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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. 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.

  3. 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

  4. 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.

  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. 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.

  7. 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.

  8. 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].

  9. 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.

  10. 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).

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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).

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. Target depth dependence of damage rate in metals by 150 MeV proton irradiation

    NASA Astrophysics Data System (ADS)

    Yoshiie, T.; Ishi, Y.; Kuriyama, Y.; Mori, Y.; Sato, K.; Uesugi, T.; Xu, Q.

    2015-01-01

    A series of irradiation experiments with 150 MeV protons was performed. The relationship between target depth (or shield thickness) and displacement damage during proton irradiation was obtained by in situ electrical resistance measurements at 20 K. Positron annihilation lifetime measurements were also performed at room temperature after irradiation, as a function of the target thickness. The displacement damage was found to be high close to the beam incident surface area, and decreased with increasing target depth. The experimental results were compared with damage production calculated with an advanced Monte Carlo particle transport code system (PHITS).

  18. 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.

  19. 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 to design

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Targets and methods for target preparation for radionuclide production

    DOEpatents

    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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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).

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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)

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  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. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  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. 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}.

  7. 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.

  8. 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.

  9. 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.

  10. 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)

  11. 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.

  12. 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).

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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)

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  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. 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)

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  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. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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’.

  19. 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.

  20. 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.

  1. 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.

  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. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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.

  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. 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.

  17. 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.

  18. Self-overcoming of the boiling condition by pressure increment in a water target irradiated by proton beam

    NASA Astrophysics Data System (ADS)

    Hong, Bong Hwan; Kang, Joonsun; Jung, In Su; Ram, Han Ga; Park, Yeun Soo; Cho, Hyung Hee

    2013-11-01

    An experiment was conducted to examine and visualize the boiling phenomena inside a water target by irradiating it with a proton beam from MC-50 cyclotron. The boiling phenomena were recorded with a CMOS camera. While an increase of the fraction of the water vapor volume is generally considered to be normal when water is boiled by a proton beam, our experiment showed the opposite result. The volume expansion of the liquid water exceeded the compressibility of the initial air volume. A grid structure in front of the entrance window foil held the target volume constant. Therefore, the phenomena inside the target underwent an isochoric process, and the pressure inside the target was increased rapidly beyond the pressure at the boiling point. Consequently, there was no more bulk boiling in the Bragg-peak region in the target water. Our results show that the boiling of the water can be controlled by controlling the equilibrium pressure of the water target.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Responses of winter wheat growth and production under subambient UV-B irradiance

    NASA Astrophysics Data System (ADS)

    Wang, Chuanhai; Zheng, Youfei; Gao, Wei; Slusser, James R.; He, Douliang

    2003-06-01

    The greater UV-B radiation has heightened concern that it has adverse impact on agricultural production and natural plant ecosystems. The effect of UV-B enhancements on plants includes reduction in grain yield, alteration in species competition, decrease in photosynthetic activity, susceptibility to disease, and changes in plant structure and pigmentation. Plant responses to UV-B enhancements also include increased accumulation of flavoids, increased leaf thickness, increased reflectance of leaves, reductions in growth, and direct damage to photosynthetic mechanisms. One-third to one-half of all plant species tested are deleteriously affected by UV-B irradiance levels "above ambient." This experiment was conducted to study responses of winter wheat growth and production under both ambient and sub-ambient UV-B irradiance (15.3% UV-B irradiance decrease from ambient level). Sub-ambient UV-B irradiance increased winter wheat growth and production, which indicates that current levels of ambient UV-B irradiance might have an adverse effect in tested areas.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  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. 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.

  12. 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.

  13. 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.

  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. 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.

  16. 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.

  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.

  18. 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.

  19. 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%.

  20. 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.

  1. 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.

  2. 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.

  3. 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).

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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).

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  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. 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.

  17. 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.

  18. 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

  19. 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

  20. 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.

  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. ``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.

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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

  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. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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

  16. 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

  17. High e+/e− Ratio Dense Pair Creation with 1021W.cm−2 Laser Irradiating Solid Targets

    PubMed Central

    Liang, E.; Clarke, T.; Henderson, A.; Fu, W.; Lo, W.; Taylor, D.; Chaguine, P.; Zhou, S.; Hua, Y.; Cen, X.; Wang, X.; Kao, J.; Hasson, H.; Dyer, G.; Serratto, K.; Riley, N.; Donovan, M.; Ditmire, T.

    2015-01-01

    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 milestones 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. PMID:26364764

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  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. 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.

  5. 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.

  6. 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.

  7. 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.

  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. 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.

  10. 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.

  11. 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.

  12. 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.

  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. 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).

  15. 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.

  16. 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).

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 77 FR 71316 - Irradiation in the Production, Processing and Handling of Food

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-30

    ... laboratory animals, FDA has extensively researched the occurrence of furan in irradiated foods over the last... that the large body of data from studies where irradiated foods were fed to laboratory animals provides... the potential dangers and unacceptability of irradiating food. FDA has also received several...

  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. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. [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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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)

  13. 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.

  14. 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.

  15. An Investigation into the Transportation of Irradiated Uranium/Aluminum Targets from a Foreign Nuclear Reactor to the Chalk River Laboratories Site in Ontario, Canada - 12249

    SciTech Connect

    Clough, Malcolm; Jackson, Austin

    2012-07-01

    This investigation required the selection of a suitable cask and development of a device to hold and transport irradiated targets from a foreign nuclear reactor to the Chalk River Laboratories in Ontario, Canada. The main challenge was to design and validate a target holder to protect the irradiated HEU-Al target pencils during transit. Each of the targets was estimated to have an initial decay heat of 118 W prior to transit. As the targets have little thermal mass the potential for high temperature damage and possibly melting was high. Thus, the primary design objective was to conceive a target holder to dissipate heat from the targets. Other design requirements included securing the targets during transportation and providing a simple means to load and unload the targets while submerged five metres under water. A unique target holder (patent pending) was designed and manufactured together with special purpose experimental apparatus including a representative cask. Aluminum dummy targets were fabricated to accept cartridge heaters, to simulate decay heat. Thermocouples were used to measure the temperature of the test targets and selected areas within the target holder and test cask. After obtaining test results, calculations were performed to compensate for differences between experimental and real life conditions. Taking compensation into consideration the maximum target temperature reached was 231 deg. C which was below the designated maximum of 250 deg. C. The design of the aluminum target holder also allowed generous clearance to insert and unload the targets. This clearance was designed to close up as the target holder is placed into the cavity of the transport cask. Springs served to retain and restrain the targets from movement during transportation as well as to facilitate conductive heat transfer. The target holder met the design requirements and as such provided data supporting the feasibility of transporting targets over a relatively long period of time

  16. 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.

  17. Targets for the production of radioisotopes and method of assembly

    DOEpatents

    Quinby, Thomas C.

    1976-01-01

    A target for preparation of radioisotopes by nuclear bombardment, and a method for its assembly are provided. A metallic sample to be bombarded is enclosed within a metallic support structure and the resulting target subjected to heat and pressure to effect diffusion bonds therebetween. The bonded target is capable of withstanding prolonged exposure to nuclear bombardment without thermal damage to the sample.

  18. 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)

  19. 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)

  20. 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.

  1. Evaluation of Fluidized Beds for Mass Production of IFE Targets

    SciTech Connect

    Huang, H.; Vermillion, B.A.; Brown, L.C.; Besenbruch, G.E.; Goodin, D.T.; Stemke, R.W.; Stephens, R.B.

    2005-01-15

    Of the building blocks of an inertial fusion energy (IFE) plant, target fabrication remains a significant credibility issue. For this reason, an extensive parametric study has been conducted on mass production of glow discharge polymer (GDP) shells in a vertical fluidized bed. Trans-2-butene was used as a reactant gas with hydrogen as a diluting and etching agent. Coating rates in the range of 1 to 2 {mu}m/h were demonstrated on batches of 30 shells where National Ignition Facility-quality surfaces were obtained for 3- to 5-{mu}m-thick coatings. Thick coatings up to 325 {mu}m were also demonstrated that are visually transparent, without void and stress fracture. A phenomenological understanding of the GDP growth mechanisms to guide future experiments was further established. Specifically, gas-phase precipitation and high-impact collisions were identified as the main surface-roughening mechanisms. The former produces dense cauliflower-like surface patterns that can be eliminated by adjusting the gas flow rates and the flow ratio. The latter produces isolated domelike surface defects that can be reduced by introducing concerted motion between the shells. By converting from a vertical to a horizontal configuration, fully transparent coatings were obtained on 350 shells. Collisions in a fluidized bed have been identified as the limiting factor in meeting IFE specifications, and a related-rotary kiln technique is recommended for scale-up.

  2. Measurement of Particle Production from the MICE Target

    SciTech Connect

    Soler, F. J. P.; Walaron, K.; Booth, C.; Carson, M.; Hodgson, P.; Howlett, L.; Smith, P.; Adams, D.; Edgecock, R.; Murray, W.; Tilley, K.; Cobb, J.; Rayner, M.; Roberts, T.

    2008-02-21

    This article describes the prototype target and the requirements for the target mechanism needed to provide a beam of muons to the Muon Ionization Cooling Experiment (MICE) from the ISIS accelerator at RAL. The mechanism has achieved the required 85g acceleration to be able to insert the target into the ISIS beam during the last 2 ms of the accelerating period. A prototype target test was used to integrate the target into ISIS and to measure the ISIS beam envelope, particle yields and beam loss, showing good agreement between data and simulations.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. Membrane-Dependent Bystander Effect Contributes to Amplification of the Response to Alpha-Particle Irradiation in Targeted and Nontargeted Cells

    SciTech Connect

    Hanot, Maite; Hoarau, Jim; Carriere, Marie; Angulo, Jaime F.; Khodja, Hicham

    2009-11-15

    Purpose: Free radicals are believed to play an active role in the bystander response. This study investigated their origin as well as their temporal and spatial impacts in the bystander effect. Methods and Materials: We employed a precise alpha-particle microbeam to target a small fraction of subconfluent osteoblastic cells (MC3T3-E1). gammaH2AX-53BP1 foci, oxidative metabolism changes, and micronuclei induction in targeted and bystander cells were assessed. Results: Cellular membranes and mitochondria were identified as two distinct reactive oxygen species producers. The global oxidative stress observed after irradiation was significantly attenuated after cells were treated with filipin, evidence for the primal role of membrane in the bystander effect. To determine the membrane's impact at a cellular level, micronuclei yield was measured when various fractions of the cell population were individually targeted while the dose per cell remained constant. Induction of micronuclei increased in bystander cells as well as in targeted cells and was attenuated by filipin treatment, demonstrating a role for bystander signals between irradiated cells in an autocrine/paracrine manner. Conclusions: A complex interaction of direct irradiation and bystander signals leads to a membrane-dependent amplification of cell responses that could influence therapeutic outcomes in tissues exposed to low doses or to environmental exposure.

  8. 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.

  9. Optimization of sedimentation of tungsten on copper substrate for production of 186gRe via 186W(p,n) nuclear reaction: Feasibility of using high current, long irradiation

    NASA Astrophysics Data System (ADS)

    Kakavand, T.; Mirzaii, M.; Khaleghi, M.; Eslami, M.

    2016-01-01

    Tungsten is recognized as one of the important metals used in cyclotron targets for production of several vital radioisotopes. Adequate adhesion of the prepared targets to its substrate is a significant parameter that makes them optimized for high current beam collisions. The target morphology should be paid special attention as another important parameter. In this work, a rather thick layer of tungsten is deposited on a copper substrate by sedimentation technique to produce 186gRe radionuclide via 186W(p,n) reaction. Consecutive sedimentation experiments are carried out to determine the best suspension solution. The prepared targets are evaluated in morphology by scanning electron microscope. A mixture of 1 g tungsten powder, 250 mg ethyl cellulose and 5 mL acetone is concluded for desirable target adhesion. Irradiation of the targets by 20 μA proton current (15 MeV energy) for 5 h shows that they can withstand the proton beam.

  10. Mechanical properties of modified 9Cr 1Mo (T91) irradiated at 300 °C in SINQ Target-3

    NASA Astrophysics Data System (ADS)

    Dai, Y.; Jia, X. J.; Farrell, K.

    2003-05-01

    Specimens of martensitic steel T91 were irradiated in the Swiss spallation neutron source (SINQ) Target-3 in a temperature range of 90-300 °C to displacement doses between 3 and 9.8 dpa. Tensile tests were performed at 22, 250 and 350 °C, and small punch (SP) tests were conducted in a temperature range of -186 to 22 °C to derive the change of the ductile-brittle transition temperature (ΔDBTT SP) of the steel after irradiation. The tensile test results demonstrate that the irradiation hardening increases with dose. The uniform elongation falls to less than 1%, while the total elongation is greater than 5% in all cases. All the tensile samples broke in a ductile fracture mode. In the present dose range the irradiation hardening does not saturate and increases even more rapidly at doses above about 6 dpa. The SP tests indicate that the DBTT SP of 0.25 mm thick T91 discs is about -153 °C for the unirradiated condition. After irradiation the DBTT SP increases significantly to -35 °C at 9.4 dpa, corresponding to an estimated DBTT CVN shift of 295 °C; and meanwhile the upper energies decrease. The ΔDBTT SP has a linear dependence on helium content. Analyses of the data indicate that the radiation hardening and the occurrence of intergranular fracture mode in the higher dose SP tests are dependent on gas content.

  11. Non-targeted transcriptomic effects upon thyroid irradiation: similarity between in-field and out-of-field responses varies with tissue type

    PubMed Central

    Langen, Britta; Rudqvist, Nils; Spetz, Johan; Swanpalmer, John; Helou, Khalil; Forssell-Aronsson, Eva

    2016-01-01

    Non-targeted effects can induce responses in tissues that have not been exposed to ionizing radiation. Despite their relevance for risk assessment, few studies have investigated these effects in vivo. In particular, these effects have not been studied in context with thyroid exposure, which can occur e.g. during irradiation of head and neck tumors. To determine the similarity between in-field and out-of-field responses in normal tissue, we used a partial body irradiation setup with female mice where the thyroid region, the thorax and abdomen, or all three regions were irradiated. After 24 h, transcriptional regulation in the kidney cortex, kidney medulla, liver, lungs, spleen, and thyroid was analyzed using microarray technology. Thyroid irradiation resulted in transcriptional regulation in the kidney medulla and liver that resembled regulation upon direct exposure of these tissues regarding both strength of response and associated biological function. The kidney cortex showed fewer similarities between the setups, while the lungs and spleen showed little similarity between in-field and out-of-field responses. Interestingly, effects were generally not found to be additive. Future studies are needed to identify the molecular mechanisms that mediate these systemic effects, so that they may be used as targets to minimize detrimental side effects in radiotherapy. PMID:27779251

  12. Non-targeted transcriptomic effects upon thyroid irradiation: similarity between in-field and out-of-field responses varies with tissue type.

    PubMed

    Langen, Britta; Rudqvist, Nils; Spetz, Johan; Swanpalmer, John; Helou, Khalil; Forssell-Aronsson, Eva

    2016-10-25

    Non-targeted effects can induce responses in tissues that have not been exposed to ionizing radiation. Despite their relevance for risk assessment, few studies have investigated these effects in vivo. In particular, these effects have not been studied in context with thyroid exposure, which can occur e.g. during irradiation of head and neck tumors. To determine the similarity between in-field and out-of-field responses in normal tissue, we used a partial body irradiation setup with female mice where the thyroid region, the thorax and abdomen, or all three regions were irradiated. After 24 h, transcriptional regulation in the kidney cortex, kidney medulla, liver, lungs, spleen, and thyroid was analyzed using microarray technology. Thyroid irradiation resulted in transcriptional regulation in the kidney medulla and liver that resembled regulation upon direct exposure of these tissues regarding both strength of response and associated biological function. The kidney cortex showed fewer similarities between the setups, while the lungs and spleen showed little similarity between in-field and out-of-field responses. Interestingly, effects were generally not found to be additive. Future studies are needed to identify the molecular mechanisms that mediate these systemic effects, so that they may be used as targets to minimize detrimental side effects in radiotherapy.

  13. Enhancing the various solvent extraction method via microwave irradiation for extraction of lipids from marine microalgae in biodiesel production.

    PubMed

    Teo, Chee Loong; Idris, Ani

    2014-11-01

    The types of microalgae strains and the method used in lipid extraction have become crucial factors which influence the productivity of crude oil. In this paper, Nannochloropsis sp. and Tetraselmis sp. were chosen as the strains and four different methods were used to extract the lipids: Hara and Radin, Folch, Chen and Bligh and Dyer. These methods were performed by using conventional heating and microwave irradiation methods. Results revealed that highest lipid yield from the different species was obtained using different extraction methods; both under microwave irradiation. The lipid yield for Tetraselmis sp. and Nannochloropsis sp. was highest when Hara and Radin (8.19%), and Folch (8.47%) methods were used respectively under microwave irradiation. The lipids extracted were then transesterified to biodiesel and the quality of the biodiesel was analyzed using the gas chromatography.

  14. Taxifolin and Fucoidin Abolish the Irradiation-Induced Increase in the Production of Reactive Oxygen Species in Rat Aorta.

    PubMed

    Arutyunyan, T V; Korystova, A F; Kublik, L N; Levitman, M Kh; Shaposhnikova, V V; Korystov, Yu N

    2016-03-01

    We studied changes in ROS content in the aorta of Wistar rats at early terms after irradiation in doses equal to single fraction used in tumor radiotherapy and the effects of taxifolin and fucoidin, blockers of leukocyte adhesion to endothelium, on ROS content. Male rats were exposed to X-rays (200 kW) in doses of 1-7.5 Gy. ROS production in aorta segments was measured in 1-48 h after irradiation by dichlorodihydrofluorescein oxidation. The content of ROS in the aorta of rats exposed to radiation in doses of 1-2.5 Gy increased in 1-24 h after irradiation, the peak ROS content was found in 2 h after irradiation. Taxifolin (100 μg/kg dihydroquercetin once a day with drinking water) and fucoidin (10 mg/kg, i.v.) abolished ROS accumulation. The content of ROS in rat aorta increased in 1-24 h after irradiation in doses used for tumor radiotherapy and this increase can be determined by leukocyte adhesion to the endothelium.

  15. 77 FR 71312 - Irradiation in the Production, Processing and Handling of Food

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-30

    ... cause tumors in laboratory animals, FDA has extensively researched the occurrence of furan in irradiated... laboratory animals provides an independent way to assess toxicological safety. These studies include those... state their opinions regarding the potential dangers and unacceptability of irradiating food. FDA...

  16. Use of Irradiated Foods

    NASA Technical Reports Server (NTRS)

    Brynjolfsson, A.

    1985-01-01

    The safety of irradiated foods is reviewed. Guidelines and regulations for processing irradiated foods are considered. The radiolytic products formed in food when it is irradiated and its wholesomeness is discussed. It is concluded that food irradiation processing is not a panacea for all problems in food processing but when properly used will serve the space station well.

  17. Microwaves and cellular immunity. I. Effect of whole body microwave irradiation on tumor necrosis factor production in mouse cells.

    PubMed

    Fesenko, E E; Makar, V R; Novoselova, E G; Sadovnikov, V B

    1999-10-01

    Whole body microwave sinusoidal irradiation of male NMRI mice with 8.15-18 GHz (1 Hz within) at a power density of 1 microW/cm2 caused a significant enhancement of TNF production in peritoneal macrophages and splenic T lymphocytes. Microwave radiation affected T cells, facilitating their capacity to proliferate in response to mitogenic stimulation. The exposure duration necessary for the stimulation of cellular immunity ranged from 5 h to 3 days. Chronic irradiation of mice for 7 days produced the decreasing of TNF production in peritoneal macrophages. The exposure of mice for 24 h increased the TNF production and immune proliferative response, and these stimulatory effects persisted over 3 days after the termination of exposure. Microwave treatment increased the endogenously produced TNF more effectively than did lipopolysaccharide, one of the most potential stimuli of synthesis of this cytokine. The role of microwaves as a factor interfering with the process of cell immunity is discussed.

  18. A Structure Identification and Toxicity Assessment of the Degradation Products of Aflatoxin B1 in Peanut Oil under UV Irradiation

    PubMed Central

    Mao, Jin; He, Bing; Zhang, Liangxiao; Li, Peiwu; Zhang, Qi; Ding, Xiaoxia; Zhang, Wen

    2016-01-01

    Aflatoxins, a group of extremely hazardous compounds because of their genotoxicity and carcinogenicity to human and animals, are commonly found in many tropical and subtropical regions. Ultraviolet (UV) irradiation is proven to be an effective method to reduce or detoxify aflatoxins. However, the degradation products of aflatoxins under UV irradiation and their safety or toxicity have not been clear in practical production such as edible oil industry. In this study, the degradation products of aflatoxin B1 (AFB1) in peanut oil were analyzed by Ultra Performance Liquid Chromatograph-Thermo Quadrupole Exactive Focus mass spectrometry/mass spectrometry (UPLC-TQEF-MS/MS). The high-resolution mass spectra reflected that two main products were formed after the modification of a double bond in the terminal furan ring and the fracture of the lactone ring, while the small molecules especially nitrogen-containing compound may have participated in the photochemical reaction. According to the above results, the possible photodegradation pathway of AFB1 in peanut oil is proposed. Moreover, the human embryo hepatocytes viability assay indicated that the cell toxicity of degradation products after UV irradiation was much lower than that of AFB1, which could be attributed to the breakage of toxicological sites. These findings can provide new information for metabolic pathways and the hazard assessment of AFB1 using UV detoxification. PMID:27845743

  19. Impact of glissile interstitial loop production in cascades on void ordering and swelling saturation under irradiation

    NASA Astrophysics Data System (ADS)

    Dubinko, V. I.

    1995-08-01

    According to the dislocation model of void ordering and swelling saturation by the present author, these phenomena arise due to the absorption by voids of perfect glissile dislocation loops produced by irradiation. The formation and glide of small interstitial loops has been also confirmed by recent molecular dynamics (MD) studies of displacement cascades. The cascade mechanism of the loop production is shown to explain an absence of visible dislocation loops in some experiments on void lattices, which is a very important argument in favor of the present theory. However, according to the MD simulations, the glide of such loops seems not to depend on the stacking fault energy of the host lattice, contrary to the predictions of the elastic continuum theory. The latter shows that high stacking energy (as in most bcc metals and in fcc Ni and Al) favors the unfaulting of small loops, which seems to be in agreement with experimentally observed void lattice formation in these metals as compared to the resistance of the low stacking energy metals (such as Cu, Ag, Au and most steels) to void lattice formation. This discrepancy between continuum theory and MD simulations shows the need for further studies of displacement cascades, in particular, in more complex systems modeling the effects of impurities on the nature of interstitial clusters. An outstanding problem is to find impurities that can facilitate the unfaulting process and, hence, void ordering and swelling saturation in those fcc metals which are currently supposed to be void lattice resistant.

  20. Investigation of the effect of contrails on global irradiance and solar energy production

    NASA Astrophysics Data System (ADS)

    Weihs, Philipp; Rennhofer, Marcus; Baumgartner, Dietmar; Wagner, Jochen; Laube, Wolfgang; Gadermaier, Josef

    2013-04-01

    In the present study we investigate the effect of contrails on global shortwave radiation and on Photovoltaic module performance. This investigation is performed using continuous hemispherical fish eye photographs of the sky, diffuse and direct shortwave measurements and short circuit current measurements of a-Si, c-Si and CdTe PV modules. These measurements have been performed at the solar observatory Kanzelhöhe (1540 m.a.s.l) located in the southern part of Austria during a period of one and half year. The time resolution of the measurements is one minute, which allows to accurately follow the formation-eventually the disappearance- or the movement of the contrails in the sky. Using the fish eye photographs we identified clear sky days with a high contrail persistence. We especially look at situations where the contrails were shading the sun. Results show that contrails shading the sun may reduce the global radiation by up to 60%. In general we however observe that during days with a high contrail persistence the diffuse irradiance is slightly increased. Finally a statistic of the contrail persistence during the period of measurement is presented and conclusions as to the relevance for the solar energy production are drawn.

  1. Production of Palladium-103 ( 103Pd) from a thin rhodium foil target - Improved cooling concept

    NASA Astrophysics Data System (ADS)

    Silverman, I.; Lavie, E.; Arenshtam, A.; Kijel, D.; Vaknin, D.; Veinguer, M.; Nagler, A.

    2007-08-01

    Palladium-103 (103Pd) is one of the commonly used radioisotopes for prostate cancer treatment. The current irradiation technique used to produce this radioisotope suffers from several serious inherent drawbacks, of which one is the low beam current due to cooling limitation and the other is the electroplating process used to prepare the target. A liquid-metal jet impingement target cooling system developed at Soreq NRC demonstrated recently a cooling capacity of 8.4 kW/cm2 while the pressure of the cooling liquid on the target back was less than 1 bar. The latter value implies that the target can be made very thin and that the copper back-plate might be removed. Hence, we propose a new target design based on the use of a thin rhodium foil directly cooled by a liquid-metal such as gallium.

  2. Enhanced biocatalysis mechanism under microwave irradiation in isoquercitrin production revealed by circular dichroism and surface plasmon resonance spectroscopy.

    PubMed

    Gong, An; Zhu, Dan; Mei, Yi-Yuan; Xu, Xiao-Hui; Wu, Fu-An; Wang, Jun

    2016-04-01

    An efficient and rapid process for isoquercitrin production by hesperidinase-catalyzed hydrolysis of rutin was successfully developed under microwave irradiation detecting the affinity by circular dichroism (CD) and surface plasmon resonance (SPR) spectroscopy. A maximum isoquercitrin yield of 91.5±2.7% was obtained in 10min with the conditions of 10g/L hesperidinase, 2g/L rutin, 30°C and microwave power density 88.9W/L. Enzymatic reaction rate and Vm/Km in the microwave reactor were 6.34-fold higher than in a continuous flow microreactor and 1.24-fold higher than in a biphasic system. CD and SPR analysis results also showed that hesperidinase has a better selectivity and affinity (3.3-fold than in a batch reactor) to generate isoquercitrin under microwave irradiation. Microwave irradiation greatly improved the reaction efficiency and productivity, leading to a more positive economical assessment. The binding affinity indicates the presence of strong multivalent interactions between rutin and hesperidinase under microwave irradiation.

  3. Pentosidine in advanced glycation end-products (AGEs) during UVA irradiation generates active oxygen species and impairs human dermal fibroblasts.

    PubMed

    Okano, Y; Masaki, H; Sakurai, H

    2001-08-01

    Our previous study reported that advanced glycation end-products (AGE)-modified BSA produced active oxygen species, *O2-, H2O2, and *OH under UVA irradiation and enhanced the cytotoxicity of UVA light. We examined whether pentosidine in AGE-modified BSA was involved in one of the mechanisms generating the active oxygen species. In biological investigations, fibroblasts exposed to UVA (20 J/cm2) in the presence of pentosidine-rich compounds (PRCs), which were prepared with L-arginine, L-lysine and glucose, showed a time-dependent leakage of the cytosolic enzyme LDH. In addition, release of LDH was suppressed by addition of DMSO and deferoxamine under UVA irradiation. From these results, it was determined that PRCs exposed to UVA damaged the plasma membrane of human dermal fibroblasts due to the conversion of *OH from H2O2 via a Fenton-like reaction. These features of PRCs exposed to UVA were consistent with those of AGE-modified BSA. In an ESR study, PRCs under UVA irradiation yielded DMPO-OH (DMPO-OH adduct) using DMPO as a spin-trapping reagent. *O2- generation from UVA-irradiated PRCs was also indicated by the combination of NBT reduction and SOD. When PRCs were exposed to UVA light controlled with a long-pass filter, WG-360, it was found that their production of *O2- was prohibited less than 50% in the NBT reduction assay. The *O2- production profile of PRCs depending on the wavelength of UVA light was similar to that of AGE-modified BSA. Furthermore, it was found that the H2O2 level was increased by PRCs exposed to UVA. These results indicated that pentosidine is an important factor of AGE-modified BSA in active oxygen generation under UVA irradiation.

  4. Soft X-ray irradiation of methanol ice: Formation of products as a function of photon energy

    SciTech Connect

    Chen, Y.-J.; Juang, K.-J.; Yih, T.-S.; Ciaravella, A.; Cecchi-Pestellini, C.; Muñoz Caro, G. M.; Jiménez-Escobar, A.

    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 CH{sub 2}OH, H{sub 2}CO, CH{sub 4}, HCOOH, HCOCH{sub 2}OH, CH{sub 3}COOH, CH{sub 3}OCH{sub 3}, HCOOCH{sub 3}, and (CH{sub 2}OH){sub 2}, as well as HCO, CO, and CO{sub 2}. 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 CH{sub 3}OH 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.

  5. INTERACTION OF LASER RADIATION WITH MATTER: Effect of a target size on the recoil momentum upon laser irradiation of absorbing materials

    NASA Astrophysics Data System (ADS)

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

    2004-10-01

    The dependence of a recoil momentum on the radius of a target irradiated by a single-pulse Nd3+:YAG laser (λ=1.064 μm, τ=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.

  6. Comparison of line x-ray emission from solid and porous nano-layer coated targets irradiated by double laser pulses

    SciTech Connect

    Fazeli, R.; Mahdieh, M. H.

    2015-11-15

    Enhancement of line x-ray emission from both solid and porous iron targets induced by irradiation of single and double laser pulses is studied numerically. The line emission from laser produced plasma is calculated within the extreme ultra-violet lithography wavelength range of 13.5–13.7 nm. The effects of pre-pulse intensity and delay time between two pulses (pre-pulse and main pulse) are examined. The results show that using double pulses irradiation in the conditions of porous target can reduce the x-ray enhancement. According to the results, the use of both pre-pulse and porous target leads to efficient absorption of the laser energy. Calculations also show that such enhanced laser absorption can ionize atoms of the target material to very high degrees of ionization, leading to decrease of the density of appropriate ions that are responsible for line emission in the selected wavelength region. By increasing the target porosity, x-ray yield was more reduced.

  7. Shielding experiments by the JASMIN Collaboration at Fermilab (II) - radioactivity measurement induced by secondary particles from the anti-proton production target

    SciTech Connect

    Hiroshi, Yashima; Norihiro, Matsuda; Yoshimi, Kasugai; Hiroshi, Nakashima; Yukio, Sakamoto; Hiroshi, Matsumura; Hiroshi, Iwase; Norikazu, Kinoshita; David, Boehnlein; Gary, Lautenschlager; Anthony, Leveling; Nikolai, Mokhov; Kamran, Vaziri; Koji, Oishi

    2011-08-01

    The JASMIN Collaboration has performed an experiment to conduct measurements of nuclear reaction rates around the anti-proton production (Pbar) target at the Fermi National Accelerator Laboratory (FNAL). At the Pbar target station, the target, consisting of an Inconel 600 cylinder, was irradiated by a 120 GeV/c proton beam from the FNAL Main Injector. The beam intensity was 3.6 x 1012 protons per second. The samples of Al, Nb, Cu, and Au were placed near the target to investigate the spatial and energy distribution of secondary particles emitted from it. After irradiation, the induced activities of the samples were measured by studying their gamma ray spectra using HPGe detectors. The production rates of 30 nuclides induced in Al, Nb, Cu, Au samples were obtained. These rates increase for samples placed in a forward (small angle) position relative to the target. The angular dependence of these reaction rates becomes larger for increasing threshold energy. These experimental results are compared with Monte Carlo calculations. The calculated results generally agree with the experimental results to within a factor of 2 to 3.

  8. Shielding experiments by the JASMIN collaboration at Fermilab (II) - Radioactivity measurement induced by secondary particles from the anti-proton production target

    SciTech Connect

    Yashima, Hiroshi; Matsuda, Norihiro; Kasugai, Yoshimi; Matsumura, Hiroshi; Iwase, Hiroshi; Kinoshita, Norikazu; Boehnlein, David; Lauten, Gary; Leveling, Anthony; Mokhov, Nikolai; Vaziri, Kamran; /Fermilab /Shimizu, Tokyo /JAEA, Ibaraki

    2011-01-01

    The JASMIN Collaboration has performed an experiment to conduct measurements of nuclear reaction rates around the anti-proton production (Pbar) target at the Fermi National Accelerator Laboratory (FNAL). At the Pbar target station, the target, consisting an Inconel 600 cylinder, was irradiated by a 120 GeV/c proton beam from the FNAL Main Injector. The beam intensity was 3.6 x 10{sub 12} protons per second. Samples of Al, Nb, Cu, and Au were placed near the target to investigate the spatial and energy distribution of secondary particles emitted from it. After irradiation, the induced activities of the samples were measured by studying their gamma ray spectra using HPGe detectors. The production rates of 30 nuclides induced in Al, Nb, Cu, Au samples were obtained. These rates increase for samples placed in a forward (small angle) position relative to the target. The angular dependence of these reaction rates becomes larger for increasing threshold energy. These experimental results are compared with Monte Carlo calculations. The calculated results generally agree with the experimental results to within a factor of 2 to 3.

  9. Shielding experiments by the JASMIN Collaboration at Fermilab (II) - radioactivity measurement induced by secondary particles from the anti-proton production target

    DOE PAGES

    Hiroshi, Yashima; Norihiro, Matsuda; Yoshimi, Kasugai; ...

    2011-08-01

    The JASMIN Collaboration has performed an experiment to conduct measurements of nuclear reaction rates around the anti-proton production (Pbar) target at the Fermi National Accelerator Laboratory (FNAL). At the Pbar target station, the target, consisting of an Inconel 600 cylinder, was irradiated by a 120 GeV/c proton beam from the FNAL Main Injector. The beam intensity was 3.6 x 1012 protons per second. The samples of Al, Nb, Cu, and Au were placed near the target to investigate the spatial and energy distribution of secondary particles emitted from it. After irradiation, the induced activities of the samples were measured bymore » studying their gamma ray spectra using HPGe detectors. The production rates of 30 nuclides induced in Al, Nb, Cu, Au samples were obtained. These rates increase for samples placed in a forward (small angle) position relative to the target. The angular dependence of these reaction rates becomes larger for increasing threshold energy. These experimental results are compared with Monte Carlo calculations. The calculated results generally agree with the experimental results to within a factor of 2 to 3.« less

  10. COPPER-64 Production Studies with Natural Zinc Targets at Deuteron Energy up to 19 Mev and Proton Energy from 141 Down to 31 Mev

    NASA Astrophysics Data System (ADS)

    Bonardi, Mauro L.; Birattari, Claudio; Groppi, Flavia; Song Mainard, Hae; Zhuikov, Boris L.; Kokhanyuk, Vladimir M.; Lapshina, Elena V.; Mebel, Michail V.; Menapace, Enzo

    2004-07-01

    High specific activity no-carrier-added 64Cu is a β-/β+ emitting radionuclide of increasing interest for PET imaging, as well as systemic and targeted radioimmunotherapy of tumors. Its peculiarity of intense Auger emitter is still under investigation. The cross-sections for production of 64Cu from Zn target of natural isotopic composition were measured in the deuteron energy range from threshold up to 19 MeV and proton energy range from 141 down to 31 MeV. The stacked-foil technique was used at both K=38 cyclotron of JRC-Ispra of CEC, Italy and 160 MeV intersection point of INR proton-LINAC in Troitsk, Russia. Several Ga, Zn, Cu, Ni, Co, V, Fe and Mn radionuclides were detected in Zn targets at the EOB. Optimized irradiation conditions are reported as a function of deuteron energy and energy loss into the Zn target, as well as target irradiation time and cooling time after radiochemistry. The activity of n.c.a. 64Cu was measured through its only γ emission of 1346 keV (i.e. 0.473 % intensity) both by instrumental and radiochemical methods, due to the non-specificity of annihilation radiation at 511 keV. To this last purpose, it was necessary to carry out a selective radiochemical separation of GaIII radionuclides by liquid/liquid extraction from the bulk of irradiated Zn targets and other spallation products, which remained in the 7 M HCl aqueous phase. Anion exchange chromatography tests had been carried out to separate the 64Cu from all others radionuclides in n.c.a. form. Theoretical calculations of cross-sections were performed with codes EMPIRE II and PENELOPE for deuteron reactions and CEF model and HMS-ALICE hybrid model for proton reactions. The theoretical results are presented and compared with the experimental values.

  11. The uneven irradiation of a target cell and its dynamic movement can mathematically explain incubation period for the induction of cancer by internally deposited radionuclides.

    PubMed

    Yamamoto, Yoichiro; Usuda, Nobuteru; Oghiso, Yoichi; Kuwahara, Yoshikazu; Fukumoto, Manabu

    2010-09-01

    Irradiation from internally deposited radionuclides induces malignant tumors. Ingested radionuclides accumulate in specific organs, which are irradiated over a lifelong period. Our aim is to elucidate why the development of malignant tumors requires long-term internal exposure, on the order of decades, despite the fact that irradiation is continuous over this period. Three major factors are considered to be responsible for the long incubation time in carcinogenesis caused by internally deposited alpha-emitters: uneven distribution of radionuclides, limited range of irradiation, and dynamic movement of tumor precursor cells. We hypothesized that target cells susceptible to malignant transformation may undergo one event by alpha particles and may then migrate outside of the range of alpha particles, thereby avoiding immediate induction of successive additional events that would lead to cell death or neoplastic changes. Based on this hypothesis, we further proposed a mathematical model to predict the relationship between dose rate and incubation period of tumors induced by internally deposited alpha-emitters. The function was non-linear and included terms of both direct and indirect radiation effects. It well fitted both human Th-ICC cases and rat Pu-induced lung cancer, suggesting that indirect radiation effects are independent from dose rate. The significance of parameters of the model is discussed.

  12. Dynamic of Nanopowder Production During Laser Target Evaporation

    NASA Astrophysics Data System (ADS)

    Trigub, M. V.; Platonov, V. V.; Fedorov, K. V.; Evtushenko, G. S.; Osipov, V. V.

    2016-12-01

    The paper presents the results of research focusing on the processes occurring when powerful laser radiation interacts with refractory oxide targets. To visualize formation of the nanoparticle cloud and large fragments, the authors used laser illumination and laser monitor methods. Image analysis allowed studying the dynamic of cloud formation from nanoparticles and determining the nature of its interaction with surrounding air. It was established that it is possible to mostly avoid the formation and ejection of a multitude of drops from the crater, if the target is evaporated by fiber laser radiation pulses with duration of no more than 200 μs. With pulse duration of 120 μs, peak power of 600 W and radiation power density of 0.4 MW/cm2, mass nanoparticle output was 30 mass%, which is 1.4 more than when the target is affected by continuous radiation of the same power.

  13. Development of a Ru complex-incorporated MOF photocatalyst for hydrogen production under visible-light irradiation.

    PubMed

    Toyao, Takashi; Saito, Masakazu; Dohshi, Satoru; Mochizuki, Katsunori; Iwata, Masatoshi; Higashimura, Hideyuki; Horiuchi, Yu; Matsuoka, Masaya

    2014-06-28

    A Ru complex-incorporated Ti-based MOF (Ti-MOF-Ru(tpy)2) has been synthesised by using a bis(4'-(4-carboxyphenyl)-terpyridine)Ru(ii) complex (Ru(tpy)2) as an organic linker. Ti-MOF-Ru(tpy)2 promotes photocatalytic hydrogen production from water containing a sacrificial electron donor under visible-light irradiation up to 620 nm.

  14. Targets to increase food production: One Health implications.

    PubMed

    McMahon, Barry J; Wall, Patrick G; Fanning, Séamus; Fahey, Alan G

    2015-01-01

    The increasing world population means that there is a requirement to expand global food production. Looking at the Republic of Ireland as an example, the risks and opportunities associated with the expansion of food production are outlined, particularly in relation to zoonoses transmission. A One Health approach to sustainable food production is required to avert a potential public health problem associated with increased agricultural expansion.

  15. Production of transplutonium elements and radiation sources based on them

    SciTech Connect

    Vasil`ev, V.Ya.; Adaev, V.A.; Gordeev, Ya.N.

    1993-12-31

    The Research Institute of Atomic Reactors (RIAR) has a complex experimental base for the required amount of transplutonium elements (TPE) production in reactors, their extraction from irradiated targets, preparing of necessary condition samples in purity and producing the radiation sources. Targets irradiation and target design are described. Californium 252 is used for neutron source production.

  16. Investigation of the Feasibility of Utilizing Gamma Emission Computed Tomography in Evaluating Fission Product Migration in Irradiated TRISO Fuel Experiments

    SciTech Connect

    Jason M. Harp; Paul A. Demkowicz

    2014-10-01

    In the High Temperature Gas-Cooled Reactor (HTGR) the TRISO particle fuel serves as the primary fission product containment. However the large number of TRISO particles present in proposed HTGRs dictates that there will be a small fraction (~10-4 to 10-5) of as manufactured and in-pile particle failures that will lead to some fission product release. The matrix material surrounding the TRISO particles in fuel compacts and the structural graphite holding the TRISO particles in place can also serve as sinks for containing any released fission products. However data on the migration of solid fission products through these materials is lacking. One of the primary goals of the AGR-3/4 experiment is to study fission product migration from failed TRISO particles in prototypic HTGR components such as structural graphite and compact matrix material. In this work, the potential for a Gamma Emission Computed Tomography (GECT) technique to non-destructively examine the fission product distribution in AGR-3/4 components and other irradiation experiments is explored. Specifically, the feasibility of using the Idaho National Laboratory (INL) Hot Fuels Examination Facility (HFEF) Precision Gamma Scanner (PGS) system for this GECT application is considered. To test the feasibility, the response of the PGS system to idealized fission product distributions has been simulated using Monte Carlo radiation transport simulations. Previous work that applied similar techniques during the AGR-1 experiment will also be discussed as well as planned uses for the GECT technique during the post irradiation examination of the AGR-2 experiment. The GECT technique has also been applied to other irradiated nuclear fuel systems that were currently available in the HFEF hot cell including oxide fuel pins, metallic fuel pins, and monolithic plate fuel.

  17. Comparison of N-nitrosodiethylamine degradation in water by UV irradiation and UV/O3: efficiency, product and mechanism.

    PubMed

    Xu, Bingbing; Chen, Zhonglin; Qi, Fei; Ma, Jun; Wu, Fengchang

    2010-07-15

    N-nitrosodiethylamine (NDEA) is a member of nitrosamines, which is strong carcinogenic. In order to explore an effective treatment method for NDEA removal from water, sole UV irradiation and UV/O(3) were carried out in this study. The removal efficiency, degradation products and pathways were compared between those two processes. Results showed that NDEA removal efficiency achieved 99% within 15 min by both UV and UV/O(3). Degradation reaction well followed pseudo-first-order kinetics. Water pH had different effect on NDEA degradation in those two processes. Acidic and neutral conditions were good for NDEA degradation by sole UV irradiation. However, NDEA underwent rapid degradation under various pH conditions in the UV/O(3) process. Though the ozone introduction in the UV/O(3) process had little effect on NDEA degradation efficiency, it had significant effect on its degradation products and pathways. Methylamine, dimethylamine, ethylamine and diethylamine were observed as aliphatic amine products of NDEA degradation in both two processes. They were assumed to arise due to N-N bond fission under UV irradiation, or due to the reaction of NDEA and hydroxyl radicals in the UV/O(3) process.

  18. Knowledge Productivity for Sustainable Innovation: Social Capital as HRD Target

    ERIC Educational Resources Information Center

    Ehlen, Corry; van der Klink, Marcel; Roentgen, Uta; Curfs, Emile; Boshuizen, Henny

    2014-01-01

    Purpose: The purpose of this paper is to test the feasibility of a conceptual model on relations between organisational innovation, knowledge productivity and social capital. It explores processes of knowledge productivity for sustainable innovation and associated HRD implications in knowledge intensive organisations, taking the perspective that…

  19. Update On The Development, Testing, And Manufacture Of High Density LEU-Foil Targets For The Production Of Mo-99

    SciTech Connect

    Creasy, John T

    2015-05-12

    This project has the objective to reduce and/or eliminate the use of HEU in commerce. Steps in the process include developing a target testing methodology that is bounding for all Mo-99 target irradiators, establishing a maximum target LEU-foil mass, developing a LEU-foil target qualification document, developing a bounding target failure analysis methodology (failure in reactor containment), optimizing safety vs. economics (goal is to manufacture a safe, but relatively inexpensive target to offset the inherent economic disadvantage of using LEU in place of HEU), and developing target material specifications and manufacturing QC test criteria. The slide presentation is organized under the following topics: Objective, Process Overview, Background, Team Structure, Key Achievements, Experiment and Activity Descriptions, and Conclusions. The High Density Target project has demonstrated: approx. 50 targets irradiated through domestic and international partners; proof of concept for two front end processing methods; fabrication of uranium foils for target manufacture; quality control procedures and steps for manufacture; multiple target assembly techniques; multiple target disassembly devices; welding of targets; thermal, hydraulic, and mechanical modeling; robust target assembly parametric studies; and target qualification analysis for insertion into very high flux environment. The High Density Target project has tested and proven several technologies that will benefit current and future Mo-99 producers.

  20. Large Scale Accelerator Production of 225Ac: Effective Cross sections for 78-192 MeV Protons Incident on 232Th Targets

    SciTech Connect

    Griswold, Justin R; Medvedev, Dmitri G.; Engle, Jonathan W.; Copping, Roy; Fitzsimmons, Jonathan M.; Radchenko, Valery; Cooley, Jason; Fassbender, Michael; Denton, David L.; Murphy, Karen E.; Owens, Allison C.; Birnbaum, Eva R.; John, Kevin D.; Nortier, Francois M.; Stracener, Daniel W; Heilbronn, Lawrence H.; Mausner, Leonard F.; Mirzadeh, Saed

    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 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 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.

  1. Analysis of Operating Strategies Using Different Target Designs For 238Pu Production

    SciTech Connect

    Thomas, Tomcy; Sherman, Steven R; Sawhney, Dr. Rapinder

    2017-01-01

    An engineering effort is underway to re-establish capability to produce 238Pu oxide at the kilogram scale in the United States. A multi-step batch process is being developed to produce this important material. Recently, a portion of this process was studied using discrete-event simulation tools to determine whether the conceptual process might achieve its yearly production goal. The study showed the conceptual process can meet the yearly production goal under some circumstances, but process improvements would be needed to ensure greater likelihood of success. This study extends the work performed previously by examining the effects of changing the reactor target design on the yearly process output. Two new reactor target configurations are considered an aluminum-clad reactor target containing 50% greater 237Np oxide content than the original target, and a zirconium alloy-clad target using no aluminum. The results indicate that use of the new aluminum-clad target configuration may allow the process to achieve the same yearly production goal in less time using fewer targets. If the zirconium alloy-clad target is used, then even fewer targets would be needed to reach the production goal, but some process changes would be required to handle the zirconium cladding. The number of days needed to process a target batch to completion, and the steady state 238Pu oxide production rate, for each configuration are compared to the results from the initial simulation study.

  2. Proton beam production by a laser ion source with hydride target

    SciTech Connect

    Okamura, M.; Stifler, C.; Palm, K.; Steski, D.; Kanesue, T.; Ikeda, S.; Kumaki, M.

    2016-02-15

    We studied proton beam production from a laser ion source using hydrogen rich target materials. In general, gas based species are not suitable for laser ion sources since formation of a dense laser target is difficult. In order to achieve reliable operation, we tested hydride targets using a sub nanosecond Q-switched Nd-YAG laser, which may help suppress target material consumption. We detected enough yields of protons from a titanium hydride target without degradation of beam current during the experiment. The combination of a sub nanosecond laser and compressed hydride target may provide stable proton beam.

  3. STEM-EDS analysis of fission products in neutron-irradiated TRISO fuel particles from AGR-1 experiment

    NASA Astrophysics Data System (ADS)

    Leng, B.; van Rooyen, I. J.; Wu, Y. Q.; Szlufarska, I.; Sridharan, K.

    2016-07-01

    Historic and recent post-irradiation-examination from the German AVR and Advanced Gas Reactor Fuel Development and Qualification Project have shown that 110 m Ag is released from intact tristructural isotropic (TRISO) fuel. Although TRISO fuel particle research has been performed over the last few decades, little is known about how metallic fission products are transported through the SiC layer, and it was not until March 2013 that Ag was first identified in the SiC layer of a neutron-irradiated TRISO fuel particle. The existence of Pd- and Ag-rich grain boundary precipitates, triple junction precipitates, and Pd nano-sized intragranular precipitates in neutron-irradiated TRISO particle coatings was investigated using Scanning Transmission Electron Microscopy and Energy Dispersive Spectroscopy analysis to obtain more information on the chemical composition of the fission product precipitates. A U-rich fission product honeycomb shape precipitate network was found near a micron-sized precipitate in a SiC grain about ∼5 μm from the SiC-inner pyrolytic carbon interlayer, indicating a possible intragranular transport path for uranium. A single Ag-Pd nano-sized precipitate was found inside a SiC grain, and this is the first research showing such finding in irradiated SiC. This finding may possibly suggest a possible Pd-assisted intragranular transport mechanism for Ag and may be related to void or dislocation networks inside SiC grains. Preliminary semi-quantitative analysis indicated the micron-sized precipitates to be Pd2Si2U with carbon existing inside these precipitates. However, the results of such analysis for nano-sized precipitates may be influenced by the SiC matrix. The results reported in this paper confirm the co-existence of Cd with Ag in triple points reported previously.

  4. Co-targeting Deoxyribonucleic Acid–Dependent Protein Kinase and Poly(Adenosine Diphosphate-Ribose) Polymerase-1 Promotes Accelerated Senescence of Irradiated Cancer Cells

    SciTech Connect

    Azad, Arun; Bukczynska, Patricia; Jackson, Susan; Haput, Ygal; Cullinane, Carleen; McArthur, Grant A.; Solomon, Benjamin

    2014-02-01

    Purpose: To examine the effects of combined blockade of DNA-dependent protein kinase (DNA-PK) and poly(adenosine diphosphate-ribose) polymerase-1 (PARP-1) on accelerated senescence in irradiated H460 and A549 non-small cell lung cancer cells. Methods and Materials: The effects of KU5788 and AG014699 (inhibitors of DNA-PK and PARP-1, respectively) on clonogenic survival, DNA double-strand breaks (DSBs), apoptosis, mitotic catastrophe, and accelerated senescence in irradiated cells were examined in vitro. For in vivo experiments, H460 xenografts established in athymic nude mice were treated with BEZ235 (a DNA-PK, ATM, and phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor) and AG014699 to determine effects on proliferation, DNA DSBs, and accelerated senescence after radiation. Results: Compared with either inhibitor alone, combination treatment with KU57788 and AG014699 reduced postradiation clonogenic survival and significantly increased persistence of Gamma-H2AX (γH2AX) foci in irradiated H460 and A549 cells. Notably, these effects coincided with the induction of accelerated senescence in irradiated cells as reflected by positive β-galactosidase staining, G2-M cell-cycle arrest, enlarged and flattened cellular morphology, increased p21 expression, and senescence-associated cytokine secretion. In irradiated H460 xenografts, concurrent therapy with BEZ235 and AG014699 resulted in sustained Gamma-H2AX (γH2AX) staining and prominent β-galactosidase activity. Conclusion: Combined DNA-PK and PARP-1 blockade increased tumor cell radiosensitivity and enhanced the prosenescent properties of ionizing radiation in vitro and in vivo. These data provide a rationale for further preclinical and clinical testing of this therapeutic combination.

  5. Production and evolution of carbonaceous material by ion irradiation in space.

    PubMed

    Strazzulla, G; Baratta, G A; Spinella, F

    1995-03-01

    We review recent experimental studies concerning the evolution, driven by ion irradiation, of carbonaceous material from frozen gas to a refractory molecular solid. Under further irradiation the latter changes to a polymer-like material and ultimately to amorphous carbon. Most of the results have been obtained by "in situ" and remote IR and Raman spectroscopy. The results have been applied to demonstrate that molecular solids may be easily formed by irradiation of frozen mantles in dense interstellar clouds. Polymer-like material and amorphous carbons may result by further irradiation of organic mantles on grains in the diffuse interstellar medium. Those grains, during the aggregation to form extended bodies like comets (T-Tau phase of the Sun), are further modified. These latter are also irradiated, after the comet formation, during their long stay in the Oort cloud. In particular it has been suggested that comet may develop an ion-produced cometary organic crust that laboratory evidences show to be stable against temperature increases experienced during passages near the Sun. The comparison between the Raman spectra of some IDP (Interplanetary Dust Particles) and the Raman spectra of some ion-produced amorphous carbons, is also discussed.

  6. High acceptor production rate in electron-irradiated n-type GaAs: Impact on defect models

    NASA Astrophysics Data System (ADS)

    Look, D. C.

    1987-09-01

    Defect production rates have been studied in electron-irradiated GaAs by temperature-dependent Hall-effect (TDH) measurements. The TDH results agree well with deep level transient spectroscopy (DLTS) results for the well-known electron traps E1, E2, and E3, but conclusively demonstrate a much higher production rate (4±1 cm-1) of acceptors below E3 than the total of all other DLTS traps. These findings strongly affect current defect models, and, e.g., are consistent with the existence of Ga sublattice damage, not seen before.

  7. Melanin production through novel processing of proopiomelanocortin in the extracellular compartment of the auricular skin of C57BL/6 mice after UV-irradiation

    PubMed Central

    Yamamoto, Hiroyuki; Yamane, Tomohiro; Iguchi, Kazuaki; Tanaka, Kiyotaka; Iddamalgoda, Arunasiri; Unno, Keiko; Hoshino, Minoru; Takeda, Atsushi

    2015-01-01

    The production of melanin is regulated by α-melanocyte-stimulating hormone (α-MSH), which is produced from proopiomelanocortin (POMC). Keratinocytes release POMC along with lower levels of α-MSH and ACTH. To clarify the mechanism of melanogenesis after ultraviolet (UV)-irradiation, this study focused on the expression of POMC and POMC-derived peptides after UV-irradiation. Western blot analysis and immunoassays indicated that both POMC and α-MSH-like immunoreactivity (α-MSH-LI) increased after UV-irradiation. However, other POMC-derived products were very low. In hypophysectomized mice, α-MSH-LI increased to the same level as in control mice after UV-irradiation. Structural analysis revealed that the major α-MSH-LI product was ACTH(1–8). Furthermore, ACTH(1–8) competed with [125I]-α-MSH for receptor binding and increased melanin production via a melanocortin-1 receptor. These results suggested that melanin was produced through ACTH(1–8) after UV-irradiation. Trypsin-like enzymatic activity, which is responsible for POMC activation, increased after UV-irradiation and was identified as tryptase. In mast cell-deficient mice, which do not produce tryptase, α-MSH-LI levels were unchanged after UV-irradiation. The present study demonstrates the production of ACTH(1–8) from POMC by tryptase, which is a novel peptide-processing mechanism in the extracellular compartment of the skin. PMID:26417724

  8. High K-alpha X-ray Conversion Efficiency From Extended Source Gas Jet Targets Irradiated by Ultra Short Laser Pulses

    SciTech Connect

    Kugland, N L; Constantin, C; Collette, A; Dewald, E; Froula, D; Glenzer, S H; Kritcher, A; Neumayer, P; Ross, J S; Niemann, C

    2007-11-01

    The absolute laser conversion efficiency to K{sub {alpha}}-like inner shell x-rays (integrated from K{sub {alpha}} to K{sub {beta}}) is observed to be an order of magnitude higher in argon gas jets than in solid targets due to enhanced emission from higher ionization stages following ultra short pulse laser irradiation. Excluding the higher ionization stages, the conversion efficiency to near-cold K{sub {alpha}} is the same in gas jets as in solid targets. These results demonstrate that gas jet targets are bright, high conversion efficiency, high repetition rate, debris-free multi-keV x-ray sources for spectrally resolved scattering and backlighting of rapidly evolving dense matter.

  9. High-power liquid-lithium jet target for neutron production

    SciTech Connect

    Halfon, S.; Feinberg, G.; Arenshtam, A.; Kijel, D.; Berkovits, D.; Eliyahu, I.; Hazenshprung, N.; Mardor, I.; Nagler, A.; Shimel, G.; Silverman, I.; Paul, M.; Friedman, M.; Tessler, M.

    2013-12-15

    A compact liquid-lithium target (LiLiT) was built and tested with a high-power electron gun at the Soreq Nuclear Research Center. The lithium target, to be bombarded by the high-intensity proton beam of the Soreq Applied Research Accelerator Facility (SARAF), will constitute an intense source of neutrons produced by the {sup 7}Li(p,n){sup 7}Be reaction for nuclear astrophysics research and as a pilot setup for accelerator-based Boron Neutron Capture Therapy. The liquid-lithium jet target acts both as neutron-producing target and beam dump by removing the beam thermal power (>5 kW, >1 MW/cm{sup 3}) with fast transport. The target was designed based on a thermal model, accompanied by a detailed calculation of the {sup 7}Li(p,n) neutron yield, energy distribution, and angular distribution. Liquid lithium is circulated through the target loop at ∼200 °C and generates a stable 1.5 mm-thick film flowing at a velocity up to 7 m/s onto a concave supporting wall. Electron beam irradiation demonstrated that the liquid-lithium target can dissipate electron power areal densities of >4 kW/cm{sup 2} and volume power density of ∼2 MW/cm{sup 3} at a lithium flow of ∼4 m/s while maintaining stable temperature and vacuum conditions. The LiLiT setup is presently in online commissioning stage for high-intensity proton beam irradiation (1.91–2.5 MeV, 1–2 mA) at SARAF.

  10. LANL sunnyside experiment: Study of neutron production in accelerator-driven targets

    NASA Astrophysics Data System (ADS)

    Morgan, G.; Butler, G.; Cappiello, M.; Carius, S.; Daemen, L.; DeVolder, B.; Frehaut, J.; Goulding, C.; Grace, R.; Green, R.; Lisowski, P.; Littleton, P.; King, J.; King, N.; Prael, R.; Stratton, T.; Turner, S.; Ullmann, J.; Venneri, F.; Yates, M.

    1995-09-01

    Measurements have been made of the neutron production in prototypic targets for accelerator driven systems. Studies were conducted on four target assemblies containing lead, lithium, tungsten, and a thorium-salt mixture. Integral data on total neutron production were obtained as well as more differential data on neutron leakage and neutron flux profiles in the blanket/moderator region. Data analysis on total neutron production is complete and shows excellent agreement with calculations using the LAHET/MCNP code system.

  11. Induced parthenogenesis by gamma-irradiated pollen in loquat for haploid production

    PubMed Central

    Blasco, Manuel; Badenes, María Luisa; del Mar Naval, María

    2016-01-01

    Successful haploid induction in loquat (Eriobotrya japonica (Thunb.) Lindl.) through in situ-induced parthenogenesis with gamma-ray irradiated pollen has been achieved. Female flowers of cultivar ‘Algerie’ were pollinated using pollen of cultivars ‘Changhong-3’, ‘Cox’ and ‘Saval Brasil’ irradiated with two doses of gamma rays, 150 and 300 Gy. The fruits were harvested 90, 105 and 120 days after pollination (dap). Four haploid plants were obtained from ‘Algerie’ pollinated with 300-Gy-treated pollen of ‘Saval Brasil’ from fruits harvested 105 dap. Haploidy was confirmed by flow cytometry and chromosome count. The haploids showed a very weak development compared to the diploid plants. This result suggests that irradiated pollen can be used to obtain parthenogenetic haploids. PMID:27795686

  12. The generation of oxidation products of benzo(a)pyrene by lipid peroxidation: a study using gamma-irradiation

    SciTech Connect

    Gower, J.D.; Wills, E.D.

    1984-09-01

    The role which active oxygen and radicals generated by the peroxidation of unsaturated fatty acids could play in the oxidation of benzo(a)pyrene has been studied using gamma-irradiation. Irradiation of benzo(a)pyrene resulted in the formation of benzo(a)pyrene 1,6-, 3,6- and 6,12-quinones and other more polar products which were analysed by h.p.l.c. OH. radicals are believed to be involved in this oxidation. The presence of polyunsaturated fatty acids and polyunsaturated lipids stimulated the formation of benzo(a)pyrene products following gamma-irradiation. Oxidation of benzo(a)pyrene also occurred over a period of days in the presence of autoxidising mackerel oil. The rate of benzo(a)pyrene oxidation was related to the extent of lipid peroxidation as determined by malonaldehyde formation. Malonaldehyde production as a result of peroxidising lipids was inhibited by benzo(a)pyrene which suggested that benzo(a)pyrene reacted directly with lipid peroxy radicals or hydroperoxides generated in the process of lipid peroxidation. These results demonstrate that oxidation products of the peroxidation of lipids and fatty acids are able to react directly with benzo(a)pyrene to form products including benzo(a)pyrene quinones without the presence of enzymes such as the cytochrome P-450 mixed function oxidase system and prostaglandin synthetase. It is possible that benzo(a)pyrene may be activated by these types of reactions in vivo or in vitro when benzo(a)pyrene is in contact with polyunsaturated lipids in foodstuffs or the intestinal lumen and peroxidation of unsaturated fats may play an important role in human carcinogenesis.

  13. [Exploring New Drug Targets through the Identification of Target Molecules of Bioactive Natural Products].

    PubMed

    Arai, Masayoshi

    2016-01-01

    With the development of cell biology and microbiology, it has become easy to culture many types of animal cells and microbes, and they are frequently used for phenotypic screening to explore medicinal seeds. On the other hand, it is recognized that cells and pathogenic microbes present in pathologic sites and infected regions of the human body display unique properties different from those under general culture conditions. We isolated several bioactive compounds from marine medicinal resources using constructed bioassay-guided separation focusing on the unique changes in the characteristics of cells and pathogenic microbes (Mycobacterium spp.) in the human body under disease conditions. In addition, we also carried out identification studies of target molecules of the bioactive compounds by methods utilizing the gene expression profile, transformants of cells or microbes, synthetic probe molecules of the isolated compounds, etc., since bioactive compounds isolated from the phenotypic screening system often target new molecules. This review presents our phenotypic screening systems, isolation of bioactive compounds from marine medicinal resources, and target identification of bioactive compounds.

  14. Systems Pharmacology-Based Discovery of Natural Products for Precision Oncology Through Targeting Cancer Mutated Genes.

    PubMed

    Fang, J; Cai, C; Wang, Q; Lin, P; Zhao, Z; Cheng, F

    2017-03-01

    Massive cancer genomics data have facilitated the rapid revolution of a novel oncology drug discovery paradigm through targeting clinically relevant driver genes or mutations for the development of precision oncology. Natural products with polypharmacological profiles have been demonstrated as promising agents for the development of novel cancer therapies. In this study, we developed an integrated systems pharmacology framework that facilitated identifying potential natural products that target mutated genes across 15 cancer types or subtypes in the realm of precision medicine. High performance was achieved for our systems pharmacology framework. In case studies, we computationally identified novel anticancer indications for several US Food and Drug Administration-approved or clinically investigational natural products (e.g., resveratrol, quercetin, genistein, and fisetin) through targeting significantly mutated genes in multiple cancer types. In summary, this study provides a powerful tool for the development of molecularly targeted cancer therapies through targeting the clinically actionable alterations by exploiting the systems pharmacology of natural products.

  15. Approaches to develop 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.

    1999-06-10

    Approaches to develop targets for production of intense radioactive ion beams (RIBs) have been evaluated over the past five years. It is acknowledged that many desired physics objectives using RIBs can be met only by using production beams of energetic protons with currents up to 100 {mu}A. Such beams can be made available at future spallation neutron facilities. The production targets will require active cooling to control operational temperatures due to internal heating caused by the production beam. A target concept has been selected, and calculational analyses of the target concept have been performed to guide the design of a prototype target for an in-beam test of the actual thermal behavior. For this test, a high-power test facility is needed; fortunately, the beam currents required exist at the TRIUMF accelerator facility. An experimental proposal has been approved for such a test.

  16. Systems Pharmacology‐Based Discovery of Natural Products for Precision Oncology Through Targeting Cancer Mutated Genes

    PubMed Central

    Fang, J; Cai, C; Wang, Q; Lin, P

    2017-01-01

    Massive cancer genomics data have facilitated the rapid revolution of a novel oncology drug discovery paradigm through targeting clinically relevant driver genes or mutations for the development of precision oncology. Natural products with polypharmacological profiles have been demonstrated as promising agents for the development of novel cancer therapies. In this study, we developed an integrated systems pharmacology framework that facilitated identifying potential natural products that target mutated genes across 15 cancer types or subtypes in the realm of precision medicine. High performance was achieved for our systems pharmacology framework. In case studies, we computationally identified novel anticancer indications for several US Food and Drug Administration‐approved or clinically investigational natural products (e.g., resveratrol, quercetin, genistein, and fisetin) through targeting significantly mutated genes in multiple cancer types. In summary, this study provides a powerful tool for the development of molecularly targeted cancer therapies through targeting the clinically actionable alterations by exploiting the systems pharmacology of natural products. PMID:28294568

  17. Differences in the production of noncharacteristic radiation in gaseous and solid targets

    NASA Technical Reports Server (NTRS)

    Laubert, R.; Peterson, R. S.; Forester, J. P.; Liao, K.-H.; Griffin, P. M.; Hayden, H.; Elston, S. B.; Pegg, D. J.; Thoe, R. S.; Sellin, I. A.

    1976-01-01

    Bell et al. (1975) found that the observed yield of noncharacteristic radiation (NCR) for a beam of S atoms hitting Al and Ne targets is of approximately equal magnitude for gaseous and solid targets under similar collision conditions. They concluded that NCR is produced predominantly in single collisions for 55-MeV S atoms on an Al target. This conclusion is tested in a similar collision system by comparing the NCR yields obtained with a 40-MeV Si(6+) ion beam on SiH4 (gaseous target) and on Al (solid target). Corrected X-ray spectra recorded in both cases clearly indicate a difference in the NCR yield for gaseous and solid targets. The results suggest that double collisions dominate the NCR production and that a single-collision production contribution of 15% to 20% is an upper limit for the projectile-target system used.

  18. Production Of High Specific Activity Copper-67

    DOEpatents

    Jamriska, Sr., David J.; Taylor, Wayne A.; Ott, Martin A.; Fowler, Malcolm; Heaton, Richard C.

    2003-10-28

    A process for the selective production and isolation of high specific activity Cu.sup.67 from proton-irradiated enriched Zn.sup.70 target comprises target fabrication, target irradiation with low energy (<25 MeV) protons, chemical separation of the Cu.sup.67 product from the target material and radioactive impurities of gallium, cobalt, iron, and stable aluminum via electrochemical methods or ion exchange using both anion and cation organic ion exchangers, chemical recovery of the enriched Zn.sup.70 target material, and fabrication of new targets for re-irradiation is disclosed.

  19. Production Of High Specific Activity Copper-67

    DOEpatents

    Jamriska, Sr., David J.; Taylor, Wayne A.; Ott, Martin A.; Fowler, Malcolm; Heaton, Richard C.

    2002-12-03

    A process for the selective production and isolation of high specific activity cu.sup.67 from proton-irradiated enriched Zn.sup.70 target comprises target fabrication, target irradiation with low energy (<25 MeV) protons, chemical separation of the Cu.sup.67 product from the target material and radioactive impurities of gallium, cobalt, iron, and stable aluminum via electrochemical methods or ion exchange using both anion and cation organic ion exchangers, chemical recovery of the enriched Zn.sup.70 target material, and fabrication of new targets for re-irradiation is disclosed.

  20. Ionic liquid as a promising biobased green solvent in combination with microwave irradiation for direct biodiesel production.

    PubMed

    Wahidin, Suzana; Idris, Ani; Shaleh, Sitti Raehanah Muhamad

    2016-04-01

    The wet biomass microalgae of Nannochloropsis sp. was converted to biodiesel using direct transesterification (DT) by microwave technique and ionic liquid (IL) as the green solvent. Three different ionic liquids; 1-butyl-3-metyhlimidazolium chloride ([BMIM][Cl], 1-ethyl-3-methylimmidazolium methyl sulphate [EMIM][MeSO4] and 1-butyl-3-methylimidazolium trifluoromethane sulfonate [BMIM][CF3SO3]) and organic solvents (hexane and methanol) were used as co-solvents under microwave irradiation and their performances in terms of percentage disruption, cell walls ruptured and biodiesel yields were compared at different reaction times (5, 10 and 15 min). [EMIM][MeSO4] showed highest percentage cell disruption (99.73%) and biodiesel yield (36.79% per dried biomass) after 15 min of simultaneous reaction. The results demonstrated that simultaneous extraction-transesterification using ILs and microwave irradiation is a potential alternative method for biodiesel production.

  1. INTERACTION OF LASER RADIATION WITH TARGETS Tomographic imaging of a target directly irradiated in experiments on the Iskra-5 iodine laser facility

    NASA Astrophysics Data System (ADS)

    Bondarenko, S. V.; Garanin, R. V.; Garanin, Sergey G.; Zhidkov, N. V.; Oreshkov, O. V.; Potapov, S. V.; Suslov, N. A.; Frolova, N. V.

    2010-12-01

    We set forth the data of experiments involving direct microtarget irradiation by the 12 second-harmonic beams (λ = 0.66 μm) of iodine laser radiation carried out on the Iskra-5 facility. For microtargets we employed glass shells ~500 μm in diameter with ~1-μm thick walls, which were filled with a DT mixture at a pressure pDT approx 3-4 atm. In one of these experiments, a tomographic image of the microtarget was recorded from the images obtained using pinhole cameras, which were arranged along seven different directions. The pinhole images were acquired in the X-ray radiation with photon energies above 1.5 keV. The procedure used for reconstructing the volume luminosity of the microtarget is described. An analysis of the tomographic image suggests that the compressed microtarget domain possesses a complex asymmetric shape; 20-30 μm sized structural elements being clearly visible. The resultant data set allowed us to estimate the initial nonuniformity of microtarget surface irradiation by the laser radiation. The rms nonuniformity of microtarget irradiance was estimated at ~60 %.

  2. Model nitride irradiated nuclear fuel: production, reaction with water and dilution in nitric acid

    SciTech Connect

    Dvoeglazov, K.; Glushenkov, A.; Sharin, A.; Arseenkov, L.; Lobachev, E.; Davydov, A.; Chebotarev, A.

    2013-07-01

    Samples of the model nuclear fuel (MNF) were made from separately synthesized nitride powders uranium-plutonium, zirconium, lanthanum and metal additives of simulators (Mo, Pd, Rh, Ag) fission products. Synthesis of initial nitride components was carried out from individual oxides, using a carbo-thermal restoration method. From MNF samples baked at a temperature of 1750 C. degrees, were made ceramographic specimens which were investigated by a scanning electron microscope. The analysis showed that distribution of the MNF components and structure of the samples corresponds to distribution of these components in the irradiated nitride fuel. The samples of MNF of nitride fuel were used for carrying out researches on dissolution in water and nitric acid. Experiments on studying the interaction of MNF with water have been made at 20, 50 and 80 C. degrees. The speed of leaching has been determined by a way of measuring the activity of water (Bq/l) in time. It is shown that an increase of temperature leads to an increase of the speed of leaching of plutonium. The formation of a precipitation, allegedly polymeric forms of plutonium, has been observed. The estimated speed of leaching of plutonium from MNF in water at 80 C. degrees is -0,0064 μgPu/(mm{sup 2}*h). From elements of FP simulators, molybdenum appears to be the most significantly leached. The dissolution of MNF in nitric acid (7,8 and 9,4 mol/l) has been carried out at boiling temperature (106-109 C. degrees). During the process of dissolution, gases were emitted. The assessment of composition of the emitted gases has been carried out. During the filtering of the solutions a precipitate whose weight makes about 2% from the weight of initial fuel has been found. Precipitate represents small powder of metal with gray color. Precipitate was investigated by a scanning electron microscope. The analysis of ranges of absorption of solution showed that the Pu(VI) share to the general content of plutonium in solution can

  3. Design and Nuclear-Safety Related Simulations of Bare-Pellet Test Irradiations for the Production of Pu-238 in the High Flux Isotope Reactor using COMSOL

    SciTech Connect

    Freels, James D; Jain, Prashant K; Hobbs, Randy W

    2012-01-01

    The Oak Ridge National Laboratory (ORNL)is developing technology to produce plutonium-238 for the National Aeronautics and Space Administration (NASA) as a power source material for powering vehicles while in deep-space[1]. The High Flux Isotope Reactor (HFIR) of ORNL has been utilized to perform test irradiations of incapsulated neptunium oxide (NpO2) and aluminum powder bare pellets for purposes of understanding the performance of the pellets during irradiation[2]. Post irradiation examinations (PIE) are currently underway to assess the effect of temperature, thermal expansion, swelling due to gas production, fission products, and other phenomena

  4. An automated flow system incorporating in-line acid dissolution of bismuth metal from a cyclotron irradiated target assembly for use in the isolation of astatine-211.

    PubMed

    O'Hara, Matthew J; Krzysko, Anthony J; Niver, Cynthia M; Morrison, Samuel S; Owsley, Stanley L; Hamlin, Donald K; Dorman, Eric F; Scott Wilbur, D

    2017-04-01

    Astatine-211 ((211)At) is a promising cyclotron-produced radionuclide being investigated for use in targeted alpha therapy. The wet chemical isolation of trace quantities of (211)At, produced within several grams of Bi metal deposited onto an aluminum cyclotron target assembly, involves a multi-step procedure. Because the (211)At isolation method is labor-intensive and complex, automation of the method is being developed to facilitate routine processing at the University of Washington and to make it easier to transfer the process to other institutions. As part of that automation effort, a module useful in the initial step of the isolation procedure, dissolution of the Bi target, was designed and tested. The computer-controlled module performs in-line dissolution of Bi metal from the target assembly using an enclosed target dissolution block, routing the resulting solubilized (211)At/Bi mixture to the subsequent process step. The primary parameters involved in Bi metal solubilization (influent HNO3 concentration and flow rate) were optimized prior to evaluation of the system using replicate (211)At-bearing cyclotron irradiated targets. The results indicate that the system performs in a predictable and reproducible manner, with cumulative Bi and (211)At recoveries following a sigmoidal function.

  5. Energy transport and isochoric heating of a low-Z, reduced-mass target irradiated with a high intensity laser pulse

    SciTech Connect

    Nishimura, H.; Nakamura, H.; Tanabe, M.; Fujiwara, T.; Yamamoto, N.; Fujioka, S.; Mima, K.; Mishra, R.; Sentoku, Y.; Mancini, R.; Hakel, P.; Ohshima, S.; Batani, D.; Veltcheva, M.; Desai, T.; Jafer, R.; Kawamura, T.; Koike, F.

    2011-02-15

    Heat transport in reduced-mass targets irradiated with a high intensity laser pulse was studied. K{alpha} lines from partially ionized chlorine embedded in the middle of a triple-layered plastic target were measured to evaluate bulk electron temperature in the tracer region inside the target. Two groups of K{alpha} lines, one from Cl{sup +}-Cl{sup 6+} (hereby called ''cold K{alpha}''), and the other from Cl{sup 9+} and Cl{sup 10+} (''shifted K{alpha}'') are observed from different regions within the target. Two-dimensional collisional particle-in-cell simulations show two distinct heating mechanisms occurring concurrently: uniform heating by refluxing electrons and local heating by diffusive electrons in the central region. These two heating processes, which made the target temperature distribution nonuniform, are responsible for producing the two groups of K{alpha} lines in the experiment. The blue-shift of cold K{alpha} lines in the experiment is the signature of higher temperatures achieved by the refluxing heating in smaller-mass targets.

  6. Comparison of the (p,xn) cross sections from /sup 238/U, /sup 235/U, and /sup 232/Th targets irradiated with 200-MeV protons

    SciTech Connect

    Chu, Y.Y.; Zhou, M.L.

    1982-01-01

    We have measured absolute cross sections for (p,xn) reactions (x ranges from 0 to 8) from /sup 238/U, /sup 235/U, and /sup 232/Th targets irradiated with 200-MeV protons at the Brookhaven AGS Linac injector. Chemical yields were determined by using /sup 239/Np and /sup 233/Pa as tracers. Yield patterns obtained in this work can be compared to the experimental results and theoretical calculations from earlier work, and they are consistent within the framework of intranuclear cascade followed by neutron evaporation and fission competition.

  7. INTERACTION OF LASER RADIATION WITH MATTER AND OTHER LASER APPLICATIONS: Changes in the emission properties of metal targets during pulse-periodic laser irradiation

    NASA Astrophysics Data System (ADS)

    Konov, Vitalii I.; Pimenov, S. M.; Prokhorov, A. M.; Chapliev, N. I.

    1988-02-01

    A scanning electron microscope was used with a pulse-periodic CO2 laser to discover the laws governing the correlation of the modified microrelief of metal surfaces, subjected to the action of multiple laser pulses, with the emission of charged particles and the luminescence of the irradiated zone. It was established that the influence of sorption and laser-induced desorption on the emission signals may be manifested differently depending on the regime of current generation in the "target-vacuum chamber" circuit.

  8. recA gene product is responsible for inhibition of deoxyribonucleic acid synthesis after ultraviolet irradiation.

    PubMed Central

    Trgovcević, Z; Petranović, D; Petranović, M; Salaj-Smic, E

    1980-01-01

    Deoxyribonucleic acid synthesis after ultraviolet irradiation was studied in wild-type, uvrA, recB, recA recB, and recA Escherichia coli strains. Inhibition of deoxyribonucleic acid synthesis, which occurs almost immediately after exposing the cells to ultraviolet radiation, depends on the functional gene recA. PMID:6997276

  9. Application of irradiation in bait production to the control of crawling insects in urban areas

    NASA Astrophysics Data System (ADS)

    Migdał, W.; Owczarczyk, H. B.; Świ ȩtosławski, J.; Świ ȩtosławski, J.

    2000-03-01

    The efficiency and palatability of two baits were studied to the control of crawling insects in urban areas: "Cockroach Kill Gel" for control of cockroaches and Faratox B for control of ants. Ionizing energy was used in producing the baits. It was concluded, that after irradiation the palatability of Faratox B improved and palatability of Cockroach Kill Gel did not change.

  10. Molybdenum target specifications for cyclotron production of 99mTc based on patient dose estimates

    NASA Astrophysics Data System (ADS)

    Hou, X.; Tanguay, J.; Buckley, K.; Schaffer, P.; Bénard, F.; Ruth, T. J.; Celler, A.

    2016-01-01

    In response to the recognized fragility of reactor-produced 99Mo supply, direct production of 99mTc via 100Mo(p,2n)99mTc reaction using medical cyclotrons has been investigated. However, due to the existence of other Molybdenum (Mo) isotopes in the target, in parallel with 99mTc, other technetium (Tc) radioactive isotopes (impurities) will be produced. They will be incorporated into the labeled radiopharmaceuticals and result in increased patient dose. The isotopic composition of the target and beam energy are main factors that determine production of impurities, thus also dose increases. Therefore, they both must be considered when selecting targets for clinical 99mTc production. Although for any given Mo target, the patient dose can be predicted based on complicated calculations of production yields for each Tc radioisotope, it would be very difficult to reverse these calculations to specify target composition based on dosimetry considerations. In this article, a relationship between patient dosimetry and Mo target composition is studied. A simple and easy algorithm for dose estimation, based solely on the knowledge of target composition and beam energy, is described. Using this algorithm, the patient dose increase due to every Mo isotope that could be present in the target is estimated. Most importantly, a technique to determine Mo target composition thresholds that would meet any given dosimetry requirement is proposed.

  11. Nano-Scale Fission Product Phases in an Irradiated U-7Mo Alloy Nuclear Fuel

    SciTech Connect

    Dennis Keiser, Jr.; Brandon Miller; James Madden; Jan-Fong Jue; Jian Gan

    2014-09-01

    Irradiated nuclear fuel is a very difficult material to characterize. Due to the large radiation fields associated with these materials, they are hard to handle and typically have to be contained in large hot cells. Even the equipment used for performing characterization is housed in hot cells or shielded glove boxes. The result is not only a limitation in the techniques that can be employed for characterization, but also a limitation in the size of features that can be resolved The most standard characterization techniques include light optical metallography (WM), scanning electron microscopy (SEM), and electron probe microanalysis (EPMA). These techniques are applied to samples that are typically prepared using grinding and polishing approaches that will always generate some mechanical damage on the sample surface. As a result, when performing SEM analysis, for example, the analysis is limited by the quality of the sample surface that can be prepared. However, a new approach for characterizing irradiated nuclear fuel has recently been developed at the Idaho National Laboratory (INL) in Idaho Falls, Idaho. It allows for a dramatic improvement in the quality of characterization that can be performed when using an instrument like an SEM. This new approach uses a dual-beam scanning microscope, where one of the beams isa focused ion beam (FIB), which can be used to generate specimens of irradiated fuel (-10µm x 10µm) for microstructural characterization, and the other beam is the electron beam of an SEM. One significant benefit of this approach is that the specimen surface being characterized has received much less damage (and smearing) than is caused by the more traditional approaches, which enables the imaging of nanometer­ sized microstructural features in the SEM. The process details are for an irradiated low-enriched uranium (LEU) U-Mo alloy fuel Another type of irradiated fuel that has been characterized using this technique is a mixed oxide fuel.

  12. Methods for chemical recovery of non-carrier-added radioactive tin from irradiated intermetallic Ti-Sb targets

    DOEpatents

    Lapshina, Elena V [Troitsk, RU; Zhuikov, Boris L [Troitsk, RU; Srivastava, Suresh C [Setauket, NY; Ermolaev, Stanislav V [Obninsk, RU; Togaeva, Natalia R [Obninsk, RU

    2012-01-17

    The invention provides a method of chemical recovery of no-carrier-added radioactive tin (NCA radiotin) from intermetallide TiSb irradiated with accelerated charged particles. An irradiated sample of TiSb can be dissolved in acidic solutions. Antimony can be removed from the solution by extraction with dibutyl ether. Titanium in the form of peroxide can be separated from tin using chromatography on strong anion-exchange resin. In another embodiment NCA radiotin can be separated from iodide solution containing titanium by extraction with benzene, toluene or chloroform. NCA radiotin can be finally purified from the remaining antimony and other impurities using chromatography on silica gel. 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.

  13. Method for fabricating .sup.99 Mo production targets using low enriched uranium, .sup.99 Mo production targets comprising low enriched uranium

    DOEpatents

    Wiencek, Thomas C.; Matos, James E.; Hofman, Gerard L.

    2000-12-12

    A radioisotope production target and a method for fabricating a radioisotope production target is provided, wherein the target comprises an inner cylinder, a foil of fissionable material circumferentially contacting the outer surface of the inner cylinder, and an outer hollow cylinder adapted to receive the substantially foil-covered inner cylinder and compress tightly against the foil to provide good mechanical contact therewith. The method for fabricating a primary target for the production of fission products comprises preparing a first substrate to receive a foil of fissionable material so as to allow for later removal of the foil from the first substrate, preparing a second substrate to receive the foil so as to allow for later removal of the foil from the second substrate; attaching the first substrate to the second substrate such that the foil is sandwiched between the first substrate and second substrate to prevent foil exposure to ambient atmosphere, and compressing the exposed surfaces of the first and second substrate to assure snug mechanical contact between the foil, the first substrate and the second substrate.

  14. Method for fabricating {sup 99}Mo production targets using low enriched uranium, {sup 99}Mo production targets comprising low enriched uranium

    DOEpatents

    Wiencek, T.C.; Matos, J.E.; Hofman, G.L.

    1997-03-25

    A radioisotope production target and a method for fabricating a radioisotope production target is provided, wherein the target comprises an inner cylinder, a foil of fissionable material circumferentially contacting the outer surface of the inner cylinder, and an outer hollow cylinder adapted to receive the substantially foil-covered inner cylinder and compress tightly against the foil to provide good mechanical contact therewith. The method for fabricating a primary target for the production of fission products comprises preparing a first substrate to receive a foil of fissionable material so as to allow for later removal of the foil from the first substrate, preparing a second substrate to receive the foil so as to allow for later removal of the foil from the second substrate; attaching the first substrate to the second substrate such that the foil is sandwiched between the first substrate and second substrate to prevent foil exposure to ambient atmosphere, and compressing the exposed surfaces of the first and second substrate to assure snug mechanical contact between the foil, the first substrate and the second substrate. 3 figs.

  15. Method for fabricating .sup.99 Mo production targets using low enriched uranium, .sup.99 Mo production targets comprising low enriched uranium

    DOEpatents

    Wiencek, Thomas C.; Matos, James E.; Hofman, Gerard L.

    1997-01-01

    A radioisotope production target and a method for fabricating a radioisotope production target is provided, wherein the target comprises an inner cylinder, a foil of fissionable material circumferentially contacting the outer surface of the inner cylinder, and an outer hollow cylinder adapted to receive the substantially foil-covered inner cylinder and compress tightly against the foil to provide good mechanical contact therewith. The method for fabricating a primary target for the production of fission products comprises preparing a first substrate to receive a foil of fissionable material so as to allow for later removal of the foil from the first substrate, preparing a second substrate to receive the foil so as to allow for later removal of the foil from the second substrate; attaching the first substrate to the second substrate such that the foil is sandwiched between the first substrate and second substrate to prevent foil exposure to ambient atmosphere, and compressing the exposed surfaces of the first and second substrate to assure snug mechanical contact between the foil, the first substrate and the second substrate.

  16. Reduction of time-averaged irradiation speckle nonuniformity in laser-driven plasmas due to target ablation

    NASA Astrophysics Data System (ADS)

    Epstein, R.

    1997-09-01

    In inertial confinement fusion (ICF) experiments, irradiation uniformity is improved by passing laser beams through distributed phase plates (DPPs), which produce focused intensity profiles with well-controlled, reproducible envelopes modulated by fine random speckle. [C. B. Burckhardt, Appl. Opt. 9, 695 (1970); Y. Kato and K. Mima, Appl. Phys. B 29, 186 (1982); Y. Kato et al., Phys. Rev. Lett. 53, 1057 (1984); Laboratory for Laser Energetics LLE Review 33, NTIS Document No. DOE/DP/40200-65, 1987 (unpublished), p. 1; Laboratory for Laser Energetics LLE Review 63, NTIS Document No. DOE/SF/19460-91, 1995 (unpublished), p. 1.] A uniformly ablating plasma atmosphere acts to reduce the contribution of the speckle to the time-averaged irradiation nonuniformity by causing the intensity distribution to move relative to the absorption layer of the plasma. This occurs most directly as the absorption layer in the plasma moves with the ablation-driven flow, but it is shown that the effect of the accumulating ablated plasma on the phase of the laser light also makes a quantitatively significant contribution. Analytical results are obtained using the paraxial approximation applied to the beam propagation, and a simple statistical model is assumed for the properties of DPPs. The reduction in the time-averaged spatial spectrum of the speckle due to these effects is shown to be quantitatively significant within time intervals characteristic of atmospheric hydrodynamics under typical ICF irradiation intensities.

  17. Using CAD software to simulate PV energy yield - The case of product integrated photovoltaic operated under indoor solar irradiation

    SciTech Connect

    Reich, N.H.; van Sark, W.G.J.H.M.; Turkenburg, W.C.; Sinke, W.C.

    2010-08-15

    In this paper, we show that photovoltaic (PV) energy yields can be simulated using standard rendering and ray-tracing features of Computer Aided Design (CAD) software. To this end, three-dimensional (3-D) sceneries are ray-traced in CAD. The PV power output is then modeled by translating irradiance intensity data of rendered images back into numerical data. To ensure accurate results, the solar irradiation data used as input is compared to numerical data obtained from rendered images, showing excellent agreement. As expected, also ray-tracing precision in the CAD software proves to be very high. To demonstrate PV energy yield simulations using this innovative concept, solar radiation time course data of a few days was modeled in 3-D to simulate distributions of irradiance incident on flat, single- and double-bend shapes and a PV powered computer mouse located on a window sill. Comparisons of measured to simulated PV output of the mouse show that also in practice, simulation accuracies can be very high. Theoretically, this concept has great potential, as it can be adapted to suit a wide range of solar energy applications, such as sun-tracking and concentrator systems, Building Integrated PV (BIPV) or Product Integrated PV (PIPV). However, graphical user interfaces of 'CAD-PV' software tools are not yet available. (author)

  18. Radiolysis products and sensory properties of electron-beam-irradiated high-barrier food-packaging films containing a buried layer of recycled low-density polyethylene.

    PubMed

    Chytiri, S D; Badeka, A V; Riganakos, K A; Kontominas, M G

    2010-04-01

    The aim was to study the effect of electron-beam irradiation on the production of radiolysis products and sensory changes in experimental high-barrier packaging films composed of polyamide (PA), ethylene-vinyl alcohol (EVOH) and low-density polyethylene (LDPE). Films contained a middle buried layer of recycled LDPE, while films containing 100% virgin LDPE as the middle buried layer were taken as controls. Irradiation doses ranged between zero and 60 kGy. Generally, a large number of radiolysis products were produced during electron-beam irradiation, even at the lower absorbed doses of 5 and 10 kGy (approved doses for food 'cold pasteurization'). The quantity of radiolysis products increased with irradiation dose. There were no significant differences in radiolysis products identified between samples containing a recycled layer of LDPE and those containing virgin LDPE (all absorbed doses), indicating the 'functional barrier' properties of external virgin polymer layers. Sensory properties (mainly taste) of potable water were affected after contact with irradiated as low as 5 kGy packaging films. This effect increased with increasing irradiation dose.

  19. Thermal performance of batch boiling water targets for 18F production.

    PubMed

    Peeples, Johanna L; Stokely, Matthew H; Michael Doster, J

    2011-10-01

    Batch boiling targets are commonly used in cyclotrons to produce Fluorine-18 by proton bombardment of Oxygen-18 enriched water. Computational models have been developed to predict the thermal performance of bottom-pressurized batch boiling production targets. The models have been validated with experimental test data from the Duke University Medical Cyclotron and the Wisconsin Medical Cyclotron. Good agreement has been observed between experimental measurements and model predictions of average target vapor fraction as a function of beam current and energy.

  20. NCI Requests Targets for Monoclonal Antibody Production and Characterization - Office of Cancer Clinical Proteomics Research

    Cancer.gov

    In an effort to provide well-characterized monoclonal antibodies to the scientific community, NCI's Antibody Characterization Program requests cancer-related protein targets for affinity production and distribution.

  1. Fuel pins with both target and fuel pellets in an isotope-production reactor

    DOEpatents

    Cawley, W.E.; Omberg, R.P.

    1982-08-19

    A method is described for producing tritium in a fast breeder reactor cooled with liquid metal. Lithium target pellets are placed in close contact with fissile fuel pellets in order to increase the tritium production rate.

  2. Assemblies with both target and fuel pins in an isotope-production reactor

    DOEpatents

    Cawley, W.E.; Omberg, R.P.

    1982-08-19

    A method is described for producing tritium in a fast breeder reactor cooled with liquid metal. Lithium target material is placed in pins adjacent to fuel pins in order to increase the tritium production rate.

  3. Comparison of γ-irradiation with other pretreatments followed with simultaneous saccharification and fermentation on bioconversion of microcrystalline cellulose for bioethanol production.

    PubMed

    Liu, Yun; Zhou, Hua; Wang, Shihui; Wang, Keqin; Su, Xiaojun

    2015-04-01

    The effect of γ-irradiation pretreatment was compared with other pretreatment methods including ionic liquids (ILs), 1% HCl, 1% H2SO4, acidic aqueous Ils (AA-ILs), on the bioconversion efficiency of microcrystalline cellulose (MCC) for bioethanol production. The efficiency of MCC pretreatment followed with simultaneous saccharification and fermentation (SSF) was firstly evaluated according to the variations of the irradiation-derived compounds and structure of MCC, as well as yeast growth curve and bioethanol yield. Results showed that the appropriate irradiation dose (891 kGy used in our work) could eliminate the negative effect of toxic irradiation-derived compounds on SSF for ethanol bioconversion with the yield value of 67%. Analyses of SEM, FT-IR, reducing sugar and bioethanol yield showed that the efficiency of pretreatment on MCC was ILs ≈ irradiation pretreatment > AA-ILs pretreatment > 1% HCl pretreatment > 1% H2SO4 pretreatment.

  4. Androgens Attenuate Vitamin D Production Induced by UVB Irradiation of the Skin of Male Mice by an Enzymatic Mechanism.

    PubMed

    Xue, Yingben; Ying, Lee; Horst, Ronald L; Watson, Gordon; Goltzman, David

    2015-12-01

    Cutaneous exposure to UVB irradiation is an important source of vitamin D. Here, we examined sex-specific differences in cutaneous vitamin D production in mice. Both male and female mice on a vitamin D-deficient diet manifested vitamin D deficiency, with mineral abnormalities, secondary hyperparathyroidism, and osteomalacia. UVB irradiation significantly increased vitamin D levels in the skin of female mice and normalized serum 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 levels, as well as mineral and skeletal abnormalities. However, in male mice, the vitamin D response to UVB was attenuated and mineral and skeletal abnormalities were not normalized. The vitamin D precursor, 7-dehydrocholesterol (7DHC), was significantly lower in the skin of male than female mice. This reduction was due to local androgen action in the skin as demonstrated by castration studies and skin-specific androgen receptor deletion in male mice, both of which reversed the male phenotype. Local androgen regulation in the skin of the CYP11A1 gene, which encodes a crucial enzyme that metabolizes cholesterol, 7DHC, and vitamin D, appeared to contribute to the gender differences in UVB-induced vitamin D production and to its reversal of vitamin D deficiency. Sex-specific, enzymatically regulated differences in cutaneous production of vitamin D may therefore be of importance to ensure vitamin D sufficiency.

  5. Estimating Oceanic Primary Production Using Vertical Irradiance and Chlorophyll Profiles from Ocean Gliders in the North Atlantic.

    PubMed

    Hemsley, Victoria S; Smyth, Timothy J; Martin, Adrian P; Frajka-Williams, Eleanor; Thompson, Andrew F; Damerell, Gillian; Painter, Stuart C

    2015-10-06

    An autonomous underwater vehicle (Seaglider) has been used to estimate marine primary production (PP) using a combination of irradiance and fluorescence vertical profiles. This method provides estimates for depth-resolved and temporally evolving PP on fine spatial scales in the absence of ship-based calibrations. We describe techniques to correct for known issues associated with long autonomous deployments such as sensor calibration drift and fluorescence quenching. Comparisons were made between the Seaglider, stable isotope ((13)C), and satellite estimates of PP. The Seaglider-based PP estimates were comparable to both satellite estimates and stable isotope measurements.

  6. Potentiating antilymphoma efficacy of chemotherapy using a liposome for integration of CD20 targeting, ultra-violet irradiation polymerizing, and controlled drug delivery

    NASA Astrophysics Data System (ADS)

    Wu, Cong; Li, Huafei; Zhao, He; Zhang, Weiwei; Chen, Yan; Yue, Zhanyi; Lu, Qiong; Wan, Yuxiang; Tian, Xiaoyu; Deng, Anmei

    2014-08-01

    Unlike most malignancies, chemotherapy but not surgery plays the most important role in treating non-Hodgkin lymphoma (NHL). Currently, liposomes have been widely used to encapsulate chemotherapeutic drugs in treating solid tumors. However, higher in vivo stability owns a much more important position for excellent antitumor efficacy in treating hematological malignancies. In this study, we finely fabricated a rituximab Fab fragment-decorated liposome based on 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine (DC8,9PC), which can form intermolecular cross-linking through the diacetylenic group by ultra-violet (UV) irradiation. Our experimental results demonstrated that after the UV irradiation, the liposomes exhibit better serum stability and slower drug release with a decreased mean diameter of approximately 285 nm. The cellular uptake of adriamycin (ADR) by this Fab-navigated liposome was about four times of free drugs. Cytotoxicity assays against CD20+ lymphoma cells showed that the half maximal (50%) inhibitory concentration (IC50) of ADR-loaded immunoliposome was only one fourth of free ADR at the same condition. In vivo studies were evaluated in lymphoma-bearing SCID mice. With the high serum stability, finely regulated structure, active targeting strategy via antigen-antibody reaction and passive targeting strategy via enhanced permeability and retention (EPR) effect, our liposome exhibits durable and potent antitumor activities both in the disseminated and localized human NHL xeno-transplant models.

  7. FST-technologies for high rep-rate production of HiPER scale cryogenic targets

    NASA Astrophysics Data System (ADS)

    Aleksandrova, I. V.; Belolipetskiy, A. A.; Kalabuhov, V. A.; Koresheva, E. R.; Koshelev, E. L.; Kutergin, A. I.; Nikitenko, A. I.; Osipov, I. E.; Panina, L. V.; Safronov, A. I.; Timasheva, T. P.; Timofeev, I. D.; Usachev, G. S.; Chtcherbakov, V. I.; Tolley, M.; Edwards, C.; Spindloe, C.

    2011-06-01

    The target factory of an Inertial Fusion Energy (IFE) power plant (or reactor) must supply the targets with a rate of 1-10 Hz including their injection and transport through the chamber. HiPER is a proposed European High Power laser Energy Research facility dedicated to demonstrate the feasibility of laser driven fusion for IFE reactor. The work of HiPER facility requires formation & delivery of cryogenic free-standing targets with a rate of more than 1 Hz. To meet these requirements, an approach to fuel layering based on conduction cooling of a batch of moving spherical targets has been developed at the Lebedev Physical Institute (LPI). The approach demands to use free-standing targets in each production step: fuel filling, fuel layering, target characterization and injection. In this report, the expert results on the development of a specialized layering module prototype for a high reprate FST formation of HiPER cryogenic targets are presented.

  8. Computational simulation of (nat)UO2, (232)ThO2 and U3O8-Al pills to estimate (p,fission) (99)Mo yield in the modeled targets irradiated by CYCLONE30 accelerator.

    PubMed

    Jozvaziri, Atieh; Gholamzadeh, Zohreh; Yousefi, Kamran; Mirvakili, Seyed Mohammad; Alizadeh, Masoomeh; Aboudzadeh, Mohammadreza

    2017-03-01

    (99)Mo is important for both therapy and imaging purposes. Accelerator and reactor-based procedures are applied to produce it. Newly proton-fission method has been taken in attention by some research centers. In the present work, computationally investigation of the (99)Mo yield in different fissionable targets irradiated by proton was aimed. The results showed UO2 pill target could be efficiently used to produce 11.12Ci/g-U saturation yield of (99)Mo using 25MeV proton irradiation of the optimized-dimension target with 70µA current.

  9. Preliminary Mark-18A (Mk-18A) Target Material Recovery Program Product Acceptance Criteria

    SciTech Connect

    Robinson, Sharon M.; Patton, Bradley D.

    2016-09-01

    The Mk-18A Target Material Recovery Program (MTMRP) was established in 2015 to preserve the unique materials, e.g. 244Pu, in 65 previously irradiated Mk-18A targets for future use. This program utilizes existing capabilities at SRS and Savannah River National Laboratory (SRNL) to process targets, recover materials from them, and to package the recovered materials for shipping to ORNL. It also utilizes existing capabilities at ORNL to receive and store the recovered materials, and to provide any additional processing of the recovered materials or residuals required to prepare them for future beneficial use. The MTMRP is presently preparing for the processing of these valuable targets which is expected to begin in ~2019. As part of the preparations for operations, this report documents the preliminary acceptance criteria for the plutonium and heavy curium materials to be recovered from the Mk-18A targets at SRNL for transport and storage at ORNL. These acceptance criteria were developed based on preliminary concepts developed for processing, transporting, and storing the recovered Mk-18A materials. They will need to be refined as these concepts are developed in more detail.

  10. Rotating target wheel system for super-heavy element production at ATLAS

    NASA Astrophysics Data System (ADS)

    Greene, John P.; Heinz, Andreas; Falout, Joe; Janssens, Robert V. F.

    2004-03-01

    A new scattering chamber housing a large diameter rotating target wheel has been designed and constructed in front of the Fragment Mass Analyzer (FMA) for the production of very heavy nuclei ( Z>100) using beams from the Argonne Tandem Linear Accelerator System (ATLAS). In addition to the target and drive system, the chamber is extensively instrumented in order to monitor target performance and deterioration. Capabilities also exist to install rotating entrance and exit windows for gas cooling of the target within the scattering chamber. The design and initial tests are described.

  11. Design and testing of thermosyphon batch targets for production of fluorine-18

    NASA Astrophysics Data System (ADS)

    Peeples, Johanna Louise

    18F is a short-lived radioisotope commonly used in Positron Emission Tomography (PET). This radionuclide is typically produced through the 18O(p,n)18 F reaction by proton bombardment of 18O-enriched water. Thermosyphon batch targets have been proposed as a means to increase 18F production due to their enhanced heat rejection capabilities. These boiling targets have been operated with up to 3.2 kW of beam power with manageable 18O enriched water volumes. The primary purpose of this work has been to develop a fundamental approach to target design from a modeling perspective, and to implement this approach to design new thermosyphon targets with enhanced production capabilities. Computational methods have been developed to predict target thermal performance and have been validated with experimental test data from the Duke University Medical Cyclotron and the Wisconsin Medical Cyclotron. These methods have been used to design a new production target for the Duke cyclotron with enhanced 18F production capabilities. Low volume test targets have been successfully operated at the Wisconsin cyclotron with beam powers in excess of the desired 1.6 kW.

  12. Mechanism of pain relief by low-power infrared irradiation: ATP is an IR-target molecule in nociceptive neurons.

    PubMed

    Yachnev, Igor L; Plakhova, Vera B; Podzorova, Svetlana A; Shelykh, Tatiana N; Rogachevsky, Ilya V; Krylov, Boris V

    2012-01-01

    Effects of infrared (IR) radiation generated by a low-power CO2-laser on the membrane of cultured dissociated nociceptive neurons of newborn rat spinal ganglia were investigated using the whole-cell patch-clamp method. Low-power IR radiation diminished the voltage sensitivity of activation gating machinery of slow sodium channels (Na(v)1.8). Ouabain known to block both transducer and pumping functions of Na+,K+-ATPase eliminated IR irradiation effects. The molecular mechanism of interaction of CO2-laser radiation with sensory membrane was proposed. The primary event of this interaction is the process of energy absorption by ATP molecules. The transfer of vibrational energy from Na+,K+- ATPase-bound and vibrationally excited ATP molecules to Na+,K+-ATPase activates this enzyme and converts it into a signal transducer. This effect leads to a decrease in the voltage sensitivity of Na(v)1.8 channels. The effect of IR-radiation was elucidated by the combined application of a very sensitive patch-clamp method and an optical facility with a controlled CO2-laser. As a result, the mechanism of interaction of non-thermal low-power IR radiation with the nociceptive neuron membrane is suggested.

  13. A Simple Model to Quantify Radiolytic Production following Electron Emission from Heavy-Atom Nanoparticles Irradiated in Liquid Suspensions.

    PubMed

    Wardlow, Nathan; Polin, Chris; Villagomez-Bernabe, Balder; Currell, Fred

    2015-11-01

    We present a simple model for a component of the radiolytic production of any chemical species due to electron emission from irradiated nanoparticles (NPs) in a liquid environment, provided the expression for the G value for product formation is known and is reasonably well characterized by a linear dependence on beam energy. This model takes nanoparticle size, composition, density and a number of other readily available parameters (such as X-ray and electron attenuation data) as inputs and therefore allows for the ready determination of this contribution. Several approximations are used, thus this model provides an upper limit to the yield of chemical species due to electron emission, rather than a distinct value, and this upper limit is compared with experimental results. After the general model is developed we provide details of its application to the generation of HO• through irradiation of gold nanoparticles (AuNPs), a potentially important process in nanoparticle-based enhancement of radiotherapy. This model has been constructed with the intention of making it accessible to other researchers who wish to estimate chemical yields through this process, and is shown to be applicable to NPs of single elements and mixtures. The model can be applied without the need to develop additional skills (such as using a Monte Carlo toolkit), providing a fast and straightforward method of estimating chemical yields. A simple framework for determining the HO• yield for different NP sizes at constant NP concentration and initial photon energy is also presented.

  14. Photodegradation kinetics of iopamidol by UV irradiation and enhanced formation of iodinated disinfection by-products in sequential oxidation processes.

    PubMed

    Tian, Fu-Xiang; Xu, Bin; Lin, Yi-Li; Hu, Chen-Yan; Zhang, Tian-Yang; Gao, Nai-Yun

    2014-07-01

    The photochemical degradation of iopamidol with low-pressure UV lamps and the formation of iodinated disinfection by-products (I-DBPs) during sequential oxidation processes including chlorine, monochloramine and chlorine dioxide were investigated in this study. Iopamidol can be effectively decomposed by UV irradiation with pseudo-first order reaction kinetics. The evaluated quantum yield was found to be 0.03318 mol einstein(-1). Results showed that iopamidol degradation rate was significantly increased by higher UV intensity and lower initial iopamidol concentration. However, the effect of solution pH was negligible. Degradation of iopamidol by UV photolysis was subjected to deiodination and hydroxylation mechanisms. The main degradation products including -OH substitutes and iodide were identified by UPLC-ESI-MS and UPLC-UV, respectively. Increasing the intensity of UV irradiation promoted the release of iodide. Destruction pathways of iopamidol photolysis were proposed. Enhanced formation of I-DBPs were observed after iopamidol photolysis followed by disinfection processes including chlorine, monochloramine and chlorine dioxide. With the increase of UV fluence, I-DBPs formation were significantly promoted.

  15. UV microbeam irradiations of the mitotic spindle. II. Spindle fiber dynamics and force production

    SciTech Connect

    Spurck, T.P.; Stonington, O.G.; Snyder, J.A.; Pickett-Heaps, J.D.; Bajer, A.; Mole-Bajer, J. )

    1990-10-01

    Metaphase and anaphase spindles in cultured newt and PtK1 cells were irradiated with a UV microbeam (285 nM), creating areas of reduced birefringence (ARBs) in 3 s that selectively either severed a few fibers or cut across the half spindle. In either case, the birefringence at the polewards edge of the ARB rapidly faded polewards, while it remained fairly constant at the other, kinetochore edge. Shorter astral fibers, however, remained present in the enlarged ARB; presumably these had not been cut by the irradiation. After this enlargement of the ARB, metaphase spindles recovered rapidly as the detached pole moved back towards the chromosomes, reestablishing spindle fibers as the ARB closed; this happened when the ARB cut a few fibers or across the entire half spindle. We never detected elongation of the cut kinetochore fibers. Rather, astral fibers growing from the pole appeared to bridge and then close the ARB, just before the movement of the pole toward the chromosomes. When a second irradiation was directed into the closing ARB, the polewards movement again stopped before it restarted. In all metaphase cells, once the pole had reestablished connection with the chromosomes, the unirradiated half spindle then also shortened to create a smaller symmetrical spindle capable of normal anaphase later. Anaphase cells did not recover this way; the severed pole remained detached but the chromosomes continued a modified form of movement, clumping into a telophase-like group. The results are discussed in terms of controls operating on spindle microtubule stability and mechanisms of mitotic force generation.

  16. Microwave irradiation of human brain tissue: production of microscopic slides within one day.

    PubMed Central

    Boon, M E; Marani, E; Adriolo, P J; Steffelaar, J W; Bots, G T; Kok, L P

    1988-01-01

    A three step method using microwave irradiation enabled microscopic slides of human brain tissue to be obtained within one working day: steps 1 and 2 hardened and solidified brain tissue; step 3 completed formalin fixation. The efficacy and precision of the method was compared with slides of conventionally processed brain tissue that had been fixed in formalin for six weeks. The microscopic quality of the sections was excellent with good presentation of brain tissue and equalled that of conventionally processed slides. Images Fig 1 Fig 2 Fig 3 PMID:3290268

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

    PubMed

    2008-08-22

    The Food and Drug Administration (FDA) is amending the food additive regulations to provide for the safe use of ionizing radiation for control of food-borne pathogens, and extension of shelf-life, in fresh iceberg lettuce and fresh spinach (hereinafter referred to in this document as "iceberg lettuce and spinach") at a dose up to 4.0 kilo Gray (kGy). This action is in partial response to a petition filed by The National Food Processors Association on behalf of The Food Irradiation Coalition.

  18. Production of organic molecules in the outer solar system by proton irradiation - Laboratory simulations

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

    Preliminary experiments to investigate the formation of colored polymers and other interesting molecules by the irradiation of gas mixtures with protons are discussed. As in previous experiments, colored polymers were produced. An important feature of the present work is the presence or absence of absorption at 5 microns in the different materials produced; Titan is quite dark at this wavelength and Io is fairly bright. Such features may provide criteria for accepting or rejecting various materials produced in these experiments as reasonable coloring agents for the outer solar system.

  19. Displacement rate dependence of irradiation creep as predicted by the production bias model

    SciTech Connect

    Woo, C.H.

    1996-04-01

    Recently, it has been shown that the non-swelling component of irradiation creep of austenitic stainless steels is relatively independent of temperature but is sensitive to the displacement rate. An earlier model of Lewthwaite and Mosedale anticipated the sensitivity of displacement rate and attributed it to the flux sensitivity of point defect recombination. The point-defect recombination process does not yield the observed temperature dependence, however, although it does predict an inverse dependence of the creep rate on the square root of the displacement rate that was experimentally observed at relatively low temperatures.

  20. Régulation de la production, par des cellules endothéliales, de cytokines pro-inflammatoires après irradiation

    NASA Astrophysics Data System (ADS)

    van der Meeren, A.; Lafont, H.; Mathé, D.

    1998-04-01

    Gamma irradiation leads to an increased production of interleukin- (IL)-6 and IL-8 by human endothelial cells. In order to regulate the radio-induced production of these pro-inflammatory cytokines, we used the immunoregulatory cytokines IL-4 and IL-10. These agents were added either before or after a 10 Gy-irradiation. Our results show that it is possible to decrease the radio-induced production of IL-6 and IL-8 with the use of IL-4 and IL-10. Differences in the intensity of the response have been observed according to the time of treatment. The anti-inflammatory potential of both IL-4 and IL-10 was more pronounced when added after irradiation. Après irradiation gamma, des cellules endothéliales humaines ont une production accrue des interleukines (IL-) -6 et -8. Dans le but de réguler la production de ces cytokines pro-inflammatoires, nous avons utilisé des cytokines dites anti-inflammatoires, l'IL-4 et l'IL-10. Ces agents ont été ajoutés soit avant soit après une irradiation de 10Gy. Nos résultats montrent qu'il est possible de diminuer les productions radio-induites d'IL-6 et d'IL-8 par l'IL-4 et l'IL-10. Des différences dans l'intensité de la réponse ont toutefois été observées selon que l'IL-4 ou l'IL-10 ont été ajoutées avant ou après irradiation; leur efficacité anti-inflammatoire étant plus marquée lorsque les cytokines sont ajoutées après l'irradiation.

  1. Generation of plasma intrinsic oscillation at the front surface of a target irradiated by a circularly polarized laser pulse

    SciTech Connect

    Zhang Xiaomei; Shen Baifei; Jin Zhangying; Wang Fengchao; Ji Liangliang

    2009-03-15

    In laser-target interaction, the effects of laser intensity on plasma oscillation at the front surface of targets have been investigated by one-dimensional particle in cell simulations. The periodical oscillations of the ion density and electrostatic field at the front surface of the targets are reported for the first time, which is considered as an intrinsic property of the target excited by the laser. The oscillation period depends only on initial plasma density and is irrelevant with laser intensity. Flattop structures with curves in ion phase space are found with a more intense laser pulse due to the larger amplitude variation of the electrostatic field. A simple but valid model is proposed to interpret the curves.

  2. Cryogenic gas target system for intense RI beam productions in nuclear astrophysics

    NASA Astrophysics Data System (ADS)

    Wakabayashi, Y.; Yamaguchi, H.; Hayakawa, S.; Kurihara, Y.; Amadio, G.; Fujikawa, H.; Binh, D. N.; He, J. J.; Kim, A.; Kubono, S.

    2008-05-01

    A cryogenic gas target system was newly developed to produce intense RI beams at the low-energy in-flight radio-isotope beam separator (CRIB) of the University of Tokyo. The main features of the cryogenic gas target system are the direct cooling of the target cell by a liquid N2 finger and the circulation of the target gas that goes through the liquid N2 tank. Hydrogen gas was cooled down to 85-90 K by liquid nitrogen and used as a secondary beam production target which has a thickness of 2.3 mg/cm2 at the gas pressure of 760 Torr. Intense RI beams, such as a 7Be beam of 2×108 particles per second, were successfully produced using the target.

  3. Cryogenic gas target system for intense RI beam productions in nuclear astrophysics

    SciTech Connect

    Wakabayashi, Y.; Yamaguchi, H.; Hayakawa, S.; Kurihara, Y.; Amadio, G.; Fujikawa, H.; Kubono, S.; Binh, D. N.; He, J. J.; Kim, A.

    2008-05-21

    A cryogenic gas target system was newly developed to produce intense RI beams at the low-energy in-flight radio-isotope beam separator (CRIB) of the University of Tokyo. The main features of the cryogenic gas target system are the direct cooling of the target cell by a liquid N{sub 2} finger and the circulation of the target gas that goes through the liquid N{sub 2} tank. Hydrogen gas was cooled down to 85-90 K by liquid nitrogen and used as a secondary beam production target which has a thickness of 2.3 mg/cm{sup 2} at the gas pressure of 760 Torr. Intense RI beams, such as a {sup 7}Be beam of 2x10{sup 8} particles per second, were successfully produced using the target.

  4. Microbial short-chain fatty acid production and extracellular enzymes activities during in vitro fermentation of polysaccharides from the seeds of Plantago asiatica L. treated with microwave irradiation.

    PubMed

    Hu, Jie-Lun; Nie, Shao-Ping; Li, Chang; Fu, Zhi-Hong; Xie, Ming-Yong

    2013-06-26

    Effects of microwave irradiation on microbial short-chain fatty acid production and the activites of extracellular enzymes during in vitro fermentation of the polysaccharide from Plantago asiatica L. were investigated in this study. It was found that the apparent viscosity, average molecular weight, and particle size of the polysaccharide decreased after microwave irradiation. Reducing sugar amount increased with molecular weight decrease, suggesting the degradation may derive from glycosidic bond rupture. The polysaccharide surface topography was changed from large flakelike structure to smaller chips. FT-IR showed that microwave irradiation did not alter the primary functional groups in the polysaccharide. However, short-chain fatty acid productions of the polysaccharide during in vitro fermentation significantly increased after microwave irradiation. Activities of microbial extracellular enzymes xylanase, arabinofuranosidase, xylosidase, and glucuronidase in fermentation cultures supplemented with microwave irradiation treated polysaccharide were also generally higher than those of untreated polysaccharide. This showed that microwave irradiation could be a promising degradation method for the production of value-added polysaccharides.

  5. Effect of relative humidity and temperature on PVC degradation under gamma irradiation: Evolution of HCl production Yields

    NASA Astrophysics Data System (ADS)

    Labed, V.; Obeid, H.; Ressayre, K.

    2013-03-01

    The separate and combined effects of the relative humidity and temperature were investigated on the HCl production yields arising from two types of PVC subjected to gamma irradiation (pure PVC and PVC formulated with plasticizing additives). The test procedure developed included experiments performed at different dose rates (400 Gy h-1 and 4 kGy h-1), temperatures (room temperature and 70 °C) and relative humidity values (<10%, 70-75%, and 100%), for irradiation doses ranging from 0.1 to 4 MGy. These operating conditions are representative of applications in a nuclear environment. For the plasticized PVC at low dose rates, raising the temperature increases the HCl production by a factor of about 1.3, with either low or high relative humidity. For pure PVC, depending on the humidity and dose rate, G(HCl) varies differently with the temperature: at low humidity and low dose rates, G(HCl) increases by a factor of 1.7 for a 45 °C temperature increase; at high humidity, the same temperature increase does not result in a significant increase of G(HCl). The influence of the relative humidity on HCl production has not been clearly identified and interpreted. The relative humidity appears to be a factor limiting the effects of temperature on the formation of HCl from pure PVC at high dose rates. The G values remain constant and even diminish under some experimental conditions. For plasticized PVC, the relative humidity has no influence on the HCl production yields.

  6. Fragment Production and Survival in Irradiated Disks: A Comprehensive Cooling Criterion

    NASA Astrophysics Data System (ADS)

    Kratter, Kaitlin M.; Murray-Clay, Ruth A.

    2011-10-01

    Accretion disks that become gravitationally unstable can fragment into stellar or substellar companions. The formation and survival of these fragments depends on the precarious balance between self-gravity, internal pressure, tidal shearing, and rotation. Disk fragmentation depends on two key factors: (1) whether the disk can get to the fragmentation boundary of Q = 1 and (2) whether fragments can survive for many orbital periods. Previous work suggests that to reach Q = 1, and have fragments survive, a disk must cool on an orbital timescale. Here we show that disks heated primarily by external irradiation always satisfy the standard cooling time criterion. Thus, even though irradiation heats disks and makes them more stable in general, once they reach the fragmentation boundary, they fragment more easily. We derive a new cooling criterion that determines fragment survival and calculate a pressure-modified Hill radius, which sets the maximum size of pressure-supported objects in a Keplerian disk. We conclude that fragmentation in protostellar disks might occur at slightly smaller radii than previously thought and recommend tests for future simulations that will better predict the outcome of fragmentation in real disks.

  7. A ROTATING METAL BAND TARGET FOR PION PRODUCTION AT MUON COLLIDERS.

    SciTech Connect

    KING,B.J.; SIMOS,N.; WEGGEL,R.V.; MOKHOV,N.V.

    2002-01-18

    A conceptual design is presented for a high power pion production target for muon colliders that is based on a rotating metal band. Three candidate materials are considered for the target band: inconel alloy 718, titanium alloy 6Al-4V grade 5 and nickel. A pulsed proton beam tangentially intercepts a chord of the target band that is inside a 20 Tesla tapered solenoidal magnetic pion capture channel similar to designs previously considered for muon colliders and neutrino factories. The target band has a radius of 2.5 meters and is continuously rotated at approximately 1 m/s to carry heat away from the production region and through a water cooling tank. The mechanical layout and cooling setup of the target are described, including the procedure for the routine replacement of the target band. A rectangular band cross section is assumed, optionally with I-beam struts to enhance stiffness and minimize mechanical vibrations. Results are presented from realistic MARS Monte Carlo computer simulations of the pion yield and energy deposition in the target and from ANSYS finite element calculations for the corresponding shock heating stresses. The target scenario is found to perform satisfactorily and with conservative safety margins for multi-MW pulsed proton beams.

  8. Two-dimensional of uniform irradiation on target with the use of the concentricity deviation lens arrays focus system of variable focus length

    NASA Astrophysics Data System (ADS)

    Zheng, Jian-zhou; Yu, Qing-xu; Lu, Yong-jun; Guan, Shou-hua; Dong, Bin

    2012-10-01

    An optical system consisted of lens array with variable focus width has been proposed for providing uniform irradiation on targets in inertial confinement fusion. This system was composed of two lenses arrays and the aspheric lens. Based on the adaxial matrix optics and the generalized diffraction integral theory, the principle of controllable focus profile was analyzed and the optimum design of the system parameters were presented, respectively. The simulated results showed that two-dimensional uniform focusing of laser beams with controllable width in the range of several hundred microns to several millimeters can be achieved by choosing appropriate system parameters. The system converted a circular laser beam into a flat-top square focused spot, presenting the transformation of beamshape and the uniform distribution of the spatial intensity at the same time. Appropriate concentricity deviation of LA was made in the design of LA focus system, so that the diffraction patterns of different beamlets did not completely overlap and the large-scale intensity fluctuation reduced effectively, and a well-irradiated laser spot and great energy efficiency can be obtained in this scheme.

  9. Joint Experiments on X-ray/Particle Emission from Plasmas Produced by Laser Irradiating Nano Structured Targets

    NASA Astrophysics Data System (ADS)

    Hegazy, H.; Allam, S. H.; Chaurasia, S.; Dhareshwar, L.; El-Sherbini, Th. M.; Kunze, H.-J.; Mank, G.; McDaniel, D. H.; Rosinski, M.; Ryc, L.; Stewart, B.; Wolowski, J.; Abd El-Ghany, H.; Abd El-Latif, G.; Abd El-Rahim, F. M.; Bedrane, Z.; Diab, F.; Farrag, A.; Hedwig, R.; Helal, A.; Pardede, M.; Refaie, A.; Sharkawy, H.; El-khatim, A., Sir

    2008-04-01

    The 1st Joint (Host Laboratory) Experiment on laser plasma involving more than twenty scientists from eight countries has been carried out at the Laser and New Materials Laboratory, Faculty of Science, Cairo University, Egypt. It was co-ordinated by the International Atomic Energy Agency (IAEA) and supported through the IAEA and the ICTP (International Centre for Theoretical Physics, Trieste). The main experimental programme was aimed at characterising the possible enhancement of x-ray and particle emission from plasmas produced by laser incidence on nano-structured targets. Laser beams at 1.064 μm of 250 mJ and 532 nm of 165 mJ focused at the target surface using a nanosecond laser type Quantel were used in the present study. In the present experiments nano-copper structures evaporated onto copper bulk disks and nano-gold structures evaporated onto gold ones were used. The thickness of the nano-materials on their bulk material was 1 μm. An ion collector and x-ray semiconductor diode were used to study the ion and x-ray emission, respectively. Both were positioned at the same port at 90° with respect to the target surface and at 90 cm from the surface in the case of the ion collector and 55 cm in the case of the x-ray detector. These experiments were performed at vacuum pressures of (5—8)×10-6 mbar. Comparison of both studies in the case of nano structured targets and bulk targets were performed at different laser fluencies (1×109-1×1012 W/cm2) on the target. A 20% increase of the X-ray emission for nano gold with respect to bulk gold was observed, however, the x-ray emission in the of nano copper and copper was the same.

  10. Joint Experiments on X-ray/Particle Emission from Plasmas Produced by Laser Irradiating Nano Structured Targets

    SciTech Connect

    Hegazy, H.; Diab, F.; Allam, S. H.; El-Sherbini, Th. M.; Abd El-Latif, G.; Farrag, A.; Helal, A.; Refaie, A.; Sharkawy, H.; Chaurasia, S.; Dhareshwar, L.; Kunze, H.-J.; Mank, G.; McDaniel, D. H.; Rosinski, M.; Ryc, L.; Wolowski, J.; Stewart, B.; Abd El-Ghany, H.; Abd El-Rahim, F. M.

    2008-04-07

    The 1st Joint (Host Laboratory) Experiment on laser plasma involving more than twenty scientists from eight countries has been carried out at the Laser and New Materials Laboratory, Faculty of Science, Cairo University, Egypt. It was co-ordinated by the International Atomic Energy Agency (IAEA) and supported through the IAEA and the ICTP (International Centre for Theoretical Physics, Trieste). The main experimental programme was aimed at characterising the possible enhancement of x-ray and particle emission from plasmas produced by laser incidence on nano-structured targets. Laser beams at 1.064 {mu}m of 250 mJ and 532 nm of 165 mJ focused at the target surface using a nanosecond laser type Quantel were used in the present study. In the present experiments nano-copper structures evaporated onto copper bulk disks and nano-gold structures evaporated onto gold ones were used. The thickness of the nano-materials on their bulk material was 1 {mu}m. An ion collector and x-ray semiconductor diode were used to study the ion and x-ray emission, respectively. Both were positioned at the same port at 90 deg. with respect to the target surface and at 90 cm from the surface in the case of the ion collector and 55 cm in the case of the x-ray detector. These experiments were performed at vacuum pressures of (5--8)x10{sup -6} mbar. Comparison of both studies in the case of nano structured targets and bulk targets were performed at different laser fluencies (1x10{sup 9}-1x10{sup 12} W/cm{sup 2}) on the target. A 20% increase of the X-ray emission for nano gold with respect to bulk gold was observed, however, the x-ray emission in the of nano copper and copper was the same.

  11. [Margin determination from clinical to planning target volume for lung cancer treated with conformal or intensity-modulated irradiation].

    PubMed

    Berthelot, K; Thureau, S; Giraud, P

    2016-10-01

    Technological progress in radiotherapy enables more precision for treatment planning and delivery. The margin determination between the clinical target volume and the planning target volumes stem from the estimation of geometric uncertainties of the tumour localization into the radiation beam. The inner motion complexity of lung tumours has led to the use of 4D computed tomography and nurtures specific dosimetric concerns. Few strategies consisting in integrating tumour motion allow margin reduction regarding inner movements. The patient immobilization and onboard imagery improvement decrease the setup uncertainties. Each step between the initial planning imagery and treatment delivery has to be analysed as systematic or random errors to calculate the optimal planning margin.

  12. A TPD and AR based comparison of accelerator neutron irradiation fields between (7)Li and W targets for BNCT.

    PubMed

    Tanaka, Kenichi; Endo, Satoru; Yonai, Shunsuke; Baba, Mamoru; Hoshi, Masaharu

    2014-06-01

    The characteristics of moderator assembly dimension was investigated for the usage of (7)Li(p,n) neutrons by 2.3-2.8MeV protons and W(p,n) neutrons by 50MeV protons. The indexes were the treatable protocol depth (TPD) and advantage depth (AD). Consequently, a configuration for W target with the Fe filter, Fluental moderator, Pb reflector showed the TPD of 5.8cm and AD of 9.3cm. Comparable indexes were found for the Li target in a geometry with the MgF2 moderator and Teflon reflector.

  13. Method using laser irradiation for the production of atomically clean crystalline silicon and germanium surfaces

    DOEpatents

    Ownby, G.W.; White, C.W.; Zehner, D.M.

    1979-12-28

    This invention relates to a new method for removing surface impurities from crystalline silicon or germanium articles, such as off-the-shelf p- or n-type wafers to be doped for use as junction devices. The principal contaminants on such wafers are oxygen and carbon. The new method comprises laser-irradiating the contaminated surface in a non-reactive atmosphere, using one or more of Q-switched laser pulses whose parameters are selected to effect melting of the surface without substantial vaporization thereof. In a typical application, a plurality of pulses is used to convert a surface region of an off-the-shelf silicon wafer to an atomically clean region. This can be accomplished in a system at a pressure below 10-/sup 8/ Torr, using Q-switched ruber-laser pulses having an energy density in the range of from about 60 to 190 MW/cm/sup 2/.

  14. Method using laser irradiation for the production of atomically clean crystalline silicon and germanium surfaces

    DOEpatents

    Ownby, Gary W.; White, Clark W.; Zehner, David M.

    1981-01-01

    This invention relates to a new method for removing surface impurities from crystalline silicon or germanium articles, such as off-the-shelf p- or n-type wafers to be doped for use as junction devices. The principal contaminants on such wafers are oxygen and carbon. The new method comprises laser-irradiating the contaminated surface in a non-reactive atmosphere, using one or more of Q-switched laser pulses whose parameters are selected to effect melting of the surface without substantial vaporization thereof. In a typical application, a plurality of pulses is used to convert a surface region of an off-the-shelf silicon wafer to an automatically clean region. This can be accomplished in a system at a pressure below 10.sup.-8 Torr, using Q-switched ruby-laser pulses having an energy density in the range of from about 60 to 190 MW/cm.sup.2.

  15. Red clouds in reducing atmospheres. [polymer production by UV irradiation in planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Khare, B. N.; Sagan, C.

    1973-01-01

    A dark reddish-brown high-molecular weight polymer is produced by long wavelength ultraviolet irradiation of abundant gases in reducing planetary atmospheres. The polymer is examined by paper chromatography, mass spectrometry, and infrared, visible, and ultraviolet spectroscopy. High carbon-number straight-chain alkanes with NH2 and, probably, OH and C = O groups are identified, along with amino acids. There are chemical similarities between this polymer and organic compounds recovered from carbonaceous chondrites and precambrian sediments. The visible and near-ultraviolet transmission spectrum of the polymer shows its absorption optical depth to be redder than lambda(-2) and perhaps similar in coloration to the clouds of Jupiter, Saturn, and Titan. The nitrile content is small, and the polymer should be semitransparent in the 5 micrometer atmospheric window. Such polymers may be a common constituent of clouds in the outer solar system and on the early earth.

  16. Computational identification of gene over-expression targets for metabolic engineering of taxadiene production.

    PubMed

    Boghigian, Brett A; Armando, John; Salas, Daniel; Pfeifer, Blaine A

    2012-03-01

    Taxadiene is the first dedicated intermediate in the biosynthetic pathway of the anticancer compound Taxol. Recent studies have taken advantage of heterologous hosts to produce taxadiene and other isoprenoid compounds, and such ventures now offer research opportunities that take advantage of the engineering tools associated with the surrogate host. In this study, metabolic engineering was applied in the context of over-expression targets predicted to improve taxadiene production. Identified targets included genes both within and outside of the isoprenoid precursor pathway. These targets were then tested for experimental over-expression in a heterologous Escherichia coli host designed to support isoprenoid biosynthesis. Results confirmed the computationally predicted improvements and indicated a synergy between targets within the expected isoprenoid precursor pathway and those outside this pathway. The presented algorithm is broadly applicable to other host systems and/or product choices.

  17. Particle production and energy deposition studies for the neutrino factory target station

    NASA Astrophysics Data System (ADS)

    Back, John J.; Densham, Chris; Edgecock, Rob; Prior, Gersende

    2013-02-01

    We present FLUKA and MARS simulation studies of the pion production and energy deposition in the Neutrino Factory baseline target station, which consists of a 4 MW proton beam interacting with a liquid mercury jet target within a 20 T solenoidal magnetic field. We show that a substantial increase in the shielding is needed to protect the superconducting coils from too much energy deposition. Investigations reveal that it is possible to reduce the magnetic field in the solenoid capture system without adversely affecting the pion production efficiency. We show estimates of the amount of concrete shielding that will be required to protect the environment from the high radiation doses generated by the target station facility. We also present yield and energy deposition results for alternative targets: gallium liquid jet, tungsten powder jet, and solid tungsten bars.

  18. Ozone Production in Irradiated Laboratory Ices Relevant to Europa and Ganymede

    NASA Astrophysics Data System (ADS)

    Cooper, P. D.; Moore, M. H.; Hudson, R. L.

    2005-08-01

    Observations suggest ozone (O3) is present on the icy surfaces of Ganymede (1), and Rhea and Dione (2). Molecular oxygen (O2) has also been observed on Europa (3) and Ganymede (4). The formation and trapping of such molecules in ice and their subsequent transportation to a sub-surface ocean may be potentially important for sustaining astrobiological life (5). It is assumed that ozone is produced in these icy surfaces by the addition of an oxygen atom to molecular oxygen, with the latter formed by prior irradiation of the water ice. The infrared absorption band of ozone in ice at 1037 cm-1 is strong and thus makes ozone a good tracer for the presence of molecular oxygen which is difficult to detect. We will present results of water/oxygen ices irradiated with 800 keV protons and show the band position and growth of ozone with increasing radiation dose. The thermal stability of this radiolytically-produced ozone has also been measured and comparisons made to the Jovian satellites. P. Cooper is grateful for the support from the National Academies Research Associateship Program. (1) Noll, K.S., Johnson, R.E., Lane, A.L., Domingue, D.L., Weaver, H.A., Science, 273, 341-343, (1996). (2) Noll, K.S., Roush, T.L., Cruikshank, D.P., Johnson, R.E., Pendleton, Y.J., Nature, 388, 45-47, (1997). (3) Spencer, J.R., Calvin, W.M., Astron. J., 124, 3400-3403, (2002). (4) Spencer, J.R., Calvin, W.M., Person, M. J., J. Geo. Res. 100 (E9), 19049-19056 (1995). (5) Chyba, C.F., Hand, K.P., Science, 292, 2026-2027, (2001).

  19. The role of repair in the survival of mammalian cells from heavy ion irradiation - Approximation to the ideal case of target theory

    NASA Technical Reports Server (NTRS)

    Lett, J. T.; Cox, A. B.; Story, M. D.

    1989-01-01

    Experiments are discussed in which the cell-cycle dependency of the repair deficiency of the S/S variant of the L5178Y murine leukemic lymphoblast was examined by treatment with the heavy ions, Ne-20, Si-28, Ar-40, Fe-56, and Nb-93. Evidence from those studies provide support for the notion that as the linear energy transfer of the incident radiation increases the ability of the S/S cell to repair radiation damage decreases until it is eliminated around 500 keV/micron. In the region of the latter linear energy transfer value, the behavior of the S/S cell approximates the ideal case of target theory where post-irradiation metabolism does not influence cell survival.

  20. INSTRUMENTS AND METHODS OF INVESTIGATION: Generation of high-order harmonics of high-power lasers in plasmas produced under irradiation of solid target surfaces by a prepulse

    NASA Astrophysics Data System (ADS)

    Ganeev, Rashid A.

    2009-01-01

    Research on high-order harmonic generation in laser-produced plasmas is reviewed. We analyze the conditions for the generation of harmonics (up to the 101st order, λ = 7.9 nm) in the propagation of laser radiation through a weakly ionized plasma prepared by irradiating the surfaces of different targets with a laser prepulse. We discuss the findings of investigations into the resonance intensity enhancement of individual harmonics in a number of plasma formations, which have demonstrated a substantial increase in the conversion efficiency in the plateau region of the harmonic-order distribution (in particular, of the 13th harmonic in indium plasmas with the efficiency 10-4). We review the results of investigations of harmonic generation in nanoparticle-containing plasmas. Different techniques for increasing the intensity and order of the generated harmonics are discussed.

  1. Jasmonoyl-l-isoleucine is required for the production of a flavonoid phytoalexin but not diterpenoid phytoalexins in ultraviolet-irradiated rice leaves.

    PubMed

    Miyamoto, Koji; Enda, Isami; Okada, Toshiki; Sato, Yumiko; Watanabe, Kohei; Sakazawa, Tomoko; Yumoto, Emi; Shibata, Kyomi; Asahina, Masashi; Iino, Moritoshi; Yokota, Takao; Okada, Kazunori; Yamane, Hisakazu

    2016-10-01

    Rice produces low-molecular-weight antimicrobial compounds known as phytoalexins, in response to not only pathogen attack but also abiotic stresses including ultraviolet (UV) irradiation. Rice phytoalexins are composed of diterpenoids and a flavonoid. Recent studies have indicated that endogenous jasmonyl-l-isoleucine (JA-Ile) is not necessarily required for the production of diterpenoid phytoalexins in blast-infected or CuCl2-treated rice leaves. However, JA-Ile is required for the accumulation of the flavonoid phytoalexin, sakuranetin. Here, we investigated the roles of JA-Ile in UV-induced phytoalexin production. We showed that UV-irradiation induces the biosynthesis of JA-Ile and its precursor jasmonic acid. We also showed that rice jasmonate biosynthesis mutants produced diterpenoid phytoalexins but not sakuranetin in response to UV, indicating that JA-Ile is required for the production of sakuranetin but not diterpenoid phytoalexins in UV-irradiated rice leaves.

  2. Continuing investigations for technology assessment of /sup 99/Mo production from LEU (low enriched Uranium) targets

    SciTech Connect

    Vandergrift, G.F.; Kwok, J.D.; Marshall, S.L.; Vissers, D.R.; Matos, J.E.

    1987-01-01

    Currently much of the world's supply of /sup 99m/Tc for medical purposes is produced from /sup 99/Mo derived from the fissioning of high enriched uranium (HEU). The need for /sup 99m/Tc is continuing to grow, especially in developing countries, where needs and national priorities call for internal production of /sup 99/Mo. This paper presents the results of our continuing studies on the effects of substituting low enriched Uranium (LEU) for HEU in targets for the production of fission product /sup 99/Mo. Improvements in the electrodeposition of thin films of uranium metal are reported. These improvements continue to increase the appeal for the substitution of LEU metal for HEU oxide films in cylindrical targets. The process is effective for targets fabricated from stainless steel or hastaloy. A cost estimate for setting up the necessary equipment to electrodeposit uranium metal on cylindrical targets is reported. Further investigations on the effect of LEU substitution on processing of these targets are also reported. Substitution of uranium silicides for the uranium-aluminum alloy or uranium aluminide dispersed fuel used in other current target designs will allow the substitution of LEU for HEU in these targets with equivalent /sup 99/Mo-yield per target and no change in target geometries. However, this substitution will require modifications in current processing steps due to (1) the insolubility of uranium silicides in alkaline solutions and (2) the presence of significant quantities of silicate in solution. Results to date suggest that both concerns can be handled and that substitution of LEU for HEU can be achieved.

  3. Simultaneous Effect of Temperature and Irradiance on Growth and Okadaic Acid Production from the Marine Dinoflagellate Prorocentrum belizeanum

    PubMed Central

    López-Rosales, Lorenzo; Gallardo-Rodríguez, Juan Jose; Sánchez-Mirón, Asterio; Cerón-García, María del Carmen; Belarbi, El Hassan; García-Camacho, Francisco; Molina-Grima, Emilio

    2014-01-01

    Benthic marine dioflagellate microalgae belonging to the genus Prorocentrum are a major source of okadaic acid (OA), OA analogues and polyketides. However, dinoflagellates produce these valuable toxins and bioactives in tiny quantities, and they grow slowly compared to other commercially used microalgae. This hinders evaluation in possible large-scale applications. The careful selection of producer species is therefore crucial for success in a hypothetical scale-up of culture, as are appropriate environmental conditions for optimal growth. A clone of the marine toxic dinoflagellate P. belizeanum was studied in vitro to evaluate its capacities to grow and produce OA as an indicator of general polyketide toxin production under the simultaneous influence of temperature (T) and irradiance (I0). Three temperatures and four irradiance levels were tested (18, 25 and 28 °C; 20, 40, 80 and 120 µE·m−2·s−1), and the response variables measured were concentration of cells, maximum photochemical yield of photosystem II (PSII), pigments and OA. Experiments were conducted in T-flasks, since their parallelepipedal geometry proved ideal to ensure optically thin cultures, which are essential for reliable modeling of growth-irradiance curves. The net maximum specific growth rate (µm) was 0.204 day−1 at 25 °C and 40 µE·m−2·s−1. Photo-inhibition was observed at I0 > 40 μEm−2s−1, leading to culture death at 120 µE·m−2·s−1 and 28 °C. Cells at I0 ≥ 80 µE·m−2·s−1 were photoinhibited irrespective of the temperature assayed. A mechanistic model for µm-I0 curves and another empirical model for relating µm-T satisfactorily interpreted the growth kinetics obtained. ANOVA for responses of PSII maximum photochemical yield and pigment profile has demonstrated that P. belizeanum is extremely light sensitive. The pool of photoprotective pigments (diadinoxanthin and dinoxanthin) and peridinin was not able to regulate the excessive light-absorption at high I0

  4. Progress in chemical processing of LEU targets for {sup 99}Mo production -- 1997

    SciTech Connect

    Vandegrift, G.F.; Conner, C.; Sedlet, J.; Wygmans, D.G.; Wu, D.; Iskander, F.; Landsberger, S.

    1997-10-01

    Presented here are recent experimental results of the continuing development activities associated with converting current processes for producing fission-product {sup 99}Mo from targets using high-enriched uranium (HEU) to low-enriched uranium (LEU). Studies were focused in four areas: (1) measuring the chemical behavior of iodine, rhodium, and silver in the LEU-modified Cintichem process, (2) performing experiments and calculations to assess the suitability of zinc fission barriers for LEU metal foil targets, (3) developing an actinide separations method for measuring alpha contamination of the purified {sup 99}Mo product, and (4) developing a cooperation with Sandia National Laboratories and Los Alamos National Laboratory that will lead to approval by the US Federal Drug Administration for production of {sup 99}Mo from LEU targets. Experimental results continue to show the technical feasibility of converting current HEU processes to LEU.

  5. WE-EF-BRA-07: High Performance Preclinical Irradiation Through Optimized Dual Focal Spot Dose Painting and Online Virtual Isocenter Radiation Field Targeting

    SciTech Connect

    Stewart, J; Lindsay, P; Jaffray, D

    2015-06-15

    Purpose: Advances in radiotherapy practice facilitated by collimation systems to shape radiation fields and image guidance to target these conformal beams have motivated proposals for more complex dose patterns to improve the therapeutic ratio. Recent progress in small animal radiotherapy platforms has provided the foundation to validate the efficacy of such interventions, but robustly delivering heterogeneous dose distributions at the scale and accuracy demanded by preclinical studies remains challenging. This work proposes a dual focal spot optimization method to paint spatially heterogeneous dose regions and an online virtual isocenter targeting method to accurately target the dose distributions. Methods: Two-dimensional dose kernels were empirically measured for the 1 mm diameter circular collimator with radiochromic film in a solid water phantom for the small and large x-ray focal spots on the X-RAD 225Cx microirradiator. These kernels were used in an optimization framework which determined a set of animal stage positions, beam-on times, and focal spot settings to optimally deliver a given desired dose distribution. An online method was developed which defined a virtual treatment isocenter based on a single image projection of the collimated radiation field. The method was demonstrated by optimization of a 6 mm circular 2 Gy target adjoining a 4 mm semicircular avoidance region. Results: The dual focal spot technique improved the optimized dose distribution with the proportion of avoidance region receiving more than 0.5 Gy reduced by 40% compared to the large focal spot technique. Targeting tests performed by irradiating ball bearing targets on radiochromic film pieced revealed the online targeting method improved the three-dimensional accuracy from 0.48 mm to 0.15 mm. Conclusion: The dual focal spot optimization and online virtual isocenter targeting framework is a robust option for delivering dose at the preclinical level and provides a new experimental

  6. MiR-23a sensitizes nasopharyngeal carcinoma to irradiation by targeting IL-8/Stat3 pathway

    PubMed Central

    Jia-Quan, Qu; Hong-Mei, Yi; Xu, Ye; Li-Na, Li; Jin-Feng, Zhu; Ta, Xiao; Li, Yuan; Jiao-Yang, Li; Yuan-Yuan, Wang; Juan, Feng; Qiu-Yan, He; Shan-Shan, Lu; Hong, Yi; Zhi-Qiang, Xiao

    2015-01-01

    Radioresistance poses a major challenge in nasopharyngeal carcinoma (NPC) treatment, but little is known about how miRNA regulates this phenomenon. In this study, we investigated the function and mechanism of miR-23a in NPC radioresistance, one of downregulated miRNAs in the radioresistant NPC cells identified by our previous microarray analysis. We observed that miR-23a was frequently downregulated in the radioresistant NPC tissues, and its decrement correlated with NPC radioresistance and poor patient survival, and was an independent predictor for reduced patient survival. In vitro radioresponse assays showed that restoration of miR-23a expression markedly increased NPC cell radiosensitivity. In a mouse model, therapeutic administration of miR-23a agomir dramatically sensitized NPC xenografts to irradiation. Mechanistically, we found that reduced miR-23a promoted NPC cell radioresistance by activating IL-8/Stat3 signaling. Moreover, the levels of IL-8 and phospho-Stat3 were increased in the radioresistance NPC tissues, and negatively associated with miR-23a level. Our data demonstrate that miR-23a is a critical determinant of NPC radioresponse and prognostic predictor for NPC patients, and its decrement enhances NPC radioresistance through activating IL-8/Stat3 signaling, highlighting the therapeutic potential of miR-23a/IL-8/Stat3 signaling axis in NPC radiosensitization. PMID:26314966

  7. Photocatalytic hydrogen production of the CdS/TiO2-WO3 ternary hybrid under visible light irradiation.

    PubMed

    Chen, Yi-Lin; Lo, Shang-Lien; Chang, Hsiang-Ling; Yeh, Hsiao-Mei; Sun, Liping; Oiu, Chunsheng

    2016-01-01

    An attractive and effective method for converting solar energy into clean and renewable hydrogen energy is photocatalytic water splitting over semiconductors. The study aimed at utilizing organic sacrificial agents in water, modeled by formic acid, in combination with visible light driven photocatalysts to produce hydrogen with high efficiencies. The photocatalytic hydrogen production of cadmium sulfide (CdS)/titanate nanotubes (TNTs) binary hybrid with specific CdS content was investigated. After visible light irradiation for 3 h, the hydrogen production rate of 25 wt% CdS/TNT achieved 179.35 μmol·h(-1). Thanks to the two-step process, CdS/TNTs-WO3 ternary hybrid can better promote the efficiency of water splitting compared with CdS/TNTs binary hybrid. The hydrogen production of 25 wt% CdS/TNTs-WO3 achieved 212.68 μmol·h(-1), under the same condition. Coating of platinum metal onto the WO3 could further promote the reaction. Results showed that 0.2 g 0.1 wt% Pt/WO3 + 0.2 g 25 wt% CdS/TNTs had the best hydrogen production rate of 428.43 μmol·h(-1). The resultant materials were well characterized by high-resolution transmission electron microscope, X-ray diffraction, scanning electron microscopy, and UV-Vis spectra.

  8. Production of the higher actinides by cyclotron bombardment of thin targets, with reference to mendelevium

    SciTech Connect

    Mikheev, N.B.; Averman, L.N.; Kamenskaya, A.N.; Nouichenko, V.L.

    1986-07-01

    A new method has been developed for preparing a thin-layer target and isolating mendelevium from a collector, which makes it possible to obtain /sup 256/Md. The target is prepared by evaporating 0.1-0.2 ml of D2EHPA under vacuum at 100-120/sup 0/C, which contains 0.5 microg of einsteinium 253, an aluminum foil of thickness 4 microm being the receiver. The target is then heated in air at 400/sup 0/C, which fixes the einsteinium firmly on the foil. The einsteinium is irradiated with ..cap alpha.. particles of energy 28 MeV at a current density of 5 microA/cm/sup 2/. The recoil nuclei are collected on a thin zinc film (2-4 mg/cm/sup 2/) evaporated onto a tantalum disk. The collector is then processed in HCl (5-7 moles/liter) and the zinc is quantitatively separated on Dowex 1 x 10 anion exchanger.

  9. Multi-facet concentrator of solar setup for irradiating the objects placed in a target plane with solar light

    DOEpatents

    Lewandowski, Allan A.; Yampolskiy, Vladislav; Alekseev, Valerie; Son, Valentin

    2001-01-01

    According to the proposed invention, this technical result is achieved so that many-facet concentrator of a solar setup for exposure of objects, placed in a target plane, to the action of solar radiation containing a supporting frame and facets differing by that the facets of the concentrator are chosen with spherical focusing reflective surfaces of equal focal lengths and with selective coatings reflecting a desired spectral fraction of solar radiation, and are arranged on the supporting frame symmetrically with respect to the common axis of the concentrator, their optical axes being directed to the single point on the optical axis of the concentrator located before the nominal focus point of the concentrator and determining the position of arranging the target plane.

  10. Measurement of secondary particle production induced by particle therapy ion beams impinging on a PMMA target

    NASA Astrophysics Data System (ADS)

    Toppi, M.; Battistoni, G.; Bellini, F.; Collamati, F.; De Lucia, E.; Durante, M.; Faccini, R.; Frallicciardi, P. M.; Marafini, M.; Mattei, I.; Morganti, S.; Muraro, S.; Paramatti, R.; Patera, V.; Pinci, D.; Piersanti, L.; Rucinski, A.; Russomando, A.; Sarti, A.; Sciubba, A.; Senzacqua, M.; Solfaroli Camillocci, E.; Traini, G.; Voena, C.

    2016-05-01

    Particle therapy is a technique that uses accelerated charged ions for cancer treatment and combines a high irradiation precision with a high biological effectiveness in killing tumor cells [1]. Informations about the secondary particles emitted in the interaction of an ion beam with the patient during a treatment can be of great interest in order to monitor the dose deposition. For this purpose an experiment at the HIT (Heidelberg Ion-Beam Therapy Center) beam facility has been performed in order to measure fluxes and emission profiles of secondary particles produced in the interaction of therapeutic beams with a PMMA target. In this contribution some preliminary results about the emission profiles and the energy spectra of the detected secondaries will be presented.

  11. Experimental Study on Fast Electrons Transport in Ultra-intense Laser Irradiated Solid Targets by Transition Radiation

    NASA Astrophysics Data System (ADS)

    Zhijian, Zheng; Guangcan, Wang; Yuqiu, Gu

    2008-11-01

    The experiment was performed with SILEX laser facility(Ti-saphhire) at LFRC in China. The SILEX parameter: wavelength 0.8μm, duration 35fs, output power 280TW, contrast 5*105, The focal spot φ10μm(F/1.7), intensity on target surface 1*10^19W/cm^2(F/3). The main diagnostic equipments are the electron spectrometer, OMA spectrometer, optical streak camera. Some experimental results are given: The spectrum of optical emission from rear surface is rather narrow around some particular frequencies(1φ, 2φ, 3φ), We ascribe and confirm that the spike-like spectral line that is coherent transition radiation; The coherent light is also seen on time-integrated image with ring-patter due to Weibel instability of the fast electron transport; Obtained experimental cure of target thickness vs OTR image intensity is relative to mean free path of fast electron; The measuring optical transition radiation(OTR) duration of 171ps much longer than 1ps duration of fast electron transport target, the possible explanation is that the OTR duration to be determined magnetic diffusion time.

  12. High Resolution Monochromatic X-Ray Imaging of Targets Irradiated by the Nike KrF Laser

    NASA Astrophysics Data System (ADS)

    Aglitskiy, Y.; Lehecka, T.; Brown, C.; Seely, J.; Feldman, U.; Obenschain, S.; Bodner, S.; Pawley, C.; Gerber, K.; Sethian, J.; Holland, G.

    1996-11-01

    Planar CH foils were accelerated by the main Nike laser driving beams and were backlit by Si plasmas. A spherically-bent quartz crystal (R=25cm, 2d=6.68703 Åimaged the radiation of He-like Si resonance line that was transmitted through the target foil. The intensity of the backlighted image (6 beams, 250 J) was 160 times greater than the self emission from a driven CH foil. The magnified (X9.6) images on DEF film had the resolution about 5 μ m (3 μ m with R=10cm). The resulting 10 μ m spatial resolution in the gated images was determined by 100 μ m resolution of the framing camera. Images of CH targets were recorded 2 nsec after the peak of the laser pulse and revealed the growth of Rayleigh-Taylor instabilities that were seeded by patterns with amplitude as small as 0.25 μ m. The image of driven smooth CH target was quite smooth compared to those of the patterned CH foil. A future imaging instrument will have multiple backlighter plasmas and better quality bent crystals that can be bent into a toroidal shape. Up to four images with higher magnification and spatial resolution of 5 μ m may be recorded on the framing camera. This work supported by the US Department of Energy

  13. Feasibility study of heavy-ion beams and compound target materials for muon production

    NASA Astrophysics Data System (ADS)

    Sohn, Jae Bum; Lee, Ju Hahn; Kim, Gi Dong; Kim, Yong Kyun

    2015-10-01

    We have investigated the feasibility of using compound materials as targets for muon production by virtue of simulations using a GEANT4 toolkit. A graphite material and two thermostable compound materials, beryllium oxide (BeO) and boron carbide (B4C), were considered as muon production targets, and their muon production rates for a 600-MeV proton beam were calculated and compared. For the thermal analysis, the total heat deposited on the targets by the proton beams and the secondary particles was calculated with the MCNPX code; then, the temperature distribution of target was derived from the calculated heat by using the ANSYS code with consideration of heat transfer mechanisms such as thermal conduction and thermal radiation. In addition, we have investigated whether the heavy-ion beams can be utilized for muon production. For various beam species such as 3He2, 4He, 7Li, 10B and 12C, their muon production rates were calculated and compared with the rates experimentally-obtained for a proton beam.

  14. Chemical proteomics approaches for identifying the cellular targets of natural products.

    PubMed

    Wright, M H; Sieber, S A

    2016-05-04

    Covering: 2010 up to 2016Deconvoluting the mode of action of natural products and drugs remains one of the biggest challenges in chemistry and biology today. Chemical proteomics is a growing area of chemical biology that seeks to design small molecule probes to understand protein function. In the context of natural products, chemical proteomics can be used to identify the protein binding partners or targets of small molecules in live cells. Here, we highlight recent examples of chemical probes based on natural products and their application for target identification. The review focuses on probes that can be covalently linked to their target proteins (either via intrinsic chemical reactivity or via the introduction of photocrosslinkers), and can be applied "in situ" - in living systems rather than cell lysates. We also focus here on strategies that employ a click reaction, the copper-catalysed azide-alkyne cycloaddition reaction (CuAAC), to allow minimal functionalisation of natural product scaffolds with an alkyne or azide tag. We also discuss 'competitive mode' approaches that screen for natural products that compete with a well-characterised chemical probe for binding to a particular set of protein targets. Fuelled by advances in mass spectrometry instrumentation and bioinformatics, many modern strategies are now embracing quantitative proteomics to help define the true interacting partners of probes, and we highlight the opportunities this rapidly evolving technology provides in chemical proteomics. Finally, some of the limitations and challenges of chemical proteomics approaches are discussed.

  15. Chemical proteomics approaches for identifying the cellular targets of natural products

    PubMed Central

    Sieber, S. A.

    2016-01-01

    Covering: 2010 up to 2016 Deconvoluting the mode of action of natural products and drugs remains one of the biggest challenges in chemistry and biology today. Chemical proteomics is a growing area of chemical biology that seeks to design small molecule probes to understand protein function. In the context of natural products, chemical proteomics can be used to identify the protein binding partners or targets of small molecules in live cells. Here, we highlight recent examples of chemical probes based on natural products and their application for target identification. The review focuses on probes that can be covalently linked to their target proteins (either via intrinsic chemical reactivity or via the introduction of photocrosslinkers), and can be applied “in situ” – in living systems rather than cell lysates. We also focus here on strategies that employ a click reaction, the copper-catalysed azide–alkyne cycloaddition reaction (CuAAC), to allow minimal functionalisation of natural product scaffolds with an alkyne or azide tag. We also discuss ‘competitive mode’ approaches that screen for natural products that compete with a well-characterised chemical probe for binding to a particular set of protein targets. Fuelled by advances in mass spectrometry instrumentation and bioinformatics, many modern strategies are now embracing quantitative proteomics to help define the true interacting partners of probes, and we highlight the opportunities this rapidly evolving technology provides in chemical proteomics. Finally, some of the limitations and challenges of chemical proteomics approaches are discussed. PMID:27098809

  16. Self-vapor cooled targets for production of I-123 at high current accelerators. [using Xe-123 production

    NASA Technical Reports Server (NTRS)

    Blue, J. W.; Scholz, K. L.; Sodd, V. J.

    1974-01-01

    The basic elements of the vapor cooled target system are shown. This system can be operated as a heat pipe or as a conventional condenser. The choice of target fluid is based on the specific nuclear reaction chosen to produce Xe-123. The reaction using I-127 was studied and shown to have a significant yield for bombarding energies from 47 to 63 MeV. The Cs-133 reaction is also included. Xenon-123 is applied to I-123 production in a purer form for thyroid studies.

  17. Effects of primary recoil energy on the production rate of mobile defects during elevated temperature irradiation

    SciTech Connect

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

    1984-11-01

    Radiation-induced segregation rates in a Ni-12.7 at.% Si alloy have been measured as a function of temperature using ions of various masses and energies. An analysis of the segregation kinetics using a simple analytical model yielded the relative efficiency of each of the ions for producing mobile defects directly from ratios of their measured segregation rates. In this paper, we also show that the relative efficiencies can also be determined from measured shifts in the peak segregation temperature. Both methods yield a strong decrease in efficiency with increasing ion mass. The reduction in efficiency for the heavior ions was found to be significantly larger than that measured at very low temperatures by resistivity techniques. The latter are often used as a basis for correlating damage structures produced at elevated temperatures. Differences between the low and high temperature measurements indicate that relative efficiencies determined from segregation measurements are more reliable for correlating microstructural changes that are produced in different irradiation environments at high temperatures.

  18. Effect of ultrasound irradiation on the production of nHAp/MWCNT nanocomposites.

    PubMed

    Lobo, Anderson O; Zanin, Hudson; Siqueira, Idalia A W B; Leite, Nelly C S; Marciano, Fernanda R; Corat, Evaldo J

    2013-10-01

    Large amounts of nanohydroxyapatite (nHAp)-multiwall carbon nanotube (MWCNT) nanocomposites are produced by two different aqueous precipitation methods. The ultrasonic irradiation (UI) and slow-drip addition under continuous magnetic stirring (DMS) methods were used to investigate the precipitation of nHAp acicular crystals. Calcium-nitrate, diammonium hydrogen phosphate, and ammonium hydroxide were used as precursor reagents. Superhydrophilic MWCNT were also employed. XPS analysis evidences that the functionalized MWCNTs are composed of 18 to 20 at.% of oxygen and that this property influences the nHAp formation. The high surface area of the MWCNT decreases the mean free path of ions, favoring the nHAp formation assisted by UI. The crystallinity was evaluated using the Scherrer equation. Semi-qualitative energy dispersive spectroscopy (EDS) analysis showed that the main components of HAp powders were calcium and phosphorus in the ratio Ca/P around of 1.67. Bioactivity properties of the nHAp/MWCNT-UI nanocomposites could be evaluated after 14 days soaking in simulated body fluid medium. Scanning electron microscopy, EDS, Fourier transform infrared attenuated total reflection spectroscopy, and X-ray diffraction techniques proved that the apatites formed on the surface and to points that the nHAp/MWCNT-UI have potential biological applications.

  19. Sporicidal performance induced by photocatalytic production of organic peroxide under visible light irradiation

    PubMed Central

    Yamaguchi, Yuichi; Shimodo, Takahito; Chikamori, Noriyasu; Usuki, Sho; Kanai, Yoshihiro; Endo, Takeshi; Katsumata, Ken-ichi; Terashima, Chiaki; Ikekita, Masahiko; Fujishima, Akira; Suzuki, Tomonori; Sakai, Hideki; Nakata, Kazuya

    2016-01-01

    Bacteria that cause serious food poisoning are known to sporulate under conditions of nutrient and water shortage. The resulting spores have much greater resistance to common sterilization methods, such as heating at 100 °C and exposure to various chemical agents. Because such bacteria cannot be inactivated with typical alcohol disinfectants, peroxyacetic acid (PAA) often is used, but PAA is a harmful agent that can seriously damage human health. Furthermore, concentrated hydrogen peroxide, which is also dangerous, must be used to prepare PAA. Thus, the development of a facile and safe sporicidal disinfectant is strongly required. In this study, we have developed an innovative sporicidal disinfection method that employs the combination of an aqueous ethanol solution, visible light irradiation, and a photocatalyst. We successfully produced a sporicidal disinfectant one hundred times as effective as commercially available PAA, while also resolving the hazards and odor problems associated with PAA. The method presented here can potentially be used as a replacement for the general disinfectants employed in the food and health industries. PMID:27666195

  20. The Epidermal Growth Factor Receptor Increases Cytokine Production and Cutaneous Inflammation in Response to Ultraviolet Irradiation

    PubMed Central

    El-Abaseri, Taghrid Bahig; Repertinger, Susan K.; Hansen, Laura A.

    2013-01-01

    The epidermal growth factor receptor (EGFR) is activated in cutaneous keratinocytes upon ultraviolet (UV) exposure and has been implicated in ultraviolet-(UV-)induced inflammation and skin tumorigenesis. Egfr mutant mice and EGFR inhibitors were used to investigate the hypothesis that EGFR activation augments inflammation following UV irradiation. Topical treatment of mouse skin with the EGFR inhibitor AG1478 before UV exposure suppressed UV-induced erythema, edema, mast cell infiltration, and neutrophil infiltration. Genetic ablation of Egfr and EGFR inhibition by AG1478 also suppressed the increase in the proinflammatory cytokines tumor necrosis factor α (TNF-α), interleukin-1α, KC (murine IL-8), and cyclooxygenase-2 (COX-2) after UV exposure of cultured keratinocytes. Finally, genetic ablation of inhibition of EGFR in cultured keratinocytes decreased p38 activation after UV, while inhibition of p38 kinase reduced COX-2 expression after UV. These data demonstrate that EGFR regulates multiple aspects of UV-induced inflammation and suggest activation of p38 kinase leading to increased COX-2 and cytokine expression as one mechanism through which it acts. PMID:23878744