dough stability was deteriorated vigorously with increasing irradiation dose. Sensory evaluation showed that lasagna produced from 0.25- and 1 kGy-irradiated semolina did not show any significant differences as compared with the control sample.

  19. Enhanced X-ray emission from laser-produced gold plasma by double pulses irradiation of nano-porous targets

    NASA Astrophysics Data System (ADS)

    Fazeli, R.

    2017-02-01

    Enhancement of the soft X-ray emission including free-free, free-bound and bound-bound emissions from Au nano-porous targets irradiated by single and double laser pulses is studied through numerical simulations. Laser pulses of duration 2 ns are used in calculations considering different prepulse intensities and a fixed intensity of 1013 Wcm-2 for the main pulse. The effects of prepulse intensity and time separation between laser pulses are studied for targets of different porosities. Results show that the X-ray yield can be enhanced significantly by a nano-porous target having optimum initial density. Such enhancement can be more improved when double laser pulses with appropriate delay time and intensities irradiate nano-porous targets. It is shown that the enhancement will be reduced when the prepulse intensity is greater than a specific value.

  20. Target irradiation facility and targetry development at 160 MeV proton beam of Moscow linac

    NASA Astrophysics Data System (ADS)

    Zhuikov, Boris L.; Kokhanyuk, Vladimir M.; Konyakhin, Nickolay A.; Vincent, John

    1999-12-01

    A facility has been built and successfully operated with the 160 MeV proton beam of Moscow Meson factory LINAC, Institute for Nuclear Research (INR) of Russian Academy of Science, Troitsk. The facility was created for various isotope production goals as well as for fundamental nuclear investigations at high intensity beam (100 μA and more). An important part of the facility targetry system is a high-intensity beam monitoring collimator device. Measurements of the temperature distribution between collimator sectors, cooling water flow and temperature, and the beam current, provide an opportunity to compute beam losses and beam position. The target holder design allows easy insertion by manipulator and simultaneous bombardment of several different targets of various types and forms, and variation of proton energy on each target over a wide range below 160 MeV. The main target utilized for commercial 82Sr isotope production is metallic rubidium in a stainless-steel container. A regular wet chemistry method has been used in this process to recover radio-strontium. A new targetry technique based on adsorption of radio-strontium from liquid metallic rubidium has been explored and is under development. It was found that strontium may be extracted from molten rubidium on several metallic or oxide flat surfaces, with the temperature of the sorbing material about 130-170°C, and the temperature of the vessel with metallic rubidium about 240-270°C. This makes it possible to provide "on-line" 82Sr production and extraction on a very high intensity beam with the use of circulating liquid rubidium targets. The same idea has been found to be fruitful to extract "on-line" and selectively a number of radionuclides directly from liquid lead targets by chemosorption processes.

  1. EFFECTS OF LASER RADIATION ON MATTER: Simulation of photon acceleration upon irradiation of a mylar target by femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Andreev, Stepan N.; Rukhadze, Anri A.; Tarakanov, V. P.; Yakutov, B. P.

    2010-01-01

    Acceleration of protons is simulated by the particle-in-cell (PIC) method upon irradiation of mylar targets of different thicknesses by femtosecond plane-polarised pulsed laser radiation and at different angles of radiation incidence on the target. The comparison of the results of calculations with the experimental data obtained in recent experiments shows their good agreement. The optimal angle of incidence (458) at which the proton energy achieves its absolute maximum is obtained.

  2. Operational high latitude surface irradiance products from polar orbiting satellites

    NASA Astrophysics Data System (ADS)

    Godøy, Øystein

    2016-12-01

    It remains a challenge to find an adequate approach for operational estimation of surface incoming short- and longwave irradiance at high latitudes using polar orbiting meteorological satellite data. In this presentation validation results at a number of North Atlantic and Arctic Ocean high latitude stations are presented and discussed. The validation results have revealed that although the method works well and normally fulfil the operational requirements, there is room for improvement. A number of issues that can improve the estimates at high latitudes have been identified. These improvements are partly related to improved cloud classification using satellite data and partly related to improved handling of multiple reflections over bright surfaces (snow and sea ice), especially in broken cloud conditions. Furthermore, the availability of validation sites over open ocean and sea ice is a challenge.

  3. Measurements of X-ray doses and spectra produced by picosecond laser-irradiated solid targets.

    PubMed

    Yang, Bo; Qiu, Rui; Yu, Minghai; Jiao, Jinlong; Lu, Wei; Yan, Yonghong; Zhang, Bo; Zhang, Zhimeng; Zhou, Weimin; Li, Junli; Zhang, Hui

    2017-05-01

    Experiments have shown that high-intensity laser interaction with a solid target can generate significant X-ray doses. This study was conducted to determine the X-ray doses and spectra produced for picosecond laser-irradiated solid targets. The photon doses and X-ray spectra in the laser forward and side directions were measured using an XG III ps 300 TW laser system. For laser intensities of 7×10(18)-4×10(19)W/cm(2), the maximum photon dose was 16.8 mSv at 50cm with a laser energy of ~153J on a 1-mm Ta target. The photon dose in the forward direction increased more significantly with increasing laser intensity than that in the side direction. For photon energies >300keV, the X-ray spectrum can be fit with an effective temperature distribution of the exponential form, dN/dE = k× exp(-E/Tx). The X-ray temperature Tx increased with the laser intensity in the forward direction with values of 0.46-0.75MeV. Tx was less strongly correlated with the laser intensity in the side direction with values of 0.29-0.32MeV. The escaping electron spectrum was also measured. The measured electron temperature was correlated with the electron temperature predicted by the ponderomotive law. The observations in this experiment were also investigated numerically. A good agreement was observed between the experimental and simulation results.

  4. Beauty, charm and hyperon production at fixed-target experiments

    SciTech Connect

    Erik Gottschalk

    2002-12-11

    Over the years fixed-target experiments have performed numerous studies of particle production in strong interactions. The experiments have been performed with different types of beam particles of varying energies, and many different target materials. Since the physics of particle production is still not understood, ongoing research of phenomena that we observe as beauty, charm and strange-particle production is crucial if we are to gain an understanding of these fundamental processes. It is in this context that recent results from fixed-target experiments on beauty, charm, and hyperon production will be reviewed.

  5. Production of a thermal stress resistant mutant Euglena gracilis strain using Fe-ion beam irradiation.

    PubMed

    Yamada, Koji; Kazama, Yusuke; Mitra, Sharbanee; Marukawa, Yuka; Arashida, Ryo; Abe, Tomoko; Ishikawa, Takahiro; Suzuki, Kengo

    2016-08-01

    Euglena gracilis is a common phytoplankton species, which also has motile flagellate characteristics. Recent research and development has enabled the industrial use of E. gracilis and selective breeding of this species is expected to further expand its application. However, the production of E. gracilis nuclear mutants is difficult because of the robustness of its genome. To establish an efficient mutation induction procedure for E. gracilis, we employed Fe-ion beam irradiation in the RIKEN RI beam factory. A decrease in the survival rate was observed with the increase in irradiation dose, and the upper limit used for E. gracilis selective breeding was around 50 Gy. For a practical trial of Fe-ion irradiation, we conducted a screening to isolate high-temperature-tolerant mutants. The screening yielded mutants that proliferated faster than the wild-type strain at 32 °C. Our results demonstrate the effectiveness of heavy-ion irradiation on E. gracilis selective breeding.

  6. Study on increasing production of natural silk by using low dose irradiation

    SciTech Connect

    Ruiying, Z.; Yinfen, Z.; Dingzhu, C.; Jinxian, R.

    1985-01-01

    Radiation effect on silkworm irradiated by low dose fast neutron and ..gamma..-ray emitted from Ra-Be neutron source are reported. It is shown that increasing production of natural silk can only be obtained by irradiation under specified conditions. It was found that an appropriate fluence employed could lead to increase hatching rate of silkworm eggs, make silkworms' bodies strong, grow fast, possess high disease resistance and reduce the whole stadium by 1/2 to 2 1/2 days. In addition, the irradiated silkworm can be expected to spin bigger cocoons with thick layers and the quality of cocoon silk are remarkable improved. The application of irradiation technique has now been extended to the suburbs of Beijing and welcomed by sericulturist.

  7. Energy plasma-target coupling in the case a periodical structure is formed within the irradiation spot as an effect of powerful laser irradiation

    NASA Astrophysics Data System (ADS)

    Ursu, I.; Apostol, I.; Craciun, D.; Dinescu, M.; Mihailescu, L. N.

    1985-10-01

    In an earlier paper (Ursu et al., 1985), it has been suggested that surface electromagnetic waves propagating on the surface of laser-irradiated samples in the presence of periodic structures formed within the beam spot may provide a competitive mechanism for supplementary energy transfer. Such a mechanism could account for the high absorptivity observed in the case of high-power laser irradiation of some metallic materials, sometimes characterized as anomalous. Here, new experimental determinations of the dependence of the energy coupling coefficient on the incident energy density are reported for TEA-CO2 and ruby laser sources and copper targets. The results are found to be consistent with the proposed supplementary energy transfer mechanism.

  8. Irradiation damage analysis on the flat plate type target plate of the divertor for fusion experimental reactors

    NASA Astrophysics Data System (ADS)

    Ishiyama, S.; Akiba, M.; Eto, M.

    1996-04-01

    To design the relevant plasma facing components of fusion experimental reactors such as ITER, irradiation damage analysis, especially on divertor structures exposed to high heat flux and heavy neutron irradiation, is one of the most important problems. This paper presents finite element analytical results of the thermal and irradiation induced stresses which occurred in the divertor structures which are exposed to neutron irradiation at 0-1 dpa with a high heat flux up to 15 MW/m 2. A type of target plate model of the divertor structure studied in present study e.g. flat plate model has bonded structure of one-dimensional high thermal conductivity carbon-carbon composite (C/C) and oxygen-free high conductivity copper (OFHC), as armor and substrate/heat sink materials, respectively. These results show that irradiation induced stresses at edges of bonded interface between an armor and a substrate/heat sink, become higher with increase of dpa and reach up to the critical values of the materials at 0 and 1 dpa. This indicates that drop-off of armor tiles from substrate structure is one of very serious problems for the safety design of target plate; thus the reduction of service conditions and change of divertor materials are important to extend lifetime of the model.

  9. Production of glass balloons for laser targets

    SciTech Connect

    Hendricks, C.D.; Dressler, J.L.

    1982-09-28

    An apparatus for producing small quantities of glass balloons for use as laser fusion targets is described. To produce precise quantities of the ingredients of one glass balloon, a jet of an aqueous solution of the glass constituents and a blowing agent is metered into uniformly sized drops by Rayleigh breakup. A small fraction of these uniform drops is then passed through an oven where the water is evaporated, the remaining solid material is fused into glass, and a blowing agent decomposes or water of hydration evolves as a vapor to blow the drop into a balloon. Photographs of the resulting glass balloons are presented.

  10. Target optimization for the photonuclear production of radioisotopes.

    PubMed

    Howard, Sean; Starovoitova, Valeriia N

    2015-02-01

    In this paper we discuss the optimum shape of a target for photonuclear production of radioisotopes using an electron linear accelerator. Different target geometries such as right cylinder, conical frustum, Gaussian volume of revolution and semi-ellipsoid have been considered for the production of (67)Cu via (68)Zn(γ,p)(67)Cu photonuclear reaction. The specific activity (SA) of (67)Cu was simulated for each target shape. Optimum ratio of radius to height for cylindrical targets was found to be between 0.2 and 0.25 for target masses ranging from 20 g to 100 g. It was shown that while some unconventional target shapes, such as semi-elliptical volume of revolution, result in slightly higher specific activities than cylindrical targets, the advantage is not significant and is outweighed by the complexity of the target production and handling. Power deposition into the target was modeled and the trade-off between the maximization of (67)Cu yield and the minimization of target heating has been discussed. The (67)Cu case can easily be extended for production of many other isotopes.

  11. Revealing the macromolecular targets of complex natural products.

    PubMed

    Reker, Daniel; Perna, Anna M; Rodrigues, Tiago; Schneider, Petra; Reutlinger, Michael; Mönch, Bettina; Koeberle, Andreas; Lamers, Christina; Gabler, Matthias; Steinmetz, Heinrich; Müller, Rolf; Schubert-Zsilavecz, Manfred; Werz, Oliver; Schneider, Gisbert

    2014-12-01

    Natural products have long been a source of useful biological activity for the development of new drugs. Their macromolecular targets are, however, largely unknown, which hampers rational drug design and optimization. Here we present the development and experimental validation of a computational method for the discovery of such targets. The technique does not require three-dimensional target models and may be applied to structurally complex natural products. The algorithm dissects the natural products into fragments and infers potential pharmacological targets by comparing the fragments to synthetic reference drugs with known targets. We demonstrate that this approach results in confident predictions. In a prospective validation, we show that fragments of the potent antitumour agent archazolid A, a macrolide from the myxobacterium Archangium gephyra, contain relevant information regarding its polypharmacology. Biochemical and biophysical evaluation confirmed the predictions. The results obtained corroborate the practical applicability of the computational approach to natural product 'de-orphaning'.

  12. Revealing the macromolecular targets of complex natural products

    NASA Astrophysics Data System (ADS)

    Reker, Daniel; Perna, Anna M.; Rodrigues, Tiago; Schneider, Petra; Reutlinger, Michael; Mönch, Bettina; Koeberle, Andreas; Lamers, Christina; Gabler, Matthias; Steinmetz, Heinrich; Müller, Rolf; Schubert-Zsilavecz, Manfred; Werz, Oliver; Schneider, Gisbert

    2014-12-01

    Natural products have long been a source of useful biological activity for the development of new drugs. Their macromolecular targets are, however, largely unknown, which hampers rational drug design and optimization. Here we present the development and experimental validation of a computational method for the discovery of such targets. The technique does not require three-dimensional target models and may be applied to structurally complex natural products. The algorithm dissects the natural products into fragments and infers potential pharmacological targets by comparing the fragments to synthetic reference drugs with known targets. We demonstrate that this approach results in confident predictions. In a prospective validation, we show that fragments of the potent antitumour agent archazolid A, a macrolide from the myxobacterium Archangium gephyra, contain relevant information regarding its polypharmacology. Biochemical and biophysical evaluation confirmed the predictions. The results obtained corroborate the practical applicability of the computational approach to natural product ‘de-orphaning’.

  13. 60Co irradiation for sterilization of veterinary mastitis products containing antibiotics and steroids

    NASA Astrophysics Data System (ADS)

    Tsuji, K.; Kane, M. P.; Rahn, P. D.; Steindler, K. A.

    Effects of 60Co irradiation for sterilization of veterinary mastitis products were evaluated. The mastitis products which were examined contained various combinations of antibiotics and steroids suspended in peanut oil vehicle. Bioburden data indicated that the unirradiated products were only occasionally contaminated with microorganisms. The D-values of the nonsterile product and environmental isolates were 0.028, 0.15, 0.017, and 0.018 Mrads for Aspergillus fumigatus, Penicillium oxalicum, Pseudomonas aeruginosa, and Pseudomonas maltophilia, respectively. The D-value of the biological indicator organism, Bacillus pumilus spores, in the vehicle was 0.27 Mrads. Thus, an irradiation dose of 1.6 Mrads would be sufficient to achieve six log cycles of destruction of the biological indicator organism. The minimum absorbed irradiation dose of 2.5 Mrads preferred by many countries for sterilization would achieve 9.3 log cycle destruction of the indicator organism and guarantee a probability of 1 × 10 -15 assurance for the most radio-resistant product isolate, Penicillium oxalicum. In order to examine short and long term chemical stabilities of active components, stability indicating high-performance liquid chromatographic (HPLC) methods for the determination of the following antibiotics and steroids were developed. They were: dihydrostreptomycin, neomycin, novobiocin, penicillin G, hydrocortisone acetate, hydrocortisone sodium succinate, and prednisolone. The rates of degradation and radiolytic degradation schemes for the majority of these compounds were elucidated. Formation of new compounds was not observed in these antibiotics and steroids upon 60Co irradiation. The compounds that increased by irradiation were inherently present in commercially available non-irradiated lots and/or can easily be formed by either acidic, basic, or thermal treatment.

  14. Study of ablation by laser irradiation of plane targets at wavelengths 1. 05, 0. 53, and 0. 35. mu. m

    SciTech Connect

    Key, M.H.; Toner, W.T.; Goldsack, T.J.; Kilkenny, J.D.; Veats, S.A.; Cunningham, P.F.; Lewis, C.L.S.

    1983-07-01

    Ablation by laser irradiation at wavelengths lambda = 1.05, 0.53, and 0.35 ..mu..m has been studied from analysis of time-resolved x-ray spectra of layered targets and of ion emission. Irradiance was varied in the range 2 x 10/sup 13/ to 2 x 10/sup 15/ W cm/sup -2/ with constant laser power and variable focal spot size. Deductions include the effect of lateral energy transport from small focal spots and ablation rates and ablation pressures obtained both in the limit of negligible transport and when lateral transport is significant. Advantages of short wavelengths for ablatively driven implosions are quantified.

  15. Demonstration of a neonlike argon soft-x-ray laser with a picosecond-laser-irradiated gas puff target.

    PubMed

    Fiedorowicz, H; Bartnik, A; Dunn, J; Smith, R F; Hunter, J; Nilsen, J; Osterheld, A L; Shlyaptsev, V N

    2001-09-15

    We demonstrate a neonlike argon-ion x-ray laser, using a short-pulse laser-irradiated gas puff target. The gas puff target was formed by pulsed injection of gas from a high-pressure solenoid valve through a nozzle in the form of a narrow slit and irradiated with a combination of long, 600-ps and short, 6-ps high-power laser pulses with a total of 10 J of energy in a traveling-wave excitation scheme. Lasing was observed on the 3p (1)S(0)?3s (1)P(1) transition at 46.9 nm and the 3d (1)P(1)?3p (1)P(1) transition at 45.1 nm. A gain of 11 cm(-1) was measured on these transitions for targets up to 0.9 cm long.

  16. Targeted irradiation of biological cells using an ion microprobe - Why a small beam spot is not sufficient for success

    NASA Astrophysics Data System (ADS)

    Fischer, B. E.; Voss, K.-O.; Du, G.

    2009-06-01

    When people plan to adapt their ion microprobe for the targeted irradiation of biological cells, they often claim that they expect a targeting accuracy in the range of their beam spot diameter, because they assume that reaching a sub-μm beam spot is the most difficult part of the job. Although many microprobes have now a beam spot diameter of some hundred nano-meters or less, nobody reached a targeting accuracy below 1 μm. Besides obvious reasons, like mechanical or thermal instabilities, there is a more difficult problem to overcome: one still needs a light microscope to locate both the microbeam and the cells to be irradiated, and there are various light-optical effects, which can give misleading information about the position of the beam and the cells.

  17. Target for the heaviest element production at RIKEN

    NASA Astrophysics Data System (ADS)

    Kaji, D.; Morimoto, K.; Yoneda, A.; Hasebe, H.; Yoshida, A.; Haba, H.; Goto, S.; Kudo, H.; Morita, K.

    2008-06-01

    A new gas-cooled rotating target system was developed for the heaviest element production. A target wheel with a diameter of 30.0 cm could be rotated up to 3000 rpm. A helium gas introduced into the target chamber mounted upstream of a gas-filled recoil separator, which enables an effective gas cooling of the target. The development has led to the successful production of heavy nuclides via cold fusion reactions of 208Pb( 64Ni,n) 271Ds, 209Bi( 64Ni,n) 272Rg, 208Pb( 70Zn,n) 277112, and 209Bi( 70Zn,n) 278113.

  18. A mechanistic study of gold nanoparticle radiosensitisation using targeted microbeam irradiation.

    PubMed

    Ghita, Mihaela; McMahon, Stephen J; Taggart, Laura E; Butterworth, Karl T; Schettino, Giuseppe; Prise, Kevin M

    2017-03-16

    Gold nanoparticles (GNPs) have been demonstrated as effective radiosensitizing agents in a range of preclinical models using broad field sources of various energies. This study aimed to distinguish between these mechanisms by applying subcellular targeting using a soft X-ray microbeam in combination with GNPs. DNA damage and repair kinetics were determined following nuclear and cytoplasmic irradiation using a soft X-ray (carbon K-shell, 278 eV) microbeam in MDA-MB-231 breast cancer and AG01522 fibroblast cells with and without GNPs. To investigate the mechanism of the GNP induced radiosensitization, GNP-induced mitochondrial depolarisation was quantified by TMRE staining, and levels of DNA damage were compared in cells with depolarised and functional mitochondria. Differential effects were observed following radiation exposure between the two cell lines. These findings were validated 24 hours after removal of GNPs by flow cytometry analysis of mitochondrial depolarisation. This study provides further evidence that GNP radiosensitisation is mediated by mitochondrial function and it is the first report applying a soft X-ray microbeam to study the radiobiological effects of GNPs to enable the separation of physical and biological effects.

  19. Clinical target volume delineation including elective nodal irradiation in preoperative and definitive radiotherapy of pancreatic cancer

    PubMed Central

    2012-01-01

    Background Radiotherapy (RT) is widely used in the treatment of pancreatic cancer. Currently, recommendation has been given for the delineation of the clinical target volume (CTV) in adjuvant RT. Based on recently reviewed pathologic data, the aim of this study is to propose criteria for the CTV definition and delineation including elective nodal irradiation (ENI) in the preoperative and definitive treatment of pancreatic cancer. Methods The anatomical structures of interest, as well as the abdominal vasculature were identified on intravenous contrast-enhanced CT scans of two different patients with pancreatic cancer of the head and the body. To delineate the lymph node area, a margin of 10 mm was added to the arteries. Results We proposed a set of guidelines for elective treatment of high-risk nodal areas and CTV delineation. Reference CT images were provided. Conclusions The proposed guidelines could be used for preoperative or definitive RT for carcinoma of the head and body of the pancreas. Further clinical investigations are needed to validate the defined CTVs. PMID:22691275

  20. Melanosomes are a primary target of Q-switched ruby laser irradiation in guinea pig skin

    SciTech Connect

    Polla, L.L.; Margolis, R.J.; Dover, J.S.; Whitaker, D.; Murphy, G.F.; Jacques, S.L.; Anderson, R.R.

    1987-09-01

    The specific targeting of melanosomes may allow for laser therapy of pigmented cutaneous lesions. The mechanism of selective destruction of pigmented cells by various lasers, however, has not been fully clarified. Black, brown, and albino guinea pigs were exposed to optical pulses at various radiant exposure doses from a Q-switched, 40 nsec, 694 nm ruby laser. Biopsies were analyzed by light and electron microscopy (EM). Albino animals failed to develop clinical or microscopic evidence of cutaneous injury after irradiation. In both black and brown animals, the clinical threshold for gross change was 0.4 J/cm2, which produced an ash-white spot. By light microscopy, alterations appeared at 0.3 J/cm2 and included separation at the dermoepidermal junction, and the formation of vacuolated epidermal cells with a peripheral cytoplasmic condensation of pigment. By EM, enlarged melanosomes with a central lucent zone were observed within affected epidermal cells at 0.3 J/cm2. At 0.8 and 1.2 J/cm2, individual melanosomes were more intensely damaged and disruption of melanosomes deep in the hair papillae was observed. Dermal-epidermal blisters were formed precisely at the lamina lucida, leaving basal cell membranes and hemidesmosomes intact. Possible mechanisms for melanosomal injury are discussed. These observations show that the effects of the Q-switched ruby laser are melanin-specific and melanin-dependent, and may be useful in the selective destruction of pigmented as well as superficial cutaneous lesions.

  1. A mechanistic study of gold nanoparticle radiosensitisation using targeted microbeam irradiation

    PubMed Central

    Ghita, Mihaela; McMahon, Stephen J.; Taggart, Laura E.; Butterworth, Karl T.; Schettino, Giuseppe; Prise, Kevin M.

    2017-01-01

    Gold nanoparticles (GNPs) have been demonstrated as effective radiosensitizing agents in a range of preclinical models using broad field sources of various energies. This study aimed to distinguish between these mechanisms by applying subcellular targeting using a soft X-ray microbeam in combination with GNPs. DNA damage and repair kinetics were determined following nuclear and cytoplasmic irradiation using a soft X-ray (carbon K-shell, 278 eV) microbeam in MDA-MB-231 breast cancer and AG01522 fibroblast cells with and without GNPs. To investigate the mechanism of the GNP induced radiosensitization, GNP-induced mitochondrial depolarisation was quantified by TMRE staining, and levels of DNA damage were compared in cells with depolarised and functional mitochondria. Differential effects were observed following radiation exposure between the two cell lines. These findings were validated 24 hours after removal of GNPs by flow cytometry analysis of mitochondrial depolarisation. This study provides further evidence that GNP radiosensitisation is mediated by mitochondrial function and it is the first report applying a soft X-ray microbeam to study the radiobiological effects of GNPs to enable the separation of physical and biological effects. PMID:28300190

  2. SU-D-304-02: Magnetically Focused Proton Irradiation of Small Field Targets

    SciTech Connect

    McAuley, GA; Slater, JM; Slater, JD; Wroe, AJ

    2015-06-15

    Purpose: To investigate the use of magnetic focusing for small field proton irradiations. It is hypothesized that magnetic focusing will provide significant dose distribution benefits over standard collimated beams for fields less than 10 mm diameter. Methods: Magnets consisting of 24 segments of radiation hard samarium-cobalt adhered into hollow cylinders were designed and manufactured. Two focusing magnets were placed on a positioning track on our Gantry 1 treatment table. Proton beams with energies of 127 and 157 MeV, 15 and 30 mm modulation, and 8 mm initial diameters were delivered to a water tank using single-stage scattering. Depth dose distributions were measured using a PTW PR60020 diode detector and transverse profiles were measured with Gafchromic EBT3 film. Monte Carlo simulations were also performed - both for comparison with experimental data and to further explore the potential of magnetic focusing in silica. For example, beam spot areas (based on the 90% dose contour) were matched at Bragg depth between simulated 100 MeV collimated beams and simulated beams focused by two 400 T/m gradient magnets. Results: Preliminary experimental results show 23% higher peak to entrance dose ratios and flatter spread out Bragg peak plateaus for 8 mm focused beams compared with uncollimated beams. Monte Carlo simulations showed 21% larger peak to entrance ratios and a ∼9 fold more efficient dose to target delivery compared to spot-sized matched collimated beams. Our latest results will be presented. Conclusion: Our results suggest that rare earth focusing magnet assemblies could reduce skin dose and beam number while delivering dose to nominally spherical radiosurgery targets over a much shorter time compared to unfocused beams. Immediate clinical applications include those associated with proton radiosurgery and functional radiosurgery of the brain and spine, however expanded treatment sites can be also envisaged.

  3. Intrafractional Target Motions and Uncertainties of Treatment Setup Reference Systems in Accelerated Partial Breast Irradiation

    SciTech Connect

    Yue, Ning J.; Goyal, Sharad; Zhou Jinghao; Khan, Atif J.; Haffty, Bruce G.

    2011-04-01

    Purpose: This study investigated the magnitude of intrafractional motion and level of accuracy of various setup strategies in accelerated partial breast irradiation (APBI) using three-dimensional conformal external beam radiotherapy. Methods and Materials: At lumpectomy, gold fiducial markers were strategically sutured to the surrounding walls of the cavity. Weekly fluoroscopy imaging was conducted at treatment to investigate the respiration-induced target motions. Daily pre- and post-RT kV imaging was performed, and images were matched to digitally reconstructed radiographs based on bony anatomy and fiducial markers, respectively, to determine the intrafractional motion magnitudes over the course of treatment. The positioning differences of the laser tattoo- and the bony anatomy-based setups compared with those of the marker-based setup (benchmark) were also determined. The study included 21 patients. Results: Although lung exhibited significant motion, the average marker motion amplitude on the fluoroscopic image was about 1 mm. Over a typical treatment time period, average intrafractional motion magnitude was 4.2 mm and 2.6 mm based on the marker and bony anatomy matching, respectively. The bony anatomy- and laser tattoo-based interfractional setup errors, with respect to the fiducial marker-based setup, were 7.1 and 9.0 mm, respectively. Conclusions: Respiration has limited effects on the target motion during APBI. Bony anatomy-based treatment setup improves the accuracy relative to that of the laser tattoo-based setup approach. Since fiducial markers are sutured directly to the surgical cavity, the marker-based approach can further improve the interfractional setup accuracy. On average, a seroma cavity exhibits intrafractional motion of more than 4 mm, a magnitude that is larger than that which is otherwise derived based on bony anatomy matching. A seroma-specific marker-based approach has the potential to improve treatment accuracy by taking the true inter

  4. WE-D-17A-04: Magnetically Focused Proton Irradiation of Small Volume Targets

    SciTech Connect

    McAuley, G; Slater, J; Wroe, A

    2014-06-15

    Purpose: To explore the advantages of magnetic focusing for small volume proton irradiations and the potential clinical benefits for radiosurgery targets. The primary goal is to create narrow elongated proton beams of elliptical cross section with superior dose delivery characteristics compared to current delivery modalities (eg, collimated beams). In addition, more general beam shapes are also under investigation. Methods: Two prototype magnets consisting of 24 segments of samarium-cobalt (Sm2Co17) permanent magnetic material adhered into hollow cylinders were manufactured for testing. A single focusing magnet was placed on a positioning track on our Gantry 1 treatment table and 15 mm diameter proton beams with energies and modulation relevant to clinical radiosurgery applications (127 to 186 MeV, and 0 to 30 mm modulation) were delivered to a terminal water tank. Beam dose distributions were measured using a PTW diode detector and Gafchromic EBT2 film. Longitudinal and transverse dose profiles were analyzed and compared to data from Monte Carlo simulations analogous to the experimental setup. Results: The narrow elongated focused beam spots showed high elliptical symmetry indicating high magnet quality. In addition, when compared to unfocused beams, peak-to-entrance depth dose ratios were 11 to 14% larger (depending on presence or extent of modulation), and minor axis penumbras were 11 to 20% smaller (again depending on modulation) for focused beams. These results suggest that the use of rare earth magnet assemblies is practical and could improve dose-sparing of normal tissue and organs at risk while delivering enhanced dose to small proton radiosurgery targets. Conclusion: Quadrapole rare earth magnetic assemblies are a promising and inexpensive method to counteract particle out scatter that tends to degrade the peak to entrance performance of small field proton beams. Knowledge gained from current experiments will inform the design of a prototype treatment

  5. Production of proton beams with narrow-band energy spectra from laser-irradiated ultrathin foils

    SciTech Connect

    Robinson, A. P. L; Gibbon, P.

    2007-01-15

    Three-dimensional gridless particle simulations of proton acceleration via irradiation of a very thin foil by a short-pulse, high-intensity laser have been performed to evaluate recently proposed microstructured target configurations. It is found that a pure proton microdot target does not by itself result in a quasimonoenergetic proton beam. Such a beam can only be produced with a very lightly doped target, in qualitative agreement with one-dimensional theory. The simulations suggest that beam quality in current experiments could be dramatically improved by choosing microdot compositions with a 5-10 times lower proton fraction.

  6. Production of proton beams with narrow-band energy spectra from laser-irradiated ultrathin foils.

    PubMed

    Robinson, A P L; Gibbon, P

    2007-01-01

    Three-dimensional gridless particle simulations of proton acceleration via irradiation of a very thin foil by a short-pulse, high-intensity laser have been performed to evaluate recently proposed microstructured target configurations. It is found that a pure proton microdot target does not by itself result in a quasimonoenergetic proton beam. Such a beam can only be produced with a very lightly doped target, in qualitative agreement with one-dimensional theory. The simulations suggest that beam quality in current experiments could be dramatically improved by choosing microdot compositions with a 5-10 times lower proton fraction.

  7. Mechanisms of volatile production from non-sulfur amino acids by irradiation

    NASA Astrophysics Data System (ADS)

    Ahn, Dong Uk; Lee, Eun Joo; Feng, Xi; Zhang, Wangang; Lee, Ji Hwan; Jo, Cheorun; Nam, Kichang

    2016-02-01

    Non-sulfur amino acid monomers were used to study the mechanisms of volatile production in meat by irradiation. Irradiation not only produced many volatiles but also increased the amounts of volatiles from non-sulfur amino acid monomers. The major reaction mechanisms involved in volatile production from each group of the amino acids by irradiation differ significantly. However, we speculate that the radiolysis of amino acid side chains were the major mechanism. In addition, Strecker degradation, especially the production of aldehydes from aliphatic group amino acids, and deamination, isomerization, decarboxylation, cyclic reaction and dehydrogenation of the initial radiolytic products were also contributed to the production of volatile compounds. Each amino acid monomers produced different odor characteristics, but the intensities of odor from all non-sulfur amino acid groups were very weak. This indicated that the contribution of volatiles produced from non-sulfur amino acids was minor. If the volatile compounds from non-sulfur amino acids, especially aldehydes, interact with other volatiles compounds such as sulfur compounds, however, they can contribute to the off-odor of irradiated meat significantly.

  8. Sensing device and method for measuring emission time delay during irradiation of targeted samples utilizing variable phase tracking

    NASA Technical Reports Server (NTRS)

    Danielson, J. D. Sheldon (Inventor)

    2006-01-01

    An apparatus for measuring emission time delay during irradiation of targeted samples by utilizing digital signal processing to determine the emission phase shift caused by the sample is disclosed. The apparatus includes a source of electromagnetic radiation adapted to irradiate a target sample. A mechanism generates first and second digital input signals of known frequencies with a known phase relationship, and a device then converts the first and second digital input signals to analog sinusoidal signals. An element is provided to direct the first input signal to the electromagnetic radiation source to modulate the source by the frequency thereof to irradiate the target sample and generate a target sample emission. A device detects the target sample emission and produces a corresponding first output signal having a phase shift relative to the phase of the first input signal, the phase shift being caused by the irradiation time delay in the sample. A member produces a known phase shift in the second input signal to create a second output signal. A mechanism is then provided for converting each of the first and second analog output signals to digital signals. A mixer receives the first and second digital output signals and compares the signal phase relationship therebetween to produce a signal indicative of the change in phase relationship between the first and second output signals caused by the target sample emission. Finally, a feedback arrangement alters the phase of the second input signal based on the mixer signal to ultimately place the first and second output signals in quadrature. Mechanisms for enhancing this phase comparison and adjustment technique are also disclosed.

  9. Cross-sections of residual nuclei from deuteron irradiation of thin thorium target at energy 7 GeV

    NASA Astrophysics Data System (ADS)

    Vespalec, Radek; Adam, Jindrich; Baldin, Anton Alexandrovich; Khushvaktov, Jurabek; Solnyshkin, Alexander Alexandrovich; Tsoupko-Sitnikov, Vsevolod Mikhailovich; Tyutyunikov, Sergey Ivanovich; Vrzalova, Jitka; Zavorka, Lukas; Zeman, Miroslav

    2017-09-01

    The residual nuclei yields are of great importance for the estimation of basic radiation-technology characteristics (like a total target activity, production of long-lived nuclides etc.) of accelerator driven systems planned for transmutation of spent nuclear fuel and for a design of radioisotopes production facilities. Experimental data are also essential for validation of nuclear codes describing various stages of a spallation reaction. Therefore, the main aim of this work is to add new experimental data in energy region of relativistic deuterons, as similar data are missing in nuclear databases. The sample made of thin natural thorium foil was irradiated at JINR Nuclotron accelerator with a deuteron beam of the total kinetic energy 7 GeV. Integral number of deuterons was determined with the use of aluminum activation detectors. Products of deuteron induced spallation reaction were qualified and quantified by means of gamma-ray spectroscopy method. Several important spectroscopic corrections were applied to obtain results of high accuracy. Experimental cumulative and independent cross-sections were determined for more than 80 isotopes including meta-stable isomers. The total uncertainty of results rarely exceeded 9%. Experimental results were compared with MCNP6.1 Monte-Carlo code predictions. Generally, experimental and calculated cross-sections are in a reasonably good agreement, with the exception of a few light isotopes in a fragmentation region, where the calculations are highly under-estimated. Measured data will be useful for future development of high-energy nuclear codes. After completion, final data will be added into the EXFOR database.

  10. Pyrolysis of Municipal Solid Waste for Syngas Production by Microwave Irradiation

    SciTech Connect

    Gedam, Vidyadhar V.; Regupathi, Iyyaswami

    2012-03-15

    In the present study, we discuss the application of microwave-irradiated pyrolysis of municipal solid waste (MSW) for total recovery of useful gases and energy. The MSW pyrolysis under microwave irradiation highly depends on the process parameters, like microwave power, microwave absorbers, and time of irradiation. The thoroughness of pyrolysis and product recovery were studied by changing the abovesaid variables. Pyrolysis of MSW occurs in the power rating range of 450-850 W-outside this power rating range, pyrolysis is not possible. Experiments were carried out using various microwave absorbers (i.e., graphite, charcoal, and iron) to enhance the pyrolysis even at lower power rating. The results show that the pyrolysis of MSW was possible even at low power ratings. The major composition of the pyrolysis gaseous product were analyzed with GC-MS which includes CO{sub 2}, CO, CH{sub 4}, etc.

  11. Effects of low-dose X-ray irradiation of eggshells on radical production.

    PubMed

    Nakagawa, K

    2014-06-01

    We investigated effects of low-dose X-ray irradiation on eggshells radical production. Eggshells irradiated by low-dose X-ray produced stable radicals. The stable radicals at the central region of the spectrum are the carbonates and CO2(•-) signals. The electron spin resonance (ESR) signals increase with increasing absorbed dose. The estimated radical concentration (spin number) was approximately 3.6 × 10(12) (spins/g) at 10-Gy dose using various known concentrations of TEMPOL (4-hydroxy-2, 2, 6, 6-tretramethylpiperidin-1-oxyl) aqueous solutions. The stable radicals in irradiated eggshells were recognized at the low-level dose (0.10 Gy). In addition, no significant dose rate (0.5-1.5 Gy/min) dependence was found for the radical production.

  12. Current and potential trade in horticultural products irradiated for phytosanitary purposes

    NASA Astrophysics Data System (ADS)

    Bustos-Griffin, Emilia; Hallman, Guy J.; Griffin, Robert L.

    2012-08-01

    The current status of trade in horticultural products irradiated for phytosanitary purposes is examined, including trends, strengths and weaknesses. A strategy is proposed to take advantage of the best future opportunities for increasing trade in irradiated horticultural products by identifying best possibilities for expanding both the number and volume of commodities for irradiation and then applying appropriate business criteria in a general analysis of the commodities, commercial scenarios, and geographic regions where the greatest potential exists for expansion. The results show that fresh fruits such as mango, papaya, citrus, grapes, and vegetables such as tomatoes, onions, asparagus, garlic, and peppers from Asia and the Americas show the greatest potential. Substantial opportunities for additional growth exist, especially as regulatory conditions become more favorable.

  13. Effects of the laser pulse irradiation point on a double layer target on the accelerated ion beam parameters

    SciTech Connect

    Morita, T.; Bulanov, S. V.; Esirkepov, T. Zh.; Koga, J.; Yamagiwa, M.

    2009-07-25

    In proton acceleration by a laser pulse obliquely incident on a double layer target, it is shown by PIC simulations that the energy spread of the generated protons can be reduced by irradiating the laser pulse on to the off-center position of the target. This provides a way to control the proton energy spectrum. High energy protons are found to come from an area shifted from the initial target center towards the propagation direction of the laser pulse. We show that high energy protons with much smaller energy spread can be obtained by appropriately adjusting the size and position of the second proton layer.

  14. Optical emission of a plasma from low-density targets irradiated with coherence-controllable laser radiation

    NASA Astrophysics Data System (ADS)

    Fronya, A. A.; Borisenko, N. G.; Puzyrev, V. N.; Sahakyan, A. T.; Starodub, A. N.; Yakushev, O. F.

    2017-03-01

    The results of experiments on the interaction of nanosecond laser radiation with low-density volume-structured targets of different density and thickness are reported. The targets were irradiated by laser radiation with controllable coherence. The primary objective was to investigate the effect of target parameters on the characteristics of radiation scattered by the plasma. The spectral characteristics of the radiation scattered by the plasma in the backward direction and in the direction of laser beam propagation were obtained. Also the radiation scattering patterns were recorded.

  15. A novel monolithic LEU foil target based on a PVD manufacturing process for (99)Mo production via fission.

    PubMed

    Hollmer, Tobias; Petry, Winfried

    2016-12-01

    (99)Mo is the most widely used radioactive isotope in nuclear medicine. Its main production route is the fission of uranium. A major challenge for a reliable supply is the conversion from highly enriched uranium (HEU) to low enriched uranium (LEU). A promising candidate to realize this conversion is the cylindrical LEU irradiation target. The target consists of a uranium foil encapsulated between two coaxial aluminum cladding cylinders. This target allows a separate processing of the irradiated uranium foil and the cladding when recovering the (99)Mo. Thereby, both the costs and the volume of highly radioactive liquid waste are significantly reduced compared to conventional targets. The presented manufacturing process is based on the direct coating of the uranium on the inside of the outer cladding cylinder. This process was realized by a cylindrical magnetron enhanced physical vapor deposition (PVD) technique. The method features a highly automated process, a good quality of the resulting uranium foils and a high material utilization.

  16. Cyclotron production of ⁹⁹mTc: recycling of enriched ¹⁰⁰Mo metal targets.

    PubMed

    Gagnon, K; Wilson, J S; Holt, C M B; Abrams, D N; McEwan, A J B; Mitlin, D; McQuarrie, S A

    2012-08-01

    There is growing interest in the large scale cyclotron production of (99m)Tc via the (100)Mo(p,2n)(99m)Tc reaction. While the use and recycling of cyclotron-irradiated enriched molybdenum targets has been reported previously in the context of (94m)Tc production, to the best of our knowledge, previous recycling studies have been limited to the use of oxide targets. To facilitate reuse of high-power enriched (100)Mo targets, this work presents and evaluates a strategy for recycling of enriched metallic molybdenum. For the irradiated (100)Mo targets in this study, an overall metal to metal recovery of 87% is reported. Evaluation of "new" and "recycled" (100)Mo revealed no changes in the molybdenum isotopic composition (as measured via ICP-MS). For similar irradiation conditions of "new" and "recycled" (100)Mo, (i.e. target thicknesses, irradiation time, and energy), comparable levels of (94g)Tc, (95g)Tc, and (96g)Tc contaminants were observed. Comparable QC specifications (i.e. aluminum ion concentration, pH, and radiochemical purity) were also reported. We finally note that [(99m)Tc]-MDP images obtained by comparing MDP labelled with generator-based (99m)Tc vs. (99m)Tc obtained following the irradiation of recycled (100)Mo demonstrated comparable biodistribution. With the goal of producing large quantities of (99m)Tc, the proposed methodology demonstrates that efficient recycling of enriched metallic (100)Mo targets is feasible and effective.

  17. Effect of irradiation on the parameters that influence quality characteristics of uncured and cured cooked turkey meat products.

    PubMed

    Feng, Xi; Moon, Sunhee; Lee, Hyunyong; Ahn, Dong U

    2016-12-01

    The objective of this study was to evaluate the effect of irradiation on lipid/protein oxidation, color changes, and off-odor volatiles production in uncured and cured cooked turkey meat products. Uncured cooked turkey breast meat and cured commercial turkey breast rolls and ham were prepared and irradiated at 0, 1.5, 3.0, and 4.5 kGy using a linear accelerator. The results showed that irradiation had little effects on lipid oxidation of cured cooked turkey products, but accelerated lipid oxidation in uncured cooked turkey breast meat (P < 0.05). Protein oxidation was increased both in cured and uncured meats (P < 0.05), but more in cured cooked meat by irradiation. The redness of uncured cooked turkey was increased (P < 0.05), but the redness of cured cooked turkey meat was faded by irradiation (P < 0.05). Irradiated cured cooked turkey meat products produced less off-odor volatile compounds (dimethyl disulfide, 3-methyl/2-methyl-butananl, and hexanal) than irradiated uncured cooked meat products due to various additives in the cured meat products. Our results suggested that irradiation resulted in different chemical reactions to pigments in uncured and cured cooked turkey meat products, but cured cooked turkey meat products have a higher tolerance to odor deterioration than uncured cooked turkey meat products. © 2016 Poultry Science Association Inc.

  18. Analysis of radiolytic products of lipid in irradiated dried squids (Todarodes pacificus).

    PubMed

    Kim, Jun-Hyoung; Seo, Hye-Young; Kim, Kyong-Su

    2004-08-01

    The lipid portion of dried squids (Todarodes pacificus) was extracted, and its hydrocarbons and 2-alkylcyclobutanones were separated using a florisil column. Both compounds were identified by gas chromatography and mass spectrometry and used to investigate the production of radiation-induced hydrocarbons and 2-alkylcyclobutanones. Concentrations of the hydrocarbons and 2-alkylcyclobutanones increased linearly with the radiation dosage. The major hydrocarbons in the irradiated dried squids were pentadecane and 1-tetradecene, which originated from palmitic acid. The amount of pentadecane was the highest among the radiation-induced hydrocarbons in the dried squids. The major 2-alkylcyclobutanone in the irradiated dried squids was 2-dodecylcyclobutanone, which was formed from the large amount of palmitic acid. 2-Tetradecylcyclobutanone, which may be produced from stearic acid in sample lipids, was also detected. Radiation-induced hydrocarbons and 2-alkylcyclobutanones were detected at > or = 0.5 kGy. These compounds were not detected in dried squids that were not irradiated. Radiation-induced hydrocarbons can be used as a detection marker for irradiated dried squids; however, the amount of 2-alkylcyclobutanones produced was not enough to be used as a marker. Radiolytic products of lipids, such as hydrocarbons or 2-alkylcyclobutanones. can be used to monitor food safety for consumers, ensuring proper irradiation labeling in foods and quarantine treatment in international trade.

  19. The influence of the irradiation regime upon mycotoxins production under experimental conditions.

    PubMed

    Uralová, M; Patzeltová, N; Havlík, F

    1987-01-01

    The paper handles the problem of the inactivation of the toxinogenic strain Aspergillus flavus following the application of gamma radiation to wheat. The amount of the applied dose and of the absorbed dose of ionizing radiation upon the inhibition of mycelium growth and toxin production were defined. The aflatoxin B1 was determined by extracting in chloroform and developed on Silufol R within the choroform; aceton system. The applied doses of gamma radiation (3-30 kGy) have show that the absorbed dose does not inhibit aflatoxin production. By combining the action of gamma radiation with humidity of the wheat (humidity 13-15%; 25% irradiation 6 kGy) an inactivation was reached. With the help of toxicologico-genetical tests (the Dominant Lethal Mutations Test, the Three Generations Test) the influence was traced of contaminated, irradiated substrates upon the health of experimental animals. It follows from the results obtained that in long-term feeding with contaminated wheat irradiated by gamma rays no positive mutagenic activity has been recorded. It allows to presume that wheat of humidity of 25% contaminated by a weakly toxigenic strain Aspergillus flavus irradiated by a dose of 6 kGy, and wheat of a humidity of 13-15%, contaminated by a strongly toxinogenic strain of Aspergillus flavus, irradiated by a dose of 6 kGy, are no genetic risk for white rats.

  20. Indirect Production of No Carrier Added (NCA) (177)Lu from Irradiation of Enriched (176)Yb: Options for Ytterbium/Lutetium Separation.

    PubMed

    Dash, Ashutosh; Chakravarty, Rubel; Knapp, Furn F Russ; Pillai, Ambikalmajan M R

    2015-01-01

    This article presents a concise review of the production of no-carrier-added (NCA) (177)Lu by the 'indirect' route by irradiating ytterbium-176 ((176)Yb)-enriched targets. The success of this production method depends on the ability to separate the microscopic amounts of NCA (177)Lu from bulk irradiated ytterbium targets. The presence of Yb(+3) from the target in the final processed (177)Lu will adversely affect the quality of (177)Lu by decreasing the specific activity and competing with Lu(+3) complexation since ytterbium will follow the same coordination chemistry. Ytterbium and lutetium are adjacent members of the lanthanide family with very similar chemical properties which makes the separation of one from the other a challenging task. This review provides a summary of the methods developed for the separation and purification of NCA (177)Lu from neutron irradiated (176)Yb-enriched targets, a critical assessment of recent developments and a discussion of the current status of this (177)Lu production method.

  1. Measurement of prompt gamma profiles in inhomogeneous targets with a knife-edge slit camera during proton irradiation.

    PubMed

    Priegnitz, M; Helmbrecht, S; Janssens, G; Perali, I; Smeets, J; Vander Stappen, F; Sterpin, E; Fiedler, F

    2015-06-21

    Proton and ion beam therapies become increasingly relevant in radiation therapy. To fully exploit the potential of this irradiation technique and to achieve maximum target volume conformality, the verification of particle ranges is highly desirable. Many research activities focus on the measurement of the spatial distributions of prompt gamma rays emitted during irradiation. A passively collimating knife-edge slit camera is a promising option to perform such measurements. In former publications, the feasibility of accurate detection of proton range shifts in homogeneous targets could be shown with such a camera. We present slit camera measurements of prompt gamma depth profiles in inhomogeneous targets. From real treatment plans and their underlying CTs, representative beam paths are selected and assembled as one-dimensional inhomogeneous targets built from tissue equivalent materials. These phantoms have been irradiated with monoenergetic proton pencil beams. The accuracy of range deviation estimation as well as the detectability of range shifts is investigated in different scenarios. In most cases, range deviations can be detected within less than 2 mm. In close vicinity to low-density regions, range detection is challenging. In particular, a minimum beam penetration depth of 7 mm beyond a cavity is required for reliable detection of a cavity filling with the present setup. Dedicated data post-processing methods may be capable of overcoming this limitation.

  2. Measurement of prompt gamma profiles in inhomogeneous targets with a knife-edge slit camera during proton irradiation

    NASA Astrophysics Data System (ADS)

    Priegnitz, M.; Helmbrecht, S.; Janssens, G.; Perali, I.; Smeets, J.; Vander Stappen, F.; Sterpin, E.; Fiedler, F.

    2015-06-01

    Proton and ion beam therapies become increasingly relevant in radiation therapy. To fully exploit the potential of this irradiation technique and to achieve maximum target volume conformality, the verification of particle ranges is highly desirable. Many research activities focus on the measurement of the spatial distributions of prompt gamma rays emitted during irradiation. A passively collimating knife-edge slit camera is a promising option to perform such measurements. In former publications, the feasibility of accurate detection of proton range shifts in homogeneous targets could be shown with such a camera. We present slit camera measurements of prompt gamma depth profiles in inhomogeneous targets. From real treatment plans and their underlying CTs, representative beam paths are selected and assembled as one-dimensional inhomogeneous targets built from tissue equivalent materials. These phantoms have been irradiated with monoenergetic proton pencil beams. The accuracy of range deviation estimation as well as the detectability of range shifts is investigated in different scenarios. In most cases, range deviations can be detected within less than 2 mm. In close vicinity to low-density regions, range detection is challenging. In particular, a minimum beam penetration depth of 7 mm beyond a cavity is required for reliable detection of a cavity filling with the present setup. Dedicated data post-processing methods may be capable of overcoming this limitation.

  3. Automated Production of High Rep Rate Foam Targets

    NASA Astrophysics Data System (ADS)

    Hall, F.; Spindloe, C.; Haddock, D.; Tolley, M.; Nazarov, W.

    2016-04-01

    Manufacturing low density targets in the numbers needed for high rep rate experiments is highly challenging. This report summarises advances from manual production to semiautomated and the improvements that follow both in terms of production time and target uniformity. The production process is described and shown to be improved by the integration of an xyz robot with dispensing capabilities. Results are obtained from manual and semiautomated production runs and compared. The variance in the foam thickness is reduced significantly which should decrease experimental variation due to target parameters and could allow for whole batches to be characterised by the measurement of a few samples. The work applies to both foil backed and free standing foam targets.

  4. A beam sweeping system for the Fermilab antiproton production target

    SciTech Connect

    Bieniosek, F.M.

    1993-08-01

    In the Main Injector era beam intensities high enough to damage the antiproton production target will be available. In order to continue to operate with a tightly-focused primary beam spot on the target, and thus maintain yield, it will be necessary to spread the hot spot on the target by use of a beam sweeping system. This report summarizes the requirements for such a system, and addresses the issues involved in the design of a sweeping system.

  5. Hot deuteron generation and neutron production in deuterated nanowire array irradiated at relativistic intensity

    NASA Astrophysics Data System (ADS)

    Curtis, Alden; Calvi, Chase; Tinsley, Jim; Hollinger, Reed; Wang, Shoujun; Rockwood, Alex; Wang, Yong; Buss, Conrad; Shlyaptsev, Vyacheslav; Kaymak, V.; Pukhov, Alexander; Rocca, Jorge

    2016-10-01

    Irradiation of arrays of aligned high aspect ratio nanowires with high contrast femtosecond laser pulses of relativistic intensity was recently shown to volumetrically heat near solid density plasmas to multi-KeV energy. Using aligned arrays of deuterated polyethylene nanowires (CD2) irradiated at laser intensities of up to 1 ×1020 W/cm2 we are able to generate near solid density plasmas in which the tail of the deuteron distribution was measured to reach energies of up to 3 MeV, in agreement with particle-in-cell simulations. Comparative measurements conducted using flat CD2 targets irradiated by the same laser pulses show the maximum deuteron energies are sub-MeV. We also observed a 100x increase in the number of neutrons produced as compared to flat CD2 targets irradiated at the same conditions, with the highest yield shots producing above 106 neutrons per Joule of laser energy. Work supported by AFOSR Award FA9560-14-10232 and NSTec SDRD program.

  6. Water-cooled grid support for high-power irradiation with thin target windows.

    PubMed

    Barnhart, T E; Converse, A K; Dabbs, K A; Nickles, R J; Buckley, K; Jivan, S; Ruth, T J; Roberts, A D

    2003-01-01

    A new thin window support system for the accelerator production of positron emitters (e.g. 17F, 18F 11C, 15O) has been developed. The integrated support grid and cooling design has been optimized for 6-13 MeV protons or deuterons. The water-cooled support grid regularly operated at > 100 microA of 6 MeV deuterons and protons. The grid performed without failure at > or = 50 microA of 13 MeV protons on a 3.1 MPa gas target using 25.4 microm aluminum target foil. Transmission for the smallest hole grid of 72% based on uniform parallel beam agreed with the measured yield of 71 +/- 1% compared to the theoretical maximum yield. Copyright 2002 Elsevier Science Ltd.

  7. High power targets for production of intense radioactive ion beams

    SciTech Connect

    Talbert, W. L.; Drake, D. M.; Wilson, M. T.; Walker, J. J.; Lenz, J. W.

    1999-04-26

    Issues are discussed in producing intense Radioactive Ion Beams (RIB) using the Isotope Separator On-Line (ISOL) approach, based on the use of thick targets employed at existing facilities. Some new physics studies may possibly be addressed by improving the performance of these existing targets through improvements in release and effusion properties to optimize the RIB yields. It is, however, acknowledged that many desired physics objectives using RIB can be met only by employing production beams of energetic light ions or protons with currents up to 100 {mu}A. Development of targets that use such intense production beams needs to address the requirement to control operational temperatures derived from internal production beam interactions with the target materials. In addition, issues arise for target materials in terms of their thermal characteristics, such as thermal conductivity and thermo-mechanical properties. A target concept is described for an in-beam test of a prototype target for actual thermal behavior under RIB production conditions. For such a test, a high-power test facility is needed; fortunately, the prototypical production beam currents required exist at the TRIUMF accelerator facility. An experimental proposal has been approved for such a test.

  8. A simplified procedure for semi-targeted lipidomic analysis of oxidized phosphatidylcholines induced by UVA irradiation.

    PubMed

    Gruber, Florian; Bicker, Wolfgang; Oskolkova, Olga V; Tschachler, Erwin; Bochkov, Valery N

    2012-06-01

    Oxidized phospholipids (OxPLs) are increasingly recognized as signaling mediators that are not only markers of oxidative stress but are also "makers" of pathology relevant to disease pathogenesis. Understanding the biological role of individual molecular species of OxPLs requires the knowledge of their concentration kinetics in cells and tissues. In this work, we describe a straightforward "fingerprinting" procedure for analysis of a broad spectrum of molecular species generated by oxidation of the four most abundant species of polyunsaturated phosphatidylcholines (OxPCs). The approach is based on liquid-liquid extraction followed by reversed-phase HPLC coupled to electrospray ionization MS/MS. More than 500 peaks corresponding in retention properties to polar and oxidized PCs were detected within 8 min at 99 m/z precursor values using a single diagnostic product ion in extracts from human dermal fibroblasts. Two hundred seventeen of these peaks were fluence-dependently and statistically significantly increased upon exposure of cells to UVA irradiation, suggesting that these are genuine oxidized or oxidatively fragmented species. This method of semitargeted lipidomic analysis may serve as a simple first step for characterization of specific "signatures" of OxPCs produced by different types of oxidative stress in order to select the most informative peaks for identification of their molecular structure and biological role.

  9. Irradiation in the production, processing and handling of food. Final rule.

    PubMed

    2012-11-30

    The Food and Drug Administration (FDA) is amending the food additive regulations to increase the maximum dose of ionizing radiation permitted in the treatment of poultry products, to include specific language intended to clarify the poultry products covered by the regulations, and to remove the limitation that any packaging used during irradiation of poultry shall not exclude oxygen. This action is in response to a petition filed by the U.S. Department of Agriculture, Food Safety and Inspection Service (USDA/FSIS).

  10. Production of {sup 4}He and tritium from Be in the COBRA-1A2 irradiation

    SciTech Connect

    Greenwood, L.R.

    1998-03-01

    The production of {sup 4}He and tritium has been calculated for beryllium irradiated in the COBRA-1A2 experiment in the Experimental Breeder Reactor II. Reaction rates were based on adjusted neutron spectra determined from reactor dosimetry measurements at three different elevations in the region of the beryllium capsules. Equations are given so that gas production can be calculated for any specific capsule elevation.

  11. Differences in Effective Target Volume Between Various Techniques of Accelerated Partial Breast Irradiation

    SciTech Connect

    Shaitelman, Simona F.; Vicini, Frank A.; Grills, Inga S.; Martinez, Alvaro A.; Yan Di; Kim, Leonard H.

    2012-01-01

    Purpose: Different cavity expansions are used to define the clinical target volume (CTV) for accelerated partial breast irradiation (APBI) delivered via balloon brachytherapy (1 cm) vs. three-dimensional conformal radiotherapy (3D-CRT) (1.5 cm). Previous studies have argued that the CTVs generated by these different margins are effectively equivalent. In this study, we use deformable registration to assess the effective CTV treated by balloon brachytherapy on clinically representative 3D-CRT planning images. Methods and Materials: Ten patients previously treated with the MammoSite were studied. Each patient had two computed tomography (CT) scans, one acquired before and one after balloon implantation. In-house deformable registration software was used to deform the MammoSite CTV onto the balloonless CT set. The deformed CTV was validated using anatomical landmarks common to both CT scans. Results: The effective CTV treated by the MammoSite was on average 7% {+-} 10% larger and 38% {+-} 4% smaller than 3D-CRT CTVs created using uniform expansions of 1 and 1.5 cm, respectively. The average effective CTV margin was 1.0 cm, the same as the actual MammoSite CTV margin. However, the effective CTV margin was nonuniform and could range from 5 to 15 mm in any given direction. Effective margins <1 cm were attributable to poor cavity-balloon conformance. Balloon size relative to the cavity did not significantly correlate with the effective margin. Conclusion: In this study, the 1.0-cm MammoSite CTV margin treated an effective volume that was significantly smaller than the 3D-CRT CTV based on a 1.5-cm margin.

  12. Enhancement of laser to X-ray conversion by counter-propagating laser beams irradiating thin gold targets

    NASA Astrophysics Data System (ADS)

    Zhao, Y.; Ge, Z. Y.; Ma, Y. Y.; Yang, X. H.; Xu, B. B.; Ramis, R.

    2017-03-01

    X-ray emission from laser irradiating solid target is an important X-ray source for various potential applications. Counter-propagating (C-P) laser beams configuration is proposed to enhance the laser to X-ray conversion efficiency (CE) from laser irradiating solid targets. One-dimensional radiation hydrodynamics simulations show that the total X-ray CE for the C-P lasers case is as high as 65%, which has a 13% improvement compared with the single laser case. The improvement is mainly caused by the enlarged radiation region, and the enhancement of X-ray emission is from soft X-ray. Detailed energy term distributions and influences of the foil thickness on the X-ray CEs for both cases are presented. It is found that the enhancement of radiation is attributed to lower thermal and kinetic energy of the C-P lasers scheme.

  13. Near monochromatic 20 Me V proton acceleration using fs laser irradiating Au foils in target normal sheath acceleration regime

    SciTech Connect

    Torrisi, L. Ceccio, G.; Cannavò, A.; Cutroneo, M.; Batani, D.; Boutoux, G.; Jakubowska, K.; Ducret, J. E.

    2016-04-15

    A 200 mJ laser pulse energy, 39 fs-pulse duration, 10 μm focal spot, p-polarized radiation has been employed to irradiate thin Au foils to produce proton acceleration in the forward direction. Gold foils were employed to produce high density relativistic electrons emission in the forward direction to generate a high electric field driving the ion acceleration. Measurements were performed by changing the focal position in respect of the target surface. Proton acceleration was monitored using fast SiC detectors in time-of-flight configuration. A high proton energy, up to about 20 Me V, with a narrow energy distribution, was obtained in particular conditions depending on the laser parameters, the irradiation conditions, and a target optimization.

  14. Recovery of 131I from alkaline solution of n-irradiated tellurium target using a tiny Dowex-1 column.

    PubMed

    Chattopadhyay, Sankha; Saha Das, Sujata

    2010-10-01

    A simple and inexpensive ion-exchange chromatography method for the separation of medically useful no-carrier-added (nca) iodine radionuclides from bulk amounts of irradiated tellurium dioxide (TeO(2)) target was developed and tested using (131)I. The radiochemical separation was performed using a very small Dowex-1x8 ion-exchange column. The overall radiochemical yield for the complete separation of (131)I was 92+/-1.8 (standard deviation) % (n=8). The separated nca (131)I was of high, approximately 99%, radionuclidic and radiochemical purity and did not contain detectable amounts of the target material. This method may be adopted for the radiochemical separation of other different iodine radionuclides produced from tellurium matrices through cyclotron as well as reactor irradiation.

  15. Generation of mutagenic transformation products during the irradiation of simulated urban atmospheres

    SciTech Connect

    Kleindienst, T.E.; Smith, D.F.; Hudgens, E.E.; Claxton, L.D.; Bufalini, J.J.

    1992-01-01

    Mixtures of air pollutants simulating urban atmospheres were irradiated in a smog chamber, and the resultant products were monitored for the production of mutagenic and other hazardous compounds. The production of biologically active compounds was detected through use of the Ames mutagenicity assay with Salmonella typhimurium, strain TA100. Irradiations of the pollutant mixture were conducted at HC/NOx ratios of 20 and 11. Overall, the mutagenicity of the products and the formation of oxygenated primary and secondary reactions products were greater for the simulations with the higher initial HC/NOx value. The origin of the mutagenicity from the reactant mixture was examined by conducting experiments with individual paraffinic, olefinic, and aromatic hydrocarbons. The chemicals examined during this aspect of the study were the paraffin n-butane, the olefin propylene, and the aromatic toluene. For the conditions studied, the activity of the toluene products was generally greater than that of propylene or n-butane, and the propylene products showed greater activity than did the n-butane products. The production of n-butane products was generally limited by its low rate of reaction with hydroxyl radicals. Photooxidation products from secondary reactions were most important in the toluene and propylene systems.

  16. Strategies for target identification of antimicrobial natural products.

    PubMed

    Farha, Maya A; Brown, Eric D

    2016-05-04

    Covering: 2000 to 2015Despite a pervasive decline in natural product research at many pharmaceutical companies over the last two decades, natural products have undeniably been a prolific and unsurpassed source for new lead antibacterial compounds. Due to their inherent complexity, natural extracts face several hurdles in high-throughout discovery programs, including target identification. Target identification and validation is a crucial process for advancing hits through the discovery pipeline, but has remained a major bottleneck. In the case of natural products, extremely low yields and limited compound supply further impede the process. Here, we review the wealth of target identification strategies that have been proposed and implemented for the characterization of novel antibacterials. Traditionally, these have included genomic and biochemical-based approaches, which, in recent years, have been improved with modern-day technology and better honed for natural product discovery. Further, we discuss the more recent innovative approaches for uncovering the target of new antibacterial natural products, which have resulted from modern advances in chemical biology tools. Finally, we present unique screening platforms implemented to streamline the process of target identification. The different innovative methods to respond to the challenge of characterizing the mode of action for antibacterial natural products have cumulatively built useful frameworks that may advocate a renovated interest in natural product drug discovery programs.

  17. Volatile profile, lipid oxidation and protein oxidation of irradiated ready-to-eat cured turkey meat products

    NASA Astrophysics Data System (ADS)

    Feng, Xi; Ahn, Dong Uk

    2016-10-01

    Irradiation had little effects on the thiobarbituric acid reactive substances (TBARS) values in ready-to-eat (RTE) turkey meat products, while it increased protein oxidation at 4.5 kGy. The volatile profile analyses indicated that the amount of sulfur compounds increased linearly as doses increased in RTE turkey meat products. By correlation analysis, a positive correlation was found between benzene/ benzene derivatives and alcohols with lipid oxidation, while aldehydes, ketones and alkane, alkenes and alkynes were positively correlated with protein oxidation. Principle component analysis showed that irradiated meat samples can be discriminated by two categories of volatile compounds: Strecker degradation products and radiolytic degradation products. The cluster analysis of volatile data demonstrated that low-dose irradiation had minor effects on the volatile profile of turkey sausages (<1.5 kGy). However, as the doses increased, the differences between the irradiated and non-irradiated cured turkey products became significant.

  18. Lymphoid irradiation in intractable rheumatoid arthritis: effects on the production of immunoglobulins and rheumatoid factors.

    PubMed Central

    Hanly, J G; Hassan, J; Moriarty, M; Whelan, A; Feighery, C; Bresnihan, B

    1985-01-01

    Changes in the production of immunoglobulins and rheumatoid factors (RF's) were studied in 20 patients with intractable rheumatoid arthritis (RA) following total doses of 750 rad or 2,000 rad lymphoid irradiation. Over a 12 month follow up period there was no consistent change in absolute serum or synovial fluid levels, or in synovial membrane production of either total IgG, IgA or IgM, or the corresponding RF fractions. The invitro production of immunoglobulins and IgM RF by peripheral blood mononuclear cells was also unaltered, except for one patient who had a dramatic rise in IgM RF production. Over the same period there was a significant overall reduction in disease activity following both doses of radiotherapy. It is concluded that the clinical response which occurs following lymphoid irradiation is not due to a reduction in RF production. Furthermore, the production of RF's appears to be unaffected by the changes in T cell immunity which occur following lymphoid irradiation. PMID:4085151

  19. LC/MS/MS identification of some folic acid degradation products after E-beam irradiation

    NASA Astrophysics Data System (ADS)

    Araújo, M. M.; Marchioni, E.; Zhao, M.; Kuntz, F.; Di Pascoli, T.; Villavicencio, A. L. C. H.; Bergaentzle, M.

    2012-08-01

    Folates belong to the B vitamin group based on the parental compound folic acid (FA). They are involved in important biochemical processes like DNA synthesis and repair. FA is composed of a pteridine ring, p-aminobenzoic acid and glutamate moieties. The human metabolism is not able to synthesize folates and therefore obtain them from diet. FA, a synthetic vitamin, is used as a food fortificant because of its low price, relative stability and increased bioavailability compared to natural folate forms. FA is known to be a sensitive compound easily degradable in aqueous solution by ultraviolet and visible light towards various by-products. Irradiation is a process for preservation of foods that uses accelerated electrons, gamma rays or X-rays. Irradiation is proposed for the treatment of various food products, eliminating or reducing pathogens and insects, increasing the storage time and replacing chemical fumigants. This study concerns the identification of degradation products of FA after E-beam irradiation. FA aqueous solutions were irradiated with a Van de Graaff electrons beam accelerator (2 MeV, 100 μA current, 20 cm scan width, dose rate about 2 kGy/s). Applied doses were between 0 (control) and 10.0 kGy. Absorbed doses were monitored with FWT 60.00 radiochromic dosimeters.

  20. Dry-distillation of astatine-211 from irradiated bismuth targets: a time-saving procedure with high recovery yields.

    PubMed

    Lindegren, S; Bäck, T; Jensen, H J

    2001-08-01

    Astatine-211 was produced via the 209Bi(alpha,2n) 211At reaction. The radionuclide was isolated with a novel procedure employing dry-distillation of the irradiated target material. The astatine was condensed as a dry residue in a PEEK-capillary cryotrap. Distillation was completed within 1-2 min with isolation yields of 92 +/- 3%. Subsequent work-up of the nuclide resulted in final recovery yields of 79 +/- 3%.

  1. Excretion of carcinoma products in irradiated C/sub 3/H/He mice. [Gamma

    SciTech Connect

    Vaage, J.; Anderson, B.; Chu, A.

    1981-02-01

    Local low-dose (200 rads) gamma-irradiation to both kidneys impaired the excretion of 3H-labeled tumor products and reduced the survival time of mice carrying carcinomas in the ascites form. Daily i.p. injections of cell-free ascites fluid into tumor-free mice for 3 weeks resulted in the death of 25 to 180 irradiated animals, with no deaths among 180 injected unirradiated controls. The only histologically visible effects of irradiation of the kidneys during ascites tumor growth or during i.p. injections of cell-free ascites fluid was a cloudy swelling of the tubular epithelium in the renal cortex together with excessive protein in the tubular lumens.

  2. Use of irradiation as quarantine treatment for agricultural products infested by mites and insects

    NASA Astrophysics Data System (ADS)

    Ignatowicz, S.; Brzostek, G.

    The criterion for efficacy of irradiation of agricultural products as a quarantine treatment should be based on the inability to perpetuate the pest at a new location rather than in causing immediate mortality. Sterility in insects and mites is achieved following irradiation of adults and immatures at much lower doses than needed to kill these pests. Irradiation of beans infested by the bean weevil, Acanthoscelidesobtectus Say, and grains infested by the grain weevil, Sitophilusgranarius (L.), and/or the rice weevil, S. oryzae (L.), at 60 Gy could be the treatment required to produce an acceptable level of quarantine security. For the acarid mites ( Acaridae), a dose of 250 Gy is suggested. At these dosages, adult survivors of the pest will be present in the treated commodities, but they will not give rise to offspring, and thus this pest would not be able to perpetuate in a new area.

  3. Formation of hazardous by-products resulting from the irradiation of natural organic matter: comparison between UV and VUV irradiation.

    PubMed

    Buchanan, W; Roddick, F; Porter, N

    2006-05-01

    The use of ultraviolet (UV) or vacuum ultraviolet (VUV) photo-oxidation followed by biological treatment for the removal of natural organic matter (NOM) in drinking water is a potential water treatment technique under investigation. This paper reports on the trihalomethane formation potential (THMFP), the haloacetic acid formation potential (HAAFP), and formation of nitrite and peroxide following both UV and VUV irradiation of NOM prior to biological treatment. The total THMFP was found to decrease with increasing UV and VUV irradiation dose, although there was a linear increase in bromoform formation. Determination of the THMFP of NOM fractions obtained after irradiation, showed that the hydrophobic fraction was dominated by chlorinated species which accounted for the majority of the total THMFP, while bromoform was observed only in the hydrophilic fraction of NOM. VUV irradiation reduced the HAAFP with increasing dose, in contrast, UV irradiation had a limited effect on the overall HAAFP. Following UV or VUV irradiation, the chlorinated species accounted for the majority of HAAFP; however, significant formation of brominated haloacetic acid (HAA) was observed. The nitrate concentration of the untreated water directly influenced the concentration of nitrite produced as a consequence of UV and VUV irradiation. Hydrogen peroxide formation was greater during VUV irradiation than during UV irradiation. Samples exposed to various doses of UV or VUV irradiation (up to 138 J cm(-2)) were deemed non-cytotoxic (African green monkey kidney cells) and non-mutagenic (Ames test).

  4. Fermilab Tevatron I project target station for antiproton production

    SciTech Connect

    Hojvat, C.; Biallas, G.; Hanson, R.; Heim, J.; Lange, F.

    1983-03-01

    Production of 8-GeV antiprotons in the Fermilab Tevatron I project will utilize 120-GeV protons from the Main Ring. The Target Station consists of an entrance collimator, the target itself, a pulsed lithium lens for anti proton collection, a pulsed magnet for the separation of the 8-GeV secondaries, and a beam dump. These components are mounted on vertical modules within the Target Service Building. Allowance has been made for future improvements to increase the collected anti proton flux. The design of the Target Station and its components is discussed.

  5. Shielding calculations for a production target for secondary beams

    SciTech Connect

    Rehm, K.E.; Back, B.B.; Jiang, C.L.

    1995-08-01

    In order to estimate the amount of shielding required for a radioactive beam facility dose rate were performed. The calculations for production targets with different geometries were performed. The calculations were performed with the MSU shielding code assuming a 500-p{mu}A 200-MeV deuteron beam stopped in a thick Al target. The target and the ion-optical elements for beam extraction are located in a 2 m{sup 3} large volume at the center of the production cell. These dose rate calculations show that with a combination of Fe and concrete it is possible to reduce the dose rate expected at the surface of a 7-m-wide cube housing the production target to less than 2 mrem/hr.

  6. Irradiation of advanced health care products - Tissues and biologics

    NASA Astrophysics Data System (ADS)

    Winters, Martell

    2014-12-01

    Radiation sterilization of tissues and biologics has become more common in recent years. As a result it has become critical to understand how to adapt the typical test methods and validation approaches to a tissue or biological product scenario. Also data evaluation sometimes becomes more critical than with traditional medical devices because for many tissues and biologics a low radiation dose is required. It is the intent behind this paper to provide information on adapting bioburden tests used in radiation validations such that the data can be most effectively used on tissues and biologics. In addition challenges with data evaluation are discussed, particularly the use of less-than values for bioburden results in radiation validation studies.

  7. Investigation of the production and properties of lattice defects induced by low temperature reactor irradiation

    NASA Astrophysics Data System (ADS)

    Mansel, W.; Mueller, P.; Marangos, J.; Wahl, D.; Wallner, G.; Weck, W.; Riem, R.; Glaeser, W.

    1984-03-01

    Defects in irradiated metals were investigated. In the project defect production rate neutron spectra in the irradiated position of a low temperature irradiation stand are determined using the multiple probe activation method. In the project Mossbauer spectroscopy the trapping of interstitial atoms on 57C-impurity atoms in W and V is observed. It is found that in W interstitial atoms are mobile at 25 K. For Mo57Co a detailed understanding of the reactions between impurity and interstitial atoms is obtained. In the project alkali metals the mobility of interstitial atoms in K, Na and Li at 5K is demonstrated by resistivity measurements; step III lies at 16K. The investigations of the magnetic resistance on irradiated or worked K show that the macroscopic, residual defect systems in the samples are responsible for the anomalous linear evolution of the longitudinal high field magnetic resistance. In the project Fermi surfaces of Bi with lattice defects de Haas-van Alphen effect measurements on irradiated Bi show an increase up to 100% of the Fermi surface cross sections of the electron ellipsoid and a simultaneous decrease of the vacancies Fermi surface cross sections.

  8. Irradiation effect on bulgogi sauce for making commercial Korean traditional meat product, bulgogi

    NASA Astrophysics Data System (ADS)

    Jo, C.; Kim, D. H.; Shin, M. G.; Kang, I. J.; Byun, M. W.

    2003-12-01

    Gamma-irradiated sauce of bulogogi, Korean traditional meat products, was compared with heat-pasteurized one to enhance its safety, quality, and commercial availability. The sauce is usually sold in refrigerated state with 2-7 days of self-life or heat-sterilized and sold in room temperature for a year. Raw vegetables, fruits and soy sauce for sauce making were highly contaminated by thermophillic microorganisms (totally 2.13×10 6 CFU/g) and coliform bacteria (totally 5.90×10 4 CFU/g) at the initial stage. Heat treatment (100°C for 30 min) was effective to control coliform and microbes counted from Salmonella-Shigella selective agar in the sauce but not on thermophillic microorganisms, resulting in a rapid spoilage after 2 weeks at 20°C. Gamma irradiation reduced the level of thermophillic microorganisms and the spoilage was prevented during storage for 4 weeks at 20°C. Protease activity of the sauce was significantly reduced by heat treatment while was not changed by irradiation at 2.5, 5.0, and 10 kGy. Sensory evaluation showed that the irradiation was better in color than nonirradiated control or heat-treated sample. Results indicate that low dose irradiation (2.5-5.0 kGy) is effective to ensure safety of bulgogi sauce with acceptable sensory quality.

  9. Directional and Spectral Irradiance in Ocean Models: Effects on Simulated Global Phytoplankton, Nutrients, and Primary Production

    NASA Technical Reports Server (NTRS)

    Gregg, Watson W.; Rousseaux, Cecile S.

    2016-01-01

    The importance of including directional and spectral light in simulations of ocean radiative transfer was investigated using a coupled biogeochemical-circulation-radiative model of the global oceans. The effort focused on phytoplankton abundances, nutrient concentrations and vertically-integrated net primary production. The importance was approached by sequentially removing directional (i.e., direct vs. diffuse) and spectral irradiance and comparing results of the above variables to a fully directionally and spectrally-resolved model. In each case the total irradiance was kept constant; it was only the pathways and spectral nature that were changed. Assuming all irradiance was diffuse had negligible effect on global ocean primary production. Global nitrate and total chlorophyll concentrations declined by about 20% each. The largest changes occurred in the tropics and sub-tropics rather than the high latitudes, where most of the irradiance is already diffuse. Disregarding spectral irradiance had effects that depended upon the choice of attenuation wavelength. The wavelength closest to the spectrally-resolved model, 500 nm, produced lower nitrate (19%) and chlorophyll (8%) and higher primary production (2%) than the spectral model. Phytoplankton relative abundances were very sensitive to the choice of non-spectral wavelength transmittance. The combined effects of neglecting both directional and spectral irradiance exacerbated the differences, despite using attenuation at 500 nm. Global nitrate decreased 33% and chlorophyll decreased 24%. Changes in phytoplankton community structure were considerable, representing a change from chlorophytes to cyanobacteria and coccolithophores. This suggested a shift in community function, from light-limitation to nutrient limitation: lower demands for nutrients from cyanobacteria and coccolithophores favored them over the more nutrient-demanding chlorophytes. Although diatoms have the highest nutrient demands in the model, their

  10. Efficient and stable proton acceleration by irradiating a two-layer target with a linearly polarized laser pulse

    NASA Astrophysics Data System (ADS)

    Wang, H. Y.; Yan, X. Q.; Chen, J. E.; He, X. T.; Ma, W. J.; Bin, J. H.; Schreiber, J.; Tajima, T.; Habs, D.

    2013-01-01

    We report an efficient and stable scheme to generate ˜200 MeV proton bunch by irradiating a two-layer targets (near-critical density layer+solid density layer with heavy ions and protons) with a linearly polarized Gaussian pulse at intensity of 6.0×1020 W/cm2. Due to self-focusing of laser and directly accelerated electrons in the near-critical density layer, the proton energy is enhanced by a factor of 3 compared to single-layer solid targets. The energy spread of proton is also remarkably reduced. Such scheme is attractive for applications relevant to tumor therapy.

  11. Possible version of the compression degradation of the thermonuclear indirect-irradiation targets at the national ignition facility and a reason for the failure of ignition

    NASA Astrophysics Data System (ADS)

    Rozanov, V. B.; Vergunova, G. A.

    2017-01-01

    The main parameters of compression of a target and tendencies at change in the irradiation conditions are determined by analyzing the published results of experiments at the megajoule National Ignition Facility (NIF) on the compression of capsules in indirect-irradiation targets by means of the one-dimensional RADIAN program in the spherical geometry. A possible version of the "failure of ignition" of an indirect-irradiation target under the NIF conditions is attributed to radiation transfer. The application of onedimensional model to analyze the National Ignition Campaign (NIC) experiments allows identifying conditions corresponding to the future ignition regime and distinguishing them from conditions under which ignition does not occur.

  12. Helium and hydrogen measurements on pure materials irradiated in SINQ Target 4

    NASA Astrophysics Data System (ADS)

    Oliver, B. M.; Dai, Y.

    2009-04-01

    Several irradiations have been performed in the Swiss Spallation Neutron Source (SINQ) to establish a materials database for mixed proton and neutron fluxes for future spallation neutron and other accelerator sources. Pure metal dosimetry materials from the second irradiation (STIP-II) have been analyzed for their total helium and hydrogen contents and their release characteristics with temperature (TDS). Total helium results are similar to those observed earlier from the first irradiation experiment (STIP-I), with concentrations ranging from ˜500 to ˜1000 appm. Hydrogen contents varied over a larger range from ˜100 to ˜60 000. 3He/ 4He ratios were generally consistent with expectations, except for Ti, Nb, and Ta which showed lower values due to 3He from decay of irradiation-generated tritium. Some differences were observed in the hydrogen TDS data for the control and irradiated materials, including some evidence for additional lower-temperature release and for multiple release peaks. Additionally, differences were noted in the releases for irradiated material that been cleaned versus material that had no cleaning.

  13. The thermal-mechanical analysis of targets for the high volume production of molybdenum-99 using a low-enriched uranium metal foil

    NASA Astrophysics Data System (ADS)

    Turner, Kyler Kriens

    Molybdenum-99 diagnostic imaging is the most commonly practiced procedure in nuclear medicine today with the majority molybdenum-99 produced with proliferation sensitive HEU. International and domestic efforts to develop non-HEU production techniques have taking the first steps toward establishing a new non-HEU molybdenum-99 based supply chain. The focus of the research presented in this work is on the analysis of a new high U-235 density LEU based molybdenum-99 production target. Converting directly to LEU using current manufacturing techniques greatly reduces the molybdenum-99 yield per target making high volume production uneconomical. The LEU based foil target analyzed in this research increases the yield per target making economic high volume production with LEU possible. The research analyzed the thermal-mechanical response of an LEU foil target during irradiation. Thermal-mechanical studies focused on deflections and stresses to assess the probability of target failure. Simpler analytical models were used to determine the proper shape of the target and to benchmark the numerical modeling software. Numerical studies using Abaqus focused on analyzing various heating and cooling conditions and assessing the effects of curvature on the target. Finally, experiments were performed to simulate low power heating and further benchmark the models. The results from all of these analyses indicate a LEU foil target could survive irradiation depending on the conditions seen during irradiation.

  14. Reduction of ochratoxin A in dry-cured meat products using gamma-irradiation.

    PubMed

    Domijan, Ana-Marija; Pleadin, Jelka; Mihaljević, Branka; Vahčić, Nada; Frece, Jadranka; Markov, Ksenija

    2015-01-01

    This study investigated the efficiency of gamma (γ)-irradiation in the reduction of ochratoxin A (OTA) present in dry-cured meat products prepared from intentionally contaminated raw materials from OTA-treated pigs. OTA concentrations determined in the samples (n = 24) ranged from 25.8 μg kg(-1) in bacon to 17.8 μg kg(-1) in smoked ham. After γ-irradiation at doses of 3, 7 and 10 kGy (i.e. the doses used in the food industry), a dose-depended OTA reduction was observed; however, it was not statistically significant. The mean OTA reduction achieved with 3-, 7- and 10-kGy γ-doses was approximated to 8.5%, 13.9% and 22.5%, respectively. The storage of irradiated samples (1 month, 4°C) did not significantly affect OTA levels. Based on the correlation between the OTA reduction level and basic chemical composition of dry-cured meat samples, OTA reduction may be linked to the samples' fat content. The results indicate that γ-irradiation can reduce OTA levels in dry-cured meat products, but only to a limited extent due to the complexity of the matrix.

  15. Nimbus 7 Solar Backscatter Ultraviolet (SBUV) spectral scan solar irradiance and Earth radiance product user's guide

    NASA Technical Reports Server (NTRS)

    Schlesinger, Barry M.; Cebula, Richard P.; Heath, Donald F.; Fleig, Albert J.

    1988-01-01

    The archived tape products from the spectral scan mode measurements of solar irradiance (SUNC tapes) and Earth radiance (EARTH tapes) by the Solar Backscatter UV (SBUV) instrument aboard Nimbus 7 are described. Incoming radiation from 160 to 400 nm is measured at intervals of 0.2 nm. The scan-to-scan repeatability of the solar irradiance measurements ranges from approximately 0.5 to 1 percent longward of 280 nm, to 2 percent around 210 nm and 4 percent near 175 nm. The repeatability of the Earth radiance values ranges from 2 to 3 percent at longer wavelengths and low zenith angles to 10 percent at shorter wavelengths and high zenith angles. The tape formats are described in detail, including file structure and contents of each type of record. Catalogs of the tapes and the time period covered are provided, along with lists of the days lacking solar irradiance measurements and the days dedicated to Earth radiance measurements. The method for production of the tapes is outlined and quality control measures are described. How radiances and irradiances are derived from the raw counts, the corrections for changes in instrument sensitivity, and related uncertainties are discussed.

  16. Monitoring of Irradiated Food Products Marketed in Italy and Evaluation of Electron Spin Resonance Signal Sensitivity of Experimentally Irradiated Fish Scales

    PubMed Central

    Carosielli, Leonardo; Mangiacotti, Michele; Chiaravalle, Eugenio; Smaldone, Giorgio; Anastasio, Aniello

    2014-01-01

    Many countries, in order to authorise the use of food irradiation, claim the availability of methods to detect the occurred treatment in addition to the respect of safe use of this technology. Among physical methods, the electron spin resonance (ESR) measuring the number of free radicals that are formed during irradiation can be applied only to those foods with cellulose, a crystalline or bone structure, in which free radicals have a shelf life greater than irradiated product. The aim of this study was to highlight an irradiation treatment in European and extra-European foods marketed in Southern Italy by the means of ESR technique. Furthermore, in order to optimise the preparation procedures the efficacy of the above mentioned method in fish scales experimentally irradiated has been evaluated. From February to September 2012, a total number of 83 samples of food products of animal and plant origin were taken at the border inspection post and at retail market and finally analysed. At the same time, the scales of grouper and barracuda have been experimentally irradiated at 0.5 kGy and were subsequently analysed using ESR. Results showed 5 frog legs out of 83 samples positive for treatment and confirm the applicability of ESR also for fish scales. PMID:27800329

  17. Fission products measured from highly-enriched uranium irradiated under 10B4C in a research reactor

    SciTech Connect

    Metz, Lori A.; Friese, Judah I.; Finn, Erin C.; Greenwood, Lawrence R.; Hines, Corey C.; King, Matthew D.; Wall, Donald E.

    2016-03-01

    Critical assemblies provide one method of achieving a fast neutron spectrum that is close to a 235U fission-energy neutron spectrum for nuclear data measurements. Previous work has demonstrated the use of a natural boron carbide capsule for spectral-tailoring in a mixed spectrum reactor as an alternate and complementary method for performing fission-energy neutron experiments. Previous fission products measurements showed that the neutron spectrum achievable with natural boron carbide was not as hard as what can be achieved with critical assemblies. New measurements performed with the Washington State University TRIGA reactor using a boron carbide capsule 96% enriched in 10B for irradiations resulted in a neutron spectrum very similar to a critical assembly and a pure 235U fission spectrum. The current work describes an experiment involving a highly-enriched uranium target irradiated under the new 10B4C capsule. Fission product yields were measured following radiochemical separations and are presented here. Reactor dosimetry measurements for characterizing neutron spectra and fluence for the enriched boron carbide capsule and critical assemblies are also discussed.

  18. Effects of gamma irradiation for inactivating Salmonella Typhimurium in peanut butter product during storage.

    PubMed

    Ban, Ga-Hee; Kang, Dong-Hyun

    2014-02-03

    Three types (A, B, and C) of peanut butter product with different water activities (0.18, 0.39, and 0.65 aw) inoculated with a 3-strain mixture of Salmonella Typhimurium were subjected to gamma irradiation (⁶⁰Co) treatment, with doses ranging from 0 to 3 kGy. The inactivation of S. Typhimurium in the 3 types of treated peanut butter product over a 14 day storage period and the influence of storage temperature at 4 (refrigerated) and 25 °C (ambient), and peanut butter product formulation were investigated. Three types of peanut butter product inoculated with S. Typhimurium to a level of ca. 6.6 log CFU/g and subjected to gamma irradiation experienced significant (p<0.05) reductions of 1.3 to 1.9, 2.6 to 2.8, and 3.5 to 4.0 log CFU/g at doses of 1, 2, and 3 kGy, respectively. The time required to reduce S. Typhimurium in peanut butter product to undetectable levels was 14, 5, and 5 days at 25°C after exposure to 3 kGy for products A, B, and C, respectively, and 7 days at 25 °C following exposure to 2 kGy for product C. During storage at 4 and 25 °C, survival of S. Typhimurium was lowest in product C compared to products A and B. Water activity (a(w)) of peanut butter product was likely the most critical factor affecting pathogen survival. When a(w) is reduced, radiolysis of water is reduced, thereby decreasing antimicrobial action. Overall, death was more rapid at 25 °C versus 4 °C for all peanut butter products during 14 day storage. Following gamma irradiation, acid values of peanut butter product were not significantly different from the control, and general observations failed to detect changes in color and aroma, even though lightness observed using a colorimeter was slightly reduced on day 0. The use of gamma irradiation has potential in preventing spoilage of post-packaged food by destroying microorganisms and improving the safety and quality of foods without compromising sensory quality.

  19. ``Sleeping reactor`` irradiations: Shutdown reactor determination of short-lived activation products

    SciTech Connect

    Jerde, E.A.; Glasgow, D.C.

    1998-09-01

    At the High-Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory, the principal irradiation system has a thermal neutron flux ({phi}) of {approximately} 4 {times} 10{sup 14} n/cm{sup 2} {center_dot} s, permitting the detection of elements via irradiation of 60 s or less. Irradiations of 6 or 7 s are acceptable for detection of elements with half-lives of as little as 30 min. However, important elements such as Al, Mg, Ti, and V have half-lives of only a few minutes. At HFIR, these can be determined with irradiation times of {approximately} 6 s, but the requirement of immediate counting leads to increased exposure to the high activity produced by irradiation in the high flux. In addition, pneumatic system timing uncertainties (about {+-} 0.5 s) make irradiations of < 6 s less reliable. Therefore, the determination of these ultra-short-lived species in mixed matrices has not generally been made at HFIR. The authors have found that very short lived activation products can be produced easily during the period after reactor shutdown (SCRAM), but prior to the removal of spent fuel elements. During this 24- to 36-h period (dubbed the ``sleeping reactor``), neutrons are produced in the beryllium reflector by the reaction {sup 9}Be({gamma},n){sup 8}Be, the gamma rays principally originating in the spent fuel. Upon reactor SCRAM, the flux drops to {approximately} 1 {times} 10{sup 10} n/cm{sup 2} {center_dot} s within 1 h. By the time the fuel elements are removed, the flux has dropped to {approximately} 6 {times} 10{sup 8}. Such fluxes are ideal for the determination of short-lived elements such as Al, Ti, Mg, and V. An important feature of the sleeping reactor is a flux that is not constant.

  20. Anopheles arabiensis sperm production after genetic manipulation, dieldrin treatment, and irradiation.

    PubMed

    Damiens, D; Vreysen, M J B; Gilles, J R L

    2013-03-01

    The use of the sterile insect technique relies on the release of sterilized mass-reared male insects which, before field releases, endure several unnatural treatments. In the case of Anopheles arabiensis (Patton) sterile insect technique program in Sudan, the genetic background of the original strain was first changed to create a genetic sexing strain that is based on a dieldrin-resistant mutation. Secondly, the eggs of the genetic sexing strain require treatment with dieldrin to allow complete elimination of female L1 larvae to enable the release of males only. Finally, male mosquitoes receive an irradiation dose of 70 Gy as pupae for sterilization. The effects of these treatments on sperm production were tested separately and in combination. Irradiation alone significantly decreased the initial sperm number and prevented new sperm production. However, the dieldrin treatment, aimed at eliminating females, appears to have an unexpected radioprotectant effect.

  1. Dominant front-side acceleration of energetic proton beams from plastic targets irradiated by an ultraintense laser pulse

    SciTech Connect

    Lee, K.; Park, S. H.; Cha, Y.-H.; Lee, Y. W.; Jeong, Y. U.; Lee, J. Y.; Kim, K. N.

    2011-01-15

    An experimental observation has been made by using aluminum-coated Mylar foils, which strongly supports that in the case of plastic target, the energetic part of the proton beam originates from the front-side of the target. When a 30 fs laser pulse with an intensity of 1.6x10{sup 19} W/cm{sup 2} was irradiated on the 12.5-{mu}m-thick Mylar side of the aluminum-coated Mylar foil, the maximum proton energy was reduced by a factor 5.5 as compared to that of 3.3 MeV observed from the single layer of the Mylar foil. With the help of a two-dimensional particle-in-cell simulation, these observations can be interpreted that in the case of plastic target, the energetic proton beam originates from the front-side of the target. In the case of an aluminum-coated 6-{mu}m-thick Mylar foil, more energetic proton beams of 4.7 MeV were also observed when the laser pulse was irradiated on the aluminum side as compared to those of 3.4 MeV from the single Mylar foil.

  2. Automatic system of production, transfer and processing of coin targets for the production of metallic radioisotopes

    NASA Astrophysics Data System (ADS)

    Pellicioli, M.; Ouadi, A.; Marchand, P.; Foehrenbacher, T.; Schuler, J.; Dick-Schuler, N.; Brasse, D.

    2017-05-01

    The work presented in this paper gathers three main technical developments aiming at 1) optimizing nuclide production by the mean of solid targets 2) automatically transferring coin targets from vault to hotcell without human intervention 3) processing target dilution and purification in hotcell automatically. This system has been installed on a ACSI TR24 cyclotron in Strasbourg France.

  3. Comparison of fission product release predictions using PARFUME with results from the AGR-1 irradiation experiment

    SciTech Connect

    Blaise Collin

    2014-09-01

    This report documents comparisons between post-irradiation examination measurements and model predictions of silver (Ag), cesium (Cs), and strontium (Sr) release from selected tristructural isotropic (TRISO) fuel particles and compacts during the first irradiation test of the Advanced Gas Reactor program that occurred from December 2006 to November 2009 in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). The modeling was performed using the particle fuel model computer code PARFUME (PARticle FUel ModEl) developed at INL. PARFUME is an advanced gas-cooled reactor fuel performance modeling and analysis code (Miller 2009). It has been developed as an integrated mechanistic code that evaluates the thermal, mechanical, and physico-chemical behavior of fuel particles during irradiation to determine the failure probability of a population of fuel particles given the particle-to-particle statistical variations in physical dimensions and material properties that arise from the fuel fabrication process, accounting for all viable mechanisms that can lead to particle failure. The code also determines the diffusion of fission products from the fuel through the particle coating layers, and through the fuel matrix to the coolant boundary. The subsequent release of fission products is calculated at the compact level (release of fission products from the compact) but it can be assessed at the particle level by adjusting the diffusivity in the fuel matrix to very high values. Furthermore, the diffusivity of each layer can be individually set to a high value (typically 10-6 m2/s) to simulate a failed layer with no capability of fission product retention. In this study, the comparison to PIE focused on fission product release and because of the lack of failure in the irradiation, the probability of particle failure was not calculated. During the AGR-1 irradiation campaign, the fuel kernel produced and released fission products, which migrated through the successive

  4. Effect of gamma irradiation and water activity on mycotoxin production of Alternaria in tomato paste and juice.

    PubMed

    Aziz, N H; Farag, S; Hassanin, M A

    1991-01-01

    Gamma-irradiation, water activity (aw) and incubation temperature were found to affect the production of tenuazonic acid (TZA) by Alternaria alternata in tomato paste and juice. By increasing the irradiation doses, the dry weight as well as TZA decreased greatly until complete inhibition at 4 kGy. Greatest production of TZA occurred at 0.98 aw (57.5 micrograms/g and 26.3 micrograms/g) for both tomato paste and juice, respectively, at 25 degrees C. Changing temperature and aw altered the relative amounts of TZA produced in tomato paste und juice by unirradiated and irradiated conidia of A. alternata. Only trace amount of TZA was detected at 0.98 aw (1.50 micrograms/g) by 3 kGy-irradiated conidia in tomato paste, while it was inhibited completely in juice. Increasing gamma-irradiation doses and decreasing water activities decreased greatly or inhibited TZA production in both tomato paste and juice.

  5. Calculation of in-target production rates for radioactive isotope beam production at TRIUMF

    NASA Astrophysics Data System (ADS)

    Garcia, Fatima; Andreoiu, Corina; Kunz, Peter; Laxdal, Aurelia

    2016-09-01

    Rare Isotope Beam (RIB) facilities around the world, such as TRIUMF, work towards development of new target materials to generate exotic species. Access to these rare radioactive isotopes is key for applications in nuclear medicine, astrophysics and fundamental nuclear science. To better understand production from these and other materials, we have built a computer simulation of the RIB targets used at the TRIUMF Isotope Separation and ACceleration (ISAC) facility, to support new target material development. Built at Simon Fraser University, the simulation runs in the GEANT4 nuclear transport toolkit, and can simulate the production rate of isotopes from a given set of beam and target characteristics. The simulation models the bombardment of a production target by an incident high-energy proton beam and calculates isotope in-target production rates different nuclear reactions. Results from the simulation will be presented, along with an evaluation of various nuclear reaction models and a experimentally determined RIB yields at the ISAC Yield Station.

  6. Gamma-irradiated β-glucan modulates signaling molecular targets of hepatocellular carcinoma in rats.

    PubMed

    Elsonbaty, Sawsan M; Zahran, Walid E; Moawed, Fatma Sm

    2017-08-01

    β-glucans are one of the most abundant forms of polysaccharides known as biological response modifiers which influence host's biological response and stimulate immune system. Accordingly, this study was initiated to evaluate irradiated β-glucan as a modulator for cellular signaling growth factors involved in the pathogenesis of hepatocellular carcinoma in rats. Hepatocellular carcinoma was induced with 20 mg diethylnitrosamine/kg BW. Rats received daily by gastric gavage 65 mg irradiated β-glucan/kg BW. It was found that treatment of rats with diethylnitrosamine induced hepatic injury and caused significant increase in liver injury markers with a concomitant significant increase in both hepatic oxidative and inflammatory indices: alpha-fetoprotein, interferon gamma, and interleukin 6 in comparison with normal and irradiated β-glucan-treated groups. Western immunoblotting showed a significant increase in the signaling growth factors: extracellular signal-regulated kinase 1 and phosphoinositide 3-kinase proteins in a diethylnitrosamine-treated group while both preventive and therapeutic irradiated β-glucan treatments recorded significant improvement versus diethylnitrosamine group via the modulation of growth factors that encounters hepatic toxicity. The transcript levels of vascular endothelial growth factor A and inducible nitric oxide synthase genes were significantly higher in the diethylnitrosamine-treated group in comparison with controls. Preventive and therapeutic treatments with irradiated β-glucan demonstrated that the transcript level of these genes was significantly decreased which demonstrates the protective effect of β-glucan. Histological investigations revealed that diethylnitrosamine treatment affects the hepatic architecture throughout the significant severe appearance of inflammatory cell infiltration in the portal area and congestion in the portal vein in association with severe degeneration and dysplasia in hepatocytes all over hepatic

  7. Isotope production and target preparation for nuclear astrophysics data

    NASA Astrophysics Data System (ADS)

    Schumann, Dorothea; Dressler, Rugard; Maugeri, Emilio Andrea; Heinitz, Stephan

    2017-09-01

    Targets are in many cases an indispensable ingredient for successful experiments aimed to produce nuclear data. With the recently observed shift to study nuclear reactions on radioactive targets, this task can become extremely challenging. Concerted actions of a certain number of laboratories able to produce isotopes and manufacture radioactive targets are urgently needed. We present here some examples of successful isotope and target production at PSI, in particular the production of 60Fe samples used for half-life measurements and neutron capture cross section experiments, the chemical processing and fabrication of lanthanide targets for capture cross section experiments at n_TOF (European Organization for Nuclear Research (CERN), Switzerland) as well as the recently performed manufacturing of highly-radioactive 7Be targets for the measurement of the 7Be(n,α)4He cross section in the energy range of interest for the Big-Bang nucleosynthesis contributing to the solving of the cosmological Li-problem. The two future projects: "Determination of the half-life and experiments on neutron capture cross sections of 53Mn" and "32Si - a new chronometer for nuclear dating" are briefly described. Moreover, we propose to work on the establishment of a dedicated network on isotope and target producing laboratories.

  8. Post-irradiation analysis of an ISOLDE lead-bismuth target: Stable and long-lived noble gas nuclides

    NASA Astrophysics Data System (ADS)

    Leya, I.; Grimberg, A.; David, J.-C.; Schumann, D.; Neuhausen, J.; Zanini, L.; Noah, E.

    2016-07-01

    We measured the isotopic concentrations of long-lived and stable He, Ne, Ar, Kr, and Xe isotopes in a sample from a lead-bismuth eutectic target irradiated with 1.0 and 1.4 GeV protons. Our data indicate for most noble gases nearly complete release with retention fractions in the range of percent or less. Higher retention fractions result from the decay of long-lived radioactive progenitors from groups 1, 2, or 7 of the periodic table. From the data we can calculate a retention fraction for 3H of 2-3%. For alkaline metals we find retention fractions of about 10%, 30%, and 50% for Na, Rb, and Cs, respectively. For the alkaline earth metal Ba we found complete retention. Finally, the measured Kr and Xe concentrations indicate that there was some release of the halogens Br and I during and/or after the irradiation.

  9. Photodegradation of malachite green under simulated and natural irradiation: kinetics, products, and pathways.

    PubMed

    Yong, Li; Zhanqi, Gao; Yuefei, Ji; Xiaobin, Hu; Cheng, Sun; Shaogui, Yang; Lianhong, Wang; Qingeng, Wang; Die, Fang

    2015-03-21

    In this work photodegradation rates and pathways of malachite green were studied under simulated and solar irradiation with the goal of assessing the potential of photolysis as a removal mechanism in real aquatic environment. Factors influencing the photodegradation process were investigated, including pH, humic acid, Fe(2+), Ca(2+), HCO3(-), and NO3(-), of which favorable conditions were optimized by the orthogonal array design under simulated sunlight irradiation in the presence of dissolved oxygen. The degradation processes of malachite green conformed to pseudo first-order kinetics and their degradation rate constants were between 0.0062 and 0.4012 h(-1). Under solar irradiation, the decolorization efficiency of most tests can reach almost 100%, and relatively thorough mineralization could be observed. Forty degradation products were detected by liquid chromatography-mass spectrometry, and thirteen small molecular products were identified by gas chromatography-mass spectrometry. Based on the analyses of the degradation products and calculation of the frontier electron density, the pathways were proposed: decomposition of conjugated structure, N-demethylation reactions, hydroxyl addition reactions, the removal of benzene ring, and the ring-opening reaction. This study has provided a reference, both for photodegradation of malachite green and future safety applications and predictions of decontamination of related triphenylmethane dyes under real conditions.

  10. The RIB production target for the SPES project

    NASA Astrophysics Data System (ADS)

    Monetti, Alberto; Andrighetto, Alberto; Petrovich, Carlo; Manzolaro, Mattia; Corradetti, Stefano; Scarpa, Daniele; Rossetto, Francesco; Martinez Dominguez, Fernando; Vasquez, Jesus; Rossignoli, Massimo; Calderolla, Michele; Silingardi, Roberto; Mozzi, Aldo; Borgna, Francesca; Vivian, Gianluca; Boratto, Enrico; Ballan, Michele; Prete, Gianfranco; Meneghetti, Giovanni

    2015-10-01

    Facilities making use of the Isotope Separator On-Line (ISOL) method for the production of Radioactive Ion Beams (RIB) attract interest because they can be used for nuclear structure and reaction studies, astrophysics research and interdisciplinary applications. The ISOL technique is based on the fast release of the nuclear reaction products from the chosen target material together with their ionization into short-lived nuclei beams. Within this context, the SPES (Selective Production of Exotic Species) facility is now under construction in Italy at INFN-LNL (Istituto Nazionale di Fisica Nucleare — Laboratori Nazionali di Legnaro). The SPES facility will produce RIBs mainly from n-rich isotopes obtained by a 40 MeV cyclotron proton beam (200 μA) directly impinging on a uranium carbide multi-foil fission target. The aim of this work is to describe and update, from a comprehensive point of view, the most important results obtained by the analysis of the on-line behavior of the SPES production target assembly. In particular an improved target configuration has been studied by comparing different codes and physics models: the thermal analyses and the isotope production are re-evaluated. Then some consequent radioprotection aspects, which are essential for the installation and operation of the facility, are presented.

  11. Production of 61Cu using natural cobalt target and its separation using ascorbic acid and common anion exchange resin.

    PubMed

    Das, Sujata Saha; Chattopadhyay, Sankha; Barua, Luna; Das, Malay Kanti

    2012-02-01

    (61)Cu was produced by (nat)Co(α, xn)(61)Cu reaction. (61)Cu production yield was 89.5 MBq/μAh (2.42 mCi/μAh) at the end of irradiation (EOI). A simple radiochemical separation method using anion exchange resin and ascorbic acid has been employed to separate the product radionuclide from inactive target material and co-produced non-isotopic impurities. The radiochemical separation yield was about 90%. Radiochemical purity of (61)Cu was >99% 1 h after EOI. Final product was suitable for making complex with N(2)S(2) type of ligands.

  12. Development of a Charged Particle Microbeam for Targeted and Single Particle Subcellular Irradiation

    SciTech Connect

    Yanch, Jacquelyn C.

    2004-03-12

    The development of a charged particle microbeam for single particle, subcellular irradiations at the Massachusetts Institute of Technology Laboratory for Accelerator Beam Applications (MIT LABA) was initiated under this NEER aeard. The Microbeam apparatus makes use of a pre-existing electrostatic accelerator with a horizontal beam tube.

  13. Small punch tests on martensitic/ferritic steels F82H, T91 and Optimax-A irradiated in SINQ Target-3

    NASA Astrophysics Data System (ADS)

    Jia, X.; Dai, Y.

    2003-12-01

    Small punch (SP) tests were conducted in a temperature range from -190 to 80 °C on martensitic/ferritic steels F82H, T91 and Optimax-A irradiated in SINQ Target-3 up to 9.4 dpa in a irradiation temperature range of 90-275 °C. Results demonstrate: (a) the irradiation hardening deduced from SP tests is reasonably consistent with the results obtained by tensile tests; (b) with increasing irradiation dose, the SP yield load increases at all test temperatures, while the displacement at the maximum load and the total displacement at failure decrease; (c) the ductile-to-brittle transition temperature (DBTT SP) increases with increasing irradiation dose, and does so more quickly at irradiation doses above ˜6-7 dpa; in addition, the ΔDBTT SP increases linearly with helium content.

  14. Gamma irradiation of medicinally important plants and the enhancement of secondary metabolite production.

    PubMed

    Vardhan, P Vivek; Shukla, Lata I

    2017-09-01

    The profitable production of some important plant-based secondary metabolites (ginsenosides, saponins, camptothecin, shikonins etc.) in vitro by gamma irradiation is a current area of interest. We reviewed different types of secondary metabolites, their mode of synthesis and effect of γ-radiation on their yield for different plants, organs and in vitro cultures (callus, suspension, hairy root). Special effort has been made to review the biochemical mechanisms underlying the increase in secondary metabolites. A comparison of yield improvement with biotic and abiotic stresses was made. Phenolic compounds increase with γ-irradiation in whole plants/plant parts; psoralen content in the common herb babchi (Psoralea corylifolia) was increased as high as 32-fold with γ-irradiation of seeds at 20 kGy. The capsaicinoids, a phenolic compound increased about 10% with 10 kGy in paprika (Capsicum annum L.). The in vitro studies show all the three types of secondary metabolites are reported to increase with γ-irradiation. Stevioside, total phenolic and flavonoids content were slightly increased in 15 Gy-treated callus cultures of stevia (Stevia rebaudiana Bert.). In terpenoids, total saponin and ginsenosides content were increased 1.4- and 1.8-fold, respectively, with 100 Gy for wild ginseng (Panax ginseng Meyer) hairy root cultures. In alkaloids, camptothecin yield increased as high as 20-fold with 20 Gy in callus cultures of ghanera (Nothapodytes foetida). Shikonins increased up to 4-fold with 16 Gy in suspension cultures of purple gromwell (Lithospermum erythrorhizon S.). The enzymes associated with secondary metabolite production were increased with γ-irradiation of 20 Gy; namely, phenylalanine ammonia-lyase (PAL) for phenolics, chalcone synthase (CHS) for flavonoids, squalene synthase (SS), squalene epoxidase (SE) and oxidosqualene cyclases (OSC) for ginsenosides and PHB (p-hydroxylbenzoic acid) geranyl transferase for shikonins. An increase in secondary

  15. Comparison of Irradiation and Wolbachia Based Approaches for Sterile-Male Strategies Targeting Aedes albopictus

    PubMed Central

    Atyame, Célestine M.; Labbé, Pierrick; Lebon, Cyrille; Weill, Mylène; Moretti, Riccardo; Marini, Francesca; Gouagna, Louis Clément; Calvitti, Maurizio; Tortosa, Pablo

    2016-01-01

    The global expansion of Aedes albopictus together with the absence of vaccines for most of the arboviruses transmitted by this mosquito has stimulated the development of sterile-male strategies aiming at controlling disease transmission through the suppression of natural vector populations. In this context, two environmentally friendly control strategies, namely the Sterile Insect Technique (SIT) and the Wolbachia-based Incompatible Insect Technique (IIT) are currently being developed in several laboratories worldwide. So far however, there is a lack of comparative assessment of these strategies under the same controlled conditions. Here, we compared the mating capacities, i.e. insemination capacity, sterilization capacity and mating competitiveness of irradiated (35 Gy) and incompatible Ae. albopictus males at different ages and ratios under laboratory controlled conditions. Our data show that there was no significant difference in insemination capacity of irradiated and incompatible males, both male types showing lower capacities than untreated males at 1 day but recovering full capacity within 5 days following emergence. Regarding mating competitiveness trials, a global observed trend is that incompatible males tend to induce a lower hatching rate than irradiated males in cage controlled confrontations. More specifically, incompatible males were found more competitive than irradiated males in 5:1 ratio regardless of age, while irradiated males were only found more competitive than incompatible males in the 1:1 ratio at 10 days old. Overall, under the tested conditions, IIT seemed to be slightly more effective than SIT. However, considering that a single strategy will likely not be adapted to all environments, our data stimulates the need for comparative assessments of distinct strategies in up-scaled conditions in order to identify the most suitable and safe sterilizing technology to be implemented in a specific environmental setting and to identify the

  16. Comparison of Irradiation and Wolbachia Based Approaches for Sterile-Male Strategies Targeting Aedes albopictus.

    PubMed

    Atyame, Célestine M; Labbé, Pierrick; Lebon, Cyrille; Weill, Mylène; Moretti, Riccardo; Marini, Francesca; Gouagna, Louis Clément; Calvitti, Maurizio; Tortosa, Pablo

    2016-01-01

    The global expansion of Aedes albopictus together with the absence of vaccines for most of the arboviruses transmitted by this mosquito has stimulated the development of sterile-male strategies aiming at controlling disease transmission through the suppression of natural vector populations. In this context, two environmentally friendly control strategies, namely the Sterile Insect Technique (SIT) and the Wolbachia-based Incompatible Insect Technique (IIT) are currently being developed in several laboratories worldwide. So far however, there is a lack of comparative assessment of these strategies under the same controlled conditions. Here, we compared the mating capacities, i.e. insemination capacity, sterilization capacity and mating competitiveness of irradiated (35 Gy) and incompatible Ae. albopictus males at different ages and ratios under laboratory controlled conditions. Our data show that there was no significant difference in insemination capacity of irradiated and incompatible males, both male types showing lower capacities than untreated males at 1 day but recovering full capacity within 5 days following emergence. Regarding mating competitiveness trials, a global observed trend is that incompatible males tend to induce a lower hatching rate than irradiated males in cage controlled confrontations. More specifically, incompatible males were found more competitive than irradiated males in 5:1 ratio regardless of age, while irradiated males were only found more competitive than incompatible males in the 1:1 ratio at 10 days old. Overall, under the tested conditions, IIT seemed to be slightly more effective than SIT. However, considering that a single strategy will likely not be adapted to all environments, our data stimulates the need for comparative assessments of distinct strategies in up-scaled conditions in order to identify the most suitable and safe sterilizing technology to be implemented in a specific environmental setting and to identify the

  17. Mass spectrometry analysis of etch products from CR-39 plastic irradiated by heavy ions

    NASA Astrophysics Data System (ADS)

    Kodaira, S.; Nanjo, D.; Kawashima, H.; Yasuda, N.; Konishi, T.; Kurano, M.; Kitamura, H.; Uchihori, Y.; Naka, S.; Ota, S.; Ideguchi, Y.; Hasebe, N.; Mori, Y.; Yamauchi, T.

    2012-09-01

    As a feasibility study, gas chromatography-mass spectrometry (GC-MS) and matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) have been applied to analyze etch products of CR-39 plastic (one of the most frequently used solid states nuclear track detector) for the understanding of track formation and etching mechanisms by heavy ion irradiation. The etch products of irradiated CR-39 dissolved in sodium hydroxide solution (NaOH) contain radiation-induced fragments. For the GC-MS analysis, we found peaks of diethylene glycol (DEG) and a small but a definitive peak of ethylene glycol (EG) in the etch products from CR-39 irradiated by 60 MeV N ion beams. The etch products of unirradiated CR-39 showed a clear peak of DEG, but no other significant peaks were found. DEG is known to be released from the CR-39 molecule as a fragment by alkaline hydrolysis reaction of the polymer. We postulate that EG was formed as a result of the breaking of the ether bond (C-O-C) of the DEG part of the CR-39 polymer by the irradiation. The mass distribution of polyallylalcohol was obtained from the etch products from irradiated and unirradiated CR-39 samples by MALDI-MS analysis. Polyallylalcohol, with the repeating mass interval of m/z = 58 Da (dalton) between m/z = 800 and 3500, was expected to be produced from CR-39 by alkaline hydrolysis. We used IAA as a matrix to assist the ionization of organic analyte in MALDI-MS analysis and found that peaks from IAA covered mass spectrum in the lower m/z region making difficult to identify CR-39 fragment peaks which were also be seen in the same region. The mass spectrometry analysis using GC-MS and MALDI-MS will be powerful tools to investigate the radiation-induced polymeric fragments and helping to understand the track formation mechanism in CR-39 by heavy ions.

  18. Aflatoxin B1, zearalenone and deoxynivalenol production on irradiated corn kernels: Influence of inoculum size.

    PubMed

    Magnoli, C; Etcheverry, M G; Cavaglieri, L; Saenz, M; Alvarez, G; Lecumberry, S

    1998-03-01

    The influence of inoculum size on aflatoxin B1 (AFB1), zearalenone (ZEN) and deoxynivalenol (DON) production was examined on irradiated corn kernels.Spore concentrations were determined in serial dilutions and adjusted to 10,10(2),10(3),10(5) and 10(6) spores/ml. Aflatoxin B1 production was dependent on the inoculum size. The high levels of aflatoxin B1 produced byA. parasiticus (21 and 30 mg/kg) were obtained with 10(2) and 10(3) spores/ml after 35 and 20 days incubation. There was no spore concentration influence on zearalenone and deoxynivalenol production after 10, 20 and 35 days incubation. At 28°C and 0.97 water activity (aw), the mean levels of zearalenone production were 382, 267 and 520 µg/kg and the mean levels on deoxynivalenol production were 697,465 and 782 µg/kg.

  19. Chemical forms of solid fission products in the irradiated uranium—plutonium mixed nitride fuel

    NASA Astrophysics Data System (ADS)

    Arai, Yasuo; Maeda, Atsushi; Shiozawa, Ken-ichi; Ohmichi, Toshihiko

    1994-06-01

    Chemical forms of solid fission products in the irradiated (U, Pu)N fuel were estimated by both thermodynamic equilibrium calculation and electron microprobe analysis on burnup simulated samples prepared by carbothermic reduction. Besides the MX type matrix phase dissolving zirconium, niobium, yttrium and rare earth elements, the existence of two kinds of inclusion was recognized. One is URu 3 type intermetallic compound constituted by uranium and platinum group elements. The other is an alloy containing molybdenum as a principal constituent. Furthermore, the swelling rate due to solid fission products precipitation was evaluated to be about 0.5% per %FIMA.

  20. Eliciting Production of L2 Target Structures through Priming Activities

    ERIC Educational Resources Information Center

    McDonough, Kim; Trofimovich, Pavel; Neumann, Heike

    2015-01-01

    This study focuses on the pedagogical applications of structural priming research in an English for academic purposes (EAP) context, investigating whether priming activities are an effective tool for eliciting production of target grammatical structures. University students across four EAP classes carried out a total of 6 information-exchange…

  1. Eliciting Production of L2 Target Structures through Priming Activities

    ERIC Educational Resources Information Center

    McDonough, Kim; Trofimovich, Pavel; Neumann, Heike

    2015-01-01

    This study focuses on the pedagogical applications of structural priming research in an English for academic purposes (EAP) context, investigating whether priming activities are an effective tool for eliciting production of target grammatical structures. University students across four EAP classes carried out a total of 6 information-exchange…

  2. What's the Regulatory Value of a Target Product Profile?

    PubMed

    Breder, Christopher D; Du, Wenny; Tyndall, Adria

    2017-07-01

    Target product profiles (TPPs) are used as a regulatory tool for dialog on clinical development or manufacturing plans. Drugs and biologics approved by the FDA that mention TPPs are associated with more efficient regulatory review times, perhaps as a result of increased planning or because the TPP promotes well-organized regulatory dialog. Published by Elsevier Ltd.

  3. Target-fueled nuclear reactor for medical isotope production

    DOEpatents

    Coats, Richard L.; Parma, Edward J.

    2017-06-27

    A small, low-enriched, passively safe, low-power nuclear reactor comprises a core of target and fuel pins that can be processed to produce the medical isotope .sup.99Mo and other fission product isotopes. The fuel for the reactor and the targets for the .sup.99Mo production are the same. The fuel can be low enriched uranium oxide, enriched to less than 20% .sup.235U. The reactor power level can be 1 to 2 MW. The reactor is passively safe and maintains negative reactivity coefficients. The total radionuclide inventory in the reactor core is minimized since the fuel/target pins are removed and processed after 7 to 21 days.

  4. Measured radionuclide production from copper, gold and lead spallation targets

    SciTech Connect

    Parish, T.A.; Belian, A.P.

    1995-10-01

    Spallation target materials are chosen so as to produce large numbers of neutrons while at the same time avoiding the creation of long-lived radioactive wastes. While there has been considerable research to determine the number of neutrons produced per incident particle for various target materials, there has been less effort to precisely quantify the types and amounts of radionuclides produced. Accurate knowledge of the radioactive species produced by spallation reactions is important for specifying waste disposal criteria for targets. In order to verify the production rates calculated by LAHET, a study has been conducted using the Texas A&M University (TAMU) Cyclotron to measure radionuclide yields from copper, gold, and lead targets.

  5. The Human Kinome Targeted by FDA Approved Multi-Target Drugs and Combination Products: A Comparative Study from the Drug-Target Interaction Network Perspective.

    PubMed

    Li, Ying Hong; Wang, Pan Pan; Li, Xiao Xu; Yu, Chun Yan; Yang, Hong; Zhou, Jin; Xue, Wei Wei; Tan, Jun; Zhu, Feng

    2016-01-01

    The human kinome is one of the most productive classes of drug target, and there is emerging necessity for treating complex diseases by means of polypharmacology (multi-target drugs and combination products). However, the advantages of the multi-target drugs and the combination products are still under debate. A comparative analysis between FDA approved multi-target drugs and combination products, targeting the human kinome, was conducted by mapping targets onto the phylogenetic tree of the human kinome. The approach of network medicine illustrating the drug-target interactions was applied to identify popular targets of multi-target drugs and combination products. As identified, the multi-target drugs tended to inhibit target pairs in the human kinome, especially the receptor tyrosine kinase family, while the combination products were able to against targets of distant homology relationship. This finding asked for choosing the combination products as a better solution for designing drugs aiming at targets of distant homology relationship. Moreover, sub-networks of drug-target interactions in specific disease were generated, and mechanisms shared by multi-target drugs and combination products were identified. In conclusion, this study performed an analysis between approved multi-target drugs and combination products against the human kinome, which could assist the discovery of next generation polypharmacology.

  6. The Human Kinome Targeted by FDA Approved Multi-Target Drugs and Combination Products: A Comparative Study from the Drug-Target Interaction Network Perspective

    PubMed Central

    Yu, Chun Yan; Yang, Hong; Zhou, Jin; Xue, Wei Wei; Tan, Jun; Zhu, Feng

    2016-01-01

    The human kinome is one of the most productive classes of drug target, and there is emerging necessity for treating complex diseases by means of polypharmacology (multi-target drugs and combination products). However, the advantages of the multi-target drugs and the combination products are still under debate. A comparative analysis between FDA approved multi-target drugs and combination products, targeting the human kinome, was conducted by mapping targets onto the phylogenetic tree of the human kinome. The approach of network medicine illustrating the drug-target interactions was applied to identify popular targets of multi-target drugs and combination products. As identified, the multi-target drugs tended to inhibit target pairs in the human kinome, especially the receptor tyrosine kinase family, while the combination products were able to against targets of distant homology relationship. This finding asked for choosing the combination products as a better solution for designing drugs aiming at targets of distant homology relationship. Moreover, sub-networks of drug-target interactions in specific disease were generated, and mechanisms shared by multi-target drugs and combination products were identified. In conclusion, this study performed an analysis between approved multi-target drugs and combination products against the human kinome, which could assist the discovery of next generation polypharmacology. PMID:27828998

  7. Fast and cost-effective cyclotron production of (61)Cu using a (nat)Zn liquid target: an opportunity for radiopharmaceutical production and R&D.

    PubMed

    do Carmo, S J C; Alves, V H P; Alves, F; Abrunhosa, A J

    2017-07-13

    Following our previous work on the production of radiometals, such as (64)Cu and (68)Ga, through the irradiation of liquid targets using a medical cyclotron, we describe in this paper a technique to produce (61)Cu through the irradiation of natural zinc using a liquid target. The proposed method is very cost-effective, as it avoids the use of expensive enriched material, and is fast, as a purified solution of (61)CuCl2 is obtained in less than 30 min after the end of beam. Considering its moderate half-life of 3.33 h and favourable decay properties as a positron emitter, (61)Cu is a very attractive nuclide for the labelling of PET tracers for pre-clinical and clinical use with PET as well as to support the intense R&D programmes being carried out worldwide by taking advantage of the rich and versatile chemistry of copper.

  8. Defect production in Ar irradiated graphene membranes under different initial applied strains

    NASA Astrophysics Data System (ADS)

    Martinez-Asencio, J.; Ruestes, C. J.; Bringa, E.; Caturla, M. J.

    2017-02-01

    Irradiation with low energy Ar ions of graphene membranes gives rise to changes in the mechanical properties of this material. These changes have been associated to the production of defects, mostly isolated vacancies. However, the initial state of the graphene membrane can also affect its mechanical response. Using molecular dynamics simulations we have studied defect production in graphene membranes irradiated with 140 eV Ar ions up to a dose of 0.075 × 1014 ions/cm2 and different initial strains, from -0.25% (compressive strain) to 0.25% (tensile strain). For all strains, the number of defects increases linearly with dose with a defect production of about 80% (80 defects every 100 ions). Defects are mostly single vacancies and di-vacancies, although some higher order clusters are also observed. Two different types of di-vacancies have been identified, the most common one being two vacancies at first nearest neighbours distance. Differences in the total number of defects with the applied strain are observed which is related to the production of a higher number of di-vacancies under compressive strain compared to tensile strain. We attribute this effect to the larger out-of-plane deformations of compressed samples that could favor the production of defects in closer proximity to others.

  9. Cellular regulation of basal and FSH-stimulated cyclic AMP production in irradiated rat testes

    SciTech Connect

    Kangasniemi, M.; Kaipia, A.; Toppari, J.; Mali, P.; Huhtaniemi, I.; Parvinen, M. )

    1990-05-01

    Basal and follicle-stimulating hormone (FSH)-stimulated cyclic AMP (cAMP) productions by seminiferous tubular segments from irradiated adult rats were investigated at defined stages of the epithelial cycle when specific spermatogenic cells were low in number. Seven days post-irradiation, depletion of spermatogonia did not influence the basal cAMP production, but FSH response increased in stages II-VIII. Seventeen days post-irradiation when spermatocytes were low in number, there was a small increase in basal cAMP level in stages VII-VIII and FSH-stimulated cAMP production increased in stages VII-XII and XIII-I. At 38 days when pachytene spermatocytes and round spermatids (steps 1-6) were low in number, a decreased basal cAMP production was measured in stages II-VI and IX-XII. FSH-stimulated cAMP output increased in stages VII-XII but decreased in stages II-VI. At 52 days when all spermatids were low in number, basal cAMP levels decreased in all stages of the cycle, whereas FSH response was elevated only in stages VII-XII. All spermatogenic cell types seem to have an effect on cAMP production by the seminiferous tubule in a stage-specific fashion. Germ cells appear to regulate Sertoli cell FSH response in a paracrine way, and a part of cAMP may originate from spermatids stimulated by an unknown FSH-dependent Sertoli cell factor. The FSH-dependent functions may control such phenomena as spermatogonial proliferation, final maturation of spermatids, and onset of meiosis.

  10. GEANT4 simulation of cyclotron radioisotope production in a solid target.

    PubMed

    Poignant, F; Penfold, S; Asp, J; Takhar, P; Jackson, P

    2016-05-01

    The use of radioisotopes in nuclear medicine is essential for diagnosing and treating cancer. The optimization of their production is a key factor in maximizing the production yield and minimizing the associated costs. An efficient approach to this problem is the use of Monte Carlo simulations prior to experimentation. By predicting isotopes yields, one can study the isotope of interest expected activity for different energy ranges. One can also study the target contamination with other radioisotopes, especially undesired radioisotopes of the wanted chemical element which are difficult to separate from the irradiated target and might result in increasing the dose when delivering the radiopharmaceutical product to the patient. The aim of this work is to build and validate a Monte Carlo simulation platform using the GEANT4 toolkit to model the solid target system of the South Australian Health and Medical Research Institute (SAHMRI) GE Healthcare PETtrace cyclotron. It includes a GEANT4 Graphical User Interface (GUI) where the user can modify simulation parameters such as the energy, shape and current of the proton beam, the target geometry and material, the foil geometry and material and the time of irradiation. The paper describes the simulation and presents a comparison of simulated and experimental/theoretical yields for various nuclear reactions on an enriched nickel 64 target using the GEANT4 physics model QGSP_BIC_AllHP, a model recently developed to evaluate with high precision the interaction of protons with energies below 200MeV available in Geant4 version 10.1. The simulation yield of the (64)Ni(p,n)(64)Cu reaction was found to be 7.67±0.074 mCi·μA(-1) for a target energy range of 9-12MeV. Szelecsenyi et al. (1993) gives a theoretical yield of 6.71mCi·μA(-1) and an experimental yield of 6.38mCi·μA(-1). The (64)Ni(p,n)(64)Cu cross section obtained with the simulation was also verified against the yield predicted from the nuclear database TENDL and

  11. MICRO/NANO-STRUCTURAL EXAMINATION AND FISSION PRODUCT IDENTIFICATION IN NEUTRON IRRADIATED AGR-1 TRISO FUEL

    SciTech Connect

    van Rooyen, I. J.; Lillo, T. M.; Wen, H. M.; Hill, C. M.; Holesinger, T. G.; Wu, Y. Q.; Aguiara, J. A.

    2016-11-01

    Advanced microscopic and microanalysis techniques were developed and applied to study irradiation effects and fission product behavior in selected low-enriched uranium oxide/uranium carbide TRISO-coated particles from fuel compacts in six capsules irradiated to burnups of 11.2 to 19.6% FIMA. Although no TRISO coating failures were detected during the irradiation, the fraction of Ag-110m retained in individual particles often varied considerably within a single compact and at the capsule level. At the capsule level Ag-110m release fractions ranged from 1.2 to 38% and within a single compact, silver release from individual particles often spanned a range that extended from 100% retention to nearly 100% release. In this paper, selected irradiated particles from Baseline, Variant 1 and Variant 3 type fueled TRISO coated particles were examined using Scanning Electron Microscopy, Atom Probe Tomography; Electron Energy Loss Spectroscopy; Precession Electron Diffraction, Transmission Electron Microscopy, Scanning Transmission Electron Microscopy (STEM), High Resolution Electron Microscopy (HRTEM) examinations and Electron Probe Micro-Analyzer. Particle selection in this study allowed for comparison of the fission product distribution with Ag retention, fuel type and irradiation level. Nano sized Ag-containing features were predominantly identified in SiC grain boundaries and/or triple points in contrast with only two sitings of Ag inside a SiC grain in two different compacts (Baseline and Variant 3 fueled compacts). STEM and HRTEM analysis showed evidence of Ag and Pd co-existence in some cases and it was found that fission product precipitates can consist of multiple or single phases. STEM analysis also showed differences in precipitate compositions between Baseline and Variant 3 fuels. A higher density of fission product precipitate clusters were identified in the SiC layer in particles from the Variant 3 compact compared with the Variant 1 compact. Trend analysis shows

  12. Microbial decontamination of cosmetic raw materials and personal care products by irradiation

    NASA Astrophysics Data System (ADS)

    Katušin-Ražem, Branka; Mihaljević, Branka; Ražem, Dušan

    2003-03-01

    Typical levels of sporadically occurring (dynamic) microbial contamination of cosmetic raw materials: pigments, abrasives and liposomes, as well as of final products for personal care: toothpaste, crayons, shampoos, cleansers and creams, were evaluated. In most cases the contamination was dominated by a single population of microorganisms, either Gram-negative bacteria or molds. The feasibility of microbial decontamination by irradiation was studied by determining the resistance to gamma radiation of contaminating microflora in situ. It was expressed as a dose required for the first 90% reduction, D first 90% red . The values in the range 1-2 kGy for molds and 0.1-0.6 kGy for Gram-negative bacteria were obtained. This relatively high susceptibility to irradiation allowed inactivation factors close to 6 to be achieved with doses generally not exceeding 3 kGy, and yielding endpoint contamination less than 10/g.

  13. Algae harvesting for biofuel production: influences of UV irradiation and polyethylenimine (PEI) coating on bacterial biocoagulation.

    PubMed

    Agbakpe, Michael; Ge, Shijian; Zhang, Wen; Zhang, Xuezhi; Kobylarz, Patricia

    2014-08-01

    There is a pressing need to develop efficient and sustainable separation technologies to harvest algae for biofuel production. In this work, two bacterial species (Escherichia coli and Rhodococus sp.) were used as biocoagulants to harvest Chlorella zofingiensis and Scenedesmus dimorphus. The influences of UV irradiation and polyethylenimine (PEI)-coating on the algal harvesting efficiency were investigated. Results showed that the UV irradiation could slightly enhance bacteria-algae biocoagulation and algal harvesting efficiency. In contrast, the PEI-coated E. coli cells noticeably increased the harvesting efficiencies from 23% to 83% for S. dimorphus when compared to uncoated E. coli cells. Based on the soft-particle Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, an energy barrier existed between uncoated E. coli cells and algal cells, whereas the PEI coating on E. coli cells eliminated the energy barrier, thereby the biocoagulation was significantly improved. Overall, this work presented groundwork toward the potential use of bacterial biomass for algal harvesting from water.

  14. Three-dimensional thermal response numerical simulation of laser irradiating simulative warhead target

    NASA Astrophysics Data System (ADS)

    Chen, Minsun; Jiang, Houman

    2015-05-01

    The thermal response of a cylindrical simulative warhead consisting of the steel casing and the TNT explosive irradiated by laser is simulated, basing on the smoothed particle hydrodynamics method. Preliminary computational simulation results show that, when the power density of 500W/cm2 continuous laser irradiation on a sealed explosive device consisting of the type 304 steel casing with thickness of 5mm and TNT explosive, compared with no airflow, the speed of 200m/s tangential airflow can reduce the thermal initiation time of 0.6s. In the case of incident laser power density is high, the convection cooling effect of tangential airflow can be neglected. The oxidation of airflow can significantly shorten the thermal initiation time of internal explosive.

  15. Production of {sup 4}He, {sup 3}He, and tritium from Be irradiated in FFTF-MOTA-2B

    SciTech Connect

    Greenwood, L.R.

    1998-03-01

    The production of {sup 4}He, {sup 3}He, and tritium has been calculated for beryllium irradiated in the Materials Open Test Assembly (MOTA)-2B experiment in the Fast Flux Test Facility (FFTF). Reaction rates were based on adjusted neutron spectra determined from reactor dosimetry measurements at seven different elevations in the irradiation assembly. Equations are given so that gas production, dpa, and neutron fluences can be calculated for any specific elevation in the MOTA-2B assembly.

  16. Arcing and rf signal generation during target irradiation by a high-energy, pulsed neutral particle beam

    SciTech Connect

    Robiscoe, R.T.

    1988-02-01

    We present a theory describing the dynamics of arc discharges in bulk dielectric materials on board space-based vehicles. Such ''punch-through'' arcs can occur in target satellites irradiated by high-energy (250 MeV), pulsed (100 mA x 10 ms) neutral particle beams. We treat the arc as a capacitively limited avalanche current in the target dielectric material, and we find expressions for the arc duration, charge transport, currents, and discharge energy. These quantities are adjusted to be consistent with known scaling laws for the area of charge depleted by the arc. After a brief account of the statistical distribution of voltages at which the arc starts and stops, we calculate the signal strength and frequency spectrum of the electromagnetic radiation broadcast by the arc. We find that arcs from thick ()similarreverse arrowto)1 cm) targets can generate rf signals detectable up to 1000 km from the target, bu a radio receiver operating at frequency 80 MHz, bandwidth 100 kHz, and detection threshold -105 dBm. These thick-target arc signals are 10 to 20 dB above ambient noise at the receiver, and they provide target hit assessment if the signal spectrum can be sampled at several frequencies in the nominal range 30-200 MHz. Thin-target ()similarreverse arrowto)1 mm) arc signals are much weaker, but when they are detecable in conjunction with thick-target signals, target discrimination is possible by comparing the signal frequency spectra. 24 refs., 12 figs.

  17. Processing of LEU targets for {sup 99}Mo production: Dissolution of U{sub 3}Si{sub 2} targets by alkaline hydrogen peroxide

    SciTech Connect

    Buchholz, B.A.; Vandegrift, G.F.

    1995-09-01

    Low-enriched uranium silicide targets designed to recover fission product {sup 99}Mo were dissolved in alkaline hydrogen peroxide (H{sub 2}O{sub 2} plus NaOH) at about 90C. Sintering of matrix aluminum powder during irradiation and heat treatment retarded aluminum dissolution and prevented silicide particle dispersion. Gas evolved during dissolution is suspected to adhere to particles and block hydroxide ion contact with aluminum. Reduction of base concentrations from 5M to O.lM NaOH yielded similar silicide dissolution and peroxide destruction rates, simplifying later processing. Future work in particle dispersion enhancement, {sup 99}Mo separation, and waste disposal is also discussed.

  18. Measurement of desorbed products during organic polymer thin film etching by plasma beam irradiation

    SciTech Connect

    Kurihara, Kazuaki; Karahashi, Kazuhiro; Egami, Akihiro; Nakamura, Moritaka

    2006-11-15

    The authors investigated the etching characteristics of three kinds of methacrylate polymer films, which have the same main chain but with different side chains, using a plasma beam irradiation apparatus. The polymers are polytbutylmethacrylate, polybenzylmethacrylate, and polycyclohexylmethacrylate. The major desorbed products during nitrogen plasma beam etching were found to be HCN and C{sub 2}N{sub 2} for all methacrylate polymer films. The desorbed products originating from the polymer structure, namely, the main chain and the side chain, were hardly observed. The energy distributions of desorbed products were mainly composed of Maxwell-Boltzmann distribution with a small component of collision cascade distribution for all three polymers and were slightly dependent on the ion energy. It is concluded that chemical sputtering, which can be defined as the production of weakly bound species by ion bombardment, followed by thermal desorption, is the significant ion induced mechanism of organic polymer etching.

  19. Fission Product Inventory and Burnup Evaluation of the AGR-2 Irradiation by Gamma Spectrometry

    SciTech Connect

    Harp, Jason M.; Demkowicz, Paul A.; Stempien, John D.

    2016-11-01

    Gamma spectrometry has been used to evaluate the burnup and fission product inventory of different components from the US Advanced Gas Reactor Fuel Development and Qualification Program's second TRISO-coated particle fuel irradiation test (AGR-2). TRISO fuel in this irradiation included both uranium carbide / uranium oxide (UCO) kernels and uranium oxide (UO2) kernels. Four of the 6 capsules contained fuel from the US Advanced Gas Reactor program, and only those capsules will be discussed in this work. The inventories of gamma-emitting fission products from the fuel compacts, graphite compact holders, graphite spacers and test capsule shell were evaluated. These data were used to measure the fractional release of fission products such as Cs-137, Cs-134, Eu-154, Ce-144, and Ag-110m from the compacts. The fraction of Ag-110m retained in the compacts ranged from 1.8% to full retention. Additionally, the activities of the radioactive cesium isotopes (Cs-134 and Cs-137) have been used to evaluate the burnup of all US TRISO fuel compacts in the irradiation. The experimental burnup evaluations compare favorably with burnups predicted from physics simulations. Predicted burnups for UCO compacts range from 7.26 to 13.15 % fission per initial metal atom (FIMA) and 9.01 to 10.69 % FIMA for UO2 compacts. Measured burnup ranged from 7.3 to 13.1 % FIMA for UCO compacts and 8.5 to 10.6 % FIMA for UO2 compacts. Results from gamma emission computed tomography performed on compacts and graphite holders that reveal the distribution of different fission products in a component will also be discussed. Gamma tomography of graphite holders was also used to locate the position of TRISO fuel particles suspected of having silicon carbide layer failures that lead to in-pile cesium release.

  20. Fission Product Inventory and Burnup Evaluation of the AGR-2 Irradiation by Gamma Spectrometry

    SciTech Connect

    Harp, Jason Michael; Stempien, John Dennis; Demkowicz, Paul Andrew

    2016-09-01

    Gamma spectrometry has been used to evaluate the burnup and fission product inventory of different components from the US Advanced Gas Reactor Fuel Development and Qualification Program's second TRISO-coated particle fuel irradiation test (AGR-2). TRISO fuel in this irradiation included both uranium carbide / uranium oxide (UCO) kernels and uranium oxide (UO2) kernels. Four of the 6 capsules contained fuel from the US Advanced Gas Reactor program, and only those capsules will be discussed in this work. The inventories of gamma-emitting fission products from the fuel compacts, graphite compact holders, graphite spacers and test capsule shell were evaluated. These data were used to measure the fractional release of fission products such as Cs-137, Cs-134, Eu-154, Ce-144, and Ag-110m from the compacts. The fraction of Ag-110m retained in the compacts ranged from 1.8% to full retention. Additionally, the activities of the radioactive cesium isotopes (Cs-134 and Cs-137) have been used to evaluate the burnup of all US TRISO fuel compacts in the irradiation. The experimental burnup evaluations compare favorably with burnups predicted from physics simulations. Predicted burnups for UCO compacts range from 7.26 to 13.15 % fission per initial metal atom (FIMA) and 9.01 to 10.69 % FIMA for UO2 compacts. Measured burnup ranged from 7.3 to 13.1 % FIMA for UCO compacts and 8.5 to 10.6 % FIMA for UO2 compacts. Results from gamma emission computed tomography performed on compacts and graphite holders that reveal the distribution of different fission products in a component will also be discussed. Gamma tomography of graphite holders was also used to locate the position of TRISO fuel particles suspected of having silicon carbide layer failures that lead to in-pile cesium release.

  1. Effect of. gamma. -ray irradiation on sugar production from plant biomass

    SciTech Connect

    Han, Y.W.; Ciegler, A.

    1982-01-01

    During the past several years, evidence has indicated the effectiveness of gamma radiation in altering lignocellulosic polymers to enhance their susceptibility to chemical and enzymatic attack. Reassessment of high-energy radiation as a tool in reducing the use of fossil fuel suggested that the procedure might have practical value in modification of lignocellulosics prior to hydrolysis to sugars for use in fermentation. Select combinations of chemical pretreatment and gamma radiation can also lead to production of feedstocks useful to the chemical synthesis industry. Preliminary research indicated that the properties of lignocellulosics are changed and a variety of compounds are produced by gamma irradiation. In general, gamma irradiation of lignocellulosics such as wood, paper, and crop residues causes depolymerization of biopolymers and decomposition of carbohydrates at dosages between 10 and 100 Mrad, and the resulting materials shows a loss of crystallinity and increase in digestibility by subsequent hydrolysis by acid and enzymes. These changes may be advantageously used for production of energy from biomass. Large quantities of gamma-emitting /sup 137/Cs are found in fission-product wastes stored since the initiation of /sup 239/Pu production during World War II. The task of disposing of the radioactive wastes produced by nuclear power plants is often cited as one of the principal drawbacks to the use of nuclear fission for electric power generation. 1 figure, 3 tables.

  2. Defect production in electron-irradiated, n-type GaAs

    NASA Astrophysics Data System (ADS)

    Look, D. C.; Sizelove, J. R.

    1987-11-01

    Energies and production rates for a pure vapor-phase epitaxial GaAs layer irradiated by 1-MeV electrons were obtained from measurements of temperature-dependent Hall (TDH) effect and were compared with published data based on deep-level transient spectroscopy (DLTS). The TDH energy and production rates of two dominant defect centers, C2 and C3, were in good agreement with DLTS data. The most important result of this study is a very high production rate (4 + or - 1/cm) for 'shallow' acceptors C(AS) lying below C3-energy. C(AS) were found to be produced at a much higher rate than all of the DLTS traps observed in this energy range, indicating that close to half of the primary defects in electron-irradiated GaAs are not seen by DLTS. For microscopic models of the electron traps C1 and C2, the high C(AS) production rate renders unnecessary the assumption that one of these centers must be an acceptor in order to explain the Hall-effect results. It is shown that all available HDT and DLTS data are consistent with the C(AS) representing Ga-sublattice damage, a fact which has not been observed before.

  3. High e+/e– ratio dense pair creation with 1021W.cm–2 laser irradiating solid targets

    DOE PAGES

    Liang, E.; Clarke, T.; Henderson, A.; ...

    2015-09-14

    In this study, we report results of new pair creation experiments using ~100 Joule pulses of the Texas Petawatt Laser to irradiate solid gold and platinum targets, with intensities up to ~1.9 × 1021 W.cm–2 and pulse durations as short as ~130 fs. Positron to electron (e+/e–) ratios >15% were observed for many thick disk and rod targets, with the highest e+/e– ratio reaching ~50% for a Pt rod. The inferred pair yield was ~ few ×1010 with emerging pair density reaching ~1015/cm3 so that the pair skin depth becomes < pair jet transverse size. These results represent major milestonesmore » towards the goal of creating a significant quantity of dense pair-dominated plasmas with e+/e– approaching 100% and pair skin depth << pair plasma size, which will have wide-ranging applications to astrophysics and fundamental physics.« less

  4. Efficient and stable proton acceleration by irradiating a two-layer target with a linearly polarized laser pulse

    SciTech Connect

    Wang, H. Y.; Yan, X. Q.; Chen, J. E.; He, X. T.; Ma, W. J.; Bin, J. H.; Schreiber, J.; Tajima, T.; Habs, D.

    2013-01-15

    We report an efficient and stable scheme to generate {approx}200 MeV proton bunch by irradiating a two-layer targets (near-critical density layer+solid density layer with heavy ions and protons) with a linearly polarized Gaussian pulse at intensity of 6.0 Multiplication-Sign 10{sup 20} W/cm{sup 2}. Due to self-focusing of laser and directly accelerated electrons in the near-critical density layer, the proton energy is enhanced by a factor of 3 compared to single-layer solid targets. The energy spread of proton is also remarkably reduced. Such scheme is attractive for applications relevant to tumor therapy.

  5. On the Production of 36Cl by High-Energy Particles in Thin- and Thick- Target Experiments

    NASA Astrophysics Data System (ADS)

    Schiekel, Th.; Herpers, U.; Sudbrock, F.; Gloris, M.; Leya, I.; Michel, R.; Synal, H.-A.; Suter, M.

    1995-09-01

    Knowledge about the production of cosmogenic nuclides in meteorites, planetary surfaces and cosmic dust is elementary for various cosmophysical studies. Completely known it would contain information about the constancy and the spectral distribution of cosmic radiation and it would allow to decipher the irradiation history of matter under the condition of solar and galactic cosmic ray exposure. Cosmic ray particle interactions with matter can be described by a thin-target approach. In this case integral excitation functions for the main target elements have to be combined with depth dependent spectra of primary and secondary particles, see for instance [1]. On the other hand thick-target simulation experiments have been accomplished [2,3] from which production rates can be directly determined. Both approaches have been investigated and successfully validated for short- as well as for long-lived nuclides, e.g ^10Be and ^26Al [3]. Now extending our investigations on the nuclide ^36Cl irradiation experiments with initial proton energies ranging from 45 MeV up to 2600 MeV have been carried out using the "stacked-foil-technique". We have yet determined integral excitation functions for proton induced production of ^36Cl from the most relevant as well as for some minor target elements in meteorites (e.g. Ca, Ti, V, Mn, Fe, Ni, Co, Cu) providing necessary data for the thin-target approach. ^36Cl in the individual targets has been measured via the ultrasensitive accelerator mass spectrometry after a radiochemical separation. For a validation of the above mentioned model calculations based on the thin-target approach by Michel et al. [1], the depth dependent elemental production rates of ^36Cl from the main target elements have been measured in two artificial meteorites made out of gabbro and iron (radii 25 cm and 10 cm respectively) irradiated isotropically with 1,6 GeV protons [3,4]. The theoretical calculations agree reasonably well with our experimental results for the

  6. Technical Note: Immunohistochemical evaluation of mouse brain irradiation targeting accuracy with 3D-printed immobilization device

    SciTech Connect

    Zarghami, Niloufar Jensen, Michael D.; Talluri, Srikanth; Dick, Frederick A.; Foster, Paula J.; Chambers, Ann F.; Wong, Eugene

    2015-11-15

    Purpose: Small animal immobilization devices facilitate positioning of animals for reproducible imaging and accurate focal radiation therapy. In this study, the authors demonstrate the use of three-dimensional (3D) printing technology to fabricate a custom-designed mouse head restraint. The authors evaluate the accuracy of this device for the purpose of mouse brain irradiation. Methods: A mouse head holder was designed for a microCT couch using CAD software and printed in an acrylic based material. Ten mice received half-brain radiation while positioned in the 3D-printed head holder. Animal placement was achieved using on-board image guidance and computerized asymmetric collimators. To evaluate the precision of beam localization for half-brain irradiation, mice were sacrificed approximately 30 min after treatment and brain sections were stained for γ-H2AX, a marker for DNA breaks. The distance and angle of the γ-H2AX radiation beam border to longitudinal fissure were measured on histological samples. Animals were monitored for any possible trauma from the device. Results: Visualization of the radiation beam on ex vivo brain sections with γ-H2AX immunohistochemical staining showed a sharp radiation field within the tissue. Measurements showed a mean irradiation targeting error of 0.14 ± 0.09 mm (standard deviation). Rotation between the beam axis and mouse head was 1.2° ± 1.0° (standard deviation). The immobilization device was easily adjusted to accommodate different sizes of mice. No signs of trauma to the mice were observed from the use of tooth block and ear bars. Conclusions: The authors designed and built a novel 3D-printed mouse head holder with many desired features for accurate and reproducible radiation targeting. The 3D printing technology was found to be practical and economical for producing a small animal imaging and radiation restraint device and allows for customization for study specific needs.

  7. Production of N-13 ammonia using a solid graphite target and the {sup 12}C (d,n) {sup 13}N nuclear reaction

    SciTech Connect

    Dence, C.S.; Welch, M.J.; Hughey, B.J.; Shefer, R.E.; Klinkowstein, R.E.

    1994-12-31

    With the appearance of new low energy accelerators dedicated to the production of short-lived isotopes, comes new approaches to the production of radiopharmaceuticals. The nuclear reaction {sup 12}C(d,n){sup 13}N was chosen for this study because of its low energy threshold (0.33 MeV) and therefore compatibility with these low energy accelerators. Low porosity graphite was chosen as the target material; irradiated graphite has been used since 1940 to extract N-13 for biological studies (4-8) but in most cases the activity was obtained as N-13 nitrogen. Kjeldahl digestion and microwave irradiation have also been applied to obtain N-13 ammonia. The authors studied the extraction of N-13 nitrogen from a solid graphite target after deuteron beam irradiation and heated in an atmosphere of pure oxygen, the authors identified the species formed and converted them to N-13 ammonia.

  8. Irradiation treatment of pharmaceutical and personal care products (PPCPs) in water and wastewater: An overview

    NASA Astrophysics Data System (ADS)

    Wang, Jianlong; Chu, Libing

    2016-08-01

    Pharmaceutical and personal care products (PPCPs), especially the pharmaceutically active compounds (PhACs) such as antibiotics and hormones have attracted great concerns worldwide for their persistence and potential threat to ecosystem and public health. This paper presents an overview on the ionizing irradiation-induced degradation of PPCPs in aqueous solution. Parameters that affect PPCPs degradation, such as the absorbed dose, solution pH, dose rate, water matrices and the presence of some inorganic ions and humic acid are evaluated. The mechanism and pathways of radiolytic degradation of PPCPs are reviewed. In many cases, PPCPs such as antibiotics and X-ray contrast agent could be removed completely by radiation, but a higher absorbed dose was needed for their mineralization and toxicity reduction. The combination of ionizing irradiation with other methods such as H2O2, ozonation and TiO2 nanoparticles could improve the degradation efficacy and reduce the cost. Ionizing irradiation is a promising alternative for degradation of PPCPs in aqueous solution.

  9. Lipid oxidation and volatile production in irradiated raw pork batters prepared with commercial soybean oil containing vitamin E

    NASA Astrophysics Data System (ADS)

    Jo, Cheorun; Ahn, Dong Uk; Byun, Myung Woo

    2001-04-01

    An emulsion-type raw pork batter was prepared using 10% (meat weight) of backfat or commercial soybean oil enriched with vitamin E to determine the effect of irradiation on lipid oxidation and volatile production during storage. Batters (approximately 100 g) were vacuum- or aerobically packaged and irradiated at 0, 2.5 or 4.5 kGy. Irradiation increased lipid oxidation of aerobically packaged raw pork batters prepared with both backfat and soybean oil. Lipid oxidation of vacuum-packaged pork batters was not influenced by irradiation except for the batter prepared with backfat at day 0. Aerobically packaged batters prepared with soybean oil had lower ( P<0.05) TBARS than that with backfat, but vacuum-packaged ones were not different. The sum of volatile compounds with short retention time (<1.80) increased by irradiation, and with storage time except for aerobic packaging at day 7. The amount of total volatile compounds had an increasing trend until day 3, but not at day 7. Irradiation increased the production of total volatile compounds in the batters prepared with soybean oil and vacuum packaged, but irradiation effect on volatile production was not consistent with other treatments.

  10. Development of additive [11C]CO2 target system in the KOTRON-13 cyclotron and its application for [11C]radiopharmaceutical production

    NASA Astrophysics Data System (ADS)

    Moon, Byung Seok; Lee, Hong Jin; Lee, Won Kyung; Hur, Min Goo; Yang, Seung Dae; Lee, Byung Chul; Kim, Sang Eun

    2015-08-01

    The KOTRON-13 cyclotron, which was developed in South Korea for the production of medical radioisotopes, has the structural limitation of only one beam-output port, restricting the production of the carbon-11 isotope. In the present study, we investigate the design of a switchable target system and develop an effective carbon-11 target in the KOTRON-13 cyclotron, for combination with the fluorine-18 target. The target system was designed by introducing a sliding-type element between the fluorine-18 and carbon-11 targets, a tailor-made C-11 target and its cooling system. For the efficient production of [11C]CO2, the desirable target shape and internal volume were determined by a Stopping and Range of Ions in Matter (SRIM) simulation program, and the target grid was modified to resist the cavity pressure during beam irradiation. We evaluated the [11C]CO2 production while varying the material and thickness of the target foil, oxygen content of the nitrogen gas, and target loading pressure. Using sliding-type equipment including an additional gate valve and a high vacuum in a beam line, the bi-directional conversion between the fluorine-18 and carbon-11 targets was efficient regarding the accurate beam irradiation on both targets. The optimal [11C]CO2 production for 30 min irradiation at 60 μA (86.6 ± 1.7 GBq in the target at EOB) was observed at a thickness of 19 μm with HAVAR® material as a target foil and a target loading pressure of 24 bar with nitrogen plus 300 ppb of oxygen gas. Additionally, the coolant cavity system in the target grid and target chamber is useful to remove the heat transferred to the target body by the internal convection of water and thereby ensure the stability of the [11C]CO2 production under a high beam current. In the application of C-11 labeled radiopharmaceuticals such as [11C]PIB, [11C]DASB, [11C]PBR28, [11C]Methionine and [11C]Clozapine, the radiochemical yields were shown to be 25-38% (decay corrected) with over 166 GBq/μmol of

  11. Alternate Tritium Production Methods Using A Liquid Lithium Target

    SciTech Connect

    Wilson, J.

    2015-10-08

    For over 60 years, the Savannah River Site’s primary mission has been the production of tritium. From the beginning, the Savannah River National Laboratory (SRNL) has provided the technical foundation to ensure the successful execution of this critical defense mission. SRNL has developed most of the processes used in the tritium mission and provides the research and development necessary to supply this critical component. This project was executed by first developing reactor models that could be used as a neutron source. In parallel to this development calculations were carried out testing the feasibility of accelerator technologies that could also be used for tritium production. Targets were designed with internal moderating material and optimized target was calculated to be capable of 3000 grams using a 1400 MWt sodium fast reactor, 850 grams using a 400 MWt sodium fast reactor, and 100 grams using a 62 MWt reactor, annually.

  12. Electroplated targets for production of unique PET radionuclides

    NASA Astrophysics Data System (ADS)

    Bui, V.; Sheh, Y.; Finn, R.; Francesconi, L.; Cai, S.; Schlyer, D.; Wieland, B.

    1995-12-01

    The past decade has witnessed the applications of positron emission tomography (PET) evolving from a purely research endeavor to a procedure which has specific clinical applications in the areas of cardiology, neurology and oncology. The growth of PET has been facilitated by developments in both medical instrumentation and radiopharmaceutical chemistry efforts. Included in this latter effort has been the low energy accelerator production and processing of unique PET radionuclides appropriate for the radiolabeling of biomolecules, i.e. monoclonal antibodies and peptides. The development and application of electroplated targets of antimony and copper for the production of iodine-124 and gallium-66 respectively, utilizing the Memorial Sloan-Kettering Cancer Center (MSKCC) cyclotron are examples of target design and development applicable to many medical accelerators.

  13. Electroplating targets for production of unique PET radionuclides

    SciTech Connect

    Bui, V.; Sheh, Y.; Finn, R.

    1994-12-31

    The past decade has witnessed the applications of Positron Emission Tomography (PET) evolving from a purely research endeavour to a procedure which has specific clinical applications in the areas of cardiology, neurology and oncology. The growth of PET has been facilitated by developments in medical instrumentation and radiopharmaceutical chemistry efforts. Included in this latter effort has been the low energy accelerator production and processing of unique PET radionuclides appropriate for the radiolabeling of biomolecules i.e. monoclonal antibodies and pepetides. The development and application of electroplated targets of antimony and copper for the production of iodine-124 and gallium-66 respectively, utilizing the Memorial Sloan-Kettering Cancer Center cyclotron are examples of target design and development applicable to many medical accelerators.

  14. Compact polarimetric SAR product and calibration considerations for target analysis

    NASA Astrophysics Data System (ADS)

    Sabry, Ramin

    2016-10-01

    Compact polarimetric (CP) data exploitation is currently of growing interest considering the new generation of such Synthetic Aperture Radar (SAR) systems. These systems offer target detection and classification capabilities comparable to those of polarimetric SARs (PolSAR) with less stringent requirements. A good example is the RADARSAT Constellation Mission (RCM). In this paper, some characteristic CP products are described and effects of CP mode deviation from ideal circular polarization transmit on classifications are modeled. The latter is important for operation of typical CP modes (e.g., RCM). The developed model can be used to estimate the ellipticity variation from CP measured data, and hence, calibrate the classification products.

  15. Production of Sulfur Allotropes in Electron Irradiated Jupiter Trojans Ice Analogs

    NASA Astrophysics Data System (ADS)

    Mahjoub, Ahmed; Poston, Michael J.; Blacksberg, Jordana; Eiler, John M.; Brown, Michael E.; Ehlmann, Bethany L.; Hodyss, Robert; Hand, Kevin P.; Carlson, Robert; Choukroun, Mathieu

    2017-09-01

    In this paper, we investigate sulfur chemistry in laboratory analogs of Jupiter Trojans and Kuiper Belt Objects (KBOs). Electron irradiation experiments of CH3OH–NH3–H2O and H2S–CH3OH–NH3–H2O ices were conducted to better understand the chemical differences between primordial planetesimals inside and outside the sublimation line of H2S. The main goal of this work is to test the chemical plausibility of the hypothesis correlating the color bimodality in Jupiter Trojans with sulfur chemistry in the incipient solar system. Temperature programmed desorption (TPD) of the irradiated mixtures allows the detection of small sulfur allotropes (S3 and S4) after the irradiation of H2S containing ice mixtures. These small, red polymers are metastable and could polymerize further under thermal processing and irradiation, producing larger sulfur polymers (mainly S8) that are spectroscopically neutral at wavelengths above 500 nm. This transformation may affect the spectral reflectance of Jupiter Trojans in a different way compared to KBOs, thereby providing a useful framework for possibly differentiating and determining the formation and history of small bodies. Along with allotropes, we report the production of organo-sulfur molecules. Sulfur molecules produced in our experiment have been recently detected by Rosetta in the coma of 67P/Churyumov–Gerasimenko. The very weak absorption of sulfur polymers in the infrared range hampers their identification on Trojans and KBOs, but these allotropes strongly absorb light at UV and Visible wavelengths. This suggests that high signal-to-noise ratio UV–Vis spectra of these objects could provide new constraints on their presence.

  16. Production of copper-64 and gallium-68 with a medical cyclotron using liquid targets

    NASA Astrophysics Data System (ADS)

    Alves, F.; Alves, V. H. P.; Do Carmo, S. J. C.; Neves, A. C. B.; Silva, M.; Abrunhosa, A. J.

    2017-06-01

    This work describes the production of two clinically relevant metal radioisotopes 64Cu and 68Ga with a medical cyclotron by the irradiation of liquid targets. New results are presented for the implementation of this methodology in a fully automated system, using commercially available equipment. Liquid target solutions containing enriched 64Ni and 68Zn were loaded, bombarded and transferred to synthesis modules where a purified solution containing the desired radiometal is obtained and can then be used to further radiolabeling within only one hour after End-Of-Bombardment (EOB). Typical production runs using enriched material lead to the production of 5 GBq and 6 GBq (0.14 MBq/(μAh ṡ mg) and 1.5 MBq/(μAh ṡ mg)) of 64Cu and 68Ga; although the technique can be used to obtain up to 25 GBq and 40 GBq, respectively, by simply scaling up the amount of the enriched material. Purified solutions containing 64Cu and 68Ga were obtained within 30 min after EOB and used to produce 64Cu-ATSM and 68Ga-DOTA-NOC, respectively, with quality parameters suitable for human use.

  17. Isotope materials availability and services for target production at the Oak Ridge National Laboratory

    SciTech Connect

    Ratledge, J.E.; Dahl, T.L.; Ottinger, C.L.; Aaron, W.S.; Adair, H.L.

    1986-01-01

    Materials available through the Isotope Distribution Program include separated stable isotopes, byproduct radiosotopes, and research quantities of source and special nuclear materials. Isotope products are routinely available in the forms listed in the product description section of the Isotopes Products and Services Catalog distributed by the Oak Ridge National Laboratory (ORNL). Different forms can be provided in some cases, usually at additional cost. Routinely available services include cyclotron target irradiations, fabrication of special physical forms, source encapsulation, ion implantation, and special purifications. Materials and services that are not offered as part of the routine distribution program may be made available from commercial sources in the United States. Specific forms of isotopic research materials include thin films and foils for use as accelerator targets, metal or other compounds in the form of bars or wires, and metal sheets. Methods of fabrication include evaporation, sputtering, rolling, electrolytic deposition, pressing, sintering, and casting. High-purity metal forms of plutonium, americium, and curium are prepared by vacuum reduction/distillation. Both fissionable and nonfissionable neutron dosimeters are prepared for determining the neutron energy spectra, flux, and fluence at various locations within a reactor. Details on what materials are available and how the materials and related services can be obtained from ORNL are described.

  18. L-shell emission from high-Z solid targets by intense 10{sup 19}W/cm{sup 2} irradiation with a 248nm laser

    SciTech Connect

    Nelson, T.R.; Borisov, A.B.; Boyer, K.

    2000-01-05

    Efficient (1.2% yield) multikilovolt x-ray emission from Ba(L) (2.4--2.8{angstrom}) and Gd(L) (1.7--2.1{angstrom}) is produced by ultraviolet (248nm) laser-excited BaF{sub 2} and Gd solids. The high efficiency is attributed to an inner shell-selective collisional electron ejection. Much effort has been expended recently in attempts to develop an efficient coherent x-ray source suitable for high-resolution biological imaging. To this end, many experiments have been performed studying the x-ray emissions from high-Z materials under intense (>10{sup 18}W/cm{sup 2}) irradiation, with the most promising results coming from the irradiation of Xe clusters with a UV (248nm) laser at intensities of 10{sup 18}--10{sup 19}W/cm{sup 2}. In this paper the authors report the production of prompt x-rays with energies in excess of 5keV with efficiencies on the order of 1% as a result of intense irradiation of BaF{sub 2} and Gd targets with a terawatt 248nm laser. The efficiency is attributed to an inner shell-selective collisional electron ejection mechanism in which the previously photoionized electrons are ponderomotively driven into an ion while retaining a portion of their atomic phase and symmetry. This partial coherence of the laser-driven electrons has a pronounced effect on the collisional cross-section for the electron ion interaction.

  19. Microalgal lipid production using the hydrolysates of rice straw pretreated with gamma irradiation and alkali solution.

    PubMed

    Joe, Min-Ho; Kim, Ji-Youn; Lim, Sangyong; Kim, Dong-Ho; Bai, Suk; Park, Hyun; Lee, Sung Gu; Han, Se Jong; Choi, Jong-Il

    2015-01-01

    Lignocellulosic biomass has long been recognized as a potential sustainable source of sugars for biofuels. However, many physicochemical structural and compositional factors inhibit the enzymatic digestibility of the lignocellulosic biomass. In this study, efficient pretreatment method of rice straw (RS) was developed and the RS hydrolysate was applied in the cultivation of microalgae for lipid production. Gamma ray irradiation (GRI) and alkali solution were used for the pretreatment, and saccharification was carried out with lignocellulolytic enzymes. When RS was pretreated by combined GRI and alkali method, the glucose and xylose saccharification yield after enzymatic hydrolysis increased up to 91.65 and 98.84 %, respectively. The enzymatic hydrolysate from the RS pretreated with the combined method was used to cultivate Chlorella protothecoides for lipid production. The maximum concentrations of biomass and fatty acid methyl ester of cells were 6.51 and 2.95 g/L, respectively. The lipid content of C. protothecoides from RS hydrolysate was comparable to that from glucose, and the lipid composition was similar between different carbon sources. These results demonstrate that the combined pretreatment with gamma irradiation was highly effective in preparing hydrolysate, and the rice straw hydrolysate could be used as an alternative carbon source for microalgal lipid production for biofuel.

  20. Effect of irradiated sodium alginate and phosphorus on biomass and artemisinin production in Artemisia annua.

    PubMed

    Aftab, Tariq; Khan, M Masroor A; Naeem, M; Idrees, Mohd; Siddiqi, T O; Moinuddin; Varshney, Lalit

    2014-09-22

    It is now being realized that irradiation products of natural bioactive agents can also be beneficially utilized to impart value addition in agriculture by converting these bioactive agents into more useful form. Polysaccharides, such as sodium alginate, have proven to be wonderful growth promoting substances in their depolymerized form for various plants. Artemisinin has been increasingly popular as an effective and safe alternative therapy against malaria; also proved effective against the highly adaptable malaria parasite, which has already become resistant to many other drugs. The drug artemisinin can be extracted from the leafy tissues of Artemisia annua. Therefore, experiments were conducted with an aim to evaluate artemisinin production and overall plant development though depolymerized sodium alginate application and nutrient supply. In the present study, sodium alginate, irradiated by Co-60 gamma rays together with various phosphorus doses, was used to study their effect on growth, physiological and biochemical processes and production of artemisinin in A. annua. Among various applied doses of phosphorus fertilizer, P40 (40 kg Pha(-1)) together with ISA80 (80 mg L(-1)) significantly improved all the parameters studied. Increase in plant height as well as weight was noted at this treatment. Dry leaf yield, artemisinin concentration in leaves and artemisinin yield was also significantly enhanced by the treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Influence of SiC grain boundary character on fission product transport in irradiated TRISO fuel

    SciTech Connect

    Lillo, T. M.; Rooyen, I. J.

    2016-02-26

    The relationship between grain boundary character and fission product migration is identified as an important knowledge gap in order to advance the understanding of fission product release from TRISO fuel particles. Precession electron diffraction (PED), a TEM-based technique, was used in this study to quickly and efficiently provide the crystallographic information needed to identify grain boundary misorientation, grain boundary type (low or high angle) and whether the boundary is coincident site lattice (CSL) – related, in irradiated SiC. Analysis of PED data showed the grain structure of the SiC layer in an irradiated TRISO fuel particle from the AGR-1 experiment to be composed mainly of twin boundaries with a small fraction of low angle grain boundaries (<10%). In general, fission products favor precipitation on random, high angle grain boundaries but can precipitate out on low angle and CSL-related grain boundaries to a limited degree. Pd is capable of precipitating out on all types of grain boundaries but most prominently on random, high angle grain boundaries. Pd-U and Pd-Ag precipitates were found on CSL-related as well as random high angle grain boundaries but not on low angle grain boundaries. In contrast, precipitates containing only Ag were found only on random, high angle grain boundaries but not on either low angle or CSL-related grain boundaries.

  2. Influence of SiC grain boundary character on fission product transport in irradiated TRISO fuel

    DOE PAGES

    Lillo, T. M.; Rooyen, I. J.

    2016-02-26

    The relationship between grain boundary character and fission product migration is identified as an important knowledge gap in order to advance the understanding of fission product release from TRISO fuel particles. Precession electron diffraction (PED), a TEM-based technique, was used in this study to quickly and efficiently provide the crystallographic information needed to identify grain boundary misorientation, grain boundary type (low or high angle) and whether the boundary is coincident site lattice (CSL) – related, in irradiated SiC. Analysis of PED data showed the grain structure of the SiC layer in an irradiated TRISO fuel particle from the AGR-1 experimentmore » to be composed mainly of twin boundaries with a small fraction of low angle grain boundaries (<10%). In general, fission products favor precipitation on random, high angle grain boundaries but can precipitate out on low angle and CSL-related grain boundaries to a limited degree. Pd is capable of precipitating out on all types of grain boundaries but most prominently on random, high angle grain boundaries. Pd-U and Pd-Ag precipitates were found on CSL-related as well as random high angle grain boundaries but not on low angle grain boundaries. In contrast, precipitates containing only Ag were found only on random, high angle grain boundaries but not on either low angle or CSL-related grain boundaries.« less

  3. EPR as an analytical tool in assessing the mineral nutrients and irradiated food products-vegetables

    NASA Astrophysics Data System (ADS)

    Prasuna, C. P. Lakshmi; Chakradhar, R. P. S.; Rao, J. L.; Gopal, N. O.

    2008-12-01

    EPR spectral investigations of some commonly available vegetables in south India, which are of global importance like Daucus carota (carrot), Cyamopsis tetragonoloba (cluster beans), Coccinia indica (little gourd) and Beta vulgaris (beet root) have been carried out. In all the vegetable samples a free radical corresponding to cellulose radical is observed. Almost all the samples under investigation exhibit Mn ions in different oxidation states. The temperature variation EPR studies are done and are discussed in view of the paramagnetic oxidation states. The radiation-induced defects have also been assessed by using the EPR spectra of such irradiated food products.

  4. Mitosis-targeting natural products for cancer prevention and therapy.

    PubMed

    Rao, Chinthalapally V; Kurkjian, Carla D; Yamada, Hiroshi Y

    2012-12-01

    Mitosis is a complex process resulting in division of a cell into two daughter cells, and its failure often results in the death of the daughter cells (via apoptotic, necrotic, or proliferative/senescent death). Many chemicals that inhibit the mitotic process (anti-mitotic drugs) have proven effective for killing cancer cells in vitro and in clinical settings. Among the most studied anti-mitotic drugs are plant-origin natural products including taxanes (e.g. paclitaxel, docetaxel) and vinca alkaloids (e.g. vincristine, vinblastine), whose validated target is the spindle microtubules. With the success of these agents, efforts have been made to develop other spindle poisons as well as to improve efficacy of existing spindle poisons with structural modifications. Novel drugs and natural products that inhibit other proteins involved in mitosis (nonmicrotubule targets) have been sought in hopes of expanding available cancer-directed therapies. Recently, significant advances have been made in the understanding of mitotic mechanisms in tumor cells as well as in normal epithelial cells. These advances help us to identify and develop potential natural agents for the prevention and treatment of cancer. This review will focus on natural products that target mitotic process and/or proteins involved in mitotic progression.

  5. Target irradiation induced bystander effects between stem-like and non stem-like cancer cells.

    PubMed

    Liu, Yu; Kobayashi, Alisa; Maeda, Takeshi; Fu, Qibin; Oikawa, Masakazu; Yang, Gen; Konishi, Teruaki; Uchihori, Yukio; Hei, Tom K; Wang, Yugang

    2015-03-01

    Tumors are heterogeneous in nature and consist of multiple cell types. Among them, cancer stem-like cells (CSCs) are suggested to be the principal cause of tumor metastasis, resistance and recurrence. Therefore, understanding the behavior of CSCs in direct and indirect irradiations is crucial for clinical radiotherapy. Here, the CSCs and their counterpart non stem-like cancer cells (NSCCs) in human HT1080 fibrosarcoma cell line were sorted and labeled, then the two cell subtypes were mixed together and chosen separately to be irradiated via a proton microbeam. The radiation-induced bystander effect (RIBE) between the CSCs and NSCCs was measured by imaging 53BP1 foci, a widely used indicator for DNA double strand break (DSB). CSCs were found to be less active than NSCCs in both the generation and the response of bystander signals. Moreover, the nitric oxide (NO) scavenger c-PTIO can effectively alleviate the bystander effect in bystander NSCCs but not in bystander CSCs, indicating a difference of the two cell subtypes in NO signal response. To our knowledge, this is the first report shedding light on the RIBE between CSCs and NSCCs, which might contribute to a further understanding of the out-of-field effect in cancer radiotherapy.

  6. Large Scale Accelerator Production of 225Ac: Effective Cross sections for 78-192 MeV Protons Incident on 232Th Targets

    DOE PAGES

    Griswold, Justin R; Medvedev, Dmitri G.; Engle, Jonathan W.; ...

    2016-09-28

    Actinium-225 and 213Bi have been used successfully in targeted alpha therapy (TAT) in preclinical and clinical research. This paper is a continuation of research activities aiming to expand the availability of 225Ac. The high energy proton spallation reaction on natural thorium metal target has been utilized to produce millicurie quantities of 225Ac. The results of sixteen irradiation experiments of Th metal at beam energies between 78 and 200 MeV are summarized in this work. Irradiations have been conducted at Brookhaven National Laboratory (BNL) and Los Alamos National Laboratory (LANL), while target dissolution and processing was carried out at Oak Ridgemore » National Laboratory (ORNL). Excitation functions for actinium and thorium isotopes as well as for some of the fission products are presented. The cross sections for production of 225Ac range from 3.6 to 16.7 mb in the incident proton energy range of 78 to 192 MeV. Based on these data, production of Curie quantities of 225Ac is possible by irradiating a 5.0 g cm-2232Th target for 10 days in either BNL or LANL proton irradiation facilities.« less

  7. Large scale accelerator production of (225)Ac: Effective cross sections for 78-192MeV protons incident on (232)Th targets.

    PubMed

    Griswold, J R; Medvedev, D G; Engle, J W; Copping, R; Fitzsimmons, J M; Radchenko, V; Cooley, J C; Fassbender, M E; Denton, D L; Murphy, K E; Owens, A C; Birnbaum, E R; John, K D; Nortier, F M; Stracener, D W; Heilbronn, L H; Mausner, L F; Mirzadeh, S

    2016-12-01

    Actinium-225 and (213)Bi have been used successfully in targeted alpha therapy (TAT) in preclinical and clinical research. This paper is a continuation of research activities aiming to expand the availability of (225)Ac. The high-energy proton spallation reaction on natural thorium metal targets has been utilized to produce millicurie quantities of (225)Ac. The results of sixteen irradiation experiments of thorium metal at beam energies between 78 and 192MeV are summarized in this work. Irradiations have been conducted at Brookhaven National Laboratory (BNL) and Los Alamos National Laboratory (LANL), while target dissolution and processing was carried out at Oak Ridge National Laboratory (ORNL). Excitation functions for actinium and thorium isotopes, as well as for some of the fission products, are presented. The cross sections for production of (225)Ac range from 3.6 to 16.7mb in the incident proton energy range of 78-192MeV. Based on these data, production of curie quantities of (225)Ac is possible by irradiating a 5.0gcm(-2 232)Th target for 10 days in either BNL or LANL proton irradiation facilities.

  8. Effect of irradiation on Nε-carboxymethyl-lysine and Nε-carboxyethyl-lysine formation in cooked meat products during storage

    NASA Astrophysics Data System (ADS)

    Yu, Ligang; He, Zhiyong; Zeng, Maomao; Zheng, Zongping; Chen, Jie

    2016-03-01

    This study investigated the effects of irradiation on Nε-carboxymethyl-lysine (CML) and Nε-carboxyethyl-lysine (CEL) formation in cooked red and white meats during storage. The results showed that irradiation did not affect CML/CEL formation (0 weeks). After 6 weeks, CML/CEL contents in the irradiated samples exhibited a higher growth rate than the non-irradiated samples, especially the red meat. The results of electron spin resonance spectrometry and 2-Thiobarbituric acid-reactive substances suggested irradiation had induced free-radical reactions and accelerated lipid oxidation during storage. A linear correlation (r=0.810-0.906, p<0.01) was found between the loss of polyunsaturated fatty acids content and increase of CML/CEL content in the irradiated samples after 0 and 6 weeks of storage. The results indicate that irradiation-induced lipid oxidation promotes CML/CEL formation, and CML/CEL formation by the lipid oxidation pathways may be an important pathway for CML/CEL accumulation in irradiated meat products during storage.

  9. Ultraviolet irradiation of DNA in vitro and in vivo produces a 3d thymine-derived product.

    PubMed

    Varghese, A J; Wang, S Y

    1967-05-19

    A new thymine-derived product was separated from DNA irradiated with utlraviolet light in vitro and in vivo. This compound was mistaken to be thymine homodiner (T=T) by other workers because it is chromatographically indistinguishable from T=T in most eluents. It has absorbancy maximums at 312, 312, and 300 millimicrons in neutral, pH 2, and pH 11 aqueous solutions, respectively. When it is irradiated in aqueous solution with wavelengths of 360 and 313 millimicrons its spectrum reverts to one similar to that of thymine. Therefore, at least three thymine-derived products can be detected in ultraviolet irradiated DNA, namely the homodimer, a material with absorbancy maximum at 312 millimicrons, and a "minor" product suggested by others to be a dimer of cytosine and thymine. In cells, the latter two are formed in aboult equal amounts. While these three products were shown to exist in the acid hydrolyzates of ultraviolet irradiated DNA, a material with absorbancy maximum at about 310 millimicrons was demonstrated to form in ultraviolet irradiated DNA without further treatment. The magnitude of this spectral increase varied directly with the incrcase in the adenine-thymine contents in the DNA as shlown by differential transmittance spectra of the irradiated Micrococcus lysodeikticus, calf thymus, Bacillus cereus, and Hemophilus influenzae DNA.

  10. Target validation: linking target and chemical properties to desired product profile.

    PubMed

    Wyatt, Paul G; Gilbert, Ian H; Read, Kevin D; Fairlamb, Alan H

    2011-01-01

    The discovery of drugs is a lengthy, high-risk and expensive business taking at least 12 years and is estimated to cost upwards of US$800 million for each drug to be successfully approved for clinical use. Much of this cost is driven by the late phase clinical trials and therefore the ability to terminate early those projects destined to fail is paramount to prevent unwanted costs and wasted effort. Although neglected diseases drug discovery is driven more by unmet medical need rather than financial considerations, the need to minimise wasted money and resources is even more vital in this under-funded area. To ensure any drug discovery project is addressing the requirements of the patients and health care providers and delivering a benefit over existing therapies, the ideal attributes of a novel drug needs to be pre-defined by a set of criteria called a target product profile. Using a target product profile the drug discovery process, clinical study design, and compound characteristics can be defined all the way back through to the suitability or druggability of the intended biochemical target. Assessment and prioritisation of the most promising targets for entry into screening programmes is crucial for maximising chances of success.

  11. Inter- and Intrafraction Target Motion in Highly Focused Single Vocal Cord Irradiation of T1a Larynx Cancer Patients.

    PubMed

    Kwa, Stefan L S; Al-Mamgani, Abrahim; Osman, Sarah O S; Gangsaas, Anne; Levendag, Peter C; Heijmen, Ben J M

    2015-09-01

    The purpose of this study was to verify clinical target volume--planning target volume (CTV-PTV) margins in single vocal cord irradiation (SVCI) of T1a larynx tumors and characterize inter- and intrafraction target motion. For 42 patients, a single vocal cord was irradiated using intensity modulated radiation therapy at a total dose of 58.1 Gy (16 fractions × 3.63 Gy). A daily cone beam computed tomography (CBCT) scan was performed to online correct the setup of the thyroid cartilage after patient positioning with in-room lasers (interfraction motion correction). To monitor intrafraction motion, CBCT scans were also acquired just after patient repositioning and after dose delivery. A mixed online-offline setup correction protocol ("O2 protocol") was designed to compensate for both inter- and intrafraction motion. Observed interfraction, systematic (Σ), and random (σ) setup errors in left-right (LR), craniocaudal (CC), and anteroposterior (AP) directions were 0.9, 2.0, and 1.1 mm and 1.0, 1.6, and 1.0 mm, respectively. After correction of these errors, the following intrafraction movements derived from the CBCT acquired after dose delivery were: Σ = 0.4, 1.3, and 0.7 mm, and σ = 0.8, 1.4, and 0.8 mm. More than half of the patients showed a systematic non-zero intrafraction shift in target position, (ie, the mean intrafraction displacement over the treatment fractions was statistically significantly different from zero; P<.05). With the applied CTV-PTV margins (for most patients 3, 5, and 3 mm in LR, CC, and AP directions, respectively), the minimum CTV dose, estimated from the target displacements observed in the last CBCT, was at least 94% of the prescribed dose for all patients and more than 98% for most patients (37 of 42). The proposed O2 protocol could effectively reduce the systematic intrafraction errors observed after dose delivery to almost zero (Σ = 0.1, 0.2, 0.2 mm). With adequate image guidance and CTV-PTV margins in LR, CC, and AP directions of 3

  12. Inter- and Intrafraction Target Motion in Highly Focused Single Vocal Cord Irradiation of T1a Larynx Cancer Patients

    SciTech Connect

    Kwa, Stefan L.S. Al-Mamgani, Abrahim; Osman, Sarah O.S.; Gangsaas, Anne; Levendag, Peter C.; Heijmen, Ben J.M.

    2015-09-01

    Purpose: The purpose of this study was to verify clinical target volume–planning target volume (CTV-PTV) margins in single vocal cord irradiation (SVCI) of T1a larynx tumors and characterize inter- and intrafraction target motion. Methods and Materials: For 42 patients, a single vocal cord was irradiated using intensity modulated radiation therapy at a total dose of 58.1 Gy (16 fractions × 3.63 Gy). A daily cone beam computed tomography (CBCT) scan was performed to online correct the setup of the thyroid cartilage after patient positioning with in-room lasers (interfraction motion correction). To monitor intrafraction motion, CBCT scans were also acquired just after patient repositioning and after dose delivery. A mixed online-offline setup correction protocol (“O2 protocol”) was designed to compensate for both inter- and intrafraction motion. Results: Observed interfraction, systematic (Σ), and random (σ) setup errors in left-right (LR), craniocaudal (CC), and anteroposterior (AP) directions were 0.9, 2.0, and 1.1 mm and 1.0, 1.6, and 1.0 mm, respectively. After correction of these errors, the following intrafraction movements derived from the CBCT acquired after dose delivery were: Σ = 0.4, 1.3, and 0.7 mm, and σ = 0.8, 1.4, and 0.8 mm. More than half of the patients showed a systematic non-zero intrafraction shift in target position, (ie, the mean intrafraction displacement over the treatment fractions was statistically significantly different from zero; P<.05). With the applied CTV-PTV margins (for most patients 3, 5, and 3 mm in LR, CC, and AP directions, respectively), the minimum CTV dose, estimated from the target displacements observed in the last CBCT, was at least 94% of the prescribed dose for all patients and more than 98% for most patients (37 of 42). The proposed O2 protocol could effectively reduce the systematic intrafraction errors observed after dose delivery to almost zero (Σ = 0.1, 0.2, 0.2 mm). Conclusions: With

  13. Mechanism Targeted Discovery of Antitumor Marine Natural Products

    PubMed Central

    Nagle, Dale G.; Zhou, Yu-Dong; Mora, Flor D.; Mohammed, Kaleem A.; Kim, Yong-Pil

    2010-01-01

    Antitumor drug discovery programs aim to identify chemical entities for use in the treatment of cancer. Many strategies have been used to achieve this objective. Natural products have always played a major role in anticancer medicine and the unique metabolites produced by marine organisms have increasingly become major players in antitumor drug discovery. Rapid advances have occurred in the understanding of tumor biology and molecular medicine. New insights into mechanisms responsible for neoplastic disease are significantly changing the general philosophical approach towards cancer treatment. Recently identified molecular targets have created exciting new means for disrupting tumor-specific cell signaling, cell division, energy metabolism, gene expression, drug resistance, and blood supply. Such tumor-specific treatments could someday decrease our reliance on traditional cytotoxicity-based chemotherapy and provide new less toxic treatment options with significantly fewer side effects. Novel molecular targets and state-of-the-art molecular mechanism-based screening methods have revitalized antitumor research and these changes are becoming an ever-increasing component of modern antitumor marine natural products research. This review describes marine natural products identified using tumor-specific mechanism-based assays for regulators of angiogenesis, apoptosis, cell cycle, macromolecule synthesis, mitochondrial respiration, mitosis, multidrug efflux, and signal transduction. Special emphasis is placed on natural products directly discovered using molecular mechanism-based screening. PMID:15279579

  14. Increased bacterial infections after transfusion of leukoreduced non-irradiated blood products in recipients of allogeneic stem cell transplants after reduced-intensity conditioning.

    PubMed

    Jaime-Pérez, José C; Villarreal-Villarreal, César D; Salazar-Riojas, Rosario; Méndez-Ramírez, Nereida; Vázquez-Garza, Eduardo; Gómez-Almaguer, David

    2015-03-01

    Blood components transfused to hematopoietic stem cell transplant (HSCT) recipients are irradiated to prevent transfusion-associated graft-versus-host disease (TA-GVHD). The effect of transfusing non-irradiated blood products in HSCT outcome, including incidence of transplant complications, bacterial infections, acute and chronic GVHD presentation, and characteristics, has not been documented. Clinical records as well as blood bank and electronic databases of HSCT patients grafted after reduced-intensity conditioning who received irradiated versus non-irradiated blood products, after blood irradiation became unavailable at our center, were scrutinized for transplant outcome, clinical evolution, engraftment characteristics including days to neutrophil and platelet recovery, acute and chronic GVHD, rate and type of infections, and additional transplant-related comorbidities. All transfused blood products were leukoreduced. A total of 156 HSCT recipients was studied, 73 received irradiated and 83 non-irradiated blood components. Bacterial infections were significantly more frequent in patients transfused with non-irradiated blood products, P = .04. Clinically relevant increased rates of fever and neutropenia and mucositis were also documented in these patients. No cases of TA-GVHD occurred. Classical GVHD developed in 37 patients (50.7%) who received irradiated blood products and 36 (43.9%) who received non-irradiated blood products, P = .42. Acute GVHD developed in 28 patients (38.4%) in the blood-irradiated and 33 patients (39.8%) in the non-irradiation group, P = .87. The 2-year GVHD-free survival rate was 40% in the irradiated versus 40.6% in the non-irradiation group, P = .071. Increased bacterial infections were found in HSCT recipients transfused with non-irradiated blood products, which ideally must always be irradiated.

  15. The Role of Non-Targeted Effects as Mediators in the Biological Effects of Proton Irradiation

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Dicello, John F.

    2006-01-01

    In recent years, the hypothesis that non-DNA targets are primary initiators and mediators of the biological effects of ionizing radiation, such as proton beams and heavy ions, has gained much interest. These phenomena have been denoted as non-targeted or bystander effects to distinguish them from the more traditionally studied model that focuses on direct damage to DNA causing chromosomal rearrangements and mutations as causative of most biological endpoints such as cell killing, tissue damage, and cancer. We review cellular and extra-cellular structures and signal transduction pathways that have been implemented in these recent studies. Non-targeted effects of interest include oxidative damage to the cytoplasm and mitochondria, disruption of the extra-cellular matrix, and modification of cytokine signaling including TGF-beta, and gap junction communication. We present an introduction to these targets and pathways, and contrast there role with DNA damage pathways.

  16. A method to achieve rapid localised deep heating in a laser irradiated solid density target

    NASA Astrophysics Data System (ADS)

    Schmitz, H.; Robinson, A. P. L.

    2016-09-01

    Rapid heating of small buried regions by laser generated fast electrons may be useful for applications such as extreme ultraviolet (XUV) radiation sources or as drivers for shock experiments. In non-structured targets, the heating profile possesses a global maximum near the front surface. This paper presents a new target design that uses resistive guiding to concentrate the fast electron current density at a finite depth inside the target. The choice of geometry uses principles of non-imaging optics. A global temperature maximum at depths up to 50 μ m into the target is achieved. Although theoretical calculations suggest that small source sizes should perform better than large ones, simulations show that a large angular spread at high intensities results in significant losses of the fast electrons to the sides. A systematic parameter scan suggests an optimal laser intensity. A ratio of 1.6 is demonstrated between the maximum ion temperature and the ion temperature at the front surface.

  17. The Role of Non-Targeted Effects as Mediators in the Biological Effects of Proton Irradiation

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Dicello, John F.

    2006-01-01

    In recent years, the hypothesis that non-DNA targets are primary initiators and mediators of the biological effects of ionizing radiation, such as proton beams and heavy ions, has gained much interest. These phenomena have been denoted as non-targeted or bystander effects to distinguish them from the more traditionally studied model that focuses on direct damage to DNA causing chromosomal rearrangements and mutations as causative of most biological endpoints such as cell killing, tissue damage, and cancer. We review cellular and extra-cellular structures and signal transduction pathways that have been implemented in these recent studies. Non-targeted effects of interest include oxidative damage to the cytoplasm and mitochondria, disruption of the extra-cellular matrix, and modification of cytokine signaling including TGF-beta, and gap junction communication. We present an introduction to these targets and pathways, and contrast there role with DNA damage pathways.

  18. Uniform irradiation of adjustable target spots in high-power laser driver

    SciTech Connect

    Jiang Xiujuan; Li Jinghui; Li Huagang; Li Yang; Lin Zunqi

    2011-09-20

    For smoothing and shaping the on-target laser patterns flexibly in high-power laser drivers, a scheme has been developed that includes a zoom lens array and two-dimensional smoothing by spectral dispersion (SSD). The size of the target pattern can be controlled handily by adjusting the focal length of the zoom lens array, while the profile of the pattern can be shaped by fine tuning the distance between the target and the focal plane of the principal focusing lens. High-frequency stripes inside the pattern caused by beamlet interference are wiped off by spectral dispersion. Detailed simulations indicate that SSD works somewhat differently for spots of different sizes. For small spots, SSD mainly smooths the intensity modulation of low-to-middle spatial frequency, while for large spots, SSD sweeps the fine speckle structure to reduce nonuniformity of middle-to-high frequency. Spatial spectra of the target patterns are given and their uniformity is evaluated.

  19. Neutron yield from a thick 13C target irradiated by 90 MeV protons

    NASA Astrophysics Data System (ADS)

    Alyakrinskiy, O.; Andrighetto, A.; Barbui, M.; Brandenburg, S.; Cinausero, M.; Dalena, B.; Dendooven, P.; Fioretto, E.; Lhersonneau, G.; Lyapin, W.; Prete, G.; Simonetti, G.; Stroe, L.; Tecchio, L. B.; Trzaska, W. H.

    2005-08-01

    In the context of the design of an intense source of low and intermediate energy neutrons, the angular and energy distributions of neutrons produced in the interaction of 90 MeV protons in a 13C target, in which the protons are stopped, have been measured by time-of-flight and activation techniques. As compared to 12C the yield is less than a factor two higher, while it is somewhat less than for a 9Be target.

  20. Liquid nanodroplet formation through phase explosion mechanism in laser-irradiated metal targets

    NASA Astrophysics Data System (ADS)

    Mazzi, Alberto; Gorrini, Federico; Miotello, Antonio

    2015-09-01

    Some quantitative aspects of laser-irradiated pure metals, while approaching phase explosion, are still not completely understood. Here, we develop a model that describes the main quantities regulating the liquid-vapor explosive phase transition and the expulsion of liquid nanodroplets that, by solidifying, give rise to nanoparticle formation. The model combines both a thermodynamics description of the explosive phase change and a Monte Carlo simulation of the randomly generated critical vapor bubbles. The calculation is performed on a set of seven metals (Al, Fe, Co, Ni, Cu, Ag, and Au) which are frequently used in pulsed laser ablation experiments. Our final predictions about the size distribution of the liquid nanodroplets and the number ratio of liquid/vapor ejected atoms are compared, whenever possible, with available molecular dynamics simulations and experimental data.

  1. Partitioning of selected fission products from irradiated oxide fuel induced by thermal treatment

    NASA Astrophysics Data System (ADS)

    Shcherbina, Natalia; Kivel, Niko; Günther-Leopold, Ines

    2013-06-01

    The release of fission products (FPs) from spent nuclear fuel (SNF) has been studied as a function of the temperature and redox conditions. The present paper concerns essentially the high temperature separation of Cs and Sr from irradiated pressurized (PWR) and boiling water reactor (BWR) fuel of different burn-up levels with use of an in-house designed system for inductive vaporization (InVap). Using thermodynamic calculations with the Module of Fission Product Release (MFPR) code along with annealing experiments on SNF in the InVap it was shown that the speciation of Cs and Sr, hence their release behavior at high temperature, is sensitive to the redox conditions during thermal treatment. It was demonstrated that annealing conditions in the InVap can be adjusted in the way to promote the release of selected FPs without significant loss of the fuel matrix or actinides: complete release of Cs and I was achieved during treatment of irradiated fuel at 1800 °C under reducing atmosphere (0.7% H2/Ar mixture). The developed partitioning procedure can be used for the SNF pretreatment as an advanced head-end step in the hydrometallurgical or pyrochemical reprocessing technology.

  2. Energy release, beam attenuation radiation damage, gas production and accumulation of long-lived activity in Pb, Pb-Bi and Hg targets

    SciTech Connect

    Shubin, Yu.N.

    1996-06-01

    The calculation and analysis of the nuclei concentrations and long-lived residual radioactivity accumulated in Pb, Pb-Bi and Hg targets irradiated by 800 MeV, 30 mA proton beam have been performed. The dominating components to the total radioactivity of radionuclides resulting from fission and spallation reactions and radiative capture by both target nuclei and accumulated radioactive nuclei for various irradiation and cooling times were analyzed. The estimations of spectral component contributions of neutron and proton fluxes to the accumulated activity were carried out. The contributions of fission products to the targets activity and partial activities of main long-lived fission products to the targets activity and partial activities of main long-lived fission products were evaluated. The accumulation of Po isotopes due to reactions induced by secondary alpha-particles were found to be important for the Pb target as compared with two-step radiative capture. The production of Tritium in the targets and its contribution to the total targets activity was considered in detail. It is found that total activities of both targets are close to one another.

  3. Feasibility study on the medical isotopes production with solution target using OSTR: (99)Mo and related isotopes

    NASA Astrophysics Data System (ADS)

    Baik, Seung-Hyuk

    1999-11-01

    Molybdenum-99 (99Mo) is the parent nuclide of Technetium-99m (99mTc), a radioisotope which is widely used in nuclear medicine. 99Mo is produced from the fission of 235U or the irradiation of 98Mo. This study shows the feasibility of the using an 'aqueous homogeneous uranium solution target' for the production of a medical isotope, 99Mo. Some of the advantages that the solution target has over a solid target include the inherent reactor safety features offered by large negative temperature and power reactivity coefficients, the fabrication convenience, the straightforward extraction process, and a low volume of waste generated. To evaluate the core configuration and the production rate of 99Mo, a three-dimensional model of the Oregon State University TRIGA Reactor (OSTR) core was developed for use with the Monte Carlo N-Particle Transport Code (MCNP) and then verified by comparing with the measured values. Two values are in good agreement within one percent in the keffective values calculated. Two types of solution targets are analyzed for the OSTR. The first one has the same outer-dimensions as an OSTR fuel element but is filled with a uranium solution. The other is the continuous flow target system (CFTS) like solution fuel reactors. Uranyl nitrate and uranyl sulfate solutions enriched to 20% or 93% are investigated as a target material without raising any safety concern to the OSTR operation. A seven-day irradiation of ten tube-type-93% enriched uranyl nitrate solution targets would produce 43% of the 99Mo required in the US for one week. The CFTS would generate 31% of the required 99Mo in a 7-day cycle. The conceptual chemical extraction processes for irradiated solution targets are developed. This work also includes an analysis of nuclear safety issues such as the radiolytic gas, thermal hydraulics, the waste, and the radiological impacts of an accident. The production of 99Mo in the OSTR with the uranium solution is technically feasible as demonstrated in this

  4. Maximizing the production of Scenedesmus obliquus in photobioreactors under different irradiation regimes: experiments and modeling.

    PubMed

    Barbera, Elena; Sforza, Eleonora; Bertucco, Alberto

    2015-11-01

    Maximizing biomass productivity and photosynthetic efficiency are key factors to develop large-scale microalgae cultivation for biodiesel production. If the photobioreactor (PBR) is not operated under proper conditions, productivity and efficiency values drop considerably. In this work, the growth of Scenedesmus obliquus in continuous flat-panel PBR is considered. Experimental data and simulations were used with the aim of determining suitable working conditions to achieve maximum productivity. Microalgae concentration and productivity have been measured in a continuous 250 mL flat-panel PBR as a function of the space-time τ. Simulations were performed at both low and high irradiance values, with different light regimes (constant light and day-night profiles). Model parameters were optimized based on laboratory-scale experimental data, and the importance of the maintenance energy requirement as a function of light intensity was outlined. The effect of different extent of axial mixing on PBR performances was investigated. Results obtained show how to determine optimum working conditions and how they could be used in the design of a large-scale PBR to achieve maximum microalgal productivity.

  5. Investigation of longitudinal proton acceleration in exploded targets irradiated by intense short-pulse laser

    SciTech Connect

    Gauthier, M.; Lévy, A.; D'Humières, E.; Beaucourt, C.; Breil, J.; Feugeas, J. L.; Nicolaï, P.; Tikhonchuk, V.; Glesser, M.; Albertazzi, B.; Chen, S. N.; Dervieux, V.; Fuchs, J.; Pépin, H.; Antici, P.

    2014-01-15

    It was recently shown that a promising way to accelerate protons in the forward direction to high energies is to use under-dense or near-critical density targets instead of solids. Simulations have revealed that the acceleration process depends on the density gradients of the plasma target. Indeed, under certain conditions, the most energetic protons are predicted to be accelerated by a collisionless shock mechanism that significantly increases their energy. We report here the results of a recent experiment dedicated to the study of longitudinal ion acceleration in partially exploded foils using a high intensity (∼5 × 10{sup 18} W/cm{sup 2}) picosecond laser pulse. We show that protons accelerated using targets having moderate front and rear plasma gradients (up to ∼8 μm gradient length) exhibit similar maximum proton energy and number compared to proton beams that are produced, in similar laser conditions, from solid targets, in the well-known target normal sheath acceleration regime. Particle-In-Cell simulations, performed in the same conditions as the experiment and consistent with the measurements, allow laying a path for further improvement of this acceleration scheme.

  6. Post irradiation examination of simulated fission product doped hyperstoichiometric mixed oxide fuel pins*1

    NASA Astrophysics Data System (ADS)

    Götzmann, O.; Kleykamp, H.

    1980-03-01

    Two miniature fuel pins containing uranium-plutonium oxide with a hyperstoichiometric oxygen-to-metal ratio and selective fission product elements have been irradiated in the BR 2 reactor at Mol, Belgium, for two reactor cycles (46 days). One of the pins had a niobium metal coating on the inner cladding surface to act as oxygen getter. Both pins were subjected to a detailed examination by ceramography and electronprobe microanalysis. The results have been interpreted in the light of a recently published thermochemical model for the cladding attack. The very different oxygen potential environments in the two pins produced entirely different clad corrosion phenomena probably due to different cladding attack mechanisms. The niobium coating worked well in reducing the oxygen potential. However, there exists a draw back with niobium due to the formation of relatively stable intermetallic phases with noble metal fission products.

  7. Effects of the storage time on the folic acid added to ready-to-eat meat products manufactured by irradiation

    NASA Astrophysics Data System (ADS)

    Galán, I.; García, M. L.; Selgas, M. D.

    2013-04-01

    Three different meat products enriched with folic acid (FA) (2.4 mg/100 g) were manufactured: hamburgers, cooked and dry fermented sausages. They were prepared as ready-to-eat (RTE) products using E-beam radiation (2 and 3 kGy) to ensure their safety. The stability of FA and sensory properties of the irradiated meat products were studied during three months of storage under freezing conditions for hamburgers and refrigeration conditions for cooked and dry fermented sausages. FA content was stable in non-irradiated and irradiated hamburgers and cooked sausages over the storage period, whereas it decreased 20% in non-irradiated dry fermented sausages and 12-8% in irradiated samples at 2 and 3 kGy, respectively. Nevertheless, the final amount remained sufficient to provide the recommended daily intake. Panelists rated the sensory properties of the hamburger as satisfactory even after irradiation and 90 days of storage. The overall acceptability of RTE cooked and dry fermented sausages improved slightly with storage (P>0.05).

  8. Magnetic collimation of fast electrons in specially engineered targets irradiated by ultraintense laser pulses

    SciTech Connect

    Cai Hongbo; Zhu Shaoping; Wu Sizhong; Chen Mo; Zhou Cangtao; He, X. T.; Yu Wei; Nagatomo, Hideo

    2011-02-15

    The efficient magnetic collimation of fast electron flow transporting in overdense plasmas is investigated with two-dimensional collisional particle-in-cell numerical simulations. It is found that the specially engineered targets exhibiting either high-resistivity-core-low-resistivity-cladding structure or low-density-core-high-density-cladding structure can collimate fast electrons. Two main mechanisms to generate collimating magnetic fields are found. In high-resistivity-core-low-resistivity-cladding structure targets, the magnetic field at the interfaces is generated by the gradients of the resistivity and fast electron current, while in low-density-core-high-density-cladding structure targets, the magnetic field is generated by the rapid changing of the flow velocity of the background electrons in transverse direction (perpendicular to the flow velocity) caused by the density jump. The dependences of the maximal magnetic field on the incident laser intensity and plasma density, which are studied by numerical simulations, are supported by our analytical calculations.

  9. Steroid hormone production in testis, ovary, and adrenal gland of immature rats irradiated in utero with /sup 60/Co

    SciTech Connect

    Inano, H.; Suzuki, K.; Ishii-Ohba, H.; Imada, Y.; Kumagai, R.; Kurihara, S.; Sato, A.

    1989-02-01

    Pregnant rats received whole-body irradiation at 20 days of gestation with 2.6 Gy lambda rays from a 60Co source. Endocrinological effects before maturation were studied using testes and adrenal glands obtained from male offspring and ovaries from female offspring irradiated in utero. Seminiferous tubules of the irradiated male offspring were remarkably atrophied with free germinal epithelium and containing only Sertoli cells. Female offspring also had atrophied ovaries. Testicular tissue obtained from intact and 60Co-irradiated rats was incubated with 14C-labeled pregnenolone, progesterone, 17 alpha-hydroxyprogesterone, and androstenedione as a substrate. Intermediates for androgen production and catabolic metabolites were isolated after the incubation. The amounts of these metabolites produced by the irradiated testes were low in comparison with the control. The activities of delta 5-3 beta-hydroxysteroid dehydrogenase, 17 alpha-hydroxylase, C17,20-lyase, and delta 4-5 alpha-reductase in the irradiated testes were 30-40% of those in nonirradiated testes. Also, the activities of 17 beta- and 20 alpha-hydroxysteroid dehydrogenases were 72 and 52% of the control, respectively. In adrenal glands, the 21-hydroxylase activity of the irradiated animals was 38% of the control, but the delta 5-3 beta-hydroxysteroid dehydrogenase activity was comparable to that of the control. On the other hand, the activity of delta 5-3 beta-hydroxysteroid dehydrogenase of the irradiated ovary was only 19% of the control. These results suggest that 60Co irradiation of the fetus in utero markedly affects the production of steroid hormones in testes, ovaries, and adrenal glands after birth.

  10. Convoy electron production in polycrystalline and monocrystalline targets

    SciTech Connect

    Huldt, S.

    1980-01-01

    The velocity distribution of electrons ejected close to the forward direction by 0.8-2 MeV/A ions traversing various solid targets, including a Au monocrystal, is measured in coincidence with emerging charge-selected ions. The velocity spectrum is observed to be independent of outgoing projectile velocity and charge state for polycrystalline targets. Measurements on the Au crystal under channeling conditions show dependences on final charge state, and are tentatively explained by assuming that the main contribution to the production yield comes from the non-channeled fraction of the ions. A simple model for the creation of the forward-ejected electrons is proposed, which accounts for most of the experimental findings.

  11. Neon gas target for the production of radioactive fluorine beams

    SciTech Connect

    Decrock, P.; Nolen, J.A.

    1998-01-01

    A neon gas target has been developed to produce radioactive fluorine. Small CF{sub 4} impurities were added to the neon gas and the recovery efficiency of {sup 18}F-labeled CF{sub 4} has been measured as a function of the impurity level. Extraction efficiencies up to 90{percent} have been obtained, which makes this technique to produce and extract radioactive fluorine from a production target a powerful method to generate intense radioactive {sup 17}F and {sup 18}F beams, using the {sup 20}Ne(p,{alpha}){sup 17}F and {sup 20}Ne(d,{alpha}){sup 18}F reactions, respectively. {copyright} {ital 1998 American Institute of Physics.}

  12. FY-15 Progress Report on Cleanup of irradiated SHINE Target Solutions Containing 140g-U/L Uranyl Sulfate

    SciTech Connect

    Bennett, Megan E.; Bowers, Delbert L.; Vandegrift, George F.

    2015-09-01

    During FY 2012 and 2013, a process was developed to convert the SHINE Target Solution (STS) of irradiated uranyl sulfate (140 g U/L) to uranyl nitrate. This process is necessary so that the uranium solution can be processed by the UREX (Uranium Extraction) separation process, which will remove impurities from the uranium so that it can be recycled. The uranyl sulfate solution must contain <0.02 M SO42- so that the uranium will be extractable into the UREXsolvent. In addition, it is desired that the barium content be below 0.0007 M, as this is the limit in the Resource Conservation and Recovery Act (RCRA).

  13. Density profile steepening due to self-generated magnetic fields in plasmas produced by laser irradiation of spherical targets

    SciTech Connect

    Vyas, P.; Srivastava, M.P.

    1995-07-01

    The density variation of plasmas produced by irradiation with laser beams on spherical targets has been studied in the steady state. This study used an adiabatic plasma model with self-generated magnetic fields included in a phenomenological manner. The density variation with a radial coordinate is found to have a steep rise through the critical density, which reaches a plateau in the overdense region, then a density minimum and finally, a rise. This variation has been compared with experimentally observed values in earlier works and is found to be in fairly good agreement. The variation of plateau density with the intensity of the laser is also compared with the experimentally observed variation. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  14. In-target electron thermalization by the Weibel instability during intense irradiation of a thin aluminum foil

    NASA Astrophysics Data System (ADS)

    Fuchs, J.; Ruyer, C.; Albertazzi, B.; Lancia, L.; Dervieux, V.; Antici, P.; Bocker, J.; Chen, S. N.; Nakatsutsumi, M.; Romagnani, L.; Shepherd, R.; Swantusch, M.; Borghesi, M.; Willi, O.; Pepin, H.; Grech, M.; Riconda, C.; Gremillet, L.

    2015-11-01

    Proton-radiography of the electromagnetic fields developing after irradiation of a 3 μm-thick Al foil by a high-intensity laser (5 ×1019 W.cm-2, 700fs, 8 μm focal spot) was performed at the Titan facility. The obtained radiographs evidence filamentary structures which develop inside the dense target, 300 μ m away from the focal spot, a few picoseconds after the laser drive. We will demonstrate that the radiographs' structures are due to magnetic fields triggered by the so-called Weibel instability, inside the dense target. For this purpose, large scale particle-in-cell simulations of hot electrons thermalization in a dense, cold and collisional target have been performed. They demonstrate the ability of the laser-heated electrons to sustain a strong temperature anisotropy during their relaxation in the thin foil. This hot electron anisotropy results in a Weibel instability, thus triggering magnetic fluctuations of spectrum consistent with the experiment over 10 picoseconds.

  15. Investigations of ultrafast charge dynamics in laser-irradiated targets by a self probing technique employing laser driven protons

    NASA Astrophysics Data System (ADS)

    Ahmed, H.; Kar, S.; Cantono, G.; Nersisyan, G.; Brauckmann, S.; Doria, D.; Gwynne, D.; Macchi, A.; Naughton, K.; Willi, O.; Lewis, C. L. S.; Borghesi, M.

    2016-09-01

    The divergent and broadband proton beams produced by the target normal sheath acceleration mechanism provide the unique opportunity to probe, in a point-projection imaging scheme, the dynamics of the transient electric and magnetic fields produced during laser-plasma interactions. Commonly such experimental setup entails two intense laser beams, where the interaction produced by one beam is probed with the protons produced by the second. We present here experimental studies of the ultra-fast charge dynamics along a wire connected to laser irradiated target carried out by employing a 'self' proton probing arrangement - i.e. by connecting the wire to the target generating the probe protons. The experimental data shows that an electromagnetic pulse carrying a significant amount of charge is launched along the wire, which travels as a unified pulse of 10s of ps duration with a velocity close to speed of light. The experimental capabilities and the analysis procedure of this specific type of proton probing technique are discussed.

  16. Design and analysis of the lithium target system for the International Fusion Materials Irradiation Facility (IFMIF)

    SciTech Connect

    Hua, T.; Smith, D.; Hassanein, A.; Gomes, I.

    1995-09-01

    Three lithium target design options are being evaluated for the IFMIF. The impact of various requirements on material selection, lifetime, operation and maintenance are discussed. Analysis for the free jet option is presented. Key aspects include jet stability, thermal and nuclear responses.

  17. Proton induced production and radiochemical isolation of 44Ti from scandium metal targets for 44Ti/44Sc generator development

    DOE PAGES

    Radchenko, Valery; Engle, Jonathan Ward; Medvedev, Dmitri G.; ...

    2017-04-07

    Scandium-44 g (half-life 3.97 h) shows promise for application in positron emission tomography (PET), due to favorable decay parameters. One of the sources of 44gSc is the 44Ti/44gSc generator, which can conveniently provide this radioisotope on a daily basis at a diagnostic facility. Titanium-44 (half-life 60.0 a), in turn, can be obtained via proton irradiation of scandium metal targets. A substantial 44Ti product batch, however, requires high beam currents, long irradiation times and an elaborate chemical procedure for 44Ti isolation and purification. This study describes the production of a combined 175 MBq (4.7 mCi) batch yield of 44Ti in weekmore » long proton irradiations at the Los Alamos Isotope Production Facility (LANL-IPF) and the Brookhaven Linac Isotope Producer (BNL-BLIP). A two-step ion exchange chromatography based chemical separation method is introduced: first, a coarse separation of 44Ti via anion exchange sorption in concentrated HCl results in a 44Tc/Sc separation factor of 102–103. A second, cation exchange based step in HCl media is then applied for 44Ti fine purification from residual Sc mass. In conclusion, this method yields a 90–97% 44Ti recovery with an overall Ti/Sc separation factor of ≥106.« less

  18. JLAB CLAS Results on Pion Production from Nuclear Target

    NASA Astrophysics Data System (ADS)

    Lee, Hyupwoo; Manly, Steven

    Preliminary results on single charged pion production in eA collisions at Ebeam = 5 GeV/c2 are presented. The data were collected using the CLAS detector, which is a multipurpose, large acceptance, magnetic spectrometer located in Hall B at the Thomas Jefferson National Accelerator Facility. Distributions in W, Q2, pπ, and θπ are shown for data produced using deuterium, carbon, iron, and lead targets. The motivation for this work is to provide distributions useful for tuning the hadronic final state interaction models used in extracting results from current and next generation neutrino oscillation experiments.

  19. Color-Center Production and Formation in Electron-Irradiated Magnesium Aluminate Spinel and Ceria

    DOE PAGES

    Costantini, Jean-Marc; Lelong, Gerald; Guillaumet, Maxime; ...

    2016-06-20

    Single crystals of magnesium aluminate spinel (MgAl2O4) with (100) or (110) orientations and cerium dioxide or ceria (CeO2) were irradiated by 1.0-MeV and 2.5-MeV electrons in a high fluence range. Point-defect production was studied by off-line UV-visible optical spectroscopy after irradiation. For spinel, regardless of both crystal orientation and electron energy, two characteristic broad bands centered at photon energies of 5.4 eV and 4.9 eV were assigned to F and F+ centers (neutral and singly-ionized oxygen vacancies), respectively, on the basis of available literature data. No clear differences in colour-centre formation were observed for the two crystal orientations. Using calculationsmore » of displacement cross sections by elastic collisions, these results are consistent with a very large threshold displacement energy (200 eV) for oxygen atoms at RT. A third very broad band centered at 3.7 eV might be attributed either to an oxygen hole center (V-type center) or an F2 dimer center (oxygen di-vacancy). The onset of recovery of these color centers took place at 200°C with almost full bleaching at 600°C. Activation energies (~0.3-0.4 eV) for defect recovery were deduced from the isochronal annealing data by using a first-order kinetics analysis. For ceria, a sub band-gap absorption feature peaked at ~3.1 eV was recorded for 2.5-MeV electron irradiation only. Assuming a ballistic process, we suggest that the latter defect might result from cerium atom displacement on the basis of computed cross sections.« less

  20. Color-Center Production and Formation in Electron-Irradiated Magnesium Aluminate Spinel and Ceria

    SciTech Connect

    Costantini, Jean-Marc; Lelong, Gerald; Guillaumet, Maxime; Weber, William J.; Takaki, Seiya; Yasuda, Kazuhiro

    2016-06-20

    Single crystals of magnesium aluminate spinel (MgAl2O4) with (100) or (110) orientations and cerium dioxide or ceria (CeO2) were irradiated by 1.0-MeV and 2.5-MeV electrons in a high fluence range. Point-defect production was studied by off-line UV-visible optical spectroscopy after irradiation. For spinel, regardless of both crystal orientation and electron energy, two characteristic broad bands centered at photon energies of 5.4 eV and 4.9 eV were assigned to F and F+ centers (neutral and singly-ionized oxygen vacancies), respectively, on the basis of available literature data. No clear differences in colour-centre formation were observed for the two crystal orientations. Using calculations of displacement cross sections by elastic collisions, these results are consistent with a very large threshold displacement energy (200 eV) for oxygen atoms at RT. A third very broad band centered at 3.7 eV might be attributed either to an oxygen hole center (V-type center) or an F2 dimer center (oxygen di-vacancy). The onset of recovery of these color centers took place at 200°C with almost full bleaching at 600°C. Activation energies (~0.3-0.4 eV) for defect recovery were deduced from the isochronal annealing data by using a first-order kinetics analysis. For ceria, a sub band-gap absorption feature peaked at ~3.1 eV was recorded for 2.5-MeV electron irradiation only. Assuming a ballistic process, we suggest that the latter defect might result from cerium atom displacement on the basis of computed cross sections.

  1. Color-center production and recovery in electron-irradiated magnesium aluminate spinel and ceria

    NASA Astrophysics Data System (ADS)

    Costantini, Jean-Marc; Lelong, Gérald; Guillaumet, Maxime; Weber, William J.; Takaki, Seiya; Yasuda, Kazuhiro

    2016-08-01

    Single crystals of magnesium aluminate spinel (MgAl2O4) with (1 0 0) or (1 1 0) orientations and cerium dioxide or ceria (CeO2) were irradiated by 1.0 MeV and 2.5 MeV electrons in a high-fluence range. Point-defect production was studied by off-line UV-visible optical spectroscopy after irradiation. For spinel, regardless of both crystal orientation and electron energy, two characteristic broad bands centered at photon energies of 5.4 eV and 4.9 eV were assigned to F and F+ centers (neutral and singly ionized oxygen vacancies), respectively, on the basis of available literature data. No clear differences in color-center formation were observed for the two crystal orientations. Using calculations from displacement cross sections by elastic collisions, these results are consistent with a very large threshold displacement energy (200 eV) for oxygen atoms at room temperature. A third very broad band centered at 3.7 eV might be attributed either to an oxygen hole center (V-type center) or an F2 dimer center (oxygen di-vacancy). The onset of recovery of these color centers took place at 200 °C with almost full bleaching at 600 °C. Activation energies (~0.3-0.4 eV) for defect recovery were deduced from the isochronal annealing data by using a first-order kinetics analysis. For ceria, a sub-band-gap absorption feature, which peaked at ~3.1 eV, was recorded for 2.5 MeV electron irradiation only. Assuming a ballistic process, we suggest that the latter defect might result from cerium atom displacement on the basis of computed cross sections.

  2. Color-Center Production and Formation in Electron-Irradiated Magnesium Aluminate Spinel and Ceria

    SciTech Connect

    Costantini, Jean-Marc; Lelong, Gerald; Guillaumet, Maxime; Weber, William J.; Takaki, Seiya; Yasuda, Kazuhiro

    2016-06-20

    Single crystals of magnesium aluminate spinel (MgAl2O4) with (100) or (110) orientations and cerium dioxide or ceria (CeO2) were irradiated by 1.0-MeV and 2.5-MeV electrons in a high fluence range. Point-defect production was studied by off-line UV-visible optical spectroscopy after irradiation. For spinel, regardless of both crystal orientation and electron energy, two characteristic broad bands centered at photon energies of 5.4 eV and 4.9 eV were assigned to F and F+ centers (neutral and singly-ionized oxygen vacancies), respectively, on the basis of available literature data. No clear differences in colour-centre formation were observed for the two crystal orientations. Using calculations of displacement cross sections by elastic collisions, these results are consistent with a very large threshold displacement energy (200 eV) for oxygen atoms at RT. A third very broad band centered at 3.7 eV might be attributed either to an oxygen hole center (V-type center) or an F2 dimer center (oxygen di-vacancy). The onset of recovery of these color centers took place at 200°C with almost full bleaching at 600°C. Activation energies (~0.3-0.4 eV) for defect recovery were deduced from the isochronal annealing data by using a first-order kinetics analysis. For ceria, a sub band-gap absorption feature peaked at ~3.1 eV was recorded for 2.5-MeV electron irradiation only. Assuming a ballistic process, we suggest that the latter defect might result from cerium atom displacement on the basis of computed cross sections.

  3. 78 FR 34565 - Irradiation in the Production, Processing, and Handling of Animal Feed and Pet Food; Electron...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-10

    ..., and Handling of Animal Feed and Pet Food; Electron Beam and X-Ray Sources for Irradiation of Poultry... generated from machine sources at energy levels not to exceed 10 million electron volts (MeV); (3) X-rays... this chapter; or (4) X-rays generated from machine sources using tantalum or gold as the target...

  4. Target volume definition for upper abdominal irradiation using CT scans obtained during inhale and exhale phases.

    PubMed

    Aruga, T; Itami, J; Aruga, M; Nakajima, K; Shibata, K; Nojo, T; Yasuda, S; Uno, T; Hara, R; Isobe, K; Machida, N; Ito, H

    2000-09-01

    To evaluate the clinical utility of a treatment-planning technique involving the use of CT images obtained during both the static exhalation phase and static inhalation phase (two-phase planning). Ten patients with pancreatic or liver tumors underwent CT scanning under static exhale and inhale conditions, after a period of mild ventilation. By setting image positions differently, we were able to treat the two-phase images as one dataset. Each gross tumor volume (GTV) was contoured separately and the mixed GTV was used for the two-phase treatment planning. Treatment plans were constructed to compare the two-phase plans with the plans constructed using static exhalation images. The shift of the center of the GTV and kidneys and the minimum dose of GTV were then calculated. The shift of the GTV ranged from 2.6 to 27. 3 mm and that of the kidneys from 2.2 to 24 mm. In some patients whose treatment was planned using exhalation planning, the minimum dose of GTV at inhalation was less than 90% of the isocenter dose. Two-phase planning is a simple technique that can visualize tumor and organ movement simultaneously using CT. It further defines adequate field margins around the tumor and prevents unexpected radiation exposure to critical organs. Routine use of this technique for upper abdominal irradiation is recommended.

  5. A quantitative and comparative study of radionuclidic and chemical impurities in water samples irradiated in a niobium target with Havar vs. niobium-sputtered Havar as entrance foils.

    PubMed

    Avila-Rodriguez, Miguel A; Wilson, John S; McQuarrie, Steve A

    2008-12-01

    Enriched and natural abundance water samples were irradiated in a niobium (Nb) chamber target with Havar and Nb-sputtered Havar foils. Irradiations were performed with 17.5MeV protons at currents from 35 to 100microA lasting for 1-2.5h. Radionuclidic and chemical (cationic) impurities were determined via gamma spectroscopy and ICP-MS, respectively. Anionic impurities were evaluated by ion chromatography. Impurities in water samples irradiated with the Havar-Nb foils were much lower than the samples irradiated with an unmodified Havar foil. No significant differences were observed in the impurity levels between samples of H(2)(18)O-enriched and natural abundance water. Radionuclidic impurities were observed to decrease after 3-4 irradiations on a fresh Havar entrance foil, and reached a constant value for subsequent irradiations with the same integrated current. For targets covered with Havar foil, radionuclidic impurities were found to be proportional to the beam-integrated current regardless of the beam power and, unexpectedly, dependant of the beam power when using a Havar-Nb foil.

  6. Low-dose gamma irradiation enhances superoxide anion production by nonirradiated cells through TGF-β1-dependent bystander signaling.

    PubMed

    Temme, Jennifer; Bauer, Georg

    2013-04-01

    We show here that low-dose gamma irradiation substantially increase in extracellular superoxide anion production in oncogenically transformed cells and tumor cells but not by nontransformed cells. The transfer of only a few cells from an irradiated culture to nonirradiated control cells was sufficient for the transmission of a signal to induce superoxide anion production in the nonirradiated cells. The number of irradiated cells that was necessary for the successful induction of superoxide anion production in the nonirradiated cells depended on radiation dose. When irradiated cells were allowed to incubate for 1 h before transmission to the nonirradiated cultures, nearly all of the cells from the irradiated cell population were able to communicate the inducing signal to nonirradiated cells. siRNA-dependent knockdown and reconstitution experiments showed that TGF-β1 was sufficient to mediate the bystander effect triggered by low-dose radiation in this experimental system. A kinetic analysis demonstrated that the enhanced superoxide anion production was substantially reduced before the release of the bystander signal by activated TGF-β.

  7. Synergistic combination of near-infrared irradiation and targeted gold nanoheaters for enhanced photothermal neural stimulation

    PubMed Central

    Eom, Kyungsik; Im, Changkyun; Hwang, Seoyoung; Eom, Seyoung; Kim, Tae-Seong; Jeong, Hae Sun; Kim, Kyung Hwan; Byun, Kyung Min; Jun, Sang Beom; Kim, Sung June

    2016-01-01

    Despite a potential of infrared neural stimulation (INS) for modulating neural activities, INS suffers from limited light confinement and bulk tissue heating. Here, a novel methodology for an advanced optical stimulation is proposed by combining near-infrared (NIR) stimulation with gold nanorods (GNRs) targeted to neuronal cell membrane. We confirmed experimentally that in vitro and in vivo neural activation is associated with a local heat generation based on NIR stimulation and GNRs. Compared with the case of NIR stimulation without an aid of GNRs, combination with cell-targeted GNRs allows photothermal stimulation with faster neural response, lower delivered energy, higher stimulation efficiency and stronger behavior change. Since the suggested method can reduce a requisite radiant exposure level and alleviate a concern of tissue damage, it is expected to open up new possibilities for applications to optical neuromodulations for diverse excitable tissues and treatments of neurological disorders. PMID:27446678

  8. Enhanced dense attosecond electron bunch generation by irradiating an intense laser on a cone target

    SciTech Connect

    Hu, Li-Xiang; Yu, Tong-Pu Shao, Fu-Qiu; Zou, De-Bin; Yin, Yan

    2015-03-15

    By using two-dimensional particle-in-cell simulations, we demonstrate enhanced spatially periodic attosecond electron bunches generation with an average density of about 10n{sub c} and cut-off energy up to 380 MeV. These bunches are acquired from the interaction of an ultra-short ultra-intense laser pulse with a cone target. The laser oscillating field pulls out the cone surface electrons periodically and accelerates them forward via laser pondermotive force. The inner cone wall can effectively guide these bunches and lead to their stable propagation in the cone, resulting in overdense energetic attosecond electron generation. We also consider the influence of laser and cone target parameters on the bunch properties. It indicates that the attosecond electron bunch acceleration and propagation could be significantly enhanced without evident divergency by attaching a plasma capillary to the original cone tip.

  9. Effect of microwave irradiation on xylanase production from wheat bran and biobleaching of eucalyptus kraft pulp.

    PubMed

    Woldesenbet, Fantahun; Virk, Antar Puneet; Gupta, Naveen; Sharma, Prince

    2012-05-01

    Microwave irradiation (MWI) was used as pretreatment of wheat bran and eucalyptus kraft pulp to examine its effect on xylanase production by Bacillus halodurans FNP 135 using solid state fermentation and biobleaching with xylanase, respectively. Irradiation of wheat bran under optimized conditions (600 W, 6 min, and 20 % consistency) resulted in 56.8, and 31.7 % increase in xylanase yield and water absorbance of wheat bran and 17.3 % reduction in reducing sugars content. Optimized MWI of kraft pulp at 850 W, 2 min, and 20 % consistency led to 0.9 % increase in brightness, 10 % decrease in kappa number, 7.7 % increase in water absorbance, 4.6 % decrease in tear factor, 0.9 % increase in burst factor, and 7.5 % increase in viscosity. Also, MWI enhanced xylanase-mediated biobleaching by increasing brightness (1.1 %) and decreasing kappa number (14.3 %) and leading to a total of about 20 % reduction in chlorine consumption. MWI is an economical, efficient, and environment-friendly pretreatment of wheat bran and pulp for enhanced enzyme yield and rapid heating, respectively.

  10. Atomic scale modeling of defect production and microstructure evolution in irradiated metals

    SciTech Connect

    Diaz de la Rubia, T.; Soneda, N.; Shimomura, Y.

    1997-04-01

    Irradiation effects in materials depend in a complex way on the form of the as-produced primary damage state and its spatial and temporal evolution. Thus, while collision cascades produce defects on a time scale of tens of picosecond, diffusion occurs over much longer time scales, of the order of seconds, and microstructure evolution over even longer time scales. In this report the authors present work aimed at describing damage production and evolution in metals across all the relevant time and length scales. They discuss results of molecular dynamics simulations of displacement cascades in Fe and V. They show that interstitial clusters are produced in cascades above 5 keV, but not vacancy clusters. Next, they discuss the development of a kinetic Monte Carlo model that enables calculations of damage evolution over much longer time scales (1000`s of s) than the picosecond lifetime of the cascade. They demonstrate the applicability of the method by presenting predictions on the fraction of freely migrating defects in {alpha}Fe during irradiation at 600 K.

  11. Influence of oxygen on defect production in electron-irradiated, boron-doped silicon

    NASA Technical Reports Server (NTRS)

    Deangelis, H. M.; Drevinsky, P. J.

    1984-01-01

    Deep level transient spectroscopy (DLTS) measurements were made on float-zone and crucible-grown, boron-doped silicon irradiated with 1-MeV electrons. The minority carrier trap attributed to a boron-related state, was not seen in low-resistivity, float-zone silicon. However, a new majority carrier trap was observed in these samples. In the case of more lightly doped material the minority carrier trap was present, and its introduction rate was lower in float-zone than in crucible-grown silicon. For 1- and 10-ohm-cm float-zone material that was oxidized during processing, the introduction rates for this trap were comparable to those for crucible-grown silicon. This behavior indicates that the minority carrier trap involves oxygen and that it may be due to a boron-oxygen complex. The majority carrier trap seen in heavily doped, float-zone silicon may also involve boron but not oxygen. Observed trap concentrations suggest that oxygen content in the regions examined by DLTS is affected by processing techniques. Other differences were observed in defect production and annealing behavior of electron-irradiated, float-zone and crucible-grown silicon.

  12. Strategies and tools to improve crop productivity by targeting photosynthesis.

    PubMed

    Nuccio, Michael L; Potter, Laura; Stiegelmeyer, Suzy M; Curley, Joseph; Cohn, Jonathan; Wittich, Peter E; Tan, Xiaoping; Davis, Jimena; Ni, Junjian; Trullinger, Jon; Hall, Rick; Bate, Nicholas J

    2017-09-26

    Crop productivity needs to substantially increase to meet global food and feed demand for a rapidly growing world population. Agricultural technology developers are pursuing a variety of approaches based on both traditional technologies such as genetic improvement, pest control and mechanization as well as new technologies such as genomics, gene manipulation and environmental modelling to develop crops that are capable of meeting growing demand. Photosynthesis is a key biochemical process that, many suggest, is not yet optimized for industrial agriculture or the modern global environment. We are interested in identifying control points in maize photoassimilation that are amenable to gene manipulation to improve overall productivity. Our approach encompasses: developing and using novel gene discovery techniques, translating our discoveries into traits and evaluating each trait in a stepwise manner that reflects a modern production environment. Our aim is to provide step change advancement in overall crop productivity and deliver this new technology into the hands of growers.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'. © 2017 The Author(s).

  13. Treatment Optimization Using Computed Tomography-Delineated Targets Should be Used for Supraclavicular Irradiation for Breast Cancer

    SciTech Connect

    Liengsawangwong, Raweewan; Yu, T.-K.; Sun, T.-L.; Erasmus, Jeremy J.; Perkins, George H.; Tereffe, Welela; Oh, Julia L.; Woodward, Wendy A.; Strom, Eric A.; Salephour, Mohammad; Buchholz, Thomas A.

    2007-11-01

    Background: The purpose of this study was to determine whether the use of optimized CT treatment planning offered better coverage of axillary level III (LIII)/supraclavicular (SC) targets than the empirically derived dose prescription that are commonly used. Materials/Methods: Thirty-two consecutive breast cancer patients who underwent CT treatment planning of a SC field were evaluated. Each patient was categorized according to body mass index (BMI) classes: normal, overweight, or obese. The SC and LIII nodal beds were contoured, and four treatment plans for each patient were generated. Three of the plans used empiric dose prescriptions, and these were compared with a CT-optimized plan. Each plan was evaluated by two criteria: whether 98% of target volume receive >90% of prescribed dose and whether < 5% of the irradiated volume received 105% of prescribed dose. Results: The mean depth of SC and LIII were 3.2 cm (range, 1.4-6.7 cm) and 3.1 (range, 1.7-5.8 cm). The depth of these targets varied according across BMI classes (p = 0.01). Among the four sets of plans, the CT-optimized plans were the most successful at achieving both of the dosimetry objectives for every BMI class (normal BMI, p = .003; overweight BMI, p < .0001; obese BMI, p < .001). Conclusions: Across all BMI classes, routine radiation prescriptions did not optimally cover intended targets for every patient. Optimized CT-based treatment planning generated the most successful plans; therefore, we recommend the use of routine CT simulation and treatment planning of SC fields in breast cancer.

  14. Neutronic and thermal-hydraulic analysis of fission molybdenum-99 production at Tehran Research Reactor using LEU plate targets.

    PubMed

    Abedi, Ebrahim; Ebrahimkhani, Marzieh; Davari, Amin; Mirvakili, Seyed Mohammad; Tabasi, Mohsen; Maragheh, Mohammad Ghannadi

    2016-12-01

    Efficient and safe production of molybdenum-99 ((99)Mo) radiopharmaceutical at Tehran Research Reactor (TRR) via fission of LEU targets is studied. Neutronic calculations are performed to evaluate produced (99)Mo activity, core neutronic safety parameters and also the power deposition values in target plates during a 7 days irradiation interval. Thermal-hydraulic analysis has been also carried out to obtain thermal behavior of these plates. Using Thermal-hydraulic analysis, it can be concluded that the safety parameters are satisfied in the current study. Consequently, the present neutronic and thermal-hydraulic calculations show efficient (99)Mo production is accessible at significant activity values in TRR current core configuration. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Thermal diffusion of ⁶⁷Ga from irradiated Zn targets.

    PubMed

    Andrade Martins, Patricia de; Osso, João Alberto

    2013-12-01

    Gallium-67 is a cyclotron produced radionuclide and ⁶⁷Ga-citrate complex scans are performed in a variety of applications in Nuclear Medicine. The aim of this study was to evaluate a new method for the chemical separation of ⁶⁷Ga from Zn targets. The method has 2 steps, first the thermal diffusion of ⁶⁷Ga with concentrated acetic acid and then purification by cation exchange in ammonium medium. The final ⁶⁷Ga solution was obtained in 0.1 mol L⁻¹ HCl with the desirable high purity.

  16. Target detection using microwave irradiances from natural sources: A passive, local and global surveillance system

    NASA Technical Reports Server (NTRS)

    Stacey, J. M.

    1984-01-01

    Detection of metal objects on or near the Earth's surface was investigated using existing, passive, microwave sensors operating from Earth orbit. The range equations are derived from basic microwave principles and theories and the expressions are given explicitly to estimate the signal to noise ratio for detecting metal targets operating as bistatic scatterers. Actual measurements are made on a range of metal objects observed from orbit using existing passive microwave receiving systems. The details of the measurements and the results are tabulated and discussed. The advantages of a passive microwave sensor as it is applied to surveillance of metal objects as viewed from aerial platforms or from orbit, are examined.

  17. Production of 89Zr via the 89Y(p,n)89Zr reaction in aqueous solution: effect of solution composition on in-target chemistry.

    PubMed

    Pandey, Mukesh K; Engelbrecht, Hendrik P; Byrne, John P; Packard, Alan B; DeGrado, Timothy R

    2014-04-01

    The existing solid target production method of radiometals requires high capital and operational expenditures, which limit the production of radiometals to the small fraction of cyclotron facilities that are equipped with solid target systems. Our objective is to develop a robust solution target method, which can be applicable to a wide array of radiometals and would be simply and easily adopted by existing cyclotron facility for the routine production of radiometals. We have developed a simplified, solution target approach for production of (89)Zr using a niobium target by 14 MeV energy proton bombardment of aqueous solutions of yttrium salts via the (89)Y(p,n)(89)Zr nuclear reaction. The production conditions were optimized, following a detailed mechanistic study of the gas evolution. Although the solution target approach avoided the expense and complication of solid target processing, rapid radiolytic formation of gases in the target represents a major impediment in the success of solution target. To address this challenge we performed a systematic mechanistic study of gas evolution. Gas evolution was found to be predominantly due to decomposition of water to molecular hydrogen and oxygen. The rate of gas evolutions varied >40-fold depending on solution composition even under the same irradiation condition. With chloride salts, the rate of gas evolution increased in the order rank Nairradiating solution minimized gas evolution. At optimized condition, (89)Zr was produced in moderate yield (4.36 ± 0.48 MBq/μA • h) and high effective specific activity (464 ± 215 MBq/μg) using the solution target approach (2.75 M yttrium nitrate, 1.5 N HNO3, 2h irradiation at 20 μA). The novel findings on substrate dependent, radiation-induced water decomposition provide fundamental data for the development and optimization of conditions for solution

  18. Three-dimensional intrafractional internal target motions in accelerated partial breast irradiation using three-dimensional conformal external beam radiotherapy.

    PubMed

    Hirata, Kimiko; Yoshimura, Michio; Mukumoto, Nobutaka; Nakamura, Mitsuhiro; Inoue, Minoru; Sasaki, Makoto; Fujimoto, Takahiro; Yano, Shinsuke; Nakata, Manabu; Mizowaki, Takashi; Hiraoka, Masahiro

    2017-07-01

    We evaluated three-dimensional intrafractional target motion, divided into respiratory-induced motion and baseline drift, in accelerated partial breast irradiation (APBI). Paired fluoroscopic images were acquired simultaneously using orthogonal kV X-ray imaging systems at pre- and post-treatment for 23 patients who underwent APBI with external beam radiotherapy. The internal target motion was calculated from the surgical clips placed around the tumour cavity. The peak-to-peak respiratory-induced motions ranged from 0.6 to 1.5mm in all directions. A systematic baseline drift of 1.5mm towards the posterior direction and a random baseline drift of 0.3mm in the lateral-medial and cranial-caudal directions were observed. The baseline for an outer tumour cavity drifted towards the lateral and posterior directions, and that for an upper tumour cavity drifted towards the cranial direction. Moderate correlations were observed between the posterior baseline drift and the patients' physical characteristics. The posterior margin for intrafractional uncertainties was larger than 5mm in patients with greater fat thickness due to the baseline drift. The magnitude of the intrafractional motion was not uniform according to the direction, patients' physical characteristics, or tumour cavity location due to the baseline drift. Therefore, the intrafractional systematic movement should be properly managed. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Triton Emission Spectra in Some Target Nuclei Irradiated by Ultra-Fast Neutrons

    NASA Astrophysics Data System (ADS)

    Tel, E.; Kaplan, A.; Aydın, A.; Büyükuslu, H.; Demirkol, İ.; Arasoğlu, A.

    2010-08-01

    High-current proton accelerator technologies make use of spallation neutrons produced in ( p,xn) and ( n,xn) nuclear reactions on high-Z targets. The produced neutrons are moderated by heavy water. These moderated neutrons are subsequently captured on 3He to produce tritium via the ( n,p) reaction. Tritium self-sufficiency must be maintained for a commercial power plant. So, working out the systematics of ( n,t) reaction cross sections and triton emission differential data are important for the given reaction taking place on various nuclei at different energies. In this study, triton emission spectra by using ultra-fast neutrons (incident neutron energy >50 MeV), the ( n,xt) reactions for some target nuclei as 16O, 27Al, 56Fe, 59Co, 208Pb and 209Bi have been investigated. In the calculations, the pre-equilibrium and equilibrium effects have been used. The calculated results have been compared with the experimental data taken from the literature.

  20. Promises and Challenges of Two-Step Targets for Production of Neutron-rich RIBs

    SciTech Connect

    Talbert, W.L.; Drake, D.M.; Hsu, H.-H.; Wilson, M.T.

    2003-08-26

    Development of a prototype two-step target to produce neutron-rich RIBs is presented, with particular emphasis on thermal analysis under high-power operation. The two-step target is an attractive concept for production of fission-product activities without interference by high-energy spallation reactions which occur in direct production targets. In this concept, a high-energy production beam interacts with a primary target of refractory metal, depositing beam energy in the primary target and producing low-energy neutrons that cause fissions in a surrounding secondary target of mixed UC2 and excess C. Thermal analysis of the composite target presents challenges in cooling the primary target while maintaining the secondary target at temperatures suitable for release of the fission products. The effects of fission energy deposition in the secondary target are discussed, along with the complexities resulting from the thermally insulating character of the secondary target material.

  1. Soft X-Ray Irradiation of Methanol Ice: Formation of Products as a Function of Photon Energy

    NASA Astrophysics Data System (ADS)

    Chen, Y.-J.; Ciaravella, A.; Muñoz Caro, G. M.; Cecchi-Pestellini, C.; Jiménez-Escobar, A.; Juang, K.-J.; Yih, T.-S.

    2013-12-01

    Pure methanol ices have been irradiated with monochromatic soft X-rays of 300 and 550 eV close to the 1s resonance edges of C and O, respectively, and with a broadband spectrum (250-1200 eV). The infrared (IR) spectra of the irradiated ices show several new products of astrophysical interest such as CH2OH, H2CO, CH4, HCOOH, HCOCH2OH, CH3COOH, CH3OCH3, HCOOCH3, and (CH2OH)2, as well as HCO, CO, and CO2. The effect of X-rays is the result of the combined interactions of photons and electrons with the ice. A significant contribution to the formation and growth of new species in the CH3OH ice irradiated with X-rays is given by secondary electrons, whose energy distribution depends on the energy of X-ray photons. Within a single experiment, the abundances of the new products increase with the absorbed energy. Monochromatic experiments show that product abundances also increase with the photon energy. However, the abundances per unit energy of newly formed species show a marked decrease in the broadband experiment as compared to irradiations with monochromatic photons, suggesting a possible regulatory role of the energy deposition rate. The number of new molecules produced per absorbed eV in the X-ray experiments has been compared to those obtained with electron and ultraviolet (UV) irradiation experiments.

  2. The oxidative stress in the liver of Carassius auratus exposed to acesulfame and its UV irradiance products.

    PubMed

    Ren, Yuhang; Geng, Jinju; Li, Fuchang; Ren, Hongqiang; Ding, Lili; Xu, Ke

    2016-11-15

    Acesulfame (ACE) is listed as an emerging contaminant due to its environmental persistence and wide occurrence in the environment. ACE can be degraded partially in the regular UV disinfection process but the eco-toxicity of its irradiation products remains unclear. This study focused on the possible oxidative status change in the liver of Carassius auratus exposed to ACE and its irradiation products. The UV degradation of ACE follows pseudo-first-order kinetics, and eight irradiation products were identified. Fish were exposed 7days to 0.1 and 10mg/L ACE (ACE group) and ACE after UV irradiance (ACE-UV group). The oxidative stress in fish liver exposed to ACE group had no distinct change. However, in the ACE-UV group, the quantity of OH was induced by 17.96-55% and the MDA content increased by 16.28-68.28% compared to control. Time-effect exposure in the ACE-UV group showed that in the first 3days the quantity of OH reached its peak, causing severe inhibition of SOD and continuous inducement of GPx. GSH helped scavenge OH and decreased below control after 3days. An increased toxicity of ACE after UV irradiance was observed and its transfer after into aquatic environment needs to be recognized as an environmental risk.

  3. Global Mapping of Underwater UV Irradiances and DNA-Weighted Exposures using TOMS and SeaWiFS Data Products

    NASA Technical Reports Server (NTRS)

    Vasilkov, Alexander; Krotkov, Nickolay; Herman, Jay; McClain, Charles; Arrigo, Kevin; Robinson, Wayne

    1999-01-01

    The global stratospheric ozone-layer depletion results In an increase in biologically harmful ultraviolet (UV) radiation reaching the surface and penetrating to ecologically significant depths in natural waters. Such an increase can be estimated on a global scale by combining satellite estimates of UV irradiance at the ocean surface from the Total Ozone Mapping Spectrometer (TOMS) satellite instrument with the SeaWIFS satellite ocean-color measurements in the visible spectral region. In this paper we propose a model of seawater optical properties in the UV spectral region based on the Case I water model in the visible range. The inputs to the model are standard monthly SeaWiFS products: chlorophyll concentration and the diffuse attenuation coefficient at 490nm. Penetration of solar UV radiation to different depths in open ocean waters is calculated using the RT (radiative transfer) quasi-single scattering approximation (QSSA). The accuracy of the QSSA approximation in the water is tested using more accurate codes. The sensitivity study of the underwater UV irradiance to atmospheric and oceanic optical properties have shown that the main environmental parameters controlling the absolute levels of the UVB (280-320nm) and DNA-weighted irradiance underwater are: solar-zenith angle, cloud transmittance, water optical properties, and total ozone. Weekly maps of underwater UV irradiance and DNA-weighted exposure are calculated using monthly-mean SeaWiFS chlorophyll and diffuse attenuation coefficient products, daily SeaWiFS cloud fraction data, and the TOMS-derived surface UV irradiance daily maps. The final products include global maps of weekly-average UVB irradiance and DNA-weighted daily exposures at 3m and 10m, and depths where the UVB irradiance and DNA-weighted dose rate at local noon are equal to 10% of their surface values.

  4. CMSAF products Cloud Fraction Coverage and Cloud Type used for solar global irradiance estimation

    NASA Astrophysics Data System (ADS)

    Badescu, Viorel; Dumitrescu, Alexandru

    2016-08-01

    Two products provided by the climate monitoring satellite application facility (CMSAF) are the instantaneous Cloud Fractional Coverage (iCFC) and the instantaneous Cloud Type (iCTY) products. Previous studies based on the iCFC product show that the simple solar radiation models belonging to the cloudiness index class n CFC = 0.1-1.0 have rRMSE values ranging between 68 and 71 %. The products iCFC and iCTY are used here to develop simple models providing hourly estimates for solar global irradiance. Measurements performed at five weather stations of Romania (South-Eastern Europe) are used. Two three-class characterizations of the state-of-the-sky, based on the iCTY product, are defined. In case of the first new sky state classification, which is roughly related with cloud altitude, the solar radiation models proposed here perform worst for the iCTY class 4-15, with rRMSE values ranging between 46 and 57 %. The spreading error of the simple models is lower than that of the MAGIC model for the iCTY classes 1-4 and 15-19, but larger for iCTY classes 4-15. In case of the second new sky state classification, which takes into account in a weighted manner the chance for the sun to be covered by different types of clouds, the solar radiation models proposed here perform worst for the cloudiness index class n CTY = 0.7-0.1, with rRMSE values ranging between 51 and 66 %. Therefore, the two new sky state classifications based on the iCTY product are useful in increasing the accuracy of solar radiation models.

  5. Cyclotron targets and production technologies used for radiopharmaceuticals in NPI

    NASA Astrophysics Data System (ADS)

    Fišer, M.; Kopička, K.; Hradilek, P.; Hanč, P.; Lebeda, O.; Pánek, J.; Vognar, M.

    2003-01-01

    This paper deals with some technical aspects of the development and production of cyclotronmade radiopharmaceuticals (excluding PET). In this field, nuclear chemistry and pharmacy are in a close contact; therefore, requirements of the both should be taken into account. The principles of cyclotron targetry, separation/recovery of materials and synthesis of active substances are given, as well as issues connected with formulation of pharmaceutical forms. As the radiopharmaceuticals should fulfil the requirements on in vivo preparations, there exist a variety of demands pertaining to Good Manufacturing Practice (GMP) concept, which is also briefly discussed. A typical production chain is presented and practical examples of real technologies based on cyclotron-made radionuclides are given as they have been used in Nuclear Physics Institute of CAS (NPI). Special attention is devoted to the technology of enriched cyclotron targets. Frequently used medicinal products employing cyclotron-produced active substances are characterised (Rb/Kr generators, 123I-labelled MIBG, OIH and MAB's). The cyclotron produced radioactive implants for transluminal coronary angioplasty (radioactive stents) are introduced as an example of a medical device developed for therapeutic application.

  6. The Collection 6 'dark-target' MODIS Aerosol Products

    NASA Technical Reports Server (NTRS)

    Levy, Robert C.; Mattoo, Shana; Munchak, Leigh A.; Kleidman, Richard G.; Patadia, Falguni; Gupta, Pawan; Remer, Lorraine

    2013-01-01

    Aerosol retrieval algorithms are applied to Moderate resolution Imaging Spectroradiometer (MODIS) sensors on both Terra and Aqua, creating two streams of decade-plus aerosol information. Products of aerosol optical depth (AOD) and aerosol size are used for many applications, but the primary concern is that these global products are comprehensive and consistent enough for use in climate studies. One of our major customers is the international modeling comparison study known as AEROCOM, which relies on the MODIS data as a benchmark. In order to keep up with the needs of AEROCOM and other MODIS data users, while utilizing new science and tools, we have improved the algorithms and products. The code, and the associated products, will be known as Collection 6 (C6). While not a major overhaul from the previous Collection 5 (C5) version, there are enough changes that there are significant impacts to the products and their interpretation. In its entirety, the C6 algorithm is comprised of three sub-algorithms for retrieving aerosol properties over different surfaces: These include the dark-target DT algorithms to retrieve over (1) ocean and (2) vegetated-dark-soiled land, plus the (3) Deep Blue (DB) algorithm, originally developed to retrieve over desert-arid land. Focusing on the two DT algorithms, we have updated assumptions for central wavelengths, Rayleigh optical depths and gas (H2O, O3, CO2, etc.) absorption corrections, while relaxing the solar zenith angle limit (up to 84) to increase pole-ward coverage. For DT-land, we have updated the cloud mask to allow heavy smoke retrievals, fine-tuned the assignments for aerosol type as function of season location, corrected bugs in the Quality Assurance (QA) logic, and added diagnostic parameters such as topographic altitude. For DT-ocean, improvements include a revised cloud mask for thin-cirrus detection, inclusion of wind speed dependence in the retrieval, updates to logic of QA Confidence flag (QAC) assignment, and

  7. Upgrading and Refining of Crude Oils and Petroleum Products by Ionizing Irradiation.

    PubMed

    Zaikin, Yuriy A; Zaikina, Raissa F

    2016-06-01

    A general trend in the oil industry is a decrease in the proven reserves of light crude oils so that any increase in future oil exploration is associated with high-viscous sulfuric oils and bitumen. Although the world reserves of heavy oil are much greater than those of sweet light oils, their exploration at present is less than 12 % of the total oil recovery. One of the main constraints is very high expenses for the existing technologies of heavy oil recovery, upgrading, transportation, and refining. Heavy oil processing by conventional methods is difficult and requires high power inputs and capital investments. Effective and economic processing of high viscous oil and oil residues needs not only improvements of the existing methods, such as thermal, catalytic and hydro-cracking, but the development of new technological approaches for upgrading and refining of any type of problem oil feedstock. One of the perspective approaches to this problem is the application of ionizing irradiation for high-viscous oil processing. Radiation methods for upgrading and refining high-viscous crude oils and petroleum products in a wide temperature range, oil desulfurization, radiation technology for refining used oil products, and a perspective method for gasoline radiation isomerization are discussed in this paper. The advantages of radiation technology are simple configuration of radiation facilities, low capital and operational costs, processing at lowered temperatures and nearly atmospheric pressure without the use of any catalysts, high production rates, relatively low energy consumption, and flexibility to the type of oil feedstock.

  8. Grain boundary effects on defect production and mechanical properties of irradiated nanocrystalline SiC

    SciTech Connect

    Jin Enze; Niu Lisha; Lin Enqiang; Song Xiaoxiong

    2012-05-15

    Grain boundaries (GBs) are known to play an important role in determining the mechanical and functional properties of nanocrystalline materials. In this study, we used molecular dynamics simulations to investigate the effects of damaged GBs on the mechanical properties of SiC that is irradiated by 10 keV Si atoms. The results reveal that irradiation promotes GB sliding and reduces the ability of GBs to block dislocations, which improves the deformation ability of nanocrystalline SiC. However, irradiation causes local rearrangements in disordered clusters and pinning of dislocations in the grain region, which restrains its deformation. These two mechanisms arise from the irradiation effects on GBs and grains, and these mechanisms compete in nanocrystalline SiC during irradiation. The irradiation effects on GBs dominate at low irradiation doses, and the effects on grains dominate at high doses; the result of these combined effects is a peak ductility of 0.09 dpa in nanocrystalline SiC.

  9. Significance of Heavy-Ion Beam Irradiation-Induced Avermectin B1a Production by Engineered Streptomyces avermitilis

    PubMed Central

    Bo, Yong-Heng; Chen, Ji-Hong; Li, Wen-Jian; Liang, Jian-Ping; Xiao, Guo-Qing; Wang, Yu-Chen; Liu, Jing; Hu, Wei; Jiang, Bo-Ling

    2017-01-01

    Heavy-ion irradiation technology has advantages over traditional methods of mutagenesis. Heavy-ion irradiation improves the mutation rate, broadens the mutation spectrum, and shortens the breeding cycle. However, few data are currently available regarding its effect on Streptomyces avermitilis morphology and productivity. In this study, the influence of heavy-ion irradiation on S. avermitilis when cultivated in approximately 10 L stirred-tank bioreactors was investigated. The specific productivity of the avermectin (AVM) B1a-producing mutant S. avermitilis 147-G58 increased notably, from 3885 to 5446 μg/mL, approximately 1.6-fold, compared to the original strain. The mycelial morphology of the mutant fermentation processes was microscopically examined. Additionally, protein and metabolite identification was performed by using SDS-PAGE, 2- and 3-dimensional electrophoresis (2DE and 3DE). The results showed that negative regulation gene deletion of mutants led to metabolic process upregulating expression of protein and improving the productivity of an avermectin B1a. The results showed that the heavy-ion beam irradiation dose that corresponded to optimal production was well over the standard dose, at approximately 80 Gy at 220 AMeV (depending on the strain). This study provides reliable data and a feasible method for increasing AVM productivity in industrial processes. PMID:28243599

  10. Neutron production in tissue-like media and shielding materials irradiated with high-energy ion beams.

    PubMed

    Gudowska, I; Kopec, M; Sobolevsky, N

    2007-01-01

    Secondary neutrons produced in high-energy therapeutic ion beams require special attention since they contribute to the dose delivered to patient, both to tumour and to the healthy tissues. Moreover, monitoring of neutron production in the beam line elements and the patient is of importance for radiation protection aspects around ion therapy facility. Monte Carlo simulations of light ion transport in the tissue-like media (water, A-150, PMMA) and materials of interest for shielding devices (graphite, steel and Pb) were performed using the SHIELD-HIT and MCNPX codes. The capability of the codes to reproduce the experimental data on neutron spectra differential both in energy and angle is demonstrated for neutron yield from the thick targets. Both codes show satisfactory agreement with the experimental data. The absorbed dose due to neutrons produced in the water and A-150 phantoms is calculated for proton (200 MeV) and carbon (390 MeV/u) beams. Secondary neutron dose contribution is approximately 0.6% of the total dose delivered to the phantoms by proton beam and at the similar level for both materials. For carbon beam the neutron dose contribution is approximately 1.0 and 1.2% for the water and A-150 phantoms, respectively. The neutron ambient dose equivalent, H(10), was determined for neutrons leaving different shielding materials after irradiation with ions of various energies.

  11. Enhanced astaxanthin production from microalga, Haematococcus pluvialis by two-stage perfusion culture with stepwise light irradiation.

    PubMed

    Park, Joon Chul; Choi, Seung Phill; Hong, Min-Eui; Sim, Sang Jun

    2014-10-01

    For efficient astaxanthin production from the culture of green microalga, Haematococcus pluvialis, a two-stage mixotrophic culture system was established with stepwise increased light irradiance. By perfusion process, high density biomass (2.47 g/L) was achieved during the vegetative stage due to no detrimental effect of inhibitory metabolites, which was 3.09 and 1.67 times higher than batch and fed-batch processes, respectively. During the induction stage, biomass and astaxanthin were subsequently produced to the very high level 12.3 g/L and 602 mg/L, under stepwise increased light irradiance (150-450 μE/m(2)/s), respectively. These results indicate that the combinatorial approach of perfusion culture during the vegetative stage and stepwise light irradiation during the induction stage is a promising strategy for the simultaneous production of high concentration of biomass and astaxanthin in microalgae including H. pluvialis.

  12. Irradiation and modified atmosphere packaging of endive influences survival and regrowth of Listeria monocytogenes and product sensory qualities

    NASA Astrophysics Data System (ADS)

    Niemira, Brendan A.; Fan, Xuetong; Sokorai, Kimberly J. B.

    2005-01-01

    Cut pieces of endive were inoculated with Listeria monocytogenes, packaged in gas-impermeable bags in air, 5/5/90% or 10/10/80% CO 2, O 2 and N2 ("Air-0", "5/5" and "10/10", respectively) and irradiated to 0.0 (control), 0.3 or 0.6 kGy. At various times during refrigerated storage, samples were taken and a determination made of (a) total microflora, (b) L. monocytogenes, (c) headspace gas composition, (d) color and (e) texture. Irradiation reduced initial microbial counts in a dose-dependant manner. Bacteria regrew during storage on Air-0 samples, but not on 5/5 or 10/10 samples. In each of the three atmospheres, O 2 declined and CO 2 increased, irrespective of radiation dose. Irradiated leaf material in Air-0 tended to retain color attributes during storage better than non-irradiated; color retention was more variable under 5/5 and 10/10 packaging. After 8 days, maximum shear force relative to the initial level was significantly reduced in 5/5 at all radiation doses, was not significantly changed in Air-0, and was dose-dependent in 10/10. By 14 days, the texture of all samples had degraded significantly. These results indicate that irradiation and modified atmosphere packaging can be combined to prevent the regrowth of L. monocytogenes during post-irradiation refrigerated storage, thereby improving product safety.

  13. [Growth and metabolite production of the marine cyanobacterium Synechococcus sp. (Chroococcales) in function to irradiance].

    PubMed

    Rosales-Loaiza, Néstor; Guevara, Miguel; Lodeiros, César; Morales, Ever

    2008-06-01

    Changes in salinity, temperature and irradiance during wet and dry seasons have induced metabolic versatility in cyanobacteria from saline environments. Cyanobacteria from these environments have biotechnological potential for the production of metabolites with pharmaceutical and industrial interest. We studied the growth, dry mass and metabolite production of the cyanobacterium Synechococcus sp. MOF-03 in function of irradiance (78, 156 and 234 micromol q m(-2) s(-1)). All batch cultures were maintained by triplicate in constant aeration, 12:12 h photoperiod, 30 +/- 2 degrees C and 35% per hundred. Maximum values of protein, carbohydrates and lipids, of 530.19 +/- 11.16, 408.94 +/- 4.27 and 56.20 +/- 1.17 microg ml(-1), respectively, were achieved at 78 micromol q m(-2) s(-1). Pigments, analyzed by HPLC, showed maximum values at 78 micromol q m(-2) s(-1) for chlorophyll a with 7.72 +/- 0.16 microg ml(-1), and at 234 micromol q m(-2) s(-1) for beta-carotene and zeaxanthin with 0.70 +/- 0.01 and 0.67 +/- 0.05 microg ml(-1). Chlorophyll a:beta-carotene ratio decreased from 17.15 to 6.91 at 78 and 234 micromol q m(-2) s(-'1); whereas beta-carotene:zeaxanthin ratio showed no changes between 78 and 156 micromol q m(-2) s(-1), around 1.21, and decreased at 234 micromol q m(-2) s(-1), to 1.04. Also, this cyanobacterium produced the greatest cell density and dry mass at 156 micromol q m(-2) s(-1), with 406.13 +/- 21.74 x l0(6) cell ml(-1) and 1.49 +/- 0.11 mg ml(-1), respectively. Exopolysaccharide production was stable between 156 y 234 micromol q m(-2) s(-1), around 110 microg ml(-1). This Synechococcus strain shows a great potential for the production of enriched biomass with high commercial value metabolites.

  14. Ion acceleration with a narrow energy spectrum by nanosecond laser-irradiation of solid target

    SciTech Connect

    Altana, C.; Lanzalone, G.; Mascali, D.; Cirrone, G. A. P.; Schillaci, F.; Tudisco, S.; Muoio, A.

    2016-02-15

    In laser-driven plasma, ion acceleration of aluminum with the production of a quasi-monoenergetic beam has occurred. A useful device to analyze the ions is the Thomson parabolas spectrometer, a well-known diagnostic that is able to obtain information on charge-to-mass ratio and energy distribution of the charged particles. At the LENS (Laser Energy for Nuclear Science) laboratory of INFN-LNS in Catania, experimental measures were carried out; the features of LENS are: Q-switched Nd:YAG laser with 2 J laser energy, 1064 nm fundamental wavelengths, and 6 ns pulse duration.

  15. Solar Irradiance Changes and Phytoplankton Productivity in Earth's Ocean Following Astrophysical Ionizing Radiation Events

    NASA Astrophysics Data System (ADS)

    Neale, Patrick J.; Thomas, Brian C.

    2016-04-01

    Two atmospheric responses to simulated astrophysical ionizing radiation events significant to life on Earth are production of odd-nitrogen species, especially NO2, and subsequent depletion of stratospheric ozone. Ozone depletion increases incident short-wavelength ultraviolet radiation (UVB, 280-315 nm) and longer (>600 nm) wavelengths of photosynthetically available radiation (PAR, 400-700 nm). On the other hand, the NO2 haze decreases atmospheric transmission in the long-wavelength UVA (315-400 nm) and short-wavelength PAR. Here, we use the results of previous simulations of incident spectral irradiance following an ionizing radiation event to predict changes in terran productivity focusing on photosynthesis of marine phytoplankton. The prediction is based on a spectral model of photosynthetic response, which was developed for the dominant genera in central regions of the ocean (Synechococcus and Prochlorococcus), and on remote-sensing-based observations of spectral water transparency, temperature, wind speed, and mixed layer depth. Predicted productivity declined after a simulated ionizing event, but the effect integrated over the water column was small. For integrations taking into account the full depth range of PAR transmission (down to 0.1% of utilizable PAR), the decrease was at most 2-3% (depending on strain), with larger effects (5-7%) for integrations just to the depth of the surface mixed layer. The deeper integrations were most affected by the decreased utilizable PAR at depth due to the NO2 haze, whereas shallower integrations were most affected by the increased surface UV. Several factors tended to dampen the magnitude of productivity responses relative to increases in surface-damaging radiation, for example, most inhibition in the modeled strains is caused by UVA and PAR, and the greatest relative increase in damaging exposure is predicted to occur in the winter when UV and productivity are low.

  16. Solar Irradiance Changes and Phytoplankton Productivity in Earth's Ocean Following Astrophysical Ionizing Radiation Events.

    PubMed

    Neale, Patrick J; Thomas, Brian C

    2016-04-01

    Two atmospheric responses to simulated astrophysical ionizing radiation events significant to life on Earth are production of odd-nitrogen species, especially NO2, and subsequent depletion of stratospheric ozone. Ozone depletion increases incident short-wavelength ultraviolet radiation (UVB, 280-315 nm) and longer (>600 nm) wavelengths of photosynthetically available radiation (PAR, 400-700 nm). On the other hand, the NO2 haze decreases atmospheric transmission in the long-wavelength UVA (315-400 nm) and short-wavelength PAR. Here, we use the results of previous simulations of incident spectral irradiance following an ionizing radiation event to predict changes in terran productivity focusing on photosynthesis of marine phytoplankton. The prediction is based on a spectral model of photosynthetic response, which was developed for the dominant genera in central regions of the ocean (Synechococcus and Prochlorococcus), and on remote-sensing-based observations of spectral water transparency, temperature, wind speed, and mixed layer depth. Predicted productivity declined after a simulated ionizing event, but the effect integrated over the water column was small. For integrations taking into account the full depth range of PAR transmission (down to 0.1% of utilizable PAR), the decrease was at most 2-3% (depending on strain), with larger effects (5-7%) for integrations just to the depth of the surface mixed layer. The deeper integrations were most affected by the decreased utilizable PAR at depth due to the NO2 haze, whereas shallower integrations were most affected by the increased surface UV. Several factors tended to dampen the magnitude of productivity responses relative to increases in surface-damaging radiation, for example, most inhibition in the modeled strains is caused by UVA and PAR, and the greatest relative increase in damaging exposure is predicted to occur in the winter when UV and productivity are low.

  17. Determination of planning target volume for whole stomach irradiation using daily megavoltage computed tomographic images.

    PubMed

    Johnson, Matthew E; Pereira, Gisele C; El Naqa, Issam M; Goddu, S Murty; Al-Lozi, Rawan; Apte, Aditya; Mansur, David B

    2012-01-01

    Whole stomach radiation therapy is often used in the management of gastric lymphoma. However, very limited data exist with regard to planning target volume requirements for the whole stomach. This study retrospectively analyzed daily megavoltage computed tomographic (CT) scans of gastric lymphoma patients in order to help determine the interfraction variation of the stomach position. Forty-one daily megavoltage CT images from 3 gastric lymphoma patients were used for stomach contouring. Each patient's megavoltage CT images were rigidly registered to their CT simulation data sets, and the margin in each direction that covered at least 95% of the daily stomach volumes was computed using a simple grid search. Patient setup variation was also calculated from the daily patient shifts. The organ motion margin was then added to the setup margin to render the total margin. A uniform margin of 2.2 cm is required to cover 95% of the stomach over the treatment course. However, direction-specific margins were observed from 1.72, 1.88, 0.92, 2.23, 1.90, and 0.86 cm for the right, left, posterior, anterior, superior, and inferior directions, respectively. The results of this study provide helpful 3-dimensional volumetric information to the limited existing data on margin requirements for whole stomach radiation therapy. Copyright © 2012 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

  18. Fast targeted gene transfection and optogenetic modification of single neurons using femtosecond laser irradiation

    PubMed Central

    Antkowiak, Maciej; Torres-Mapa, Maria Leilani; Witts, Emily C.; Miles, Gareth B.; Dholakia, Kishan; Gunn-Moore, Frank J.

    2013-01-01

    A prevailing problem in neuroscience is the fast and targeted delivery of DNA into selected neurons. The development of an appropriate methodology would enable the transfection of multiple genes into the same cell or different genes into different neighboring cells as well as rapid cell selective functionalization of neurons. Here, we show that optimized femtosecond optical transfection fulfills these requirements. We also demonstrate successful optical transfection of channelrhodopsin-2 in single selected neurons. We extend the functionality of this technique for wider uptake by neuroscientists by using fast three-dimensional laser beam steering enabling an image-guided “point-and-transfect” user-friendly transfection of selected cells. A sub-second transfection timescale per cell makes this method more rapid by at least two orders of magnitude when compared to alternative single-cell transfection techniques. This novel technology provides the ability to carry out large-scale cell selective genetic studies on neuronal ensembles and perform rapid genetic programming of neural circuits. PMID:24257461

  19. Cooperative effect of roscovitine and irradiation targets angiogenesis and induces vascular destabilization in human breast carcinoma.

    PubMed

    Maggiorella, L; Aubel, C; Haton, C; Milliat, F; Connault, E; Opolon, P; Deutsch, E; Bourhis, J

    2009-02-01

    Angiogenesis is considered as an essential process for tumour development and invasion. Previously, we demonstrated that cyclin-dependent kinase inhibition by roscovitine induces a radiosensitization and a synergistic antitumoral effect in human carcinoma but its effect on the microenvironment and tumour angiogenesis remains unknown. Here, we investigated the effect of the combination roscovitine and ionizing radiation (IR) on normal cells in vitro and on tumour angiogenesis in MDA-MB 231 tumour xenografts. We observed that the combination roscovitine and IR induced a marked reduction of angiogenic hot spot and microvascular density in comparison with IR or roscovitine treatments alone. The Ang-2/Tie-2 ratio was increased in presence of reduced vascular endothelial growth factor level suggesting vessel destabilization. In vitro, no radiosensitization effect of roscovitine was found in endothelial, fibroblast, and keratinocyte cells. IR potentiated the antiproliferative effect of roscovitine without inducing apoptosis in endothelial cells. Roscovitine decreased IR-stimulated vascular endothelial growth factor secretion of MDA-MB 231 and endothelial cells. A reduction in the endothelial cells invasion and the capillary-like tube formation in Matrigel were observed following the combination roscovitine and IR. This combined treatment targets angiogenesis resulting in microvessel destabilization without inducing normal cell toxicity.

  20. Fast targeted gene transfection and optogenetic modification of single neurons using femtosecond laser irradiation

    NASA Astrophysics Data System (ADS)

    Antkowiak, Maciej; Torres-Mapa, Maria Leilani; Witts, Emily C.; Miles, Gareth B.; Dholakia, Kishan; Gunn-Moore, Frank J.

    2013-11-01

    A prevailing problem in neuroscience is the fast and targeted delivery of DNA into selected neurons. The development of an appropriate methodology would enable the transfection of multiple genes into the same cell or different genes into different neighboring cells as well as rapid cell selective functionalization of neurons. Here, we show that optimized femtosecond optical transfection fulfills these requirements. We also demonstrate successful optical transfection of channelrhodopsin-2 in single selected neurons. We extend the functionality of this technique for wider uptake by neuroscientists by using fast three-dimensional laser beam steering enabling an image-guided ``point-and-transfect'' user-friendly transfection of selected cells. A sub-second transfection timescale per cell makes this method more rapid by at least two orders of magnitude when compared to alternative single-cell transfection techniques. This novel technology provides the ability to carry out large-scale cell selective genetic studies on neuronal ensembles and perform rapid genetic programming of neural circuits.

  1. Characterization of microRNAs and their target genes associated with transcriptomic changes in gamma-irradiated Arabidopsis.

    PubMed

    Kim, J H; Go, Y S; Kim, J K; Chung, B Y

    2016-07-29

    MicroRNAs (miRNAs) regulate gene expression in response to biotic and abiotic stress in plants. We investigated gamma-ray-responsive miRNAs in Arabidopsis wild-type and cmt3-11t mutant plants using miRNA microarray analysis. miRNA expression was differentiated between the wild-type and cmt3-11t mutants. miR164a, miR169d, miR169h, miR172b*, and miR403 were identified as repressible in the wild-type and/or cmt3-11t mutant in response to gamma irradiation, while miR827, miR840, and miR850 were strongly inducible. These eight miRNA genes contain UV-B-responsive cis-elements, including G-box, I-box core, ARE, and/or MBS in the putative promoter regions. Moreover, Box 4, MBS, TCA-element, and Unnamed_4, as well as CAAT- and TATA-box, were identified in these eight miRNA genes. However, a positive correlation between the transcriptions of miRNAs and their putative target genes was only observed between miR169d and At1g30560 in the wild-type, and between miR827 and At1g70700 in the cmt3-11t mutant. Quantitative RT-PCR analysis confirmed that the transcription of miR164a, miR169d, miR169h, miR172b*, miR403, and miR827 differed after gamma irradiation depending on the genotype (wild-type, cmt3-11t, drm2, drd1-6, and ddm1-2) and developmental stage (14 or 28 days after sowing). In contrast, high transcriptional induction of miR840 and miR850 was observed in these six genotypes regardless of the developmental stage. Although the actual target genes and functions of miR840 and miR850 remain to be determined, our results indicate that these two miRNAs may be strongly induced and reproducible genetic markers in Arabidopsis plants exposed to gamma rays.

  2. Influence of gamma irradiation on productivity indices of the edible Emperor moth caterpillar, Cirina forda (Lepidoptera: Saturniidae).

    PubMed

    Odeyemi, M O; Fasoranti, J O; Ande, A T; Olayemi, I K

    2013-08-01

    This study was aimed at generating baseline information for sustainable genetic improvement of Cirana forda larvae for entomophagy, through the use of gamma irradiation. Eggs of C. forda were irradiated with increasing doses of gamma rays from 0 to 200 Gy and raised through larval instal stages under laboratory conditions. The Body Weight (BW) and Head Capsule Width (HCW) of the larval instar stages were monitored as indices of productivity. Successful larval emergence was recorded for all irradiation doses tested and BW of the 1st and 2nd instar larvae were not significantly (p > 0.05) different between the control and treated groups (range = 0.021 +/- 0.003 g/larva in the 200 Gy treatment to 0.028 +/- 0.003 g/larva in the control group and 0.105 +/- 0.003 g/larva in 20 Gy treatment to 0.172 +/- 0.009 g/larva in the control group, respectively). On the other hand, BW during the 3rd and 4th larval instars were significantly (p < 0.05) lower among the irradiated treatments than control. Pattern of distribution of HCW was different from that of BW; as HCW increased with irradiation dose from 10-50 Gy during the 3rd and 4th larval instars. Also, HCW during the 5th instar larvae among the irradiated treatments (range = 5.256 +/- 0.012 to 5.662 +/- 0.026 mm) were not higher than that of the 6th instar in the control group (6.065 +/- 0.010 mm). These results suggest promising potentials of the use of gamma irradiation in sustainably improving the productivity of C. forda larvae for entomophagy.

  3. Potential use of gamma irradiation in the production of mussel and oyster reference materials for paralytic shellfish poisoning toxins.

    PubMed

    Turner, Andrew D; Hatfield, Robert G; Powell, Andy L; Higman, Wendy

    2010-05-01

    Bivalve shellfish samples containing paralytic shellfish poisoning toxins were subjected to gamma irradiation dosage trials in order to assess the potential suitability of the technique in the production of toxin reference materials. Two candidate reference materials of tissue homogenates, mussels (Mytilus sp.) and native oysters (Ostrea edulis), were prepared in-house. Both were subjected to gamma irradiation at four different dose levels, 3.0, 6.0, 13.0 and 18.1 kGy. Bacterial levels were shown to be eliminated in the mussels and significantly reduced in the oysters following irradiation at all four dose levels. Paralytic shellfish poisoning (PSP) toxin concentrations were not significantly reduced in any of the samples indicating the treatment had no adverse affect on the initial stability of any of the PSP toxins monitored. Chromatographic results showed near-identical profiles for treated and non-treated samples inferring that no fluorescent toxin degradation products or matrix interferences were produced during the irradiation process. Results therefore proved that gamma irradiation treatment reduced bacterial levels within paralytic shellfish poisoning reference materials without compromising analyte content, with the subsequent potential to enhance the stability of future candidate reference materials treated in this manner.

  4. Electron microscopic evaluation and fission product identification of irradiated TRISO coated particles from the AGR-1 experiment: A preliminary Study

    SciTech Connect

    I J van Rooyen; D E Janney; B D Miller; J L Riesterer; P A Demkowicz

    2012-10-01

    ABSTRACT Post-irradiation examination of coated particle fuel from the AGR-1 experiment is in progress at Idaho National Laboratory and Oak Ridge National Laboratory. In this presentation a brief summary of results from characterization of microstructures in the coating layers of selected irradiated fuel particles with burnup of 11.3% and 19.3% FIMA will be given. The main objective of the characterization were to study irradiation effects, fuel kernel porosity, layer debonding, layer degradation or corrosion, fission-product precipitation, grain sizes, and transport of fission products from the kernels across the TRISO layers. Characterization techniques such as scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, and wavelength dispersive spectroscopy were used. A new approach to microscopic quantification of fission-product precipitates is also briefly demonstrated. The characterization emphasized fission-product precipitates in the SiC-IPyC interface, SiC layer and the fuel-buffer interlayer, and provided significant new insights into mechanisms of fission-product transport. Although Pd-rich precipitates were identified at the SiC-IPyC interlayer, no significant SiC-layer thinning was observed for the particles investigated. Characterization of these precipitates highlighted the difficulty of measuring low concentration Ag in precipitates with significantly higher concentrations of contain Pd and U. Different approaches to resolving this problem are discussed. Possible microstructural differences between particles with high and low releases of Ag particles are also briefly discussed, and an initial hypothesis is provided to explain fission-product precipitate compositions and locations. No SiC phase transformations or debonding of the SiC-IPyC interlayer as a result of irradiation were observed. Lessons learned from the post-irradiation examination are described and future actions are recommended.

  5. Partitioning of fission products from irradiated nitride fuel using inductive vaporization

    SciTech Connect

    Shcherbina, N.; Kulik, D.A.; Kivel, N.; Potthast, H.D.; Guenther-Leopold, I.

    2013-07-01

    Irradiated nitride fuel (Pu{sub 0.3}Zr{sub 0.7})N fabricated at PSI in frame of the CONFIRM project and having a burn-up of 10.4 % FIMA (Fission per Initial Metal Atom) has been investigated by means of inductive vaporization. The study of thermal stability and release behavior of Pu, Am, Zr and fission products (FPs) was performed in a wide temperature range (up to 2300 C. degrees) and on different redox conditions. On-line monitoring by ICP-MS detected low nitride stability and significant loss of Pu and Am at T>1900 C. degrees during annealing under inert atmosphere (Ar). The oxidative pre-treatment of nitride fuel on air at 1000 C. degrees resulted in strong retention of Pu and Am in the solid, as well as of most FPs. Thermodynamic modelling of elemental speciation using GEM-Selektor v.3 code (Gibbs Energy Minimization Selektor), supported by a comprehensive literature review on thermodynamics of actinides and FPs, revealed a number of binary compounds of Cs, Mo, Te, Sr and Ba to occur in the solid. Speciation of some FPs in the fuel is discussed and compared to earlier results of electron probe microanalysis (EPMA). Predominant vapor species predicted by GEM-Selektor calculations were Pu(g), Am(g) and N{sub 2}. Nitrogen can be completely released from the fuel after complete oxidation at 1000 C. degrees. With regard to the irradiated nitride reprocessing technology, this result can have an important practical application as an alternative way for {sup 15}N recovery. (authors)

  6. The use of gamma spectrometry in the determination of fission products migration in irradiated fuel

    SciTech Connect

    2015-07-01

    Non destructive examinations realized in hot cells of LECA STAR facility give main data on irradiated fuel rods and pins. Among those examinations, gamma spectrometry allows access to fuel, inside the cladding, thanks to gamma rays of fission products such as {sup 137}Cs, {sup 154}Eu coming from pellets... From those gamma scannings we can detect the position and the length of the fuel column and of its pellets, calculate local burnup.. In the database of our lab we have already such gamma scannings on hundreds of rods or pins with different fuels, claddings and irradiations conditions (under nominal or non nominal). We have detected that in specific cases, an unusual shape of the {sup 137}Cs scanning (distribution quite different from those of {sup 154}Eu) can be explained by the migration of this isotope, moving to the cold sides of the pellet. This phenomenon is mainly associated with an increasing of the pellet's temperature. Based on our observations, we have developed a quantitative approach of the changes on the {sup 137}Cs scannings through the calculation of appropriate 'indicators'. Those calculations allow us to be able to localize, quantify and compare the {sup 137}Cs migration all along rods or pins. Those migration results are so quickly and easily achievable from gamma measurements and can then be easily correlated to other observations realized with destructive examinations, puncturing and calculations, already realized or to come. Because such a migration is the result of temperature increasing in the pellets, our indicators can be directly associated with this local temperature. In perspective, thermically activated phenomena such as geometrical changes in the shape of the pellets, fission gas release... can also indirectly be deduced from our indicators. (authors)

  7. Change in colony morphology and kinetics of tylosin production after UV and gamma irradiation mutagenesis of Streptomyces fradiae NRRL-2702.

    PubMed

    Khaliq, Shazia; Akhtar, Kalsoom; Afzal Ghauri, Muhammad; Iqbal, Ruqia; Mukhtar Khalid, Ahmad; Muddassar, Muhammad

    2009-01-01

    Tylosin is a macrolide antibiotic used as veterinary drug and growth promoter. Attempts were made for hyper production of tylosin by a strain of Streptomyces fradiae NRRL-2702 through irradiation mutagenesis. Ultraviolet (UV) irradiation of wild-type strain caused development of six morphologically altered colony types on agar plates. After screening using Bacillus subtilis bioassay only morphological mutants indicated the production of tylosin. An increase of 2.7+/-0.22-fold in tylosin production (1500mg/l) in case of mutant UV-2 in complex medium was achieved as compared to wild-type strain (550mg/l). Gamma irradiation of mutant UV-2 using (60)Co gave one morphologically altered colony type gamma-1, which gave 2500mg/l tylosin yield in complex medium. Chemically defined media promoted tylosin production upto 3800mg/l. Maximum value of q(p) (3.34mg/gh) was observed by mutant gamma-1 as compared to wild strain (0.81mg/gh). Moreover, UV irradiation associated changes were unstable with loss of tylosin activity whereas mutant gamma-1 displayed high stability on subsequent culturing.

  8. Influence of SiC grain boundary character on fission product transport in irradiated TRISO fuel

    NASA Astrophysics Data System (ADS)

    Lillo, T. M.; van Rooyen, I. J.

    2016-05-01

    In this study, the fission product precipitates at silicon carbide grain boundaries from an irradiated TRISO particle were identified and correlated with the associated grain boundary characteristics. Precession electron diffraction in the transmission electron microscope provided the crystallographic information needed to identify grain boundary misorientation and boundary type (i.e., low angle, random high angle or coincident site lattice (CSL)-related). The silicon carbide layer was found to be composed mainly of twin boundaries and small fractions of random high angle and low angle grain boundaries. Most fission products were found at random, high-angle grain boundaries, with small fractions at low-angle and CSL-related grain boundaries. Palladium (Pd) was found at all types of grain boundaries while Pd-uranium and Pd-silver precipitates were only associated with CSL-related and random, high-angle grain boundaries. Precipitates containing only Ag were found only at random, high-angle grain boundaries, but not at low angle or CSL-related grain boundaries.

  9. A new mechanism for hydroxyl radical production in irradiated nanoparticle solutions.

    PubMed

    Sicard-Roselli, Cécile; Brun, Emilie; Gilles, Manon; Baldacchino, Gérard; Kelsey, Colin; McQuaid, Harold; Polin, Chris; Wardlow, Nathan; Currell, Frederick

    2014-08-27

    The absolute yield of hydroxyl radicals per unit of deposited X-ray energy is determined for the first time for irradiated aqueous solutions containing metal nanoparticles based on a "reference" protocol. Measurements are made as a function of dose rate and nanoparticle concentration. Possible mechanisms for hydroxyl radical production are considered in turn: energy deposition in the nanoparticles followed by its transport into the surrounding environment is unable to account for observed yield whereas energy deposition in the water followed by a catalytic-like reaction at the water-nanoparticle interface can account for the total yield and its dependence on dose rate and nanoparticle concentration. This finding is important because current models used to account for nanoparticle enhancement to radiobiological damage only consider the primary interaction with the nanoparticle, not with the surrounding media. Nothing about the new mechanism appears to be specific to gold, the main requirements being the formation of a structured water layer in the vicinity of the nanoparticle possibly through the interaction of its charge and the water dipoles. The massive hydroxyl radical production is relevant to a number of application fields, particularly nanomedicine since the hydroxyl radical is responsible for the majority of radiation-induced DNA damage.

  10. Target product selection - where can Molecular Pharming make the difference?

    PubMed

    Paul, Mathew J; Teh, Audrey Y H; Twyman, Richard M; Ma, Julian K-C

    2013-01-01

    Four major developments have taken place in the world of Molecular Pharming recently. In the USA, the DARPA initiative challenged plant biotechnology companies to develop strategies for the large-scale manufacture of influenza vaccines, resulting in a successful Phase I clinical trial; in Europe the Pharma-Planta academic consortium gained regulatory approval for a plant-derived monoclonal antibody and completed a first-in-human phase I clinical trial; the Dutch pharmaceutical company Synthon acquired the assets of Biolex Therapeutics, an established Molecular Pharming company with several clinical candidates produced in their proprietary LEX system based on aquatic plants; and finally, the Israeli biotechnology company Protalix Biotherapeutics won FDA approval for the commercial release of a recombinant form of the enzyme glucocerebrosidase produced in carrot cells, the first plant biotechnology-derived biopharmaceutical in the world approved for the market. Commercial momentum is gathering pace with additional candidates now undergoing or awaiting approval for phase III clinical trials. Filling the product pipeline is vital to establish commercial sustainability, and the selection of appropriate target products for Molecular Pharming will be a critical factor. An interesting feature of the four stories outlined above is that they span the use of very different platform technologies addressing different types of molecules which aim to satisfy distinct market demands. In each case, Molecular Pharming was an economically and technically suitable approach, but this decisionmaking process is not necessarily straightforward. Although the various technologies available to Molecular Pharming are broad ranging and flexible, competing technologies are better established, so there needs to be a compelling reason to move into plants. It is most unlikely that plant biotechnology will be the answer for the whole biologics field. In this article, we discuss the current plant

  11. Culture of the green microalga Botryococcus braunii Showa with LED irradiation eliminating violet light enhances hydrocarbon production and recovery.

    PubMed

    Atobe, Sueko; Saga, Kiyotaka; Maeyama, Haruko; Fujiwara, Kazuhiro; Okada, Shigeru; Imou, Kenji

    2014-01-01

    The green microalga Botryococcus braunii (B. braunii), race B, was cultured under light-emitting diode (LED) irradiation with and without violet light. This study examined the effect of violet light on hydrocarbon recovery and production in B. braunii. C34 botryococcene hydrocarbons were efficiently extracted by thermal pretreatments at lower temperatures when the alga was cultured without violet light. The hydrocarbon content was also higher (approximately 3%) in samples cultured without violet light. To elucidate the mechanism of effective hydrocarbon recovery and production, we examined structural components of the extracellular matrix (ECM). The amounts of extracellular carotenoids and water-soluble polymers extracted by thermal pretreatment from the ECM were decreased when the alga was cultured without violet light. These results indicate that LED irradiation without violet light is more effective for hydrocarbon recovery and production in B. braunii. Furthermore, structural ECM components are closely involved in hydrocarbon recovery and production in B. braunii.

  12. Production of site/time specific hourly irradiances -- Satellite remote sensing vs. network interpolation

    SciTech Connect

    Perez, R.; Seals, R.; Zelenka, A.

    1996-11-01

    In this paper, the authors compare the accuracy of satellite-derived time/site specific hourly irradiances, with that of irradiances obtained via extrapolation and/or interpolation of nearby ground-measuring stations. A comprehensive study undertaken by the International Energy Agency [Zelenka et al., 1992] had addressed this question, but had limited its scope to daily total irradiances. The present study focuses on hourly data.

  13. Fission product release and microstructure changes of irradiated MOX fuel at high temperatures

    NASA Astrophysics Data System (ADS)

    Colle, J.-Y.; Hiernaut, J.-P.; Wiss, T.; Beneš, O.; Thiele, H.; Papaioannou, D.; Rondinella, V. V.; Sasahara, A.; Sonoda, T.; Konings, R. J. M.

    2013-11-01

    burnups correspond reasonably well with measurement of Walker et al. [11]. All those data are shown Fig. 2.Fragments of 2-8 mg were chosen for the experiments. Since these specimens are small compared to the drilled sample size and were taken randomly, the precise radial position could not be determined, in particular the specimens of sample type, A and B could be from close radial locations.Specimens from each drilled sample type were annealed up to complete vaporisation (˜2600 K) at a speed of about 10 K min-1 in a Knudsen effusion mass spectrometer (KEMS) described previously [13,14]. In addition to helium and to the FGs all the species present in the vapour between 83 and 300 a.m.u. were measured during the heating. Additionally, the 85Kr isotope was analysed in a cold trap by β and γ counting. The long-lived fission gas isotopes correspond to masses 131, 132, 134 and 136 for Xe and 83, 84, 85 and 86 for Kr. The absolute quantities of gas released from specimens of sample types A and B were also determined using the in-house built Q-GAMES (Quantitative gas measurement system), described in detail in [15].For each of the samples, fragments were also annealed and measured in the KEMS up to specific temperatures corresponding to different stages of the FGs or He release. These fragments were subsequently analysed by Scanning Electron Microscopy (SEM, Philips XL40) [16] in order to investigate the relationship between structural changes, burn-up, irradiation temperature and fission products release. SEM observations were also done on the samples before the KEMS experiments and the fracture surface appearance of the samples is shown in Fig. 3, revealing the presence of the high burnup structure (HBS) in the Pu-rich agglomerates.A summary of the 12 samples analysed by KEMS, SEM and Q-GAMES is given in Table 1. At 1300 K no clear change potentially related to gas release appears in the UM and PA. At 1450 K a beginning of grain boundaries opening can be observed as well as

  14. Mapping patterns of nodal metastases in esophageal carcinoma: rethinking the clinical target volume for supraclavicular nodal irradiation

    PubMed Central

    Luo, Yijun; Liu, Yuhui; Wang, Xiaoli; Zhang, Bin; Yu, Jinming; Wang, Chengang; Huang, Yong

    2016-01-01

    Background To map detail distribution of metastatic supraclavicular (SCV) lymph nodes (LN) in esophageal cancer (EC) patients and determine the precise radiation therapy clinical target volume (CTV). Methods A total of 101 thoracic esophageal carcinoma patients after surgery experienced SCV LN metastasis were retrospectively examined. The SCV region is further divided into four subgroups. Using hand drawings registration, nodes were mapped to a template computed tomogram to provide a visual impression of nodal frequencies and anatomic distribution. Results In all, 158 nodes were considered to be clinical metastatic in the SCV region in the 101 patients, 74 on the left and 84 on the right. Seven of 158 (4.4%) positive LN were located in group I, 78 of 158 (49.37%) were located in group II, 72 of 158 nodes (45.6%) were located in group III, 1 of 158 (0.63%) located in group IV. Conclusions According to our results, the SCV group II and group III are considered to be the high risk regions of esophageal squamous cell carcinoma (ESCC) LN metastasis, which were defined as elective nodal irradiation (ENI) areas. PMID:28066592

  15. Study of neutron spectra in a water bath from a Pb target irradiated by 250 MeV protons

    NASA Astrophysics Data System (ADS)

    Li, Yan-Yan; Zhang, Xue-Ying; Ju, Yong-Qin; Ma, Fei; Zhang, Hong-Bin; Chen, Liang; Ge, Hong-Lin; Wan, Bo; Luo, Peng; Zhou, Bin; Zhang, Yan-Bin; Li, Jian-Yang; Xu, Jun-Kui; Wang, Song-Lin; Yang, Yong-Wei; Yang, Lei

    2015-04-01

    Spallation neutrons were produced by the irradiation of Pb with 250 MeV protons. The Pb target was surrounded by water which was used to slow down the emitted neutrons. The moderated neutrons in the water bath were measured by using the resonance detectors of Au, Mn and In with a cadmium (Cd) cover. According to the measured activities of the foils, the neutron flux at different resonance energies were deduced and the epithermal neutron spectra were proposed. Corresponding results calculated with the Monte Carlo code MCNPX were compared with the experimental data to check the validity of the code. The comparison showed that the simulation could give a good prediction for the neutron spectra above 50 eV, while the finite thickness of the foils greatly effected the experimental data in low energy. It was also found that the resonance detectors themselves had great impact on the simulated energy spectra. Supported by National Natural Science Foundation and Strategic Priority Research Program of the Chinese Academy of Sciences (11305229, 11105186, 91226107, 91026009, XDA03030300)

  16. Space-resolved K α emission measurement of warm dense titanium targets irradiated by intense laser pulses

    NASA Astrophysics Data System (ADS)

    Bae, Leejin; Cho, Minsang; Kang, Gyeongbo; Kim, Minju; Kim, Young Hoon; Lee, Jong-Won; Cho, Byoung-Ick; Zastrau, Ulf

    2016-10-01

    Measurements of characteristic inner-shell K α emission have been widely used and reliable spectroscopic plasma diagnostics. Intense laser-plasma interactions on the solid target generate multiple electron distributions, i.e. hot relativistic and low energy bulk electrons. The bulk electrons create warm dense (10 100 eV and solid density) conditions in titanium foil and induce the shifts of K α emission spectra by creating M-shell vacancies. Therefore, modified K α emission spectra can be served as a bulk electron temperature. In this contribution, we present the titanium K α imaging spectroscopy experiment using a toroidally bent crystal, and the K-shell emission spectrum simulations using the collisional-radiative code SCFLY, for various bulk electron temperatures. The spatial distribution of electron temperature in the titanium foil which is irradiated by an intense laser pulse could be obtained, and possible electron transport mechanism will be discussed. This work was supported by NRF of Korea (No. NRF-2016R1A2B4009631 and NRF-2016H1A2A1909533), and the TBP research project of GIST.

  17. Development, Production and Validation of the NOAA Solar Irradiance Climate Data Record

    NASA Astrophysics Data System (ADS)

    Coddington, O.; Lean, J.; Pilewskie, P.; Snow, M. A.; Lindholm, D. M.

    2015-12-01

    A new climate data record of Total Solar Irradiance (TSI) and Solar Spectral Irradiance (SSI), including source code and supporting documentation is now publicly available as part of the National Oceanographic and Atmospheric Administration's (NOAA) National Centers for Environmental Information (NCEI) Climate Data Record (CDR) Program. Daily and monthly averaged values of TSI and SSI, with associated time and wavelength dependent uncertainties, are estimated from 1882 to the present with yearly averaged values since 1610, updated quarterly for the foreseeable future. The new Solar Irradiance Climate Data Record, jointly developed by the University of Colorado at Boulder's Laboratory for Atmospheric and Space Physics (LASP) and the Naval Research Laboratory (NRL), is constructed from solar irradiance models that determine the changes from quiet Sun conditions when bright faculae and dark sunspots are present on the solar disk. The magnitudes of the irradiance changes that these features produce are determined from linear regression of the proxy Mg II index and sunspot area indices against the approximately decade-long solar irradiance measurements made by instruments on the SOlar Radiation and Climate Experiment (SORCE) spacecraft. We describe the model formulation, uncertainty estimates, operational implementation and validation approach. Future efforts to improve the uncertainty estimates of the Solar Irradiance CDR arising from model assumptions, and augmentation of the solar irradiance reconstructions with direct measurements from the Total and Spectral Solar Irradiance Sensor (TSIS: launch date, July 2017) are also discussed.

  18. Development and processing of LEU targets for {sup 99}Mo production

    SciTech Connect

    Snelgrove, J.L.; Vandegrift, G.F.; Hofman, G.L.

    1997-04-01

    Most of the world`s supply of {sup 99m}Tc for medical purposes is currently produced from the decay of {sup 99}Mo derived from the fissioning of high-enriched uranium (HEU). Substantial progress has been made in developing targets and chemical processes for producing {sup 99}Mo using low-enriched uranium (LEU). Target development has been focused on a uranium-metal foil target as a replacement for the coated-UO{sub 2} Cintichem-type target. Although the first designs were not successful because of ion mixing-induced bonding of the uranium foil to the target tubes, recent irradiations of modified targets have proven successful. Only minor modifications of the Cintichem chemical process are required for the uranium-metal foil targets. A demonstration using prototypically irradiated targets is anticipated in February 1997. Progress has also been made in basic dissolution of both uranium-metal foil and aluminum-clad U{sub 3}Si{sub 2} dispersion fuel targets.

  19. Target and method for the production of fission product molybdenum-99

    DOEpatents

    Vandegrift, G.F.; Vissers, D.R.; Marshall, S.L.; Varma, R.

    1987-10-26

    A target for the reduction of fission product Mo-99 is prepared from uranium of low U-235 enrichment by coating a structural support member with a preparatory coating of a substantially oxide-free substrate metal. Uranium metal is electrodeposited from a molten halide electrolytic bath onto a substrate metal. The electrodeposition is performed at a predetermined direct current rate or by using pulsed plating techniques which permit relaxation of accumulated uranium ion concentrations within the melt. Layers of as much as to 600 mg/cm/sup 2/ of uranium can be prepared to provide a sufficient density to produce acceptable concentrations of fission product Mo-99. 2 figs.

  20. Target and method for the production of fission product molybdenum-99

    DOEpatents

    Vandegrift, George F.; Vissers, Donald R.; Marshall, Simon L.; Varma, Ravi

    1989-01-01

    A target for the reduction of fission product Mo-99 is prepared from uranium of low U-235 enrichment by coating a structural support member with a preparatory coating of a substantially oxide-free substrate metal. Uranium metal is electrodeposited from a molten halide electrolytic bath onto a substrate metal. The electrodeposition is performed at a predetermined direct current rate or by using pulsed plating techniques which permit relaxation of accumulated uranium ion concentrations within the melt. Layers of as much as to 600 mg/cm.sup.2 of uranium can be prepared to provide a sufficient density to produce acceptable concentrations of fission product Mo-99.