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Sample records for high-energy proton beams

  1. Hardness assurance for proton direct ionization-induced SEEs using a high-energy proton beam

    DOE PAGESBeta

    Dodds, Nathaniel Anson; Schwank, James R.; Shaneyfelt, Marty R.; Dodd, Paul E.; Doyle, Barney Lee; Trinczek, M.; Blackmore, E. W.; Rodbell, K. P.; Reed, R. A.; Pellish, J. A.; et al

    2014-11-06

    The low-energy proton energy spectra of all shielded space environments have the same shape. This shape is easily reproduced in the laboratory by degrading a high-energy proton beam, producing a high-fidelity test environment. We use this test environment to dramatically simplify rate prediction for proton direct ionization effects, allowing the work to be done at high-energy proton facilities, on encapsulated parts, without knowledge of the IC design, and with little or no computer simulations required. Proton direct ionization (PDI) is predicted to significantly contribute to the total error rate under the conditions investigated. Scaling effects are discussed using data frommore » 65-nm, 45-nm, and 32-nm SOI SRAMs. These data also show that grazing-angle protons will dominate the PDI-induced error rate due to their higher effective LET, so PDI hardness assurance methods must account for angular effects to be conservative. As a result, we show that this angular dependence can be exploited to quickly assess whether an IC is susceptible to PDI.« less

  2. Hardness assurance for proton direct ionization-induced SEEs using a high-energy proton beam

    SciTech Connect

    Dodds, Nathaniel Anson; Schwank, James R.; Shaneyfelt, Marty R.; Dodd, Paul E.; Doyle, Barney Lee; Trinczek, M.; Blackmore, E. W.; Rodbell, K. P.; Reed, R. A.; Pellish, J. A.; LaBel, K. A.; Marshall, P. W.; Swanson, Scot E.; Vizkelethy, Gyorgy; Van Deusen, Stuart B.; Sexton, Frederick W.; Martinez, Marino J.; Gordon, M. S.

    2014-11-06

    The low-energy proton energy spectra of all shielded space environments have the same shape. This shape is easily reproduced in the laboratory by degrading a high-energy proton beam, producing a high-fidelity test environment. We use this test environment to dramatically simplify rate prediction for proton direct ionization effects, allowing the work to be done at high-energy proton facilities, on encapsulated parts, without knowledge of the IC design, and with little or no computer simulations required. Proton direct ionization (PDI) is predicted to significantly contribute to the total error rate under the conditions investigated. Scaling effects are discussed using data from 65-nm, 45-nm, and 32-nm SOI SRAMs. These data also show that grazing-angle protons will dominate the PDI-induced error rate due to their higher effective LET, so PDI hardness assurance methods must account for angular effects to be conservative. As a result, we show that this angular dependence can be exploited to quickly assess whether an IC is susceptible to PDI.

  3. Response of a tungsten powder target to an incident high energy proton beam

    NASA Astrophysics Data System (ADS)

    Caretta, O.; Davenne, T.; Densham, C.; Fitton, M.; Loveridge, P.; O'Dell, J.; Charitonidis, N.; Efthymiopoulos, I.; Fabich, A.; Rivkin, L.

    2014-10-01

    The experiment described in this paper is the first study of the response of a static tungsten powder sample to an impinging high energy proton beam pulse. The experiment was carried out at the HiRadMat facility at CERN. Observations include high speed videos of a proton beam induced perturbation of the powder sample as well as data from a laser Doppler vibrometer measuring the oscillations of the powder container. A comparison with a previous analogous experiment which studied a proton beam interaction with mercury is made.

  4. ABSOLUTE MEASUREMENT OF THE POLARIZATION OF HIGH ENERGY PROTON BEAMS AT RHIC

    SciTech Connect

    MAKDISI,Y.; BRAVAR, A. BUNCE, G. GILL, R.; HUANG, H.; ET AL.

    2007-06-25

    The spin physics program at the Relativistic Heavy Ion Collider (RHIC) requires knowledge of the beam polarization to better than 5%. Such a goal is made the more difficult by the lack of knowledge of the analyzing power of high energy nuclear physics processes. To overcome this, a polarized hydrogen jet target was constructed and installed at one intersection region in RHIC where it intersects both beams and utilizes the precise knowledge of the jet atomic hydrogen beam polarization to measure the analyzing power in proton-proton elastic scattering in the Nuclear Coulomb Interference (CNI) region at the prescribed RHIC proton beam energy. The reverse reaction is used to assess the absolute beam polarization. Simultaneous measurements taken with fast high statistics polarimeters that measure the p-Carbon elastic scattering process also in the CNI region use the jet results to calibrate the latter.

  5. Laser-driven high-energy proton beam with homogeneous spatial profile from a nanosphere target

    NASA Astrophysics Data System (ADS)

    Margarone, D.; Kim, I. J.; Psikal, J.; Kaufman, J.; Mocek, T.; Choi, I. W.; Stolcova, L.; Proska, J.; Choukourov, A.; Melnichuk, I.; Klimo, O.; Limpouch, J.; Sung, J. H.; Lee, S. K.; Korn, G.; Jeong, T. M.

    2015-07-01

    A high-energy, high-yield proton beam with a good homogeneous profile has been generated from a nanosphere target irradiated by a short (30-fs), intense (7 ×1020 W /cm2 ) laser pulse. A maximum proton energy of 30 MeV has been observed with a high proton number of 7 ×1010 in the energy range 5-30 MeV. A homogeneous spatial profile with a uniformity (standard deviation from an average value within 85% beam area) of 15% is observed with the nanosphere dielectric target. Particle-in-cell simulations show the enhancement of proton cutoff energy and proton number with the nanosphere target and reveal that the homogeneous beam profile is related with a broadened angular distribution of hot electrons, which is initiated by the nanosphere structure. The homogeneous spatial properties obtained with the nanosphere target will be advantageous in developing laser-driven proton sources for practical applications in which high-quality beams are required.

  6. Detecting cavitation in mercury exposed to a high-energy pulsed proton beam.

    PubMed

    Manzi, Nicholas J; Chitnis, Parag V; Holt, R Glynn; Roy, Ronald A; Cleveland, Robin O; Riemer, Bernie; Wendel, Mark

    2010-04-01

    The Oak Ridge National Laboratory Spallation Neutron Source employs a high-energy pulsed proton beam incident on a mercury target to generate short bursts of neutrons. Absorption of the proton beam produces rapid heating of the mercury, resulting in the formation of acoustic shock waves and the nucleation of cavitation bubbles. The subsequent collapse of these cavitation bubbles promote erosion of the steel target walls. Preliminary measurements using two passive cavitation detectors (megahertz-frequency focused and unfocused piezoelectric transducers) installed in a mercury test target to monitor cavitation generated by proton beams with charges ranging from 0.041 to 4.1 muC will be reported on. Cavitation was initially detected for a beam charge of 0.082 muC by the presence of an acoustic emission approximately 250 mus after arrival of the incident proton beam. This emission was consistent with an inertial cavitation collapse of a bubble with an estimated maximum bubble radius of 0.19 mm, based on collapse time. The peak pressure in the mercury for the initiation of cavitation was predicted to be 0.6 MPa. For a beam charge of 0.41 muC and higher, the lifetimes of the bubbles exceeded the reverberation time of the chamber ( approximately 300 mus), and distinct windows of cavitation activity were detected, a phenomenon that likely resulted from the interaction of the reverberation in the chamber and the cavitation bubbles. PMID:20370004

  7. Detecting cavitation in mercury exposed to a high-energy pulsed proton beam

    SciTech Connect

    Manzi, Nicholas J; Chitnis, Parag V; Holt, Ray G; Roy, Ronald A; Cleveland, Robin O; Riemer, Bernie; Wendel, Mark W

    2010-01-01

    The Oak Ridge National Laboratory Spallation Neutron Source employs a high-energy pulsed proton beam incident on a mercury target to generate short bursts of neutrons. Absorption of the proton beam produces rapid heating of the mercury, resulting in the formation of acoustic shock waves and the nucleation of cavitation bubbles. The subsequent collapse of these cavitation bubbles promote erosion of the steel target walls. Preliminary measurements using two passive cavitation detectors (megahertz-frequency focused and unfocused piezoelectric transducers) installed in a mercury test target to monitor cavitation generated by proton beams with charges ranging from 0.041 to 4.1 C will be reported on. Cavitation was initially detected for a beam charge of 0.082 C by the presence of an acoustic emission approximately 250 s after arrival of the incident proton beam. This emission was consistent with an inertial cavitation collapse of a bubble with an estimated maximum bubble radius of 0.19 mm, based on collapse time. The peak pressure in the mercury for the initiation of cavitation was predicted to be 0.6 MPa. For a beam charge of 0.41 C and higher, the lifetimes of the bubbles exceeded the reverberation time of the chamber (~300 s), and distinct windows of cavitation activity were detected, a phenomenon that likely resulted from the interaction of the reverberation in the chamber and the cavitation bubbles.

  8. Study of the effects of high-energy proton beams on escherichia coli

    NASA Astrophysics Data System (ADS)

    Park, Jeong Chan; Jung, Myung-Hwan

    2015-10-01

    Antibiotic-resistant bacterial infection is one of the most serious risks to public health care today. However, discouragingly, the development of new antibiotics has progressed little over the last decade. There is an urgent need for alternative approaches to treat antibiotic-resistant bacteria. Novel methods, which include photothermal therapy based on gold nano-materials and ionizing radiation such as X-rays and gamma rays, have been reported. Studies of the effects of high-energy proton radiation on bacteria have mainly focused on Bacillus species and its spores. The effect of proton beams on Escherichia coli (E. coli) has been limitedly reported. Escherichia coli is an important biological tool to obtain metabolic and genetic information and is a common model microorganism for studying toxicity and antimicrobial activity. In addition, E. coli is a common bacterium in the intestinal tract of mammals. In this research, the morphological and the physiological changes of E. coli after proton irradiation were investigated. Diluted solutions of cells were used for proton beam radiation. LB agar plates were used to count the number of colonies formed. The growth profile of the cells was monitored by using the optical density at 600 nm. The morphology of the irradiated cells was observed with an optical microscope. A microarray analysis was performed to examine the gene expression changes between irradiated samples and control samples without irradiation. E coli cells have observed to be elongated after proton irradiation with doses ranging from 13 to 93 Gy. Twenty-two were up-regulated more than twofold in proton-irradiated samples (93 Gy) compared with unexposed one.

  9. Dosimetric characteristics of four PTW microDiamond detectors in high-energy proton beams

    NASA Astrophysics Data System (ADS)

    Marsolat, F.; De Marzi, L.; Patriarca, A.; Nauraye, C.; Moignier, C.; Pomorski, M.; Moignau, F.; Heinrich, S.; Tromson, D.; Mazal, A.

    2016-09-01

    Small diamond detectors are useful for the dosimetry of high-energy proton beams. However, linear energy transfer (LET) dependence has been observed in the literature with such solid state detectors. A novel synthetic diamond detector has recently become commercially available from the manufacturer PTW-Freiburg (PTW microDiamond type 60019). This study was designed to thoroughly characterize four microDiamond detectors in clinical proton beams, in order to investigate their response and their reproducibility in high LET regions. Very good dosimetric characteristics were observed for two of them, with good stability of their response (deviation less than 0.4% after a pre-irradiation dose of approximately 12 Gy), good repeatability (coefficient of variation of 0.06%) and a sensitivity of approximately 0.85 nC Gy‑1. A negligible dose rate dependence was also observed for these two microDiamonds with a deviation of the sensitivity less than 0.7% with respect to the one measured at the reference dose rate of 2.17 Gy min‑1, in the investigated dose rate range from 1.01 Gy min‑1 to 5.52 Gy min‑1. Lateral dose profile measurements showed the high spatial resolution of the microDiamond oriented with its stem perpendicular to the beam axis and with its small sensitive thickness of about 1 μm in the scanning profile direction. Finally, no significant LET dependence was found with these two diamond dosimeters in comparison to a reference ionization chamber (model IBA PPC05). These good results were in accordance to the literature. However, this study showed also a non reproducibility between the devices in terms of stability, sensitivity and LET dependence, since the two other microDiamonds characterized in this work showed different dosimetric characteristics making them not suitable for proton beam dosimetry with a maximum difference of the peak-to-plateau ratio of 6.7% relative to the reference ionization chamber in a clinical 138 MeV proton beam.

  10. Dosimetric characteristics of four PTW microDiamond detectors in high-energy proton beams.

    PubMed

    Marsolat, F; De Marzi, L; Patriarca, A; Nauraye, C; Moignier, C; Pomorski, M; Moignau, F; Heinrich, S; Tromson, D; Mazal, A

    2016-09-01

    Small diamond detectors are useful for the dosimetry of high-energy proton beams. However, linear energy transfer (LET) dependence has been observed in the literature with such solid state detectors. A novel synthetic diamond detector has recently become commercially available from the manufacturer PTW-Freiburg (PTW microDiamond type 60019). This study was designed to thoroughly characterize four microDiamond detectors in clinical proton beams, in order to investigate their response and their reproducibility in high LET regions. Very good dosimetric characteristics were observed for two of them, with good stability of their response (deviation less than 0.4% after a pre-irradiation dose of approximately 12 Gy), good repeatability (coefficient of variation of 0.06%) and a sensitivity of approximately 0.85 nC Gy(-1). A negligible dose rate dependence was also observed for these two microDiamonds with a deviation of the sensitivity less than 0.7% with respect to the one measured at the reference dose rate of 2.17 Gy min(-1), in the investigated dose rate range from 1.01 Gy min(-1) to 5.52 Gy min(-1). Lateral dose profile measurements showed the high spatial resolution of the microDiamond oriented with its stem perpendicular to the beam axis and with its small sensitive thickness of about 1 μm in the scanning profile direction. Finally, no significant LET dependence was found with these two diamond dosimeters in comparison to a reference ionization chamber (model IBA PPC05). These good results were in accordance to the literature. However, this study showed also a non reproducibility between the devices in terms of stability, sensitivity and LET dependence, since the two other microDiamonds characterized in this work showed different dosimetric characteristics making them not suitable for proton beam dosimetry with a maximum difference of the peak-to-plateau ratio of 6.7% relative to the reference ionization chamber in a clinical 138 MeV proton beam. PMID:27499356

  11. Dynamics of high-energy proton beam acceleration and focusing from hemisphere-cone targets by high-intensity lasers.

    PubMed

    Qiao, B; Foord, M E; Wei, M S; Stephens, R B; Key, M H; McLean, H; Patel, P K; Beg, F N

    2013-01-01

    Acceleration and focusing of high-energy proton beams from fast-ignition (FI) -related hemisphere-cone assembled targets have been numerically studied by hybrid particle-in-cell simulations and compared with those from planar-foil and open-hemisphere targets. The whole physical process including the laser-plasma interaction has been self-consistently modeled for 15 ps, at which time the protons reach asymptotic motion. It is found that the achievable focus of proton beams is limited by the thermal pressure gradients in the co-moving hot electrons, which induce a transverse defocusing electric field that bends proton trajectories near the axis. For the advanced hemisphere-cone target, the flow of hot electrons along the cone wall induces a local transverse focusing sheath field, resulting in a clear enhancement in proton focusing; however, it leads to a significant loss of longitudinal sheath potential, reducing the total conversion efficiency from laser to protons. PMID:23410447

  12. Interaction of High-Energy Proton Beam with a Thin Target and Multiplicities of Neutron

    SciTech Connect

    Demirkol, I.; Tatar, M.; Safak, M. S.; Arasoglu, A.; Tel, E.

    2007-04-23

    An important ingredient in the performance of accelerator driven systems for energy production, waste transmutation and other applications are the number of spallation neutrons produced per incident proton. The neutron multiplicities, angular and energy distributions are usually calculated using simulation codes. We have presented multiplicities of the neutrons emitted in the interaction of a high-energy proton (1500 MeV) with a thin target Pb, Bi. In this study we have used the code ISABEL to calculate multiplicities of the neutron emitted. The results obtained have been compared with the available data.

  13. Laser-induced generation of ultraintense proton beams for high energy-density science

    SciTech Connect

    Badziak, J.; Jablonski, S.; Parys, P.; Rosinski, M.; Suchanska, R.; Wolowski, J.; Antici, P.; Fuchs, J.; Mancic, A.; Szydlowski, A.

    2008-06-24

    Basic properties of high-current high-intensity ion beam generation using laser-induced skin-layer ponderomotive acceleration (SLPA) are discussed. The results of a recent experiment, in which 0.35-ps laser pulse of intensity up to 2x10{sup 19} W/cm{sup 2} irradiated a thin (1-3 {mu}m) PS (plastic) or Au/PS target (PS covered by 0.1-0.2 {mu}m Au front layer), are presented. It is shown that multi-MA proton beams of current densities >1 TA/cm{sup 2} and intensities > 10{sup 18} W/cm{sup 2} at the source can be produced when the laser-target interaction conditions approach the SLPA requirements. The proton beam parameters as well as the laser-protons energy conversion efficiency substantially depend on the target structure and can be significantly increased with the use of a double-layer Au/PS target. A prospect for the application of SLPA-driven proton beams in ICF fast ignition research is outlined.

  14. Impact of high energy high intensity proton beams on targets: Case studies for Super Proton Synchrotron and Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Tahir, N. A.; Sancho, J. Blanco; Shutov, A.; Schmidt, R.; Piriz, A. R.

    2012-05-01

    The Large Hadron Collider (LHC) is designed to collide two proton beams with unprecedented particle energy of 7 TeV. Each beam comprises 2808 bunches and the separation between two neighboring bunches is 25 ns. The energy stored in each beam is 362 MJ, sufficient to melt 500 kg copper. Safety of operation is very important when working with such powerful beams. An accidental release of even a very small fraction of the beam energy can result in severe damage to the equipment. The machine protection system is essential to handle all types of possible accidental hazards; however, it is important to know about possible consequences of failures. One of the critical failure scenarios is when the entire beam is lost at a single point. In this paper we present detailed numerical simulations of the full impact of one LHC beam on a cylindrical solid carbon target. First, the energy deposition by the protons is calculated with the FLUKA code and this energy deposition is used in the BIG2 code to study the corresponding thermodynamic and the hydrodynamic response of the target that leads to a reduction in the density. The modified density distribution is used in FLUKA to calculate new energy loss distribution and the two codes are thus run iteratively. A suitable iteration step is considered to be the time interval during which the target density along the axis decreases by 15%-20%. Our simulations suggest that the full LHC proton beam penetrates up to 25 m in solid carbon whereas the range of the shower from a single proton in solid carbon is just about 3 m (hydrodynamic tunneling effect). It is planned to perform experiments at the experimental facility HiRadMat (High Radiation Materials) at CERN using the proton beam from the Super Proton Synchrotron (SPS), to compare experimental results with the theoretical predictions. Therefore simulations of the response of a solid copper cylindrical target hit by the SPS beam were performed. The particle energy in the SPS beam is 440

  15. High energy beam lines

    NASA Astrophysics Data System (ADS)

    Marchetto, M.; Laxdal, R. E.

    2014-01-01

    The ISAC post accelerator comprises an RFQ, DTL and SC-linac. The high energy beam lines connect the linear accelerators as well as deliver the accelerated beams to two different experimental areas. The medium energy beam transport (MEBT) line connects the RFQ to the DTL. The high energy beam transport (HEBT) line connects the DTL to the ISAC-I experimental stations (DRAGON, TUDA-I, GPS). The DTL to superconducting beam (DSB) transport line connects the ISAC-I and ISAC-II linacs. The superconducting energy beam transport (SEBT) line connects the SC linac to the ISAC-II experimental station (TUDA-II, HERACLES, TIGRESS, EMMA and GPS). All these lines have the function of transporting and matching the beams to the downstream sections by manipulating the transverse and longitudinal phase space. They also contain diagnostic devices to measure the beam properties.

  16. Evaluation of the dosimetric properties of a synthetic single crystal diamond detector in high energy clinical proton beams

    SciTech Connect

    Mandapaka, A. K.; Ghebremedhin, A.; Patyal, B.; Marinelli, Marco; Prestopino, G.; Verona, C.; Verona-Rinati, G.

    2013-12-15

    Purpose: To investigate the dosimetric properties of a synthetic single crystal diamond Schottky diode for accurate relative dose measurements in large and small field high-energy clinical proton beams.Methods: The dosimetric properties of a synthetic single crystal diamond detector were assessed by comparison with a reference Markus parallel plate ionization chamber, an Exradin A16 microionization chamber, and Exradin T1a ion chamber. The diamond detector was operated at zero bias voltage at all times. Comparative dose distribution measurements were performed by means of Fractional depth dose curves and lateral beam profiles in clinical proton beams of energies 155 and 250 MeV for a 14 cm square cerrobend aperture and 126 MeV for 3, 2, and 1 cm diameter circular brass collimators. ICRU Report No. 78 recommended beam parameters were used to compare fractional depth dose curves and beam profiles obtained using the diamond detector and the reference ionization chamber. Warm-up/stability of the detector response and linearity with dose were evaluated in a 250 MeV proton beam and dose rate dependence was evaluated in a 126 MeV proton beam. Stem effect and the azimuthal angle dependence of the diode response were also evaluated.Results: A maximum deviation in diamond detector signal from the average reading of less than 0.5% was found during the warm-up irradiation procedure. The detector response showed a good linear behavior as a function of dose with observed deviations below 0.5% over a dose range from 50 to 500 cGy. The detector response was dose rate independent, with deviations below 0.5% in the investigated dose rates ranging from 85 to 300 cGy/min. Stem effect and azimuthal angle dependence of the diode signal were within 0.5%. Fractional depth dose curves and lateral beam profiles obtained with the diamond detector were in good agreement with those measured using reference dosimeters.Conclusions: The observed dosimetric properties of the synthetic single

  17. LiF TLD-100 as a Dosimeter in High Energy Proton Beam Therapy-Can It Yield Accurate Results?

    SciTech Connect

    Zullo, John R. Kudchadker, Rajat J.; Zhu, X. Ronald; Sahoo, Narayan; Gillin, Michael T.

    2010-04-01

    In the region of high-dose gradients at the end of the proton range, the stopping power ratio of the protons undergoes significant changes, allowing for a broad spectrum of proton energies to be deposited within a relatively small volume. Because of the potential linear energy transfer dependence of LiF TLD-100 (thermolumescent dosimeter), dose measurements made in the distal fall-off region of a proton beam may be less accurate than those made in regions of low-dose gradients. The purpose of this study is to determine the accuracy and precision of dose measured using TLD-100 for a pristine Bragg peak, particularly in the distal fall-off region. All measurements were made along the central axis of an unmodulated 200-MeV proton beam from a Probeat passive beam-scattering proton accelerator (Hitachi, Ltd., Tokyo, Japan) at varying depths along the Bragg peak. Measurements were made using TLD-100 powder flat packs, placed in a virtual water slab phantom. The measurements were repeated using a parallel plate ionization chamber. The dose measurements using TLD-100 in a proton beam were accurate to within {+-}5.0% of the expected dose, previously seen in our past photon and electron measurements. The ionization chamber and the TLD relative dose measurements agreed well with each other. Absolute dose measurements using TLD agreed with ionization chamber measurements to within {+-} 3.0 cGy, for an exposure of 100 cGy. In our study, the differences in the dose measured by the ionization chamber and those measured by TLD-100 were minimal, indicating that the accuracy and precision of measurements made in the distal fall-off region of a pristine Bragg peak is within the expected range. Thus, the rapid change in stopping power ratios at the end of the range should not affect such measurements, and TLD-100 may be used with confidence as an in vivo dosimeter for proton beam therapy.

  18. Proton beam therapy facility

    SciTech Connect

    Not Available

    1984-10-09

    It is proposed to build a regional outpatient medical clinic at the Fermi National Accelerator Laboratory (Fermilab), Batavia, Illinois, to exploit the unique therapeutic characteristics of high energy proton beams. The Fermilab location for a proton therapy facility (PTF) is being chosen for reasons ranging from lower total construction and operating costs and the availability of sophisticated technical support to a location with good access to patients from the Chicago area and from the entire nation. 9 refs., 4 figs., 26 tabs.

  19. PRaVDA: High Energy Physics towards proton Computed Tomography

    NASA Astrophysics Data System (ADS)

    Price, T.

    2016-07-01

    Proton radiotherapy is an increasingly popular modality for treating cancers of the head and neck, and in paediatrics. To maximise the potential of proton radiotherapy it is essential to know the distribution, and more importantly the proton stopping powers, of the body tissues between the proton beam and the tumour. A stopping power map could be measured directly, and uncertainties in the treatment vastly reduce, if the patient was imaged with protons instead of conventional x-rays. Here we outline the application of technologies developed for High Energy Physics to provide clinical-quality proton Computed Tomography, in so reducing range uncertainties and enhancing the treatment of cancer.

  20. Theoretical study of the effect of the size of a high-energy proton beam of the Large Hadron Collider on the formation and propagation of shock waves in copper irradiated by 450-GeV proton beams

    NASA Astrophysics Data System (ADS)

    Ryazanov, A. I.; Stepakov, A. V.; Vasilyev, Ya. S.; Ferrari, A.

    2014-02-01

    The interaction of 450-GeV protons with copper, which is the material of the collimators of the Large Hadron Collider, has been theoretically studied. A theoretical model for the formation and propagation of shock waves has been proposed on the basis of the analysis of the energy released by a proton beam in the electronic subsystem of the material owing to the deceleration of secondary particles appearing in nuclear reactions induced by this beam on the electronic subsystem of the material. The subsequent transfer of the energy from the excited electronic subsystem to the crystal lattice through the electron-phonon interaction has been described within the thermal spike model [I.M. Lifshitz, M.I. Kaganov, and L.V. Tanatarov, Sov. Phys. JETP 4, 173 (1957); I.M. Lifshitz, M.I. Kaganov, and L.V. Tanatarov, At. Energ. 6, 391 (1959); K. Yasui, Nucl. Instrum. Methods Phys. Res., Sect. B 90, 409 (1994)]. The model of the formation of shock waves involves energy exchange processes between excited electronic and ionic subsystems of the irradiated material and is based on the hydrodynamic approximation proposed by Zel'dovich [Ya.B. Zel'dovich and Yu.P. Raizer, Physics of Shock Waves and High-Temperature Hydrodynamic Phenomena (Nauka, Moscow, 1966; Dover, New York, 2002)]. This model makes it possible to obtain the space-time distributions of the main physical characteristics (temperatures of the ionic and electronic subsystems, density, pressure, etc.) in materials irradiated by high-energy proton beams and to analyze the formation and propagation of shock waves in them. The nonlinear differential equations describing the conservation laws of mass, energy, and momentum of electrons and ions in the Euler variables in the case of the propagation of shock waves has been solved with the Godunov scheme [S. K. Godunov, A.V. Zabrodin, M.Ya. Ivanov, A.N. Kraiko, and G.P. Prokopov, Numerical Solution of Multidimensional Problems in Gas Dynamics (Nauka, Moscow, 1976) [in Russian

  1. Fission foil detector calibrations with high energy protons

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Frank, A. L.

    1995-01-01

    Fission foil detectors (FFD's) are passive devices composed of heavy metal foils in contact with muscovite mica films. The heavy metal nuclei have significant cross sections for fission when irradiated with neutrons and protons. Each isotope is characterized by threshold energies for the fission reactions and particular energy-dependent cross sections. In the FFD's, fission fragments produced by the reactions are emitted from the foils and create latent particle tracks in the adjacent mica films. When the films are processed surface tracks are formed which can be optically counted. The track densities are indications of the fluences and spectra of neutrons and/or protons. In the past, detection efficiencies have been calculated using the low energy neutron calibrated dosimeters and published fission cross sections for neutrons and protons. The problem is that the addition of a large kinetic energy to the (n,nucleus) or (p,nucleus) reaction could increase the energies and ranges of emitted fission fragments and increase the detector sensitivity as compared with lower energy neutron calibrations. High energy calibrations are the only method of resolving the uncertainties in detector efficiencies. At high energies, either proton or neutron calibrations are sufficient since the cross section data show that the proton and neutron fission cross sections are approximately equal. High energy proton beams have been utilized (1.8 and 4.9 GeV, 80 and 140 MeV) for measuring the tracks of fission fragments emitted backward and forward.

  2. High energy protons generation by two sequential laser pulses

    SciTech Connect

    Wang, Xiaofeng; Shen, Baifei E-mail: zhxm@siom.ac.cn; Zhang, Xiaomei E-mail: zhxm@siom.ac.cn; Wang, Wenpeng; Xu, Jiancai; Yi, Longqing; Shi, Yin

    2015-04-15

    The sequential proton acceleration by two laser pulses of relativistic intensity is proposed to produce high energy protons. In the scheme, a relativistic super-Gaussian (SG) laser pulse followed by a Laguerre-Gaussian (LG) pulse irradiates dense plasma attached by underdense plasma. A proton beam is produced from the target and accelerated in the radiation pressure regime by the short SG pulse and then trapped and re-accelerated in a special bubble driven by the LG pulse in the underdense plasma. The advantages of radiation pressure acceleration and LG transverse structure are combined to achieve the effective trapping and acceleration of protons. In a two-dimensional particle-in-cell simulation, protons of 6.7 GeV are obtained from a 2 × 10{sup 22 }W/cm{sup 2} SG laser pulse and a LG pulse at a lower peak intensity.

  3. CRYSTALLINE BEAMS AT HIGH ENERGIES.

    SciTech Connect

    WEI, J.; OKAMOTO, H.; YURI, Y.; SESSLER, A.; MACHIDA, S.

    2006-06-23

    Previously it was shown that by crystallizing each of the two counter-circulating beams, a much larger beam-beam tune shift can be tolerated during the beam-beam collisions; thus a higher luminosity can be reached for colliding beams [1]. On the other hand, crystalline beams can only be formed at energies below the transition energy ({gamma}{sub T}) of the accelerators [2]. In this paper, we investigate the formation of crystals in a high-{gamma}{sub T} lattice that also satisfies the maintenance condition for a crystalline beam [3].

  4. High energy polarized beams from hyperon decays

    SciTech Connect

    Underwood, D.G.

    1986-01-01

    The use of various ways to utilize lambda decays to obtain polarized beams of protons and antiprotons is emphasized. Examples described are the Fermilab polarized beam, now under construction, and the use of similar techniques at other energies. Beam transport, spin precession and reversal systems, and polarimeters are also discussed. 8 refs., 4 figs.

  5. High energy laser beam dump

    SciTech Connect

    Halpin, John

    2004-09-14

    The laser beam dump is positioned in a housing. An absorbing glass plate means is operatively connected to the housing. A heat sync means for extracting heat from the absorbing glass plate means is operatively connected to the housing and operatively connected to the absorbing glass plate means.

  6. Overview of the APT High-Energy Beam Transport and Beam Expanders

    NASA Astrophysics Data System (ADS)

    Shafer, R. E.; Blind, B.; Gray, E. R.; Gilpatrick, J. D.; Barlow, D.; Lawrence, G. P.

    1997-05-01

    The APT high energy beam transport (HEBT) and beam expanders transport the 1700-MeV, 100-mA cw proton beam from the linac to any of three end stations. The HEBT includes extensive beam diagnostics, collimators, and dejitter correction, to monitor and control the 170-MW proton beam prior to expansion. One zero-degree beam line and two achromatic bends transport the beam to one of three beam expanders. These nonlinear beam expanders, making use of higher order multipole magnets and dithering dipoles, expand the beam to a uniform density, 16-cm wide by 160-cm high rectangular profile on the tritium-production targets. The overall optics design will be reviewed, and beam simulations will be presented.

  7. Polarized proton beams since the ZGS

    SciTech Connect

    Krisch, A.D.

    1994-12-31

    The author discusses research involving polarized proton beams since the ZGS`s demise. He begins by reminding the attendee that in 1973 the ZGS accelerated the world`s first high energy polarized proton beam; all in attendance at this meeting can be proud of this accomplishment. A few ZGS polarized proton beam experiments were done in the early 1970`s; then from about 1976 until 1 October 1979, the majority of the ZGS running time was polarized running. A great deal of fundamental physics was done with the polarized beam when the ZGS ran as a dedicated polarized proton beam from about Fall 1977 until it shut down on 1 October 1979. The newly created polarization enthusiats then dispersed; some spread polarized seeds al over the world by polarizing beams elsewhere; some wound up running the High Energy and SSC programs at DOE.

  8. Overview of the APT high-energy beam transport and beam expanders

    SciTech Connect

    Shafer, R.E.; Blind, B.; Gray, E.R.

    1997-08-01

    The APT high energy beam transport (HEBT) and beam expanders convey the 1700-MeV, 100-mA cw proton beam from the linac to the tritium target/blanket assembly, or a tuning beam stop. The HEBT includes extensive beam diagnostics, collimators, and beam jitter correction, to monitor and control the 170-MW beam prior to expansion. A zero-degree beamline conveys the beam to the beam stop, and an achromatic bend conveys the beam to the tritium production target. Nonlinear beam expanders make use of higher-order multipole magnets and dithering dipoles to expand the beam to a uniform-density, 16-cm wide by 160-cm high rectangular profile on the tritium-production target. The overall optics design will be reviewed, and beam simulations will be presented.

  9. Fundamentals of high energy electron beam generation

    NASA Astrophysics Data System (ADS)

    Turman, B. N.; Mazarakis, M. G.; Neau, E. L.

    High energy electron beam accelerator technology has been developed over the past three decades in response to military and energy-related requirements for weapons simulators, directed-energy weapons, and inertially-confined fusion. These applications required high instantaneous power, large beam energy, high accelerated particle energy, and high current. These accelerators are generally referred to as 'pulsed power' devices, and are typified by accelerating potential of millions of volts (MV), beam current in thousands of amperes (KA), pulse duration of tens to hundreds of nanoseconds, kilojoules of beam energy, and instantaneous power of gigawatts to teffawatts (10(exp 9) to 10(exp 12) watts). Much of the early development work was directed toward single pulse machines, but recent work has extended these pulsed power devices to continuously repetitive applications. These relativistic beams penetrate deeply into materials, with stopping range on the order of a centimeter. Such high instantaneous power deposited in depth offers possibilities for new material fabrication and processing capabilities that can only now be explored. Fundamental techniques of pulse compression, high voltage requirements, beam generation and transport under space-charge-dominated conditions will be discussed in this paper.

  10. Measurement of high energy resolution inelastic proton scattering at and close to zero degrees

    NASA Astrophysics Data System (ADS)

    Tamii, A.; Fujita, Y.; Matsubara, H.; Adachi, T.; Carter, J.; Dozono, M.; Fujita, H.; Fujita, K.; Hashimoto, H.; Hatanaka, K.; Itahashi, T.; Itoh, M.; Kawabata, T.; Nakanishi, K.; Ninomiya, S.; Perez-Cerdan, A. B.; Popescu, L.; Rubio, B.; Saito, T.; Sakaguchi, H.; Sakemi, Y.; Sasamoto, Y.; Shimbara, Y.; Shimizu, Y.; Smit, F. D.; Tameshige, Y.; Yosoi, M.; Zenhiro, J.

    2009-07-01

    Measurements of inelastic proton scattering with high energy resolution at forward scattering angles including 0∘ are described. High-resolution halo-free beams were accelerated by the cyclotron complex at the Research Center for Nuclear Physics. Instrumental background events were minimized using the high-quality beam. The remaining instrumental background events were eliminated by applying a background subtraction method. As a result, clean spectra were obtained even for a heavy target nucleus such as Pb208. A high energy resolution of 20 keV (FWHM) and a scattering angle resolution of ±0.6∘ were achieved at an incident proton energy of 295 MeV.

  11. High Energy Polarized e+e‑ Beams

    NASA Astrophysics Data System (ADS)

    Shatunov, Yu.; Koop, I.; Otboev, A.; Mane, S.

    2016-02-01

    Recently, the wide discussion about Higgs-factory design again returns to problem of high energy polarized electrons and positrons. It’s good known the radiative beam polarization at LEP-collider. It was obtained after spin resonance suppression at Z0 pick, but didn’t appear at energies above 70 GeV due to an enhancement of unavoidable depolarization effects. We examine in this paper various ideas for radiative polarization at TLEP/FCC-ee and formulate some estimates for the polarization buildup time and the asymptotic polarization. Using wigglers, a useful degree of polarization (for energy calibration), with a time constant of about 1 h, may be possible up to the threshold of W pair production. At higher energies such as the threshold of Higgs production, attaining a useful level of polarization may be difficult in a planar ring. With Siberian Snakes, wigglers and some imagination, polarization of reasonable magnitude, with a reasonable time constant (of not more than about 1 h), may be achievable at very high energies.

  12. Single event upset and charge collection measurements using high energy protons and neutrons

    SciTech Connect

    Normand, E.; Oberg, D.L.; Wert, J.L.; Ness, J.D.; Majewski, P.P. ); Wender, S.; Gavron, A. )

    1994-12-01

    RAMs, microcontrollers and surface barrier detectors were exposed to beams of high energy protons and neutrons to measure the induced number of upsets as well as energy deposition. The WNR facility at Los Alamos provided a neutron spectrum similar to that of the atmospheric neutrons. Its effect on devices was compared to that of protons with energies of 200, 400, 500, and 800 MeV. Measurements indicate that SEU cross sections for 400 MeV protons are similar to those induced by the atmospheric neutron spectrum.

  13. Features of possible polarized photon beams at high energy and corresponding physics programme or the proton structure function using real photons

    SciTech Connect

    Tannenbaum, M.J.

    1980-01-01

    In the range of electron energies available at Fermilab, 100 GeV less than or equal to E less than or equal to 500 GeV, coherent Bremsstrahlung in crystals, particularly diamond, gives a huge enhancement to the equivalent photon spectrum at large values of x where x = k/E. The photons in this enhancement are polarized. Requirements on electron beam energy spread, angular divergence and spot size imposed by the use of a diamond as a radiator are discussed. The physics program emphasizes hard processes and tests of QCD using polarization.

  14. Spectroscopic investigation of the formation of hypochlorite, radiolysis by-product in 5 M NaCI featuring high-energy proton beam line experiments.

    SciTech Connect

    Hartmann, T.; Wetteland, C. J.; Marczak, Stanislaw; Walthall, M.; Paviet-Hartmann, P.

    2002-01-01

    Because geological salt formations are considered possible sites for radioactive waste disposal, plausible inundation scenario of salt repository will allow chloride brines to be formed, which consequently will be exposed to radiation from the waste. Key radioelements in Intermediate Level Waste (ILW),H igh Level Waste (HLW) or TRU waste have been found to be plutonium, americium, neptunium, uranium, and technetium. Therefore, the effect of radiolysis on high-saline brine under simulated repository conditions are of particular importance because it results in oxidizing chlorine-containing species, such as hypochlorite (OC1-), and hypochlorous acid (HOCI), which may oxidize actinide species to higher oxidation states. Meaningful predictions of long-term redox conditions in a nuclear repository strongly rely on estimations of G-values of the irradiation-induced formation of the oxidizers OC1- and HOCI. G-values not only depend on the total absorbed doses over the relevant timeframe, but also on the kind of irradiation involved. In fact, the G-values of hypochlorite produced by {alpha}-, {beta}-, {gamma}-, or neutron irradiation differ by an order of magnitude, depending on different LET cross-sections. To overcome the serious constrains and obstacles of conventional radiochemical work within GBq/L activity levels, we are going to simulate {alpha}-irradiation of chloride brines by the adaptation of beam-line experiments. Our long-term goal is to demonstrate how the main oxidizing chloride species such as hypochlorite caused by radiolysis may affect the overall behavior of actinides under salt repository conditions. This paper describes our first steps towards the production, the identification and the determination of these oxidizing species by beam line experiments.

  15. Proton-proton and proton-antiproton elastic scattering at high energies: Theory, phenomenology, and experiment

    SciTech Connect

    Wu, Tai Tsun.

    1990-01-01

    This is a brief review of the progress in the understanding, during the past twenty years, of hadronic elastic scattering near the forward direction at high energies. On the basis of quantum gauge field theories, the Pomeron is found to be a branch cut above 1. Using the physical picture that this result implies, phenomenology for proton-proton and antiproton-proton elastic scattering is constructed. Two noteworthy features are that, at high energies, both the total cross section and the ratio of the integrated elastic cross section to the total cross section to the total cross section are increasing functions of the center-of-mass energy. Detailed predictions are given for the elastic differential cross sections, Coulomb interference and the ratios of the real to imaginary parts of the forward amplitudes. These predictions have been extensively and accurately confirmed by experiments, and have also been given both for future experiments on existing accelerators and for experiments on future accelerators. 14 refs., 2 figs.

  16. Proton-proton and proton-antiproton elastic scattering at high energies: Theory, phenomenology, and experiment

    SciTech Connect

    Wu, Tai Tsun

    1990-12-31

    This is a brief review of the progress in the understanding, during the past twenty years, of hadronic elastic scattering near the forward direction at high energies. On the basis of quantum gauge field theories, the Pomeron is found to be a branch cut above 1. Using the physical picture that this result implies, phenomenology for proton-proton and antiproton-proton elastic scattering is constructed. Two noteworthy features are that, at high energies, both the total cross section and the ratio of the integrated elastic cross section to the total cross section to the total cross section are increasing functions of the center-of-mass energy. Detailed predictions are given for the elastic differential cross sections, Coulomb interference and the ratios of the real to imaginary parts of the forward amplitudes. These predictions have been extensively and accurately confirmed by experiments, and have also been given both for future experiments on existing accelerators and for experiments on future accelerators. 14 refs., 2 figs.

  17. Investigation of high-energy-proton effects in aluminum

    SciTech Connect

    Czajkowski, C.J.; Snead, C.L. Jr.; Todosow, M.

    1997-12-01

    Specimens of 1100 aluminum were exposed to several fluences of 23.5-GeV protons at the Brookhaven Alternating Gradient Synchrotron. Although this energy is above those currently being proposed for spallation-neutron applications, the results can be viewed as indicative of trends and other microstructural evolution with fluence that take place with high-energy proton exposures such as those associated with an increasing ratio of gas generation to dpa. TEM investigation showed significantly larger bubble size and lower density of bubbles compared with lower-energy proton results. Additional testing showed that the tensile strength increased with fluence as expected, but the microhardness decreased, a result for which an intepretation is still under investigation.

  18. Hole-boring radiation pressure acceleration as a basis for producing high-energy proton bunches

    NASA Astrophysics Data System (ADS)

    Robinson, A. P. L.; Trines, R. M. G. M.; Dover, N. P.; Najmudin, Z.

    2012-11-01

    The production of high-energy protons by the ‘hole-boring’ radiation pressure acceleration (HB-RPA) mechanism of laser-driven ion acceleration is examined in the case where the plasma has a density less than a0nc in 2D. Previously this was examined in 1D (Robinson 2011 Phys. Plasmas 18 056701) and was motivated by previous predictions of the non-linear criterion for an ultra-intense laser pulse to penetrate a dense plasma. By reducing the density well below a0nc the proton energies achieved increases considerably, thus leading to proton energies >100 MeV at laser intensities close to current capabilities. The results show that good quality proton beams with proton energies >100 MeV can be obtained via HB-RPA using targets with densities in the range 12-20nc and laser intensities in the range 5 × 1021-3 × 1022 W cm-2.

  19. About multiple scattering of high energy protons in crystal deflectors

    NASA Astrophysics Data System (ADS)

    Taratin, A. M.; Scandale, W.

    2015-07-01

    The process of multiple scattering of high energy protons in a silicon crystal at its amorphous orientation was studied by simulation of proton trajectories in the model of binary collisions and by a straight simulation of the sequences of proton collisions with atoms when their impact parameters are randomly and uniformly distributed on the symmetry cell for a given crystallography direction. The value of the RMS deflection of multiple scattering obtained by the simulation is in a good agreement with the experiment and more than 15% larger than it follows from the Moliere theory. The obtained RMS deflection used in the Gaussian approach of multiple scattering well describes dechanneling of protons in the frame of the planar potential model. Different number of proton collisions with atoms occurs along the same crystal length for different crystal orientations. However, the change of the collision number is compensated by the corresponding change of the mean square deflection in a single collision. Therefore, multiple scattering is the same for different crystal orientations. The generator of multiple scattering for amorphous crystal orientations was proposed.

  20. Possibilities of polarized protons in Sp anti p S and other high energy hadron colliders

    SciTech Connect

    Courant, E.D.

    1984-01-01

    The requirements for collisions with polarized protons in hadron colliders above 200 GeV are listed and briefly discussed. Particular attention is given to the use of the ''Siberan snake'' to eliminate depolarizing resonances, which occur when the spin precession frequency equals a frequency contained in the spectrum of the field seen by the beam. The Siberian snake is a device which makes the spin precession frequency essentially constant by using spin rotators, which precess the spin by 180/sup 0/ about either the longitudinal or transverse horizontal axis. It is concluded that operation with polarized protons should be possible at all the high energy hadron colliders. (LEW)

  1. Si film separation obtained by high energy proton implantation

    SciTech Connect

    Braley, C.; Mazen, F.; Papon, A.-M.; Rieutord, F.; Charvet, A.-M.; Ntsoenzok, E.

    2012-11-06

    High energy protons implantation in the 1-1.5 MeV range can be used to detach free-standing thin silicon films with thickness between 15 and 30 {mu}m. Recently, we showed that Si orientation has a strong effect on the layer separation threshold fluence and efficiency. While complete delamination of (111)Si films is achieved, (100)Si films separation is more challenging due to blistering phenomena or partial separation of the implanted layer. In this work, we study the fracture mechanism in (100) and (111)Si after high energy implantation in order to understand the origin of such a behavior. We notably point out that fracture precursor defects, i.e. the platelets, preferentially form on (111) planes, as a consequence of the low strain level in the damaged region in our implantation conditions. Fracture therefore propagates easily in (111)Si, while it requires higher fluence to overcome unfavorable precursors orientation and propagate in (100)Si.

  2. Superintense ion beam with high energy density

    NASA Astrophysics Data System (ADS)

    Dudnikov, Vadim; Dudnikova, Galina

    2008-04-01

    The energy density of ion beam accumulated in a storage ring can be increased dramatically with using of space charge compensation as was demonstrated in experiments [1]. The intensity of said superintense beam can be far greater than a space charge limit without space charge compensation. The model of secondary plasma build up with secondary ion-electron emission as a source of delayed electrons has been presented and discussed. This model can be used for explanation of bunched beam instability with electron surviving after gap, for prediction of e-cloud generation in coasting and long bunches beam, and can be important for pressure rise in worm and cold sections of storage rings. A fast desorption by ion of physically adsorbed molecules can explain a ``first pulse Instability''. Application of this model for e-p instability selfstabilization and superintense circulating beam accumulation is considered. Importance of secondary plasma for high perveance ion beam stabilization in ion implantation will be considered. Preliminary results of simulation of electron and ion accumulation will be presented. [1]. Belchenko et al., Xth International Particle Accelerator Conference, Protvino, 1977, Vol. 2, p. 287.

  3. High-energy protons from submicron-sized targets

    SciTech Connect

    Bychenkov, V. Yu.; Govras, E. A.; Brantov, A. V.; Popov, K. I.

    2012-07-11

    Improving of intensity contrast ratio of intense short laser pulses is making it possible to use submicron-sized targets, both spherical and plane, in the interest of proton acceleration for different applications. The way of improving of the ion beam quality is utilization of targets with two ion species - heavy ions (majority) and light ions, e.g. protons, (minority). Two different approaches, analytical theory and particle-in-cell simulations (PIC) are presented for studying the characteristics of laser-triggered ions due to the Coulomb-like mechanism of particle acceleration from submicron-sized targets. The comparative analysis of explosions of heterogeneous (layered) and homogeneously mixed targets for production of best quality ion bunches has been performed. We also found the regime of anisotropic proton acceleration from spherical targets with light and heavy ions relevant to the experiments with submicron-diameter droplets from water spray target irradiated by an ultrashort intense laser pulse.

  4. Polarized proton beams in RHIC

    SciTech Connect

    Zelenski, A.

    2010-10-04

    The polarized beam for RHIC is produced in the optically-pumped polarized H{sup -} ion source and then accelerated in Linac to 200 MeV for strip-injection to Booster and further accelerated 24.3 GeV in AGS for injection in RHIC. In 2009 Run polarized protons was successfully accelerated to 250 GeV beam energy. The beam polarization of about 60% at 100 GeV beam energy and 36-42% at 250 GeV beam energy was measured with the H-jet and p-Carbon CNI polarimeters. The gluon contribution to the proton spin was studied in collisions of longitudinally polarized proton beams at 100 x 100 GeV. At 250 x 250 GeV an intermediate boson W production with the longitudinally polarized beams was studied for the first time.

  5. Proton-proton colliding beam facility ISABELLE

    SciTech Connect

    Hahn, H

    1980-01-01

    This paper attempts to present the status of the ISABELLE construction project, which has the objective of building a 400 + 400 GeV proton colliding beam facility. The major technical features of the superconducting accelerators with their projected performance are described. Progress made so far, difficulties encountered, and the program until completion in 1986 is briefly reviewed.

  6. High energy laser testbed for accurate beam pointing control

    NASA Astrophysics Data System (ADS)

    Kim, Dojong; Kim, Jae Jun; Frist, Duane; Nagashima, Masaki; Agrawal, Brij

    2010-02-01

    Precision laser beam pointing is a key technology in High Energy Laser systems. In this paper, a laboratory High Energy Laser testbed developed at the Naval Postgraduate School is introduced. System identification is performed and a mathematical model is constructed to estimate system performance. New beam pointing control algorithms are designed based on this mathematical model. It is shown in both computer simulation and experiment that the adaptive filter algorithm can improve the pointing performance of the system.

  7. Acoustical problems in high energy pulsed E-beams lasers

    NASA Technical Reports Server (NTRS)

    Horton, T. E.; Wylie, K. F.

    1976-01-01

    During the pulsing of high energy, CO2, electron beam lasers, a significant fraction of input energy ultimately appears as acoustical disturbances. The magnitudes of these disturbances were quantified by computer analysis. Acoustical and shock impedance data are presented on materials (Rayleigh type) which show promise in controlling acoustical disturbance in E-beam systems.

  8. Proton beam monitor chamber calibration.

    PubMed

    Gomà, C; Lorentini, S; Meer, D; Safai, S

    2014-09-01

    The first goal of this paper is to clarify the reference conditions for the reference dosimetry of clinical proton beams. A clear distinction is made between proton beam delivery systems which should be calibrated with a spread-out Bragg peak field and those that should be calibrated with a (pseudo-)monoenergetic proton beam. For the latter, this paper also compares two independent dosimetry techniques to calibrate the beam monitor chambers: absolute dosimetry (of the number of protons exiting the nozzle) with a Faraday cup and reference dosimetry (i.e. determination of the absorbed dose to water under IAEA TRS-398 reference conditions) with an ionization chamber. To compare the two techniques, Monte Carlo simulations were performed to convert dose-to-water to proton fluence. A good agreement was found between the Faraday cup technique and the reference dosimetry with a plane-parallel ionization chamber. The differences-of the order of 3%-were found to be within the uncertainty of the comparison. For cylindrical ionization chambers, however, the agreement was only possible when positioning the effective point of measurement of the chamber at the reference measurement depth-i.e. not complying with IAEA TRS-398 recommendations. In conclusion, for cylindrical ionization chambers, IAEA TRS-398 reference conditions for monoenergetic proton beams led to a systematic error in the determination of the absorbed dose to water, especially relevant for low-energy proton beams. To overcome this problem, the effective point of measurement of cylindrical ionization chambers should be taken into account when positioning the reference point of the chamber. Within the current IAEA TRS-398 recommendations, it seems advisable to use plane-parallel ionization chambers-rather than cylindrical chambers-for the reference dosimetry of pseudo-monoenergetic proton beams. PMID:25109620

  9. Propagation of high-energy laser beams through metallic aerosols

    SciTech Connect

    Zardecki, A.; Armstrong, R.L.

    1988-08-01

    By combining the results of the hydrodynamic code CON1D and the beam propagation code LASER, we investigate the propagation of high-energy laser beams through vaporizing metallic aerosols in the regime for which the plasma generation becomes important. An effective plasma absorption coefficient allows us to set up a coupled system of equations describing the system consisting of the beam and vapor. 14 refs., 5 figs.

  10. Development of an abort gap monitor for high-energy proton rings

    SciTech Connect

    Beche, Jean-Francois; Byrd, John; De Santis, Stefano; Denes, Peter; Placidi, Massimo; Turner, William; Zolotorev, Max

    2004-05-03

    The fill pattern in proton synchrotrons usually features an empty gap, longer than the abort kicker raise time, for machine protection. This gap is referred to as the ''abort gap'' and any particles, which may accumulate in it due to injection errors and diffusion between RF buckets, would be lost inside the ring, rather than in the beam dump, during the kicker firing. In large proton rings, due to the high energies involved, it is vital to monitor the build up of charges in the abort gap with a high sensitivity. We present a study of an abort gap monitor based on a photomultiplier with a gated microchannel plate, which would allow for detecting low charge densities by monitoring the synchrotron radiation emitted. We show results of beam test experiments at the Advanced Light Source using a Hamamatsu 5916U MCP-PMT and compare them to the specifications for the Large Hadron Collider

  11. Beam halo in mismatched proton beams.

    SciTech Connect

    Wangler, Thomas P.,; Allen, C. K.; Chan, D.; Colestock, P. L. ,; Crandall, K. R.; Qiang, J.; Garnett, R. W.; Lysenko, W. P.; Gilpatrick, J. D.; Schneider, J. D.; Schulze, M. E.; Sheffield, R. L.; Smith, H. V.

    2002-01-01

    Progress was made during the past decade towards a better understanding of halo formation caused by beam mismatch in high-intensity beams. To test these ideas an experiment was carried out at Los Alamos with proton beams in a 52-quadrupole focusing channel. Rms emittances and beam widths were obtained from measured beam profiles for comparison with the maximum emittance growth predictions of a free-energy model and the maximum haloamplitude predictions of a particle-core model. The experimental results are also compared with multiparticle simulations. In this paper we will present the experimental results and discuss the implications with respect to the validity of both the models and the simulations. Keywords: beam halo, emittance growth, beam profiles, simulations, space charge, mismatch

  12. BEAM HALO IN PROTON LINAC BEAMS

    SciTech Connect

    T. WANGLER; K. CRANDALL

    2000-08-01

    In this paper we review the present picture of km halo in proton linacs. Space-charge forces acting in mismatched beams have been identified as a major cause of beam-halo. We present a definition of halo based on a ratio of moments of the distribution of the beam coordinates. We find from our initial studies that for halo detined in this way, a beam can have rms emittance growth without halo growth, but halo growth is always accompanied by rms emittance growth. We describe the beam-halo experiment that is in preparation at Los Alamos, which will address questions about the beam profiles, maximum particle amplitudes, and rms emittance growth associated with the halo.

  13. Proton-Proton On Shell Optical Potential at High Energies and the Hollowness Effect

    NASA Astrophysics Data System (ADS)

    Arriola, Enrique Ruiz; Broniowski, Wojciech

    2016-04-01

    We analyze the usefulness of the optical potential as suggested by the double spectral Mandelstam representation at very high energies, such as in the proton-proton scattering at ISR and the LHC. Its particular meaning regarding the interpretation of the scattering data up to the maximum available measured energies is discussed. Our analysis reconstructs 3D dynamics from the effective transverse 2D impact parameter representation and suggests that besides the onset of gray nucleons at the LHC there appears an inelasticity depletion (hollowness) which precludes convolution models at the attometer scale.

  14. Proton-Proton On Shell Optical Potential at High Energies and the Hollowness Effect

    NASA Astrophysics Data System (ADS)

    Arriola, Enrique Ruiz; Broniowski, Wojciech

    2016-07-01

    We analyze the usefulness of the optical potential as suggested by the double spectral Mandelstam representation at very high energies, such as in the proton-proton scattering at ISR and the LHC. Its particular meaning regarding the interpretation of the scattering data up to the maximum available measured energies is discussed. Our analysis reconstructs 3D dynamics from the effective transverse 2D impact parameter representation and suggests that besides the onset of gray nucleons at the LHC there appears an inelasticity depletion (hollowness) which precludes convolution models at the attometer scale.

  15. Laser-Produced and Accelerated High Energy Protons

    NASA Astrophysics Data System (ADS)

    Cowan, Thomas

    2005-04-01

    Ultra-low emittance, multi-MeV proton beams have recently been produced by the interaction of high-intensity short-pulse lasers with thin metallic foils [1]. The acceleration process proceeds in two steps. First the laser ponderomotively accelerates huge, MA currents of ˜MeV electrons which propagate through the foil and form a dense relativistic electron sheath on the non-irradiated rear surface. This sheath produces an electrostatic field >10^12 V/m that ionizes the surface atoms almost instantaneously, forming a ˜1 nm thick ion layer which, together with the electron sheath, resembles a virtual cathode. The ions are accelerated initially normal to the foil surface, followed by a diverging plasma expansion phase driven by the electron plasma pressure. By structuring the rear surface of the foil, we have succeeded to produce modulations in the transverse phase space of the ions, which resemble fiducial ``beamlets'' within the envelope of the expanding plasma. This allows one to image the initial accelerating sheath, and map the plasma expansion of the beam envelope, to fully reconstruct the transverse phase space. We find that for protons of 10 MeV, the normalized transverse rms emittance is less than 0.004 π mm.mrad [1], i.e. 100-fold better than typical RF accelerators and at substantially higher ion currents exceeding 10 kA. Recent results will be reported on stripping the electrons while maintaining the low emittance from experiments at the LULI 100 TW laser, and theoretical estimates of the lowest emittance which can be expected based on ion heating mechanisms during the initial sheath formation and ion acceleration processes, will be presented. [1] T.E. Cowan, J. Fuchs, H. Ruhl et al., Phys. Rev. Lett. 92, 204801 (2004).

  16. Ion Desorption Stability in Superconducting High Energy Physics Proton Colliders

    SciTech Connect

    Turner, W.C.

    1995-05-29

    In this paper we extend our previous analysis of cold beam tube vacuum in a superconducting proton collider to include ion desorption in addition to thermal desorption and synchrotron radiation induced photodesorption. The new ion desorption terms introduce the possibility of vacuum instability. This is similar to the classical room temperature case but now modified by the inclusion of ion desorption coefficients for cryosorbed (physisorbed) molecules which can greatly exceed the coefficients for tightly bound molecules. The sojourn time concept for physisorbed H{sub 2} is generalized to include photodesorption and ion desorption as well as the usually considered thermal desorption. The ion desorption rate is density dependent and divergent so at the onset of instability the sojourn time goes to zero. Experimental data are used to evaluate the H{sub 2} sojourn time for the conditions of the Large Hadron Collider (LHC) and the situation is found to be stable. The sojourn time is dominated by photodesorption for surface density s(H{sub 2}) less than a monolayer and by thermal deposition for s(H{sub 2}) greater than a monolayer. For a few percent of a monolayer, characteristic of a beam screen, the photodesorption rate exceeds ion desorption rate by more than two orders of magnitude. The photodesorption rate corresponds to a sojourn time of approximately 100 sec. The paper next turns to the evaluation of stability margins and inclusion of gases heavier than H{sub 2} (CO, CO{sub 2} and CH{sub 4}), where ion desorption introduces coupling between molecular species. Stability conditions are worked out for a simple cold beam tube, a cold beam tube pumped from the ends and a cold beam tube with a co-axial perforated beam screen. In each case a simple inequality for stability of a single component is replaced by a determinant that must be greater than zero for a gas mixture. The connection with the general theory of feedback stability is made and it is shown that the gains

  17. CGC/saturation approach for high energy soft interactions: v2 in proton-proton collisions

    NASA Astrophysics Data System (ADS)

    Gotsman, E.; Levin, E.; Maor, U.; Tapia, S.

    2016-04-01

    In this paper we continue our program to construct a model for high energy soft interactions, based on the CGC/saturation approach. We demonstrate that in our model, which describes diffractive physics as well as multiparticle production at high energy, the density variation mechanism leads to the value of v2 , which is about 60%-70% of the measured v2 . Bearing in mind that in the CGC/saturation approach there are two other mechanisms present, Bose enhancement in the wave function and local anisotropy, we believe that the azimuthal long range rapidity correlations in proton-proton collisions stem from the CGC/saturation physics, and not from quark-gluon plasma production.

  18. Optical system design for high-energy particle beam diagnostics.

    SciTech Connect

    Yang, B. X. Y.

    2002-08-29

    Radiation generated by high-energy particle beams is widely used to characterize the beam properties. While the wavelengths of radiation may vary from visible to x-rays, the physics underlying the engineering designs are similar. In this tutorial, we discuss the basic considerations for the optical system design in the context of beam instrumentation and the constraints applied by high-radiation environments. We cover commonly used optical diagnostics: fluorescence flags, visible and x-ray synchrotron radiation imaging. Emphases will be on achieving desired resolution, accuracy, and reproducibility.

  19. Focusing dynamics of high-energy density, laser-driven ion beams.

    PubMed

    Chen, S N; d'Humières, E; Lefebvre, E; Romagnani, L; Toncian, T; Antici, P; Audebert, P; Brambrink, E; Cecchetti, C A; Kudyakov, T; Pipahl, A; Sentoku, Y; Borghesi, M; Willi, O; Fuchs, J

    2012-02-01

    The dynamics of the focusing of laser-driven ion beams produced from concave solid targets was studied. Most of the ion beam energy is observed to converge at the center of the cylindrical targets with a spot diameter of 30  μm, which can be very beneficial for applications requiring high beam energy densities. Also, unbalanced laser irradiation does not compromise the focusability of the beam. However, significant filamentation occurs during the focusing, potentially limiting the localization of the energy deposition region by these beams at focus. These effects could impact the applicability of such high-energy density beams for applications, e.g., in proton-driven fast ignition. PMID:22400936

  20. High-efficiency deflection of high energy protons due to channeling along the <110> axis of a bent silicon crystal

    NASA Astrophysics Data System (ADS)

    Scandale, W.; Arduini, G.; Butcher, M.; Cerutti, F.; Garattini, M.; Gilardoni, S.; Lechner, A.; Masi, A.; Mirarchi, D.; Montesano, S.; Redaelli, S.; Rossi, R.; Smirnov, G.; Breton, D.; Burmistrov, L.; Chaumat, V.; Dubos, S.; Maalmi, J.; Puill, V.; Stocchi, A.; Bagli, E.; Bandiera, L.; Germogli, G.; Guidi, V.; Mazzolari, A.; Dabagov, S.; Murtas, F.; Addesa, F.; Cavoto, G.; Iacoangeli, F.; Galluccio, F.; Afonin, A. G.; Chesnokov, Yu. A.; Durum, A. A.; Maisheev, V. A.; Sandomirskiy, Yu. E.; Yanovich, A. A.; Kovalenko, A. D.; Taratin, A. M.; Denisov, A. S.; Gavrikov, Yu. A.; Ivanov, Yu. M.; Lapina, L. P.; Malyarenko, L. G.; Skorobogatov, V. V.; James, T.; Hall, G.; Pesaresi, M.; Raymond, M.

    2016-09-01

    A deflection efficiency of about 61% was observed for 400 GeV/c protons due to channeling, most strongly along the <110> axis of a bent silicon crystal. It is comparable with the deflection efficiency in planar channeling and considerably larger than in the case of the <111> axis. The measured probability of inelastic nuclear interactions of protons in channeling along the <110> axis is only about 10% of its amorphous level whereas in channeling along the (110) planes it is about 25%. High efficiency deflection and small beam losses make this axial orientation of a silicon crystal a useful tool for the beam steering of high energy charged particles.

  1. Spacecraft Power Beaming Using High-Energy Lasers, Experimental Validation

    SciTech Connect

    Michael, Sherif

    2008-04-28

    The lifetime of many spacecrafts are often limited by degradation of their electrical power subsystem, e.g. radiation-damaged solar arrays or failed batteries. Being able to beam power from terrestrial sites using high energy lasers, could alleviate this limitation, extending the lifetime of billions of dollars of satellite assets, as well as providing additional energy for electric propulsion that can be used for stationkeeping and orbital changes. In addition, extensive research at the Naval Postgraduate School (NPS) has shown the potential for annealing damaged solar cells using lasers. This paper describes that research and a proposed experiment to demonstrate the relevant concepts of high energy laser power beaming to an NPS-built and operated satellite. Preliminary results of ground experiment of laser illuminations of some of the solar panels of one of the spacecrafts are also presented.

  2. Spacecraft Power Beaming Using High-Energy Lasers, Experimental Validation

    NASA Astrophysics Data System (ADS)

    Michael, Sherif

    2008-04-01

    The lifetime of many spacecrafts are often limited by degradation of their electrical power subsystem, e.g. radiation-damaged solar arrays or failed batteries. Being able to beam power from terrestrial sites using high energy lasers, could alleviate this limitation, extending the lifetime of billions of dollars of satellite assets, as well as providing additional energy for electric propulsion that can be used for stationkeeping and orbital changes. In addition, extensive research at the Naval Postgraduate School (NPS) has shown the potential for annealing damaged solar cells using lasers. This paper describes that research and a proposed experiment to demonstrate the relevant concepts of high energy laser power beaming to an NPS-built and operated satellite. Preliminary results of ground experiment of laser illuminations of some of the solar panels of one of the spacecrafts are also presented.

  3. Test of an amorphous silicon detector in medical proton beams

    NASA Astrophysics Data System (ADS)

    Martišíková, M.; Hesse, B. M.; Nairz, O.; Jäkel, O.

    2011-05-01

    Ion beam radiation therapy for cancer treatment allows for improved dose confinement to the target in comparison with the standard radiation therapy using high energy photons. Dose delivery to the patient using focused ion beam scanning over the target volume is going to be increasingly used in the upcoming years. The high precision of the dose delivery achieved in this way has to be met by practical methods for beam monitoring with sufficient spatial resolution in two dimensions. Flat panel detectors, used for photon portal imaging at the newest medical linear accelerators, are an interesting candidate for this purpose. Initial detector tests presented here were performed using proton beams with the highest available energy. The investigations include measurements of beam profiles at different beam intensities and for different beam width, as well as the signal linearity. Radiation damage was also investigated. The obtained results show that the detector is a promising candidate to be used in the therapeutic proton beams.

  4. High-energy proton imaging for biomedical applications

    DOE PAGESBeta

    Prall, Matthias; Durante, Marco; Berger, Thomas; Przybyla, B.; Graeff, C.; Lang, Phillipp M.; LaTessa, Ciara; Shestov, Less; Simoniello, P.; Danly, Christopher R.; et al

    2016-06-10

    The charged particle community is looking for techniques exploiting proton interactions instead of X-ray absorption for creating images of human tissue. Due to multiple Coulomb scattering inside the measured object it has shown to be highly non-trivial to achieve sufficient spatial resolution. We present imaging of biological tissue with a proton microscope. This device relies on magnetic optics, distinguishing it from most published proton imaging methods. For these methods reducing the data acquisition time to a clinically acceptable level has turned out to be challenging. In a proton microscope, data acquisition and processing are much simpler. This device even allowsmore » imaging in real time. The primary medical application will be image guidance in proton radiosurgery. Proton images demonstrating the potential for this application are presented. As a result, tomographic reconstructions are included to raise awareness of the possibility of high-resolution proton tomography using magneto-optics.« less

  5. High-energy proton imaging for biomedical applications

    NASA Astrophysics Data System (ADS)

    Prall, M.; Durante, M.; Berger, T.; Przybyla, B.; Graeff, C.; Lang, P. M.; Latessa, C.; Shestov, L.; Simoniello, P.; Danly, C.; Mariam, F.; Merrill, F.; Nedrow, P.; Wilde, C.; Varentsov, D.

    2016-06-01

    The charged particle community is looking for techniques exploiting proton interactions instead of X-ray absorption for creating images of human tissue. Due to multiple Coulomb scattering inside the measured object it has shown to be highly non-trivial to achieve sufficient spatial resolution. We present imaging of biological tissue with a proton microscope. This device relies on magnetic optics, distinguishing it from most published proton imaging methods. For these methods reducing the data acquisition time to a clinically acceptable level has turned out to be challenging. In a proton microscope, data acquisition and processing are much simpler. This device even allows imaging in real time. The primary medical application will be image guidance in proton radiosurgery. Proton images demonstrating the potential for this application are presented. Tomographic reconstructions are included to raise awareness of the possibility of high-resolution proton tomography using magneto-optics.

  6. High-energy proton imaging for biomedical applications

    PubMed Central

    Prall, M.; Durante, M.; Berger, T.; Przybyla, B.; Graeff, C.; Lang, P. M.; LaTessa, C.; Shestov, L.; Simoniello, P.; Danly, C.; Mariam, F.; Merrill, F.; Nedrow, P.; Wilde, C.; Varentsov, D.

    2016-01-01

    The charged particle community is looking for techniques exploiting proton interactions instead of X-ray absorption for creating images of human tissue. Due to multiple Coulomb scattering inside the measured object it has shown to be highly non-trivial to achieve sufficient spatial resolution. We present imaging of biological tissue with a proton microscope. This device relies on magnetic optics, distinguishing it from most published proton imaging methods. For these methods reducing the data acquisition time to a clinically acceptable level has turned out to be challenging. In a proton microscope, data acquisition and processing are much simpler. This device even allows imaging in real time. The primary medical application will be image guidance in proton radiosurgery. Proton images demonstrating the potential for this application are presented. Tomographic reconstructions are included to raise awareness of the possibility of high-resolution proton tomography using magneto-optics. PMID:27282667

  7. High-energy proton imaging for biomedical applications.

    PubMed

    Prall, M; Durante, M; Berger, T; Przybyla, B; Graeff, C; Lang, P M; LaTessa, C; Shestov, L; Simoniello, P; Danly, C; Mariam, F; Merrill, F; Nedrow, P; Wilde, C; Varentsov, D

    2016-01-01

    The charged particle community is looking for techniques exploiting proton interactions instead of X-ray absorption for creating images of human tissue. Due to multiple Coulomb scattering inside the measured object it has shown to be highly non-trivial to achieve sufficient spatial resolution. We present imaging of biological tissue with a proton microscope. This device relies on magnetic optics, distinguishing it from most published proton imaging methods. For these methods reducing the data acquisition time to a clinically acceptable level has turned out to be challenging. In a proton microscope, data acquisition and processing are much simpler. This device even allows imaging in real time. The primary medical application will be image guidance in proton radiosurgery. Proton images demonstrating the potential for this application are presented. Tomographic reconstructions are included to raise awareness of the possibility of high-resolution proton tomography using magneto-optics. PMID:27282667

  8. High-energy accelerator for beams of heavy ions

    DOEpatents

    Martin, Ronald L.; Arnold, Richard C.

    1978-01-01

    An apparatus for accelerating heavy ions to high energies and directing the accelerated ions at a target comprises a source of singly ionized heavy ions of an element or compound of greater than 100 atomic mass units, means for accelerating the heavy ions, a storage ring for accumulating the accelerated heavy ions and switching means for switching the heavy ions from the storage ring to strike a target substantially simultaneously from a plurality of directions. In a particular embodiment the heavy ion that is accelerated is singly ionized hydrogen iodide. After acceleration, if the beam is of molecular ions, the ions are dissociated to leave an accelerated singly ionized atomic ion in a beam. Extraction of the beam may be accomplished by stripping all the electrons from the atomic ion to switch the beam from the storage ring by bending it in magnetic field of the storage ring.

  9. Isochoric heating of matter by laser-accelerated high-energy protons

    NASA Astrophysics Data System (ADS)

    Fuchs, Julien; Mancic, Ana; Robiche, Jerome; Antici, Patrizio; Lancia, Livia; Audebert, Patrick; Combis, Patrick; Renaudin, Patrick; Kimura, Tomoaki; Kodama, Ryosuke; Nakatsutsumi, Motoaki

    2008-04-01

    Producing matter at a high temperature (1-25 eV) and solid density is of prime interest for fundamental plasma physics or ICF. The use of laser-based high energy proton beams to achieve such state of matter is interesting since they are short (< 1 ps) and they deposit their energy volumetrically; thus can heat, before they expand, much thicker samples than allowed using laser-heating. We performed, using two intense short pulses of the LULI 100 TW facility, experiments to characterize the achieved state of matter, coupled to a detailed hydro-modeling. A laser-generated proton beam irradiated and heated a secondary target positioned after a vacuum gap. Three diagnostics were used: (i) 1D time-resolved optical self-emission of the heated target rear-surface at two wavelengths, (ii) time-resolved interferometry of a chirped probe beam reflecting off the heated target rear-surface, (iii) x-ray absorption spectroscopy through the heated target using a laser-produced backlighter detecting its Kα-edge softening.

  10. High energy density plasma science with an ultrarelativistic electron beam

    NASA Astrophysics Data System (ADS)

    Joshi, C.; Blue, B.; Clayton, C. E.; Dodd, E.; Huang, C.; Marsh, K. A.; Mori, W. B.; Wang, S.; Hogan, M. J.; O'Connell, C.; Siemann, R.; Watz, D.; Muggli, P.; Katsouleas, T.; Lee, S.

    2002-05-01

    An intense, high-energy electron or positron beam can have focused intensities rivaling those of today's most powerful laser beams. For example, the 5 ps (full-width, half-maximum), 50 GeV beam at the Stanford Linear Accelerator Center (SLAC) at 1 kA and focused to a 3 micron rms spot size gives intensities of >1020 W/cm-2 at a repetition rate of >10 Hz. Unlike a ps or fs laser pulse which interacts with the surface of a solid target, the particle beam can readily tunnel through tens of cm of steel. However, the same particle beam can be manipulated quite effectively by a plasma that is a million times less dense than air! This is because of the incredibly strong collective fields induced in the plasma by the Coulomb force of the beam. The collective fields in turn react back onto the beam leading to many clearly observable phenomena. The beam paraticles can be: (1) Deflected leading to focusing, defocusing, or even steering of the beam; (2) undulated causing the emission of spontaneous betatron x-ray radiation and; (3) accelerated or decelerated by the plasma fields. Using the 28.5 GeV electron beam from the SLAC linac a series of experiments have been carried out that demonstrate clearly many of the above mentioned effects. The results can be compared with theoretical predictions and with two-dimensional and three-dimensional, one-to-one, particle-in-cell code simulations. These phenomena may have practical applications in future technologies including optical elements in particle beam lines, synchrotron light sources, and ultrahigh gradient accelerators.

  11. Fast IMRT with narrow high energy scanned photon beams

    SciTech Connect

    Andreassen, Bjoern; Straaring t, Sara Janek; Holmberg, Rickard; Naefstadius, Peder; Brahme, Anders

    2011-08-15

    Purpose: Since the first publications on intensity modulated radiation therapy (IMRT) in the early 1980s almost all efforts have been focused on fairly time consuming dynamic or segmental multileaf collimation. With narrow fast scanned photon beams, the flexibility and accuracy in beam shaping increases, not least in combination with fast penumbra trimming multileaf collimators. Previously, experiments have been performed with full range targets, generating a broad bremsstrahlung beam, in combination with multileaf collimators or material compensators. In the present publication, the first measurements with fast narrow high energy (50 MV) scanned photon beams are presented indicating an interesting performance increase even though some of the hardware used were suboptimal. Methods: Inverse therapy planning was used to calculate optimal scanning patterns to generate dose distributions with interesting properties for fast IMRT. To fully utilize the dose distributional advantages with scanned beams, it is necessary to use narrow high energy beams from a thin bremsstrahlung target and a powerful purging magnet capable of deflecting the transmitted electron beam away from the generated photons onto a dedicated electron collector. During the present measurements the scanning system, purging magnet, and electron collimator in the treatment head of the MM50 racetrack accelerator was used with 3-6 mm thick bremsstrahlung targets of beryllium. The dose distributions were measured with diodes in water and with EDR2 film in PMMA. Monte Carlo simulations with geant4 were used to study the influence of the electrons transmitted through the target on the photon pencil beam kernel. Results: The full width at half-maximum (FWHM) of the scanned photon beam was 34 mm measured at isocenter, below 9.5 cm of water, 1 m from the 3 mm Be bremsstrahlung target. To generate a homogeneous dose distribution in a 10 x 10 cm{sup 2} field, the authors used a spot matrix of 100 equal intensity

  12. High energy electron beam irradiation of water, wastewater and sludge

    SciTech Connect

    Kurucz, C.N.; Waite, T.D.; Cooper, W.J.; Nickelsen, M.J.

    1991-12-31

    Research on the use of high energy electrons for treating water, wastewater and wastewater sludge has been under way for approximately twenty years. Much of this work has been supported by the National Science Foundation and an overview of that support has been reported on by Bryan. The results of recent work, especially the most recent project at the Miami Electron Beam Research Facility (EBRF), has stimulated great interest in the area of utilizing this technology for treating environmental problems. This facility is located at the Miami Dade Central District (Virginia Key) Wastewater Treatment Plant in Miami, Florida, and is unique in that it is the only electron beam system set up for large scale treatment of wastewater. High energy electron beam irradiation as a treatment process has potential application in many areas of water, wastewater and industrial waste treatment and in the area of toxic/hazardous waste disposal. This chapter will discuss these applications and present selected results to date. Electron beam technology is described and the underlying chemistry is reviewed to provide a basis for interpretation of results obtained so far, and to point out the necessary information on water quality that is required to quantitatively describe the effectiveness of the process. 55 refs., 10 figs., 5 tabs.

  13. High Energy Density Science with Ultrarelativistic Electron Beams

    NASA Astrophysics Data System (ADS)

    Joshi, Chan

    2001-10-01

    An intense, high-energy electron or positron beam can have focused intensities rivaling those of today's most powerful lasers. For example, the 5 ps (FWHM), 50 GeV beam at the Stanford Linear Accelerator Center at 1 kA and focused to a 3 micron rms spot size gives intensities of > 10^20 W/cm^2 at a repetition rate of 10 Hz. Unlike a ps or fs laser pulse, the particle beam can readily bore through several mm of steel due to the rigidity of its flux component. However, the same particle beam can be manipulated quite strongly by a plasma that is a million times less dense than air! This is because of the incredibly strong collective fields induced in the plasma by the Coulomb force of the beam. The collective fields in turn react back onto the beam leading to many clearly-observable phenomena. The beam can be: (1) deflected leading focusing, defocusing, or even steering of the beam; (2) undulated causing the emission of spontaneous betatron x-ray radiation and; (3) accelerated or de-accelerated by the plasma fields. Using the 28.5 GeV electron and positron beams from the SLAC linac we have carried out a series of experiments that demonstrate clearly the above mentioned effects. The results are compared with theoretical predictions and 3D, one-to-one PIC code simulations using the code OSIRIS. These phenomena may have practical application in future technologies including optical elements in particle beam lines, synchrotron light sources, and ultra-high gradient accelerators.

  14. HIGH ENERGY DENSITY PHYSICS EXPERIMENTS WITH INTENSE HEAVY ION BEAMS

    SciTech Connect

    Henestroza, E.; Leitner, M.; Logan, B.G.; More, R.M.; Roy, P.K.; Ni, P.; Seidl, P.A.; Waldron, W.L.; Barnard, J.J.

    2010-03-16

    The US heavy ion fusion science program has developed techniques for heating ion-beam-driven warm dense matter (WDM) targets. The WDM conditions are to be achieved by combined longitudinal and transverse space-charge neutralized drift compression of the ion beam to provide a hot spot on the target with a beam spot size of about 1 mm, and pulse length about 1-2 ns. As a technique for heating volumetric samples of matter to high energy density, intense beams of heavy ions are capable of delivering precise and uniform beam energy deposition dE/dx, in a relatively large sample size, and the ability to heat any solid-phase target material. Initial experiments use a 0.3 MeV K+ beam (below the Bragg peak) from the NDCX-I accelerator. Future plans include target experiments using the NDCX-II accelerator, which is designed to heat targets at the Bragg peak using a 3-6 MeV lithium ion beam. The range of the beams in solid matter targets is about 1 micron, which can be lengthened by using porous targets at reduced density. We have completed the fabrication of a new experimental target chamber facility for WDM experiments, and implemented initial target diagnostics to be used for the first target experiments in NDCX-1. The target chamber has been installed on the NDCX-I beamline. The target diagnostics include a fast multi-channel optical pyrometer, optical streak camera, VISAR, and high-speed gated cameras. Initial WDM experiments will heat targets by compressed NDCX-I beams and will explore measurement of temperature and other target parameters. Experiments are planned in areas such as dense electronegative targets, porous target homogenization and two-phase equation of state.

  15. HIGH ENERGY DENSITY PHYSICS EXPERIMENTS WITH INTENSE HEAVY ION BEAMS

    SciTech Connect

    Bieniosek, F.M.; Henestroza, E.; Leitner, M.; Logan, B.G.; More, R.M.; Roy, P.K.; Ni, P.; Seidl, P.A.; Waldron, W.L.; Barnard, J.J.

    2008-08-01

    The US heavy ion fusion science program has developed techniques for heating ion-beam-driven warm dense matter (WDM) targets. The WDM conditions are to be achieved by combined longitudinal and transverse space-charge neutralized drift compression of the ion beam to provide a hot spot on the target with a beam spot size of about 1 mm, and pulse length about 1-2 ns. As a technique for heating volumetric samples of matter to high energy density, intense beams of heavy ions are capable of delivering precise and uniform beam energy deposition dE/dx, in a relatively large sample size, and the ability to heat any solid-phase target material. Initial experiments use a 0.3 MeV K+ beam (below the Bragg peak) from the NDCX-I accelerator. Future plans include target experiments using the NDCX-II accelerator, which is designed to heat targets at the Bragg peak using a 3-6 MeV lithium ion beam. The range of the beams in solid matter targets is about 1 micron, which can be lengthened by using porous targets at reduced density. We have completed the fabrication of a new experimental target chamber facility for WDM experiments, and implemented initial target diagnostics to be used for the first target experiments in NDCX-1. The target chamber has been installed on the NDCX-I beamline. The target diagnostics include a fast multi-channel optical pyrometer, optical streak camera, VISAR, and high-speed gated cameras. Initial WDM experiments will heat targets by compressed NDCX-I beams and will explore measurement of temperature and other target parameters. Experiments are planned in areas such as dense electronegative targets, porous target homogenization and two-phase equation of state.

  16. Highly Compressed Ion Beam for High Energy Density Science

    SciTech Connect

    Friedman, A.; Barnard, J.J.; Briggs, R.J.; Callahan, D.A.; Caporaso, G.J.; Celata, C.M.; Davidson, R.C.; Faltens, A.; Grisham, L.; Grote, D.P.; Henestroza, E.; Kaganovich I.; Lee, E.P.; Lee, R.W.; Leitner, M.; Logan, B.G.; Nelson, S.D.; Olson, C.L.; Penn, G.; Reginato,L.R.; Renk, T.; Rose, D.; Seessler, A.; Staples, J.W.; Tabak, M.; Thoma,C.; Waldron, W.; Welch, D.R.; Wurtele, J.; Yu, S.S.

    2005-05-16

    The Heavy Ion Fusion Virtual National Laboratory is developing the intense ion beams needed to drive matter to the High Energy Density regimes required for Inertial Fusion Energy and other applications. An interim goal is a facility for Warm Dense Matter studies, wherein a target is heated volumetrically without being shocked, so that well-defined states of matter at 1 to 10 eV are generated within a diagnosable region. In the approach they are pursuing, low to medium mass ions with energies just above the Bragg peak are directed onto thin target ''foils,'' which may in fact be foams with mean densities 1% to 10% of solid. This approach complements that being pursued at GSI Darmstadt, wherein high-energy ion beams deposit a small fraction of their energy in a cylindrically target. They present the beam requirements for Warm Dense Matter experiments. The authors discuss neutralized drift compression and final focus experiments and modeling. They describe suitable accelerator architectures based on Drift-Tube Linac, RF, single-gap, Ionization-Front Accelerator, and Pulse-Line Ion Accelerator concepts. The last of these is being pursued experimentally. Finally, they discuss plans toward a user facility for target experiments.

  17. Feasibility of ceramic joining with high energy electron beams

    SciTech Connect

    Turman, B.N.; Glass, S.J.; Halbleib, J.A.; Helmich, D.R.; Loehman, R.E.; Clifford, J.R.

    1995-01-01

    Joining structural ceramics is possible using high melting point metals such as Mo and Pt that are heated with a high energy electron beam, with the potential for producing joints with high temperature capability. A 10 MeV electron beam can penetrate through 1 cm of ceramic, offering the possibility of buried interface joining. Because of transient heating and the lower heat capacity of the metal relative to the ceramic, a pulsed high power beam has the potential for melting the metal without decomposing or melting the adjacent ceramic. The authors have demonstrated the feasibility of the process with a series of 10 MeV, 1 kW electron beam experiments. Shear strengths up to 28 NTa have been measured for Si{sub 3}N{sub 4}-Mo-Si{sub 3}N{sub 4}. These modest strengths are due to beam non-uniformity and the limited area of bonding. The bonding mechanism appears to be a thin silicide reaction layer. Si{sub 3}N{sub 4}-Si{sub 3}N{sub 4} joints with no metal layer were also produced, apparently bonded an yttrium apatite grain boundary phase.

  18. Production of Actinium-225 via High Energy Proton Induced Spallation of Thorium-232

    SciTech Connect

    Harvey, James T.; Nolen, Jerry; Vandergrift, George; Gomes, Itacil; Kroc, Tom; Horwitz, Phil; McAlister, Dan; Bowers, Del; Sullivan, Vivian; Greene, John

    2011-12-30

    The science of cancer research is currently expanding its use of alpha particle emitting radioisotopes. Coupled with the discovery and proliferation of molecular species that seek out and attach to tumors, new therapy and diagnostics are being developed to enhance the treatment of cancer and other diseases. This latest technology is commonly referred to as Alpha Immunotherapy (AIT). Actinium-225/Bismuth-213 is a parent/daughter alpha-emitting radioisotope pair that is highly sought after because of the potential for treating numerous diseases and its ability to be chemically compatible with many known and widely used carrier molecules (such as monoclonal antibodies and proteins/peptides). Unfortunately, the worldwide supply of actinium-225 is limited to about 1,000mCi annually and most of that is currently spoken for, thus limiting the ability of this radioisotope pair to enter into research and subsequently clinical trials. The route proposed herein utilizes high energy protons to produce actinium-225 via spallation of a thorium-232 target. As part of previous R and D efforts carried out at Argonne National Laboratory recently in support of the proposed US FRIB facility, it was shown that a very effective production mechanism for actinium-225 is spallation of thorium-232 by high energy proton beams. The base-line simulation for the production rate of actinium-225 by this reaction mechanism is 8E12 atoms per second at 200 MeV proton beam energy with 50 g/cm2 thorium target and 100 kW beam power. An irradiation of one actinium-225 half-life (10 days) produces {approx}100 Ci of actinium-225. For a given beam current the reaction cross section increases slightly with energy to about 400 MeV and then decreases slightly for beam energies in the several GeV regime. The object of this effort is to refine the simulations at proton beam energies of 400 MeV and above up to about 8 GeV. Once completed, the simulations will be experimentally verified using 400 MeV and 8 Ge

  19. Radiation damage in zircon by high-energy electron beams

    SciTech Connect

    Jiang Nan; Spence, John C. H.

    2009-06-15

    Radiation damage induced by high-energy (200 keV) electron irradiation in zircon has been studied thoroughly using imaging, diffraction, and electron energy-loss spectroscopy techniques in transmission electron microscopy. Both structural and compositional changes during the damage were measured using the above techniques in real time. It was found that the damage was mainly caused by the preferential sputtering of O. The loss of O occurred initially within small sporadic regions with dimension of several nanometers, resulting in the direct transformation of zircon into Zr{sub x}Si{sub y}. These isolated patches gradually connect each other and eventually cover the whole area of the electron beam. These differ from the previous observations either in the self-irradiated natural and synthetic zircon or in ion-beam irradiated thin zircon specimen.

  20. Producing titanium-niobium alloy by high energy beam

    NASA Astrophysics Data System (ADS)

    Sharkeev, Yu. P.; Golkovski, M. G.; Glukhov, I. A.; Eroshenko, A. Yu.; Bataev, V. A.; Fortuna, S. V.

    2016-01-01

    The research is involved in producing a Ti-Nb alloy surface layer on titanium substrate by high energy beam method, as well as in examining their structures and mechanical properties. Applying electron-beam cladding it was possible to produce a Ti-Nb alloy surface layer of several millimeters, where the niobium concentration was up to 40% at. and the structure itself could be related to martensite quenching structure. At the same time, a significant microhardness increase of 3200-3400 MPa was observed, which, in its turn, is connected with the formation of martensite structure. Cladding material of Ti-Nb composition could be the source in producing alloys of homogeneous microhardness and desired concentration of alloying niobium element.

  1. Fragmentation of positively-charged biological ions activated with a beam of high-energy cations.

    PubMed

    Chingin, Konstantin; Makarov, Alexander; Denisov, Eduard; Rebrov, Oleksii; Zubarev, Roman A

    2014-01-01

    First results are reported on the fragmentation of multiply protonated polypeptide ions produced in electrospray ionization mass spectrometry (ESI-MS) with a beam of high-energy cations as a source of activation. The ion beam is generated with a microwave plasma gun installed on a benchtop Q Exactive mass spectrometer. Precursor polypeptide ions are activated when trapped inside the collision cell of the instrument (HCD cell), and product species are detected in the Orbitrap analyzer. Upon exposure to the beam of air plasma cations (∼100 μA, 5 s), model precursor species such as multiply protonated angiotensin I and ubiquitin dissociated across a variety of pathways. Those pathways include the cleavages of C-CO, C-N as well as N-Cα backbone bonds, accordingly manifested as b/y, a, and c/z fragment ion series in tandem mass spectra. The fragmentation pattern observed includes characteristic fragments of collision-induced dissociation (CID) (b/y/a fragments) as well as electron capture/transfer dissociation (ECD, ETD) (c/z fragments), suggesting substantial contribution of both vibrational and electronic excitation in our experiments. Besides backbone cleavages, notable amounts of nondissociated precursor species were observed with reduced net charge, formed via electron or proton transfer between the colliding partners. Peaks corresponding to increased charge states of the precursor ions were also detected, which is the major distinctive feature of ion beam activation. PMID:24236851

  2. Proton beam therapy control system

    DOEpatents

    Baumann, Michael A.; Beloussov, Alexandre V.; Bakir, Julide; Armon, Deganit; Olsen, Howard B.; Salem, Dana

    2008-07-08

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  3. Proton beam therapy control system

    DOEpatents

    Baumann, Michael A; Beloussov, Alexandre V; Bakir, Julide; Armon, Deganit; Olsen, Howard B; Salem, Dana

    2013-12-03

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  4. Proton beam therapy control system

    DOEpatents

    Baumann, Michael A; Beloussov, Alexandre V; Bakir, Julide; Armon, Deganit; Olsen, Howard B; Salem, Dana

    2013-06-25

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  5. Proton beam therapy control system

    DOEpatents

    Baumann, Michael A.; Beloussov, Alexandre V.; Bakir, Julide; Armon, Deganit; Olsen, Howard B.; Salem, Dana

    2010-09-21

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  6. The Quest for Spinning Glue in High-Energy Polarized Proton-Proton Collisions at RHIC

    SciTech Connect

    Surrow, Bernd

    2007-10-26

    The STAR experiment at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) is carrying out a spin physics program colliding transverse or longitudinal polarized proton beams at {radical}(s) = 200-500 GeV to gain a deeper insight into the spin structure and dynamics of the proton. These studies provide fundamental tests of Quantum Chromodynamics (QCD).One of the main objectives of the STAR spin physics program is the determination of the polarized gluon distribution function through a measurement of the longitudinal double-spin asymmetry, A{sub LL}, for various processes. Recent results will be shown on the measurement of A{sub LL} for inclusive jet production, neutral pion production and charged pion production at {radical}(s) = 200 GeV.

  7. Development of hollow electron beams for proton and ion collimation

    SciTech Connect

    Stancari, G.; Drozhdin, A.I.; Kuznetsov, G.; Shiltsev, V.; Still, D.A.; Valishev, A.; Vorobiev, L.G.; Assmann, R.; Kabantsev, A.; /UC, San Diego

    2010-06-01

    Magnetically confined hollow electron beams for controlled halo removal in high-energy colliders such as the Tevatron or the LHC may extend traditional collimation systems beyond the intensity limits imposed by tolerable material damage. They may also improve collimation performance by suppressing loss spikes due to beam jitter and by increasing capture efficiency. A hollow electron gun was designed and built. Its performance and stability were measured at the Fermilab test stand. The gun will be installed in one of the existing Tevatron electron lenses for preliminary tests of the hollow-beam collimator concept, addressing critical issues such as alignment and instabilities of the overlapping proton and electron beams.

  8. The clinical case for proton beam therapy

    PubMed Central

    2012-01-01

    Abstract Over the past 20 years, several proton beam treatment programs have been implemented throughout the United States. Increasingly, the number of new programs under development is growing. Proton beam therapy has the potential for improving tumor control and survival through dose escalation. It also has potential for reducing harm to normal organs through dose reduction. However, proton beam therapy is more costly than conventional x-ray therapy. This increased cost may be offset by improved function, improved quality of life, and reduced costs related to treating the late effects of therapy. Clinical research opportunities are abundant to determine which patients will gain the most benefit from proton beam therapy. We review the clinical case for proton beam therapy. Summary sentence Proton beam therapy is a technically advanced and promising form of radiation therapy. PMID:23083010

  9. A new luminescence beam profile monitor for intense proton and heavy ion beams

    SciTech Connect

    Tsang,T.; Bellavia, S.; Connolly, R.; Gassner, D.; Makdisi, Y.; Russo, T.; Thieberger, P.; Trbojevic, D.; Zelenski, A.

    2008-10-01

    A new luminescence beam profile monitor is realized in the polarized hydrogen gas jet target at the Relativistic Heavy Ion Collider (RHIC) facility. In addition to the spin polarization of the proton beam being routinely measured by the hydrogen gas jet, the luminescence produced by beam-hydrogen excitation leads to a strong Balmer series lines emission. A selected hydrogen Balmer line is spectrally filtered and imaged to produce the transverse RHIC proton beam shape with unprecedented details on the RHIC beam profile. Alternatively, when the passage of the high energy RHIC gold ion beam excited only the residual gas molecules in the beam path, sufficient ion beam induced luminescence is produced and the transverse gold ion beam profile is obtained. The measured transverse beam sizes and the calculated emittances provide an independent confirmation of the RHIC beam characteristics and to verify the emittance conservation along the RHIC accelerator. This optical beam diagnostic technique by making use of the beam induced fluorescence from injected or residual gas offers a truly noninvasive particle beam characterization, and provides a visual observation of proton and heavy ion beams. Combined with a longitudinal bunch measurement system, a 3-dimensional spatial particle beam profile can be reconstructed tomographically.

  10. Internal spin structure of the proton from high energy polarized e-p scattering

    SciTech Connect

    Hughes, V.W.; Baum, G.; Bergstroem, M.R.

    1981-02-01

    A review is given of experimental knowledge of the spin dependent structure functions of the proton, which is based on inclusive high energy scattering of longitudinal polarized electrons by longitudinally polarized protons in both the deep inelastic and resonance regions, and includes preliminary results from our most recent SLAC experiment. Implications for scaling, sum rules, models of proton structure, and the hyperfine structure interval in hydrogen are given. Possible future directions of research are indicated.

  11. Measuring pion beta decay with high-energy pion beams

    SciTech Connect

    McFarlane, W.K. Temple Univ., Philadelphia, PA ); Hoffman, C.M. )

    1993-01-01

    Improved measurements of the pion beta decay rate are possible with an intense high-energy pion beam. The rate for the decay [pi][sup +] [yields] [pi][sup 0]e[sup +]v[epsilon] is predicted by the Standard Model (SM) to be R([pi][sup +] [yields] [pi][sup 0]e[sup +]v[epsilon]) = 0.3999[plus minus]0.0005 s[sup [minus]1]. The best experimental number, obtained using in-flight decays, is R([pi][sup +] [yields] [pi][sup 0]e[sup +]v[epsilon]) = 0.394 [plus minus] 0.015 s[sup [minus]1]. A precise measurement would test the SM by testing the unitarity of the Cabibbo-Kobayashi-Maskawa matrix for which one analysis of the nuclear beta decay data has shown a 0.4% discrepancy. Several nuclear correction factors, needed for nuclear decay, are not present for pion beta decay, so that an experiment at the 0.2% level would be a significant one. Detailed study of possible designs will be needed, as well as extensive testing of components. The reduction of systematic errors to the 0.1% level can only be done over a period of years with a highly stable apparatus and beam. At a minimum, three years of occupancy of a beam line, with 800 hours per year, would be required.

  12. Measuring pion beta decay with high-energy pion beams

    SciTech Connect

    McFarlane, W.K. |; Hoffman, C.M.

    1993-02-01

    Improved measurements of the pion beta decay rate are possible with an intense high-energy pion beam. The rate for the decay {pi}{sup +} {yields} {pi}{sup 0}e{sup +}v{epsilon} is predicted by the Standard Model (SM) to be R({pi}{sup +} {yields} {pi}{sup 0}e{sup +}v{epsilon}) = 0.3999{plus_minus}0.0005 s{sup {minus}1}. The best experimental number, obtained using in-flight decays, is R({pi}{sup +} {yields} {pi}{sup 0}e{sup +}v{epsilon}) = 0.394 {plus_minus} 0.015 s{sup {minus}1}. A precise measurement would test the SM by testing the unitarity of the Cabibbo-Kobayashi-Maskawa matrix for which one analysis of the nuclear beta decay data has shown a 0.4% discrepancy. Several nuclear correction factors, needed for nuclear decay, are not present for pion beta decay, so that an experiment at the 0.2% level would be a significant one. Detailed study of possible designs will be needed, as well as extensive testing of components. The reduction of systematic errors to the 0.1% level can only be done over a period of years with a highly stable apparatus and beam. At a minimum, three years of occupancy of a beam line, with 800 hours per year, would be required.

  13. Application of Monte Carlo to Proton Beam Radiation Therapy

    NASA Astrophysics Data System (ADS)

    Siebers, J. V.

    As with photon and electron radiotherapy, the future of dose calculation for hadron beams will be based upon Monte Carlo algorithms. Benchmark calculations of the LAHET Monte Carlo code with respect to measured in-phantom dose distributions show that the proton physics modules in LAHET accurately reproduce measured results. Since MCNP-X incorporates the proton and high energy neutron physics modules from LAHET, similar agreement with MCNP-X is expected. In addition to beam-line simulations, MCNP-X has the ability to input the lattice geometry required for simulating patient treatments based on CT data sets. The ability of MCNP-X to perform patient dose calculation simulations for proton radiotherapy was demonstrated by simulating a two-beam prostate treatment plan. While MCNP-X is fully capable to perform patient-planning calculations, currently, it is too time consuming to be used for routine patient planning.

  14. Fabrication of devices for channeling-based high-energy micro-beams

    NASA Astrophysics Data System (ADS)

    Antonini, A.; Guidi, V.; Martinelli, G.; Milan, E.

    2007-05-01

    Presently MeV energy micro-beams are employed to study the cell response to radiation-induced damage. In fact, one of the frontiers is the study of radiobiological effects of particle radiation on human tissues. At relatively low energy (of the order of MeV), micro-beam facilities have been constructed to irradiate living cells with the aim to understand the architecture of biological tissues on radiation response and its behaviour at low dose. Interaction of radiation at high energy (GeV or higher) and its effects have indeed been considered for interplanetary space missions where a human equipage is being submitted to prolonged interaction with direct cosmic radiation. Thus, some particle accelerator laboratories study methods for implementation of micro-beam facilities to address the interaction of high-energy protons and ions with cells. A channeling-based scheme for generation of micro-beams has been proposed in the past; two designs for micro-collimator devices have been considered in this study and preliminary samples have been accordingly produced.

  15. Proton Structure in High-Energy High-Multiplicity p-p Collisions

    NASA Astrophysics Data System (ADS)

    Głazek, Stanisław D.; Kubiczek, Patryk

    2016-06-01

    A few-body proton image, expected to be derivable from QCD in the renormalization group procedure for effective particles, is used within the Monte Carlo Glauber model to calculate the anisotropy coefficients in the initial collision-state of matter in high-energy high-multiplicity proton-proton interaction events. We estimate the ridge-like correlations in the final hadronic state by assuming their proportionality to the initial collision-state anisotropy. In our estimates, some distinct few-body proton structures appear capable of accounting for the magnitude of p-p ridge effect, with potentially discernible differences in dependence on multiplicity.

  16. Focusing of short-pulse high-intensity laser-accelerated proton beams

    NASA Astrophysics Data System (ADS)

    Bartal, Teresa; Foord, Mark E.; Bellei, Claudio; Key, Michael H.; Flippo, Kirk A.; Gaillard, Sandrine A.; Offermann, Dustin T.; Patel, Pravesh K.; Jarrott, Leonard C.; Higginson, Drew P.; Roth, Markus; Otten, Anke; Kraus, Dominik; Stephens, Richard B.; McLean, Harry S.; Giraldez, Emilio M.; Wei, Mingsheng S.; Gautier, Donald C.; Beg, Farhat N.

    2012-02-01

    Recent progress in generating high-energy (>50MeV) protons from intense laser-matter interactions (1018-1021Wcm-2 refs , , , , , , ) has opened up new areas of research, with applications in radiography, oncology, astrophysics, medical imaging, high-energy-density physics, and ion-proton beam fast ignition. With the discovery of proton focusing with curved surfaces, rapid advances in these areas will be driven by improved focusing technologies. Here we report on the first investigation of the generation and focusing of a proton beam using a cone-shaped target. We clearly show that the focusing is strongly affected by the electric fields in the beam in both open and enclosed (cone) geometries, bending the trajectories near the axis. Also in the cone geometry, a sheath electric field effectively `channels' the proton beam through the cone tip, substantially improving the beam focusing properties. These results agree well with particle simulations and provide the physics basis for many future applications.

  17. Relations Between Microwave Bursts and Near-Earth High-Energy Proton Enhancements and Their Origin

    NASA Astrophysics Data System (ADS)

    Grechnev, V. V.; Kiselev, V. I.; Meshalkina, N. S.; Chertok, I. M.

    2015-10-01

    We further study the relations between parameters of bursts at 35 GHz recorded with the Nobeyama Radio Polarimeters during 25 years and solar proton events (Grechnev et al. in Publ. Astron. Soc. Japan 65, S4, 2013a). Here we address the relations between the microwave fluences at 35 GHz and near-Earth proton fluences above 100 MeV to find information on their sources and evaluate their diagnostic potential. The correlation between the microwave and proton fluences is pronouncedly higher than between their peak fluxes. This probably reflects a dependence of the total number of protons on the duration of the acceleration process. In events with strong flares, the correlation coefficients of high-energy proton fluences with microwave and soft X-ray fluences are higher than those with the speeds of coronal mass ejections. The results indicate a statistically larger contribution of flare processes to high-energy proton fluxes. Acceleration by shock waves seems to be less important at high energies in events associated with strong flares, although its contribution is probable and possibly prevails in weaker events. The probability of a detectable proton enhancement was found to directly depend on the peak flux, duration, and fluence of the 35 GHz burst, while the role of the Big Flare Syndrome might have been overestimated previously. Empirical diagnostic relations are proposed.

  18. Monoenergetic proton backlighter for measuring E and B fields and for radiographing implosions and high-energy density plasmas (invited)

    SciTech Connect

    Li, C. K.; Seguin, F. H.; Frenje, J. A.; Rygg, J. R.; Petrasso, R. D.; Town, R. P. J.; Amendt, P. A.; Hatchett, S. P.; Landen, O. L.; Mackinnon, A. J.; Patel, P. K.; Smalyuk, V. A.; Knauer, J. P.; Sangster, T. C.; Stoeckl, C.

    2006-10-15

    A novel monoenergetic proton backlighter source and matched imaging detector have been utilized on the OMEGA laser system to study electric (E) and magnetic (B) fields generated by laser-plasma interactions and will be utilized in the future to radiograph implosions and high-energy density (HED) plasmas. The backlighter consists of an imploding glass microballoon with D {sup 3}He fuel, producing 14.7 MeV D {sup 3}He protons and 3 MeV DD protons that are then passed through a mesh that divides the protons into beamlets. For quantitative study of E+B field structure, monoenergetic protons have several unique advantages compared to the broad energy spectrum used in previous experiments. Recent experiments have been performed with a single laser beam (intensity of {approx}10{sup 14} W/cm{sup 2}) interacting with a CH foil, and B fields of {approx}0.5 MG and E fields of {approx}1.5x10{sup 8} V/m have been measured using proton deflectometry. LASNEX simulations are being used to interpret these experiments. Additional information will also be presented on the application of this technique to measuring E and B fields associated with Hohlraums and directly driven implosions, to radiographically mapping the areal density ({rho}R) distribution in imploded capsules, and to radiographing HED plasmas.

  19. High-energy tritium beams as current drivers in tokamak reactors

    SciTech Connect

    Mikkelsen, D.R.; Grisham, L.R.

    1983-04-01

    The effect on neutral-beam design and reactor performance of using high-energy (approx. 3-10 MeV) tritium neutral beams to drive steady-state tokamak reactors is considered. The lower current of such beams leads to several advantages over lower-energy neutral beams. The major disadvantage is the reduction of the reactor output caused by the lower current-drive efficiency of the high-energy beams.

  20. Measurements of the proton-air cross section with high energy cosmic ray experiments

    NASA Astrophysics Data System (ADS)

    Abbasi, Rasha

    2016-07-01

    Detecting Ultra High Energy Cosmic Rays (UHECRs) enables us to measure the proton-air inelastic cross section σinel p-air at energies that we are unable to access with particle accelerators. The proton-proton cross section σp-p is subsequently inferred from the proton-air cross section at these energies. UHECR experiments have been reportingon the proton-air inelastic cross section starting with the Fly's Eye in 1984 at √s =30 TeV and ending with the most recent result of the Telescope Array experiment at √s = 95 TeV in 2015. In this proceeding, I will summarize the most recent experimental results on the σinel p-air measurements from the UHECR experiments.

  1. Isochoric heating of matter by laser-accelerated high-energy protons

    NASA Astrophysics Data System (ADS)

    Antici, P.; Fuchs, J.; Atzeni, S.; Benuzzi, A.; Brambrink, E.; Esposito, M.; Koenig, M.; Ravasio, A.; Schreiber, J.; Schiavi, A.; Audebert, P.

    2006-06-01

    We describe an experiment on isochoric heating of matter by intense laser-accelerated protons. The experiment was performed using the LULI 100 TW facility with 15-20 J on target energy and > 1019 W.cm - 2 maximum focused intensity. Focusing the laser on a 10 micron thick Au foil, we accelerated forward a laminar proton beam with a maximum energy of 16 MeV. This proton beam irradiated and heated a secondary target positioned after a variable vacuum gap. The heating was diagnosed by 1D and 2D time-resolved measurements of the optical self-emission of the heated target rear-surface. Detailed results as a function of the Z and the thickness of the secondary target as well as analysis, including a full modelling of the target heating with a 2D hydro-code (DUED) coupled to a proton energy deposition code, were obtained. We have also studied the efficiency of heating as a function of the primary target topology, i.e. either flat, which results in a diverging proton beam, or curved, which has the ability of focusing partly the proton beam.

  2. Results on damage induced by high-energy protons in LYSO calorimeter crystals

    NASA Astrophysics Data System (ADS)

    Dissertori, G.; Luckey, D.; Nessi-Tedaldi, F.; Pauss, F.; Quittnat, M.; Wallny, R.; Glaser, M.

    2014-05-01

    Lutetium-Yttrium Orthosilicate doped with Cerium (LYSO), as a bright scintillating crystal, is a candidate for calorimetry applications in strong ionising-radiation fields and large high-energy hadron fluences are expected at the CERN Large Hadron Collider after the planned High-Luminosity upgrade. There, proton-proton collisions will produce fast hadron fluences up to ~ 5 ×1014cm-2 in the large-rapidity regions of the calorimeters. The performance of LYSO has been investigated, after exposure to different fluences of 24 GeV c-1 protons. Measured changes in optical transmission as a function of proton fluence are presented, and the evolution over time due to spontaneous recovery at room temperature is studied. The activation of materials will also be an issue in the described environment. Studies of the ambient dose induced by LYSO and its evolution with time, in comparison with other scintillating crystals, have also been performed through measurements and FLUKA simulations.

  3. A Nuclear Interaction Model for Understanding Results of Single Event Testing with High Energy Protons

    NASA Technical Reports Server (NTRS)

    Culpepper, William X.; ONeill, Pat; Nicholson, Leonard L.

    2000-01-01

    An internuclear cascade and evaporation model has been adapted to estimate the LET spectrum generated during testing with 200 MeV protons. The model-generated heavy ion LET spectrum is compared to the heavy ion LET spectrum seen on orbit. This comparison is the basis for predicting single event failure rates from heavy ions using results from a single proton test. Of equal importance, this spectra comparison also establishes an estimate of the risk of encountering a failure mode on orbit that was not detected during proton testing. Verification of the general results of the model is presented based on experiments, individual part test results, and flight data. Acceptance of this model and its estimate of remaining risk opens the hardware verification philosophy to the consideration of radiation testing with high energy protons at the board and box level instead of the more standard method of individual part testing with low energy heavy ions.

  4. Canted-Cosine-Theta Superconducting Accelerator Magnets for High Energy Physics and Ion Beam Cancer Therapy

    NASA Astrophysics Data System (ADS)

    Brouwer, Lucas Nathan

    Advances in superconducting magnet technology have historically enabled the construction of new, higher energy hadron colliders. Looking forward to the needs of a potential future collider, a significant increase in magnet field and performance is required. Such a task requires an open mind to the investigation of new design concepts for high field magnets. Part I of this thesis will present an investigation of the Canted-Cosine-Theta (CCT) design for high field Nb3Sn magnets. New analytic and finite element methods for analysis of CCT magnets will be given, along with a discussion on optimization of the design for high field. The design, fabrication, and successful test of the 2.5 T NbTi dipole CCT1 will be presented as a proof-of-principle step towards a high field Nb3Sn magnet. Finally, the design and initial steps in the fabrication of the 16 T Nb3Sn dipole CCT2 will be described. Part II of this thesis will investigate the CCT concept extended to a curved magnet for use in an ion beam therapy gantry. The introduction of superconducting technology in this field shows promise to reduce the weight and cost of gantries, as well as open the door to new beam optics solutions with high energy acceptance. An analytic approach developed for modeling curved CCT magnets will be presented, followed by a design study of a superconducting magnet for a proton therapy gantry. Finally, a new magnet concept called the "Alternating Gradient CCT" (AG-CCT) will be introduced. This concept will be shown to be a practical magnet solution for achieving the alternating quadrupole fields desired for an achromatic gantry, allowing for the consideration of treatment with minimal field changes in the superconducting magnets. The primary motivation of this thesis is to share new developments for Canted-Cosine-Theta superconducting magnets, with the hope this design will improve technology for high energy physics and ion beam cancer therapy.

  5. Centrality-dependent forward J/ψ production in high energy proton-nucleus collisions

    NASA Astrophysics Data System (ADS)

    Ducloué, B.; Lappi, T.; Mäntysaari, H.

    2016-03-01

    Forward J/ψ production and suppression in high energy proton-nucleus collisions can be an important probe of gluon saturation. In an earlier work we studied this process in the Color Glass Condensate framework and showed that using the Glauber approach to extrapolate the dipole cross section of a proton to a nucleus leads to results closer to experimental data than previous calculations in this framework. Here we investigate the centrality dependence of the nuclear suppression in this model and show a comparison of our results with recent LHC data.

  6. High energy proton irradiation induced pinning centers in Bi-2212 and Bi-2223 superconductors

    SciTech Connect

    Willis, J.O.; Safar, H.; Cho, J.H.

    1995-12-01

    Bi-2212 single crystals and Bi-2223/Ag-sheathed tapes were irradiated with high energy protons. TEM images reveal the production of randomly oriented (splayed) columnar defects with an amorphous core of {approximately}10 nm diameter caused by the fissioning of Bi nuclei. The critical current density J{sub c} and irreversibility line both substantially increased with the proton dose for both crystals and tapes, especially for the magnetic field parallel to the c axis. An irradiated tape had a J{sub c} value {approximately}100 times greater than that of an unirradiated one at 1 T and 75 K.

  7. Fan-beam intensity modulated proton therapy

    SciTech Connect

    Hill, Patrick; Westerly, David; Mackie, Thomas

    2013-11-15

    Purpose: This paper presents a concept for a proton therapy system capable of delivering intensity modulated proton therapy using a fan beam of protons. This system would allow present and future gantry-based facilities to deliver state-of-the-art proton therapy with the greater normal tissue sparing made possible by intensity modulation techniques.Methods: A method for producing a divergent fan beam of protons using a pair of electromagnetic quadrupoles is described and particle transport through the quadrupole doublet is simulated using a commercially available software package. To manipulate the fan beam of protons, a modulation device is developed. This modulator inserts or retracts acrylic leaves of varying thickness from subsections of the fan beam. Each subsection, or beam channel, creates what effectively becomes a beam spot within the fan area. Each channel is able to provide 0–255 mm of range shift for its associated beam spot, or stop the beam and act as an intensity modulator. Results of particle transport simulations through the quadrupole system are incorporated into the MCNPX Monte Carlo transport code along with a model of the range and intensity modulation device. Several design parameters were investigated and optimized, culminating in the ability to create topotherapy treatment plans using distal-edge tracking on both phantom and patient datasets.Results: Beam transport calculations show that a pair of electromagnetic quadrupoles can be used to create a divergent fan beam of 200 MeV protons over a distance of 2.1 m. The quadrupole lengths were 30 and 48 cm, respectively, with transverse field gradients less than 20 T/m, which is within the range of water-cooled magnets for the quadrupole radii used. MCNPX simulations of topotherapy treatment plans suggest that, when using the distal edge tracking delivery method, many delivery angles are more important than insisting on narrow beam channel widths in order to obtain conformal target coverage

  8. Fan-beam intensity modulated proton therapy

    PubMed Central

    Hill, Patrick; Westerly, David; Mackie, Thomas

    2013-01-01

    Purpose: This paper presents a concept for a proton therapy system capable of delivering intensity modulated proton therapy using a fan beam of protons. This system would allow present and future gantry-based facilities to deliver state-of-the-art proton therapy with the greater normal tissue sparing made possible by intensity modulation techniques. Methods: A method for producing a divergent fan beam of protons using a pair of electromagnetic quadrupoles is described and particle transport through the quadrupole doublet is simulated using a commercially available software package. To manipulate the fan beam of protons, a modulation device is developed. This modulator inserts or retracts acrylic leaves of varying thickness from subsections of the fan beam. Each subsection, or beam channel, creates what effectively becomes a beam spot within the fan area. Each channel is able to provide 0–255 mm of range shift for its associated beam spot, or stop the beam and act as an intensity modulator. Results of particle transport simulations through the quadrupole system are incorporated into the MCNPX Monte Carlo transport code along with a model of the range and intensity modulation device. Several design parameters were investigated and optimized, culminating in the ability to create topotherapy treatment plans using distal-edge tracking on both phantom and patient datasets. Results: Beam transport calculations show that a pair of electromagnetic quadrupoles can be used to create a divergent fan beam of 200 MeV protons over a distance of 2.1 m. The quadrupole lengths were 30 and 48 cm, respectively, with transverse field gradients less than 20 T/m, which is within the range of water-cooled magnets for the quadrupole radii used. MCNPX simulations of topotherapy treatment plans suggest that, when using the distal edge tracking delivery method, many delivery angles are more important than insisting on narrow beam channel widths in order to obtain conformal target coverage

  9. Comment on 'Proton beam monitor chamber calibration'.

    PubMed

    Palmans, Hugo; Vatnitsky, Stanislav M

    2016-09-01

    We comment on a recent article (Gomà et al 2014 Phys. Med. Biol. 59 4961-71) which compares different routes of reference dosimetry for the energy dependent beam monitor calibration in scanned proton beams. In this article, a 3% discrepancy is reported between a Faraday cup and a plane-parallel ionization chamber in the experimental determination of the number of protons per monitor unit. It is further claimed that similar discrepancies between calorimetry and ionization chamber based dosimetry indicate that [Formula: see text]-values tabulated for proton beams in IAEA TRS-398 might be overestimated. In this commentary we show, however, that this supporting argument misrepresents the evidence in the literature and that the results presented, together with published data, rather confirm that there exist unresolved problems with Faraday cup dosimetry. We also show that the comparison in terms of the number of protons gives a biased view on the uncertainty estimates for both detectors while the quantity of interest is absorbed dose to water or dose-area-product to water, even if a beam monitor is calibrated in terms of the number of protons. Gomà et al (2014 Phys. Med. Biol. 59 4961-71) also report on the discrepancy between cylindrical and plane-parallel ionization chambers and confirm experimentally that in the presence of a depth dose gradient, theoretical values of the effective point of measurement, or alternatively a gradient correction factor, account for the discrepancy. We believe this does not point to an error or shortcoming of IAEA TRS-398, which prescribes taking the centre of cylindrical ionization chambers as reference point, since it recommends reference dosimetry to be performed in the absence of a depth dose gradient. But these observations reveal that important aspects of beam monitor calibration in scanned proton beams are not addressed in IAEA TRS-398 given that those types of beams were not widely implemented at the time of its publication

  10. Oblique incidence for broad monoenergetic proton beams

    SciTech Connect

    Jette, David; Yuan Jiankui; Chen Weimin

    2010-11-15

    Purpose: The depth dose of a monoenergetic broad parallel proton beam has been modeled in a number of ways, but evidently not yet for oblique incidence. The purpose of this investigation is to find an accurate analytic formula for this case, which can then be used to model the depth dose of a broad beam with an initial Gaussian angular distribution. Methods: The Bortfeld model of depth dose in a broad normally incident proton beam has been extended to the case of oblique incidence. This extension uses an empirically determined Gaussian parameter {sigma}{sub x} which (roughly) characterizes the off-axis dose of a proton pencil beam. As with Bortfeld's work, the modeling is done in terms of parabolic cylinder functions. To obtain the depth dose for an initial angular distribution, the result is integrated over the angle of incidence, weighted by a Gaussian probability function. The predictions of the theory have been compared to MCNPX Monte Carlo calculations for four phantom materials (water, bone, aluminum, and copper) and for initial proton energies of 50, 100, 150, 200, and 250 MeV. Results: Comparisons of the depth dose predicted by this theory with Monte Carlo calculations have established that with very good accuracy, {sigma}{sub x} can be taken to be independent both of the depth and of the angle of incidence. As a function of initial proton range or of initial proton energy, {sigma}{sub x} has been found to obey a power law to very high accuracy. Good fits to Monte Carlo calculations have also been found for an initial Gaussian angular distribution. Conclusions: This investigation is the first step in the accurate modeling of a proton pencil beam with initial Gaussian angular distribution. It provides the longitudinal factor, with its Bragg peak buildup and sharp distal falloff. A transverse factor must still be incorporated into this theory and this will give the lateral penumbra of a collimated proton beam. Also, it will be necessary to model the dose of

  11. Proton-beam technique dates fine wine

    NASA Astrophysics Data System (ADS)

    Dumé, Belle

    2008-10-01

    Nuclear physicists in France have invented a way to authenticate the vintage of rare wine without needing a sommelier's keen nose or even a corkscrew. The technique, which involves firing high-energy protons at wine bottles, can determine how old the bottles are and even where they come from. The new method could help unmask counterfeit wines - a growing problem in the fine-wine industry, where a bottle can sell for thousands of Euros.

  12. High-energy proton radiation damage of high-purity germanium detectors

    NASA Technical Reports Server (NTRS)

    Pehl, R. H.; Varnell, L. S.; Metzger, A. E.

    1978-01-01

    Quantitative studies of radiation damage in high-purity germanium gamma-ray detectors due to high-energy charged particles have been carried out; two 1.0 cm thick planar detectors were irradiated by 6 GeV/c protons. Under proton bombardment, degradation in the energy resolution was found to begin below 7 x 10 to the 7th protons/sq cm and increased proportionately in both detectors until the experiment was terminated at a total flux of 5.7 x 10 to the 8th protons/sq cm, equivalent to about a six year exposure to cosmic-ray protons in space. At the end of the irradiation, the FWHM resolution measured at 1332 keV stood at 8.5 and 13.6 keV, with both detectors of only marginal utility as a spectrometer due to the severe tailing caused by charge trapping. Annealing these detectors after proton damage was found to be much easier than after neutron damage.

  13. Sparse-view proton computed tomography using modulated proton beams

    SciTech Connect

    Lee, Jiseoc; Kim, Changhwan; Cho, Seungryong; Min, Byungjun; Kwak, Jungwon; Park, Seyjoon; Lee, Se Byeong; Park, Sungyong

    2015-02-15

    Purpose: Proton imaging that uses a modulated proton beam and an intensity detector allows a relatively fast image acquisition compared to the imaging approach based on a trajectory tracking detector. In addition, it requires a relatively simple implementation in a conventional proton therapy equipment. The model of geometric straight ray assumed in conventional computed tomography (CT) image reconstruction is however challenged by multiple-Coulomb scattering and energy straggling in the proton imaging. Radiation dose to the patient is another important issue that has to be taken care of for practical applications. In this work, the authors have investigated iterative image reconstructions after a deconvolution of the sparsely view-sampled data to address these issues in proton CT. Methods: Proton projection images were acquired using the modulated proton beams and the EBT2 film as an intensity detector. Four electron-density cylinders representing normal soft tissues and bone were used as imaged object and scanned at 40 views that are equally separated over 360°. Digitized film images were converted to water-equivalent thickness by use of an empirically derived conversion curve. For improving the image quality, a deconvolution-based image deblurring with an empirically acquired point spread function was employed. They have implemented iterative image reconstruction algorithms such as adaptive steepest descent-projection onto convex sets (ASD-POCS), superiorization method–projection onto convex sets (SM-POCS), superiorization method–expectation maximization (SM-EM), and expectation maximization-total variation minimization (EM-TV). Performance of the four image reconstruction algorithms was analyzed and compared quantitatively via contrast-to-noise ratio (CNR) and root-mean-square-error (RMSE). Results: Objects of higher electron density have been reconstructed more accurately than those of lower density objects. The bone, for example, has been reconstructed

  14. STOCHASTIC COOLING OF HIGH-ENERGY BUNCHED BEAMS

    SciTech Connect

    BLASKIEWICZ,M.; BRENNAN, J.M.

    2007-06-25

    Stochastic cooling of 100 GeV/nucleon bunched beams has been achieved in the Relativistic Heavy Ion Collider (RHIC). The physics and technology of the longitudinal cooling system are discussed, and plans for a transverse cooling system are outlined.

  15. Innermost Van Allen Radiation Belt for High Energy Protons at Saturn

    NASA Technical Reports Server (NTRS)

    Cooper, John F.

    2008-01-01

    The high energy proton radiation belts of Saturn are energetically dominated by the source from cosmic ray albedo neutron decay (CRAND), trapping of protons from beta decay of neutrons emitted from galactic cosmic ray nuclear interactions with the main rings. These belts were originally discovered in wide gaps between the A-ring, Janus/Epimetheus, Mimas, and Enceladus. The narrow F and G rings significant affected the CRAND protons but did not produce total depletion. Voyager 2 measurements subsequently revealed an outermost CRAND proton belt beyond Enceladus. Although the source rate is small, the trapping times limited by radial magnetospheric diffusion are very long, about ten years at peak measured flux inwards of the G ring, so large fluxes can accumulate unless otherwise limited in the trapping region by neutral gas, dust, and ring body interactions. One proposed final extension of the Cassini Orbiter mission would place perikrone in a 3000-km gap between the inner D ring and the upper atmosphere of Saturn. Experience with CRAND in the Earth's inner Van Allen proton belt suggests that a similar innermost belt might be found in this comparably wide region at Saturn. Radial dependence of magnetospheric diffusion, proximity to the ring neutron source, and northward magnetic offset of Saturn's magnetic equator from the ring plane could potentially produce peak fluxes several orders of magnitude higher than previously measured outside the main rings. Even brief passes through such an intense environment of highly penetrating protons would be a significant concern for spacecraft operations and science observations. Actual fluxes are limited by losses in Saturn's exospheric gas and in a dust environment likely comparable to that of the known CRAND proton belts. The first numerical model of this unexplored radiation belt is presented to determine limits on peak magnitude and radial profile of the proton flux distribution.

  16. Water corrosion measurements on tungsten irradiated with high energy protons and spallation neutrons

    NASA Astrophysics Data System (ADS)

    Maloy, Stuart A.; Scott Lillard, R.; Sommer, Walter F.; Butt, Darryl P.; Gac, Frank D.; Willcutt, Gordon J.; Louthan, McIntyre R.

    2012-12-01

    A detailed analysis was performed on the degradation of a tungsten target under water cooling while being exposed to a 761 MeV proton beam at an average current of 0.867 mA to a maximum fluence of 1.3 × 1021 protons/cm2. The target consisted of 3 mm diameter tungsten rods arranged in bundles and cooled with deionized water flowing over their length. Degradation of the tungsten was measured through analyzing water resistivity, tungsten concentration in water samples that were taken during irradiation and through dimensional measurements on the rods after irradiation. Chemical analysis of irradiated water samples showed W concentrations up to 35 μg/ml. Gamma analysis showed increases in concentrations of many isotopes including W-178, Lu-171, Tm-167, Tm-166, Yb-169 and Hf-175. Dimensional measurements performed after irradiation on the W rods revealed a decrease in diameter as a function of position that followed closely the Gaussian proton beam profile along the rod length and indicated a definite beam-effect. A general decrease in diameter, especially on the coolant-water entrance point where turbulent flow was likely, also suggests a chemically and mechanically-driven corrosion effect. A method to estimate the apparent corrosion rate based on proton fluence is presented and application of this method estimates the material loss rate at about 1.9 W atoms/incident proton. From this result, the corrosion rate of tungsten in a 761 MeV, 0.867 mA proton beam was calculated to be 0.073 cm/full power year. of irradiation.

  17. Production of high energy and low flux protons using 2D(3He,p)4He for space detector calibrations

    NASA Astrophysics Data System (ADS)

    Wang, Y. Q.; Burward-Hoy, J. M.; Tesmer, J. R.

    2014-08-01

    In this report, we want to demonstrate that besides the conventional use for elemental analysis and depth profiling by ion beam analysis (IBA), particles generated through ion-solid interactions in IBA may find other novel and important applications. Specifically, we use Rutherford backscattered and nuclear reaction produced high energy proton particles to calibrate an energetic particle subsystem (called ZEP) of the Space and Atmospheric Burst Reporting System (SABRS) at Los Alamos National Laboratory (LANL). To simulate low radiation flux in the space, we have devised an experiment that uses an ultrathin (∼51.8 nm) self-support gold foil to scatter a proton beam from a 3 MV Tandem accelerator into the ZEP subsystem. Direct backscattering from the thin gold foil produces proton particles with tunable energies of 0.2-6.0 MeV and desired counting rates of <10 kHz. To extend the proton particle energy beyond the Tandem's limit of 6 MeV, a high Q-value nuclear reaction, 2D + 3He → p + 4He + 18.352 MeV, was used. This reaction allows us to obtain as high as 25.6 MeV proton particles on our 3 MV tandem accelerator, more than 4 times as high as the accelerator's maximum proton beam energy, and has greatly extended our proton energy range for this calibration activity. Preliminary ZEP subsystem calibration results are presented.

  18. Laser-Foil Acceleration of High-Energy Protons in Small-Scale Plasma Gradients

    SciTech Connect

    Fuchs, J.; Audebert, P.; Cecchetti, C. A.; Borghesi, M.; Romagnani, L.; Grismayer, T.; Mora, P.; D'Humieres, E.; Sentoku, Y.; Antici, P.; Atzeni, S.; Schiavi, A.; Pipahl, A.; Toncian, T.; Willi, O.

    2007-07-06

    Proton beams laser accelerated from thin foils are studied for various plasma gradients on the foil rear surface. The beam maximum energy and spectral slope reduce with the gradient scale length, in good agreement with numerical simulations. The results also show that the jxB mechanism determines the temperature of the electrons driving the ion expansion. Future ion-driven fast ignition of fusion targets will use multikilojoule petawatt laser pulses, the leading part of which will induce target preheat. Estimates based on the data show that this modifies by less than 10% the ion beam parameters.

  19. Laser-foil acceleration of high-energy protons in small-scale plasma gradients.

    PubMed

    Fuchs, J; Cecchetti, C A; Borghesi, M; Grismayer, T; d'Humières, E; Antici, P; Atzeni, S; Mora, P; Pipahl, A; Romagnani, L; Schiavi, A; Sentoku, Y; Toncian, T; Audebert, P; Willi, O

    2007-07-01

    Proton beams laser accelerated from thin foils are studied for various plasma gradients on the foil rear surface. The beam maximum energy and spectral slope reduce with the gradient scale length, in good agreement with numerical simulations. The results also show that the jxB mechanism determines the temperature of the electrons driving the ion expansion. Future ion-driven fast ignition of fusion targets will use multikilojoule petawatt laser pulses, the leading part of which will induce target preheat. Estimates based on the data show that this modifies by less than 10% the ion beam parameters. PMID:17678159

  20. Energy Production Demonstrator for Megawatt Proton Beams

    SciTech Connect

    Pronskikh, Vitaly S.; Mokhov, Nikolai V.; Novitski, Igor; Tyutyunnikov, Sergey I.

    2014-07-16

    A preliminary study of the Energy Production Demonstrator (EPD) concept - a solid heavy metal target irradiated by GeV-range intense proton beams and producing more energy than consuming - is carried out. Neutron production, fission, energy deposition, energy gain, testing volume and helium production are simulated with the MARS15 code for tungsten, thorium, and natural uranium targets in the proton energy range 0.5 to 120 GeV. This study shows that the proton energy range of 2 to 4 GeV is optimal for both a natU EPD and the tungsten-based testing station that would be the most suitable for proton accelerator facilities. Conservative estimates, not including breeding and fission of plutonium, based on the simulations suggest that the proton beam current of 1 mA will be sufficient to produce 1 GW of thermal output power with the natU EPD while supplying < 8% of that power to operate the accelerator. The thermal analysis shows that the concept considered has a problem due to a possible core meltdown; however, a number of approaches (a beam rastering, in first place) are suggested to mitigate the issue. The efficiency of the considered EPD as a Materials Test Station (MTS) is also evaluated in this study.

  1. Studies of beam heating of proton beam profile monitor SEM's

    SciTech Connect

    Pavlovich, Zarko; Osiecki, Thomas H.; Kopp, Sacha E.; /Texas U.

    2005-05-01

    The authors present calculations of the expected temperature rise of proton beam profile monitors due to beam heating. The profile monitors are secondary emission monitors (SEM's) to be made of Titanium foils. The heating is studied to understand whether there is any loss of tension or alignment of such devices. Additionally, calculations of thermally-induced dynamic stress are presented. Ti foil is compared to other materials and also to wire SEM's. The calculations were initially performed for the NuMI beam, where the per-pulse intensity is quite high; for completeness the calculations are also performed for other beam energies and intensities.

  2. Method and apparatus for laser-controlled proton beam radiology

    DOEpatents

    Johnstone, Carol J.

    1998-01-01

    A proton beam radiology system provides cancer treatment and proton radiography. The system includes an accelerator for producing an H.sup.- beam and a laser source for generating a laser beam. A photodetachment module is located proximate the periphery of the accelerator. The photodetachment module combines the H.sup.- beam and laser beam to produce a neutral beam therefrom within a subsection of the H.sup.- beam. The photodetachment module emits the neutral beam along a trajectory defined by the laser beam. The photodetachment module includes a stripping foil which forms a proton beam from the neutral beam. The proton beam is delivered to a conveyance segment which transports the proton beam to a patient treatment station. The photodetachment module further includes a laser scanner which moves the laser beam along a path transverse to the cross-section of the H.sup.- beam in order to form the neutral beam in subsections of the H.sup.- beam. As the scanning laser moves across the H.sup.- beam, it similarly varies the trajectory of the proton beam emitted from the photodetachment module and in turn varies the target location of the proton beam upon the patient. Intensity modulation of the proton beam can also be achieved by controlling the output of the laser.

  3. Method and apparatus for laser-controlled proton beam radiology

    DOEpatents

    Johnstone, C.J.

    1998-06-02

    A proton beam radiology system provides cancer treatment and proton radiography. The system includes an accelerator for producing an H{sup {minus}} beam and a laser source for generating a laser beam. A photodetachment module is located proximate the periphery of the accelerator. The photodetachment module combines the H{sup {minus}} beam and laser beam to produce a neutral beam therefrom within a subsection of the H{sup {minus}} beam. The photodetachment module emits the neutral beam along a trajectory defined by the laser beam. The photodetachment module includes a stripping foil which forms a proton beam from the neutral beam. The proton beam is delivered to a conveyance segment which transports the proton beam to a patient treatment station. The photodetachment module further includes a laser scanner which moves the laser beam along a path transverse to the cross-section of the H{sup {minus}} beam in order to form the neutral beam in subsections of the H{sup {minus}} beam. As the scanning laser moves across the H{sup {minus}} beam, it similarly varies the trajectory of the proton beam emitted from the photodetachment module and in turn varies the target location of the proton beam upon the patient. Intensity modulation of the proton beam can also be achieved by controlling the output of the laser. 9 figs.

  4. Innovative radiotherapy of sarcoma: Proton beam radiation.

    PubMed

    DeLaney, Thomas F; Haas, Rick L M

    2016-07-01

    This review on proton beam radiotherapy (PBT) focusses on an historical overview, cost-effectiveness, techniques, acute and late toxicities and clinical results of PBT for sarcoma patients. PBT has gained its place among the armamentarium of modern radiotherapy techniques. For selected patients, it can be cost-effective. PMID:27258968

  5. The practical experience of a total conversion to high energy electron beam processing

    NASA Astrophysics Data System (ADS)

    Descamps, Th.

    1995-02-01

    The total conversion of a manufacturing site to a new sterilisation method, high energy electron beam, combined with the rearrangement of the concerned assortment of products is a vast program. The result is a modern and efficient sterilisation tool.

  6. Golden beam data for proton pencil-beam scanning.

    PubMed

    Clasie, Benjamin; Depauw, Nicolas; Fransen, Maurice; Gomà, Carles; Panahandeh, Hamid Reza; Seco, Joao; Flanz, Jacob B; Kooy, Hanne M

    2012-03-01

    Proton, as well as other ion, beams applied by electro-magnetic deflection in pencil-beam scanning (PBS) are minimally perturbed and thus can be quantified a priori by their fundamental interactions in a medium. This a priori quantification permits an optimal reduction of characterizing measurements on a particular PBS delivery system. The combination of a priori quantification and measurements will then suffice to fully describe the physical interactions necessary for treatment planning purposes. We consider, for proton beams, these interactions and derive a 'Golden' beam data set. The Golden beam data set quantifies the pristine Bragg peak depth-dose distribution in terms of primary, multiple Coulomb scatter, and secondary, nuclear scatter, components. The set reduces the required measurements on a PBS delivery system to the measurement of energy spread and initial phase space as a function of energy. The depth doses are described in absolute units of Gy(RBE) mm² Gp⁻¹, where Gp equals 10⁹ (giga) protons, thus providing a direct mapping from treatment planning parameters to integrated beam current. We used these Golden beam data on our PBS delivery systems and demonstrated that they yield absolute dosimetry well within clinical tolerance. PMID:22330090

  7. Golden beam data for proton pencil-beam scanning

    NASA Astrophysics Data System (ADS)

    Clasie, Benjamin; Depauw, Nicolas; Fransen, Maurice; Gomà, Carles; Panahandeh, Hamid Reza; Seco, Joao; Flanz, Jacob B.; Kooy, Hanne M.

    2012-03-01

    Proton, as well as other ion, beams applied by electro-magnetic deflection in pencil-beam scanning (PBS) are minimally perturbed and thus can be quantified a priori by their fundamental interactions in a medium. This a priori quantification permits an optimal reduction of characterizing measurements on a particular PBS delivery system. The combination of a priori quantification and measurements will then suffice to fully describe the physical interactions necessary for treatment planning purposes. We consider, for proton beams, these interactions and derive a ‘Golden’ beam data set. The Golden beam data set quantifies the pristine Bragg peak depth-dose distribution in terms of primary, multiple Coulomb scatter, and secondary, nuclear scatter, components. The set reduces the required measurements on a PBS delivery system to the measurement of energy spread and initial phase space as a function of energy. The depth doses are described in absolute units of Gy(RBE) mm2 Gp-1, where Gp equals 109 (giga) protons, thus providing a direct mapping from treatment planning parameters to integrated beam current. We used these Golden beam data on our PBS delivery systems and demonstrated that they yield absolute dosimetry well within clinical tolerance.

  8. Regolith Biological Shield for a Lunar Outpost from High Energy Solar Protons

    NASA Astrophysics Data System (ADS)

    Pham, Tai T.; El-Genk, Mohamed S.

    2008-01-01

    Beyond Earth atmosphere, natural space radiation from Galactic Cosmic Rays and Solar Energetic Protons (SEPs) represents a significant hazard to both manned and robotic missions. For lunar settlements, protecting astronauts from SEPs is a key safety issue that needs to be addressed by identifying appropriate shielding materials. This paper investigates the interaction of SEPs with the lunar regolith, and quantifies the effectiveness of the regolith as a biological shield for a human habitat, compared to aluminum, presently the standard shielding material. Also calculated is the shielding thickness to reduce the dose in the habitat to those recommended by International Radiation Protection Committee and by NASA for operation on the international space station. The present calculations are for the most energetic solar event of February 1956, which included high energy protons up to 1000 MeV. Results show that the lunar regolith is as effective as aluminum for shielding lunar outposts. A large thickness of the regolith (~30 g/cm2) would be needed to reduce the dose in the habitat from high energy protons below the 30 days flight crew limit of 25 Rem (or 250 mSv) and significantly more shielding would be needed (~150 g/cm2) to reduce the dose down to the limit for radiation workers of 5 Rem (or 50 mSv).

  9. Regolith Biological Shield for a Lunar Outpost from High Energy Solar Protons

    SciTech Connect

    Pham, Tai T.; El-Genk, Mohamed S.

    2008-01-21

    Beyond Earth atmosphere, natural space radiation from Galactic Cosmic Rays and Solar Energetic Protons (SEPs) represents a significant hazard to both manned and robotic missions. For lunar settlements, protecting astronauts from SEPs is a key safety issue that needs to be addressed by identifying appropriate shielding materials. This paper investigates the interaction of SEPs with the lunar regolith, and quantifies the effectiveness of the regolith as a biological shield for a human habitat, compared to aluminum, presently the standard shielding material. Also calculated is the shielding thickness to reduce the dose in the habitat to those recommended by International Radiation Protection Committee and by NASA for operation on the international space station. The present calculations are for the most energetic solar event of February 1956, which included high energy protons up to 1000 MeV. Results show that the lunar regolith is as effective as aluminum for shielding lunar outposts. A large thickness of the regolith ({approx}30 g/cm{sup 2}) would be needed to reduce the dose in the habitat from high energy protons below the 30 days flight crew limit of 25 Rem (or 250 mSv) and significantly more shielding would be needed ({approx}150 g/cm{sup 2}) to reduce the dose down to the limit for radiation workers of 5 Rem (or 50 mSv)

  10. Beam-Flattener Design for High Energy Radiographic Inspection

    NASA Technical Reports Server (NTRS)

    Grandin, Robert; Rudolphi, Thomas

    2009-01-01

    This report documents the work done to develop a beam flattener for use in the inspection of rocket motors at ATK Space Systems Utah facilities. The following pages provide a brief introduction to the necessity of this project, comprehensive description of the design methodology, and experimentally-based conclusions regarding project success.

  11. Microstructured snow targets for high energy quasi-monoenergetic proton acceleration

    NASA Astrophysics Data System (ADS)

    Schleifer, E.; Nahum, E.; Eisenmann, S.; Botton, M.; Baspaly, A.; Pomerantz, I.; Abricht, F.; Branzel, J.; Priebe, G.; Steinke, S.; Andreev, A.; Schnuerer, M.; Sandner, W.; Gordon, D.; Sprangle, P.; Ledingham, K. W. D.; Zigler, A.

    2013-05-01

    Compact size sources of high energy protons (50-200MeV) are expected to be key technology in a wide range of scientific applications 1-8. One promising approach is the Target Normal Sheath Acceleration (TNSA) scheme 9,10, holding record level of 67MeV protons generated by a peta-Watt laser 11. In general, laser intensity exceeding 1018 W/cm2 is required to produce MeV level protons. Another approach is the Break-Out Afterburner (BOA) scheme which is a more efficient acceleration scheme but requires an extremely clean pulse with contrast ratio of above 10-10. Increasing the energy of the accelerated protons using modest energy laser sources is a very attractive task nowadays. Recently, nano-scale targets were used to accelerate ions 12,13 but no significant enhancement of the accelerated proton energy was measured. Here we report on the generation of up to 20MeV by a modest (5TW) laser system interacting with a microstructured snow target deposited on a Sapphire substrate. This scheme relax also the requirement of high contrast ratio between the pulse and the pre-pulse, where the latter produces the highly structured plasma essential for the interaction process. The plasma near the tip of the snow target is subject to locally enhanced laser intensity with high spatial gradients, and enhanced charge separation is obtained. Electrostatic fields of extremely high intensities are produced, and protons are accelerated to MeV-level energies. PIC simulations of this targets reproduce the experimentally measured energy scaling and predict the generation of 150 MeV protons from laser power of 100TW laser system18.

  12. Baseline measures for net-proton distributions in high energy heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Netrakanti, P. K.; Luo, X. F.; Mishra, D. K.; Mohanty, B.; Mohanty, A.; Xu, N.

    2016-03-01

    We report a systematic comparison of the recently measured cumulants of the net-proton distributions for 0-5% central Au + Au collisions in the first phase of the Beam Energy Scan (BES) Program at the Relativistic Heavy Collider facility to various kinds of possible baseline measures. These baseline measures correspond to an assumption that the proton and anti-proton distributions follow Poisson statistics, Binomial statistics, obtained from a transport model calculation and from a hadron resonance gas model. The higher order cumulant net-proton data for the center of mass energies (√{sNN}) of 19.6 and 27 GeV are observed to deviate from most of the baseline measures studied. The deviations are predominantly due to the difference in shape of the proton distributions between data and those obtained in the baseline measures. We also present a detailed study on the relevance of the independent production approach as a baseline for comparison with the measurements at various beam energies. Our studies point to the need of either more detailed baseline models for the experimental measurements or a description via QCD calculations in order to extract the exact physics process that leads to deviation of the data from the baselines presented.

  13. Spin-spin correlations in proton-proton collisions at high energy and threshold enhancements

    SciTech Connect

    de Teramond, G.F.

    1988-05-01

    The striking effects in the spin structure observed in elastic proton collisions and the Nuclear Transparency phenomenon recently discovered at BNL are described in terms of heavy quark threshold enhancements. The deviations from scaling laws and the broadening of the angular distributions at resonance are also consistent with the introduction of new degrees of freedom in the pp system. This implies new s-channel physics. Predictions are given for the spin effects in pp collisions near 18.5 GeV/c at large p/sub T//sup 2/ where new measurements are planned. 9 refs., 4 figs.

  14. Shielding Benchmark Experiments Through Concrete and Iron with High-Energy Proton and Heavy Ion Accelerators

    NASA Astrophysics Data System (ADS)

    Nakamura, T.; Sasaki, M.; Nunomiya, T.; Nakao, N.; Kim, E.; Kurosawa, T.; Taniguchi, S.; Iwase, H.; Uwamino, Y.; Shibata, T.; Ito, S.; Fukumura, A.; Perry, D. R.; Wright, P.

    The deep penetration of neutrons through thick shield has become a very serious problem in the shielding design of high-energy, high-intensity accelerator facility. In the design calculation, the Monte Carlo transport calculation through thick shields has large statistical errors and the basic nuclear data and model used in the existing Monte Carlo codes are not well evaluated because of very few experimental data. It is therefore strongly needed to do the deep penetration experiment as shielding benchmark for investigating the calculation accuracy. Under this circumference, we performed the following two shielding experiments through concrete and iron, one with a 800 MeV proton accelerator of the Rutherford Appleton Laboratory (RAL), England and the other with a high energy heavy iron accelerator of the National Institute of Radiological Sciences (NIRS), Japan. Here these two shielding benchmark experiments are outlined.

  15. High energy proton-proton elastic scattering at the Large Hadron Collider and nucleon structure

    NASA Astrophysics Data System (ADS)

    Luddy, Richard Joseph

    To gain insight into the structure of the nucleon, we pursue the development of the phenomenological model of Islam et al. (IIFS model) for high energy elastic pp and p¯p scattering. We determine the energy dependence of the parameters of the IIFS model using the available elastic differential cross section data from SPS Collider and Tevatron and the known asymptotic behavior of sigmatot (s) and rho(s) from dispersion relation calculations and more recent analyses of Cudell et al. (COMPETE Collaboration). Next, we incorporate a high energy elastic valence quark-quark scattering amplitude into the model based on BFKL pomeron to describe small impact parameter (large | t|) pp collisions. Finally, we predict the pp elastic differential cross section at the unprecedented c.m. energy of s = 14.0 TeV at the Large Hadron Collider (LHC). This prediction assumes crucial significance---because of an approved experiment at LHC: TOTal and Elastic Measurement (TOTEM). The TOTEM group plans to measure pp elastic dsigma/dt at 14.0 TeV all the way from momentum transfer |t| = 0 to |t| ≃ 10 GeV 2. Their measurement will stringently test not only the diffraction and o-exchange descriptions of the original IIFS model, but also the additional valence quark-quark scattering contribution that we find to be dominant for large |t|. Successful quantitative verification of the predicted dsigma/dt will mean that our picture of the nucleon with an outer cloud of qq¯ condensed ground state, an inner core of topological baryonic charge, and a still smaller core of massless valence quarks provides a realistic description of nucleon structure.

  16. PROTON BEAM REQUIREMENTS FOR A NEUTRINO FACTORY AND MUON COLLIDER

    SciTech Connect

    Zisman, Michael S.

    2009-12-11

    Both a Neutrino Factory and a Muon Collider place stringent demands on the proton beam used to generate the desired beam of muons. Here we discuss the advantages and challenges of muon accelerators and the rationale behind the requirements on proton beam energy, intensity, bunch length, and repetition rate. Example proton driver configurations that have been considered in recent years are also briefly indicated.

  17. Dose distribution outside the target volume for 170-MeV proton beam.

    PubMed

    Pachnerová Brabcová, K; Ambrožová, I; Kubančák, J; Puchalska, M; Vondráček, V; Molokanov, A G; Sihver, L; Davídková, M

    2014-10-01

    Dose delivered outside the proton field during radiotherapy can potentially lead to secondary cancer development. Measurements with a 170-MeV proton beam were performed with passive detectors (track etched detectors and thermoluminescence dosemeters) in three different depths along the Bragg curve. The measurement showed an uneven decrease of the dose outside of the beam field with local enhancements. The major contribution to the delivered dose is due to high-energy protons with linear energy transfer (LET) up to 10 keV µm(-1). However, both measurement and preliminary Monte Carlo calculation also confirmed the presence of particles with higher LET. PMID:24759915

  18. Experimental validation of beam quality correction factors for proton beams

    NASA Astrophysics Data System (ADS)

    Gomà, Carles; Hofstetter-Boillat, Bénédicte; Safai, Sairos; Vörös, Sándor

    2015-04-01

    This paper presents a method to experimentally validate the beam quality correction factors (kQ) tabulated in IAEA TRS-398 for proton beams and to determine the kQ of non-tabulated ionization chambers (based on the already tabulated values). The method is based exclusively on ionometry and it consists in comparing the reading of two ionization chambers under the same reference conditions in a proton beam quality Q and a reference beam quality 60Co. This allows one to experimentally determine the ratio between the kQ of the two ionization chambers. In this work, 7 different ionization chamber models were irradiated under the IAEA TRS-398 reference conditions for 60Co beams and proton beams. For the latter, the reference conditions for both modulated beams (spread-out Bragg peak field) and monoenergetic beams (pseudo-monoenergetic field) were studied. For monoenergetic beams, it was found that the experimental kQ values obtained for plane-parallel chambers are consistent with the values tabulated in IAEA TRS-398; whereas the kQ values obtained for cylindrical chambers are not consistent—being higher than the tabulated values. These results support the suggestion (of previous publications) that the IAEA TRS-398 reference conditions for monoenergetic proton beams should be revised so that the effective point of measurement of cylindrical ionization chambers is taken into account when positioning the reference point of the chamber at the reference depth. For modulated proton beams, the tabulated kQ values of all the ionization chambers studied in this work were found to be consistent with each other—except for the IBA FC65-G, whose experimental kQ value was found to be 0.6% lower than the tabulated one. The kQ of the PTW Advanced Markus chamber, which is not tabulated in IAEA TRS-398, was found to be 0.997 ± 0.042 (k = 2), based on the tabulated value of the PTW Markus chamber.

  19. Optimum angle-cut of collimator for dense objects in high-energy proton radiography

    NASA Astrophysics Data System (ADS)

    Hai-Bo, Xu; Na, Zheng

    2016-02-01

    The use of minus identity lenses with an angle-cut collimator can achieve high contrast images in high-energy proton radiography. This article presents the principles of choosing the angle-cut aperture of the collimator for different energies and objects. Numerical simulation using the Monte Carlo code Geant4 has been implemented to investigate the entire radiography for the French test object. The optimum angle-cut apertures of the collimators are also obtained for different energies. Supported by NSAF (11176001) and Science and Technology Developing Foundation of China Academy of Engineering Physics (2012A0202006)

  20. Lattice design and beam dynamics studies of the high energy beam transport line in the RAON heavy ion accelerator

    NASA Astrophysics Data System (ADS)

    Jin, Hyunchang; Jang, Ji-Ho; Jang, Hyojae; Jeon, Dong-O.

    2015-12-01

    In RAON heavy ion accelerator, beams generated by superconducting electron cyclotron resonance ion source (ECR-IS) or Isotope Separation On-Line (ISOL) system are accelerated by lower energy superconducting linac and high energy superconducting linac. The accelerated beams are used in the high energy experimental hall which includes bio-medical and muon-SR facilities, after passing through the high energy beam transport lines. At the targets of those two facilities, the stable and small beams meeting the requirements rigorously are required in the transverse plane. Therefore the beams must be safely sent to the targets and simultaneously satisfy the two requirements, the achromatic condition and the mid-plane symmetric condition, of the targets. For this reason, the lattice design of the high energy beam transport lines in which the long deflecting sections are included is considered as a significant issue in the RAON accelerator. In this paper, we will describe the calculated beam optics satisfying the conditions and present the result of particle tracking simulations with the designed lattice of the high energy beam transport lines in the RAON accelerator. Also, the orbit distortion caused by the machine imperfections and the orbit correction with correctors will be discussed.

  1. Measurements of high-energy radiation generation from laser-wakefield accelerated electron beams

    SciTech Connect

    Schumaker, W. Vargas, M.; Zhao, Z.; Behm, K.; Chvykov, V.; Hou, B.; Maksimchuk, A.; Nees, J.; Yanovsky, V.; Thomas, A. G. R.; Krushelnick, K.; Sarri, G.; Dromey, B.; Zepf, M.

    2014-05-15

    Using high-energy (∼0.5 GeV) electron beams generated by laser wakefield acceleration (LWFA), bremsstrahlung radiation was created by interacting these beams with various solid targets. Secondary processes generate high-energy electrons, positrons, and neutrons, which can be measured shot-to-shot using magnetic spectrometers, short half-life activation, and Compton scattering. Presented here are proof-of-principle results from a high-resolution, high-energy gamma-ray spectrometer capable of single-shot operation, and high repetition rate activation diagnostics. We describe the techniques used in these measurements and their potential applications in diagnosing LWFA electron beams and measuring high-energy radiation from laser-plasma interactions.

  2. Thermomechanical response of Large Hadron Collider collimators to proton and ion beam impacts

    NASA Astrophysics Data System (ADS)

    Cauchi, Marija; Assmann, R. W.; Bertarelli, A.; Carra, F.; Cerutti, F.; Lari, L.; Redaelli, S.; Mollicone, P.; Sammut, N.

    2015-04-01

    The CERN Large Hadron Collider (LHC) is designed to accelerate and bring into collision high-energy protons as well as heavy ions. Accidents involving direct beam impacts on collimators can happen in both cases. The LHC collimation system is designed to handle the demanding requirements of high-intensity proton beams. Although proton beams have 100 times higher beam power than the nominal LHC lead ion beams, specific problems might arise in case of ion losses due to different particle-collimator interaction mechanisms when compared to protons. This paper investigates and compares direct ion and proton beam impacts on collimators, in particular tertiary collimators (TCTs), made of the tungsten heavy alloy INERMET® 180. Recent measurements of the mechanical behavior of this alloy under static and dynamic loading conditions at different temperatures have been done and used for realistic estimates of the collimator response to beam impact. Using these new measurements, a numerical finite element method (FEM) approach is presented in this paper. Sequential fast-transient thermostructural analyses are performed in the elastic-plastic domain in order to evaluate and compare the thermomechanical response of TCTs in case of critical beam load cases involving proton and heavy ion beam impacts.

  3. Stable topological insulators achieved using high energy electron beams

    PubMed Central

    Zhao, Lukas; Konczykowski, Marcin; Deng, Haiming; Korzhovska, Inna; Begliarbekov, Milan; Chen, Zhiyi; Papalazarou, Evangelos; Marsi, Marino; Perfetti, Luca; Hruban, Andrzej; Wołoś, Agnieszka; Krusin-Elbaum, Lia

    2016-01-01

    Topological insulators are potentially transformative quantum solids with metallic surface states which have Dirac band structure and are immune to disorder. Ubiquitous charged bulk defects, however, pull the Fermi energy into the bulk bands, denying access to surface charge transport. Here we demonstrate that irradiation with swift (∼2.5 MeV energy) electron beams allows to compensate these defects, bring the Fermi level back into the bulk gap and reach the charge neutrality point (CNP). Controlling the beam fluence, we tune bulk conductivity from p- (hole-like) to n-type (electron-like), crossing the Dirac point and back, while preserving the Dirac energy dispersion. The CNP conductance has a two-dimensional character on the order of ten conductance quanta and reveals, both in Bi2Te3 and Bi2Se3, the presence of only two quantum channels corresponding to two topological surfaces. The intrinsic quantum transport of the topological states is accessible disregarding the bulk size. PMID:26961901

  4. Stable topological insulators achieved using high energy electron beams

    NASA Astrophysics Data System (ADS)

    Zhao, Lukas; Konczykowski, Marcin; Deng, Haiming; Korzhovska, Inna; Begliarbekov, Milan; Chen, Zhiyi; Papalazarou, Evangelos; Marsi, Marino; Perfetti, Luca; Hruban, Andrzej; Wołoś, Agnieszka; Krusin-Elbaum, Lia

    2016-03-01

    Topological insulators are potentially transformative quantum solids with metallic surface states which have Dirac band structure and are immune to disorder. Ubiquitous charged bulk defects, however, pull the Fermi energy into the bulk bands, denying access to surface charge transport. Here we demonstrate that irradiation with swift (~2.5 MeV energy) electron beams allows to compensate these defects, bring the Fermi level back into the bulk gap and reach the charge neutrality point (CNP). Controlling the beam fluence, we tune bulk conductivity from p- (hole-like) to n-type (electron-like), crossing the Dirac point and back, while preserving the Dirac energy dispersion. The CNP conductance has a two-dimensional character on the order of ten conductance quanta and reveals, both in Bi2Te3 and Bi2Se3, the presence of only two quantum channels corresponding to two topological surfaces. The intrinsic quantum transport of the topological states is accessible disregarding the bulk size.

  5. Stable topological insulators achieved using high energy electron beams.

    PubMed

    Zhao, Lukas; Konczykowski, Marcin; Deng, Haiming; Korzhovska, Inna; Begliarbekov, Milan; Chen, Zhiyi; Papalazarou, Evangelos; Marsi, Marino; Perfetti, Luca; Hruban, Andrzej; Wołoś, Agnieszka; Krusin-Elbaum, Lia

    2016-01-01

    Topological insulators are potentially transformative quantum solids with metallic surface states which have Dirac band structure and are immune to disorder. Ubiquitous charged bulk defects, however, pull the Fermi energy into the bulk bands, denying access to surface charge transport. Here we demonstrate that irradiation with swift (∼2.5 MeV energy) electron beams allows to compensate these defects, bring the Fermi level back into the bulk gap and reach the charge neutrality point (CNP). Controlling the beam fluence, we tune bulk conductivity from p- (hole-like) to n-type (electron-like), crossing the Dirac point and back, while preserving the Dirac energy dispersion. The CNP conductance has a two-dimensional character on the order of ten conductance quanta and reveals, both in Bi2Te3 and Bi2Se3, the presence of only two quantum channels corresponding to two topological surfaces. The intrinsic quantum transport of the topological states is accessible disregarding the bulk size. PMID:26961901

  6. Beam-halo measurements in high-current proton beams

    SciTech Connect

    Allen, C.K.; Chan, K.C.D.; Colestock, P.L.; Crandall, K.R.; Garnett, R.W.; Gilpatrick, J.D.; Lysenko, W.; Qiang, J.; Schneider, J.D.; Schulze, M.E.; Sheffield, R.L.; Smith, H.V.; Wangler, T.P.

    2002-01-11

    We present results from an experimental study of the beam halo in a high-current 6.7-MeV proton beam propagating through a 52-quadrupole periodic-focusing channel. The gradients of the first four quadrupoles were independently adjusted to match or mismatch the injected beam. Emittances and beamwidths were obtained from measured profiles for comparisons with maximum emittance-growth predictions of a free-energy model and maximum halo-amplitude predictions of a particle-core model. The experimental results support both models and the present theoretical picture of halo formation.

  7. Calibration of a proton beam energy monitor

    SciTech Connect

    Moyers, M. F.; Coutrakon, G. B.; Ghebremedhin, A.; Shahnazi, K.; Koss, P.; Sanders, E.

    2007-06-15

    Delivery of therapeutic proton beams requires an absolute energy accuracy of {+-}0.64 to 0.27 MeV for patch fields and a relative energy accuracy of {+-}0.10 to 0.25 MeV for tailoring the depth dose distribution using the energy stacking technique. Achromatic switchyard tunes, which lead to better stability of the beam incident onto the patient, unfortunately limit the ability of switchyard magnet tesla meters to verify the correct beam energy within the tolerances listed above. A new monitor to measure the proton energy before each pulse is transported through the switchyard has been installed into a proton synchrotron. The purpose of this monitor is to correct and/or inhibit beam delivery when the measured beam energy is outside of the tolerances for treatment. The monitor calculates the beam energy using data from two frequency and eight beam position monitors that measure the revolution frequency of the proton bunches and the effective offset of the orbit from the nominal radius of the synchrotron. The new energy monitor has been calibrated by measuring the range of the beam through water and comparing with published range-energy tables for various energies. A relationship between depth dose curves and range-energy tables was first determined using Monte Carlo simulations of particle transport and energy deposition. To reduce the uncertainties associated with typical scanning water phantoms, a new technique was devised in which the beam energy was scanned while fixed thickness water tanks were sandwiched between two fixed parallel plate ionization chambers. Using a multitude of tank sizes, several energies were tested to determine the nominal accelerator orbit radius. After calibration, the energy reported by the control system matched the energy derived by range measurements to better than 0.72 MeV for all nine energies tested between 40 and 255 MeV with an average difference of -0.33 MeV. A study of different combinations of revolution frequency and radial

  8. Calibration of a proton beam energy monitor.

    PubMed

    Moyers, M F; Coutrakon, G B; Ghebremedhin, A; Shahnazi, K; Koss, P; Sanders, E

    2007-06-01

    Delivery of therapeutic proton beams requires an absolute energy accuracy of +/-0.64 to 0.27 MeV for patch fields and a relative energy accuracy of +/-0.10 to 0.25 MeV for tailoring the depth dose distribution using the energy stacking technique. Achromatic switchyard tunes, which lead to better stability of the beam incident onto the patient, unfortunately limit the ability of switchyard magnet tesla meters to verify the correct beam energy within the tolerances listed above. A new monitor to measure the proton energy before each pulse is transported through the switchyard has been installed into a proton synchrotron. The purpose of this monitor is to correct and/or inhibit beam delivery when the measured beam energy is outside of the tolerances for treatment. The monitor calculates the beam energy using data from two frequency and eight beam position monitors that measure the revolution frequency of the proton bunches and the effective offset of the orbit from the nominal radius of the synchrotron. The new energy monitor has been calibrated by measuring the range of the beam through water and comparing with published range-energy tables for various energies. A relationship between depth dose curves and range-energy tables was first determined using Monte Carlo simulations of particle transport and energy deposition. To reduce the uncertainties associated with typical scanning water phantoms, a new technique was devised in which the beam energy was scanned while fixed thickness water tanks were sandwiched between two fixed parallel plate ionization chambers. Using a multitude of tank sizes, several energies were tested to determine the nominal accelerator orbit radius. After calibration, the energy reported by the control system matched the energy derived by range measurements to better than 0.72 MeV for all nine energies tested between 40 and 255 MeV with an average difference of -0.33 MeV. A study of different combinations of revolution frequency and radial

  9. A review on photoneutrons characteristics in radiation therapy with high-energy photon beams

    PubMed Central

    Naseri, Alireza; Mesbahi, Asghar

    2010-01-01

    In radiation therapy with high-energy photon beams (E > 10 MeV) neutrons are generated mainly in linacs head thorough (γ,n) interactions of photons with nuclei of high atomic number materials that constitute the linac head and the beam collimation system. These neutrons affect the shielding requirements in radiation therapy rooms and also increase the out-of-field radiation dose of patients undergoing radiation therapy with high-energy photon beams. In the current review, the authors describe the factors influencing the neutron production for different medical linacs based on the performed measurements and Monte Carlo studies in the literature. PMID:24376940

  10. High-Efficiency Volume Reflection of an Ultrarelativistic Proton Beam with a Bent Silicon Crystal

    SciTech Connect

    Scandale, Walter; Still, Dean A.; Baricordi, Stefano; Dalpiaz, Pietro; Fiorini, Massimiliano; Guidi, Vincenzo; Martinelli, Giuliano; Mazzolari, Andrea; Milan, Emiliano; Ambrosi, Giovanni; Azzarello, Philipp; Battiston, Roberto; Bertucci, Bruna; Burger, William J.; Ionica, Maria; Zuccon, Paolo; Cavoto, Gianluca; Santacesaria, Roberta; Valente, Paolo; Vallazza, Erik

    2007-04-13

    The volume reflection phenomenon was detected while investigating 400 GeV proton interactions with bent silicon crystals in the external beam H8 of the CERN Super Proton Synchrotron. Such a process was observed for a wide interval of crystal orientations relative to the beam axis, and its efficiency exceeds 95%, thereby surpassing any previously observed value. These observations suggest new perspectives for the manipulation of high-energy beams, e.g., for collimation and extraction in new-generation hadron colliders, such as the CERN Large Hadron Collider.

  11. Experimental study of proton beam halo in mismatched beams

    SciTech Connect

    Allen, C. K.; Chan, K. D.; Colestock, P. L. ,; Garnett, R. W.; Gilpatrick, J. D.; Qiang, J.; Lysenko, W. P.; Smith, H. V.; Schneider, J. D.; Sheffield, R. L.; Wangler, Thomas P.,; Schulze, M. E.; Crandall, K. R.

    2002-01-01

    We report measurements of transverse beam-halo formation in mismatched proton beams in a 52-quadrupole FODO-transport channel following the 6.7 MeV RFQ at the Low-Energy Demonstration Accelerator (LEDA) at Los Alamos. Beam profiles in both transverse planes were measured using a new diagnostic device that consists of a movable carbon filament for measurement of the beam core, and scraper plates for measurement of the outer part of the distributions. The initial results indicate a surprisingly strong growth rate of the rms emittance even for the modest space-charge tune depressions of the experiment. Our results are consistent with the complete transfer of free energy of the mismatched beams into emittance growth within 10 envelope oscillations for both the breathing and the quadrupole modes.

  12. Beam Dynamics Aspects of High Current Beams in a Superconducting Proton Linac

    NASA Astrophysics Data System (ADS)

    Bellomo, Giovanni; Pagani, Carlo; Pierini, Paolo

    1997-05-01

    High current CW proton linac accelerators have been recently proposed for nuclear waste transmutation and concurrent energy production. In most of the designs the high energy part (100 MeV up to 1-2 GeV) of the linac employs low frequency superconducting structures (352-700 MHz). Here we present beam dynamics issues for the high current (10-50 mA) beams in the superconducting section of such an accelerator, based on 352 MHz β-graded, LEP style cavities, as proposed at Linac 96(C. Pagani, G. Bellomo, P. Pierini, ``A High Current Proton Linac with 352 MHz SC Cavities'', Proceedings of the XVIII Int. Linear Acc. Conf., eds. C. Hill, M. Vretenar, CERN 96-07, 15 November 1996). In particular, smooth beam propagation along the linac has been reached with decreasing phase advances along the linac, and the design has been updated to match the beam dynamics results. Mismatching oscillations are discussed, as they are considered to cause beam halo and, consequently, beam losses.

  13. Proton beam radiotherapy of iris melanoma

    SciTech Connect

    Damato, Bertil . E-mail: Bertil@damato.co.uk; Kacperek, Andrzej; Chopra, Mona; Sheen, Martin A.; Campbell, Ian R.; Errington, R. Douglas

    2005-09-01

    Purpose: To report on outcomes after proton beam radiotherapy of iris melanoma. Methods and Materials: Between 1993 and 2004, 88 patients with iris melanoma received proton beam radiotherapy, with 53.1 Gy in 4 fractions. Results: The patients had a mean age of 52 years and a median follow-up of 2.7 years. The tumors had a median diameter of 4.3 mm, involving more than 2 clock hours of iris in 32% of patients and more than 2 hours of angle in 27%. The ciliary body was involved in 20%. Cataract was present in 13 patients before treatment and subsequently developed in another 18. Cataract had a 4-year rate of 63% and by Cox analysis was related to age (p = 0.05), initial visual loss (p < 0.0001), iris involvement (p < 0.0001), and tumor thickness (p < 0.0001). Glaucoma was present before treatment in 13 patients and developed after treatment in another 3. Three eyes were enucleated, all because of recurrence, which had an actuarial 4-year rate of 3.3% (95% CI 0-8.0%). Conclusions: Proton beam radiotherapy of iris melanoma is well tolerated, the main problems being radiation-cataract, which was treatable, and preexisting glaucoma, which in several patients was difficult to control.

  14. Mechanical response of proton beam irradiated nitinol

    NASA Astrophysics Data System (ADS)

    Afzal, Naveed; Ghauri, I. M.; Mubarik, F. E.; Amin, F.

    2011-01-01

    The present investigation deals with the study of mechanical behavior of proton beam irradiated nitinol at room temperature. The specimens in austenitic phase were irradiated over periods of 15, 30, 45 and 60 min at room temperature using 2 MeV proton beam obtained from Pelletron accelerator. The stress-strain curves of both unirradiated and irradiated specimens were obtained using a universal testing machine at room temperature. The results of the experiment show that an intermediate rhombohedral (R) phase has been introduced between austenite and martensite phase, which resulted in the suppression of direct transformation from austenite to martensite (A-M). Stresses required to start R-phase ( σRS) and martensitic phase ( σMS) were observed to decrease with increase in exposure time. The hardness tests of samples before and after irradiation were also carried out using Vickers hardness tester. The comparison reveals that the hardness is higher in irradiated specimens than that of the unirradiated one. The increase in hardness is quite sharp in specimens irradiated for 15 min, which then increases linearly as the exposure time is increased up to 60 min. The generation of R-phase, variations in the transformation stresses σRS and σMS and increase in hardness of irradiated nitinol may be attributed to lattice disorder and associated changes in crystal structure induced by proton beam irradiation.

  15. Development of Ultra Small Shock Tube for High Energy Molecular Beam Source

    NASA Astrophysics Data System (ADS)

    Miyoshi, Nobuya; Nagata, Shuhei; Kinefuchi, Ikuya; Shimizu, Kazuya; Takagi, Shu; Matsumoto, Yoichiro

    2008-12-01

    A molecular beam source exploiting a small shock tube is described for potential generation of high energy beam in a range of 1-5 eV without any undesirable impurities. The performance of a non-diaphragm type shock tube with an inner diameter of 2 mm was evaluated by measuring the acceleration and attenuation process of shock waves. With this shock tube installed in a molecular beam source, we measured the time-of-flight distributions of shock-heated beams, which demonstrated the ability of controlling the beam energy with the initial pressure ratio of the shock tube.

  16. Development of Ultra Small Shock Tube for High Energy Molecular Beam Source

    SciTech Connect

    Miyoshi, Nobuya; Nagata, Shuhei; Kinefuchi, Ikuya; Shimizu, Kazuya; Matsumoto, Yoichiro; Takagi, Shu

    2008-12-31

    A molecular beam source exploiting a small shock tube is described for potential generation of high energy beam in a range of 1-5 eV without any undesirable impurities. The performance of a non-diaphragm type shock tube with an inner diameter of 2 mm was evaluated by measuring the acceleration and attenuation process of shock waves. With this shock tube installed in a molecular beam source, we measured the time-of-flight distributions of shock-heated beams, which demonstrated the ability of controlling the beam energy with the initial pressure ratio of the shock tube.

  17. SU-E-T-577: Obliquity Factor and Surface Dose in Proton Beam Therapy

    SciTech Connect

    Das, I; Andersen, A; Coutinho, L

    2015-06-15

    Purpose: The advantage of lower skin dose in proton beam may be diminished creating radiation related sequalae usually seen with photon and electron beams. This study evaluates the surface dose as a complex function of beam parameters but more importantly the effect of beam angle. Methods: Surface dose in proton beam depends on the beam energy, source to surface distance, the air gap between snout and surface, field size, material thickness in front of surface, atomic number of the medium, beam angle and type of nozzle (ie double scattering, (DS), uniform scanning (US) or pencil beam scanning (PBS). Obliquity factor (OF) is defined as ratio of surface dose in 0° to beam angle Θ. Measurements were made in water phantom at various beam angles using very small microdiamond that has shown favorable beam characteristics for high, medium and low proton energy. Depth dose measurements were performed in the central axis of the beam in each respective gantry angle. Results: It is observed that surface dose is energy dependent but more predominantly on the SOBP. It is found that as SSD increases, surface dose decreases. In general, SSD, and air gap has limited impact in clinical proton range. High energy has higher surface dose and so the beam angle. The OF rises with beam angle. Compared to OF of 1.0 at 0° beam angle, the value is 1.5, 1.6, 1,7 for small, medium and large range respectively for 60 degree angle. Conclusion: It is advised that just like range and SOBP, surface dose should be clearly understood and a method to reduce the surface dose should be employed. Obliquity factor is a critical parameter that should be accounted in proton beam therapy and a perpendicular beam should be used to reduce surface dose.

  18. Spatial shaping of intense femtosecond beams for the generation of high-energy attosecond pulses

    NASA Astrophysics Data System (ADS)

    Constant, E.; Dubrouil, A.; Hort, O.; Petit, S.; Descamps, D.; Mével, E.

    2012-04-01

    We generate high-order harmonics with a spatially shaped TW laser beam. We present and analyse in detail a new approach for shaping an intense laser field to a flat-top intensity profile near focus. We show that this approach is well adapted for high harmonic generation with high-energy fundamental pulses and highlight the possibilities for generating high-energy attosecond pulses.

  19. The non-orthogonal fixed beam arrangement for the second proton therapy facility at the National Accelerator Center

    NASA Astrophysics Data System (ADS)

    Schreuder, A. N.; Jones, D. T. L.; Conradie, J. L.; Fourie, D. T.; Botha, A. H.; Müller, A.; Smit, H. A.; O'Ryan, A.; Vernimmen, F. J. A.; Wilson, J.; Stannard, C. E.

    1999-06-01

    The medical user group at the National Accelerator Center (NAC) is currently unable to treat all eligible patients with high energy protons. Developing a second proton treatment room is desirable since the 200 MeV proton beam from the NAC separated sector cyclotron is currently under-utilized during proton therapy sessions. During the patient positioning phase in one treatment room, the beam could be used for therapy in a second room. The second proton therapy treatment room at the NAC will be equipped with two non-orthogonal beam lines, one horizontal and one at 30 degrees to the vertical. The two beams will have a common isocentre. This beam arrangement together with a versatile patient positioning system (commercial robot arm) will provide the radiation oncologist with a diversity of possible beam arrangements and offers a reasonable cost-effective alternative to an isocentric gantry.

  20. The non-orthogonal fixed beam arrangement for the second proton therapy facility at the National Accelerator Center

    SciTech Connect

    Schreuder, A. N.; Jones, D. T. L.; Conradie, J. L.; Fourie, D. T.; Botha, A. H.; Mueller, A.; Smit, H. A.; O'Ryan, A.; Vernimmen, F. J. A.; Wilson, J.; Stannard, C. E.

    1999-06-10

    The medical user group at the National Accelerator Center (NAC) is currently unable to treat all eligible patients with high energy protons. Developing a second proton treatment room is desirable since the 200 MeV proton beam from the NAC separated sector cyclotron is currently under-utilized during proton therapy sessions. During the patient positioning phase in one treatment room, the beam could be used for therapy in a second room. The second proton therapy treatment room at the NAC will be equipped with two non-orthogonal beam lines, one horizontal and one at 30 degrees to the vertical. The two beams will have a common isocentre. This beam arrangement together with a versatile patient positioning system (commercial robot arm) will provide the radiation oncologist with a diversity of possible beam arrangements and offers a reasonable cost-effective alternative to an isocentric gantry.

  1. Characterization of warm dense matter produced by laser-accelerated high-energy protons

    NASA Astrophysics Data System (ADS)

    Nakatsutsumi, M.; Fuchs, J.; Mancic, A.; Robiche, J.; Renaudin, P.; Combis, P.; Dorchies, F.; Harmand, M.; Maynard, G.; Vassaux, J.; Mora, P.; Antici, P.; Fourmaux, S.; Audebert, P.

    2008-11-01

    Producing warm dense plasmas (WDM: solid density, few eV ˜ few 10s eV) is of interest for fundamental plasma physics or ICF. Laser-produced proton heating is of interest since they are short (<1ps) and deposit their energy volumetrically. Experiments were performed using the LULI 100 TW facility to create and characterize WDM. We used, (i) 2D time-resolved optical self-emission of the heated target, (ii) surface expansion velocity measurement through phase measurements of a reflecting probe beam, and (iii) x-ray absorption spectroscopy. We showed that we could produce quasi-uniform heating of solids, as suited for e.g. EoS measurements. Time-resolved solid-liquid-plasma transition has been measured, as well as energy-loss of MeV protons in warm dense plasmas.

  2. Characterization of the high-energy neutron beam of the PRISMA beamline using a diamond detector

    NASA Astrophysics Data System (ADS)

    Cazzaniga, C.; Frost, C. D.; Minniti, T.; Schooneveld, E.; Perelli Cippo, E.; Tardocchi, M.; Rebai, M.; Gorini, G.

    2016-07-01

    The high-energy neutron component (En > 10 MeV) of the neutron spectrum of PRISMA, a beam-line at the ISIS spallation source, has been characterized for the first time. Neutron measurements using a Single-crystal Diamond Detector at a short-pulse source are obtained by a combination of pulse height and time of flight analysis. An XY scan provides a 2D map of the high-energy neutron beam which has a diameter of about 40 mm. The high neutron flux, that has been found to be (3.8 ± 0.7) · 105 cm‑2s‑1 for En > 10 MeV in the centre, opens up for a possible application of the beam-line as a high-energy neutron irradiation position. Results are of interest for the development of the ChipIR beam-line, which will feature an atmospheric-like neutron spectrum for chip irradiation experiment. Furthermore, these results demonstrate that diamond detectors can be used at spallation sources to investigate the transport of high-energy neutrons down instruments which is of interest in general to designers as high-energy neutrons are a source of background in thermal beamlines.

  3. Three-hadron angular correlations in high-energy proton-proton and nucleus-nucleus collisions from perturbative QCD

    SciTech Connect

    Ayala, Alejandro; Ortiz, Antonio; Paic, Guy; Jalilian-Marian, Jamal; Magnin, J.; Tejeda-Yeomans, Maria Elena

    2011-08-15

    We study three-hadron azimuthal angular correlations in high-energy proton-proton and central nucleus-nucleus collisions at the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider at midrapidity. We use the leading-order parton matrix elements for 2{yields}3 processes and include the effect of parton energy loss in the quark-gluon plasma using the modified fragmentation function approach. For the case when the produced hadrons have either the same or not too different momenta, we observe two away-side peaks at 2{pi}/3 and 4{pi}/3. We consider the dependence of the angular correlations on energy loss parameters that have been used in studies of single inclusive hadron production at RHIC. Our results on the angular dependence of the cross section agree well with preliminary data by the PHENIX Collaboration. We comment on the possible contribution of 2{yields}3 processes to dihadron angular correlations and how a comparison of the two processes may help characterize the plasma further.

  4. Production of qq pairs in proton-nucleus collisions at high energies

    SciTech Connect

    Kovchegov, Yuri V.; Tuchin, Kirill

    2006-09-01

    We calculate production of quark-antiquark pairs in high energy proton-nucleus collisions both in the quasiclassical approximation of McLerran-Venugopalan model and including quantum small-x evolution. The resulting production cross section is explicitly expressed in terms of Glauber-Mueller multiple rescatterings in the classical case and in terms of dipole-nucleus scattering amplitude in the quantum evolution case. We generalize the result of [K. Tuchin, Phys. Lett. B 593, 66 (2004).] beyond the aligned jet configurations. We expand on the earlier results of Blaizot, Gelis and Venugopalan [J. P. Blaizot, F. Gelis, and R. Venugopalan, Nucl. Phys. A743, 57 (2004).] by deriving quark production cross section including quantum evolution corrections in rapidity intervals both between the quarks and the target and between the quarks and the projectile.

  5. Production of qq¯ pairs in proton-nucleus collisions at high energies

    NASA Astrophysics Data System (ADS)

    Kovchegov, Yuri V.; Tuchin, Kirill

    2006-09-01

    We calculate production of quark-antiquark pairs in high energy proton-nucleus collisions both in the quasiclassical approximation of McLerran-Venugopalan model and including quantum small-x evolution. The resulting production cross section is explicitly expressed in terms of Glauber-Mueller multiple rescatterings in the classical case and in terms of dipole-nucleus scattering amplitude in the quantum evolution case. We generalize the result of [K. Tuchin, Phys. Lett. B 593, 66 (2004).PYLBAJ0370-269310.1016/j.physletb.2004.04.057] beyond the aligned jet configurations. We expand on the earlier results of Blaizot, Gelis and Venugopalan [J. P. Blaizot, F. Gelis, and R. Venugopalan, Nucl. Phys. A743, 57 (2004).] by deriving quark production cross section including quantum evolution corrections in rapidity intervals both between the quarks and the target and between the quarks and the projectile.

  6. A prediction model for bipolar RAMs in a high energy ion/proton environment

    NASA Technical Reports Server (NTRS)

    Myers, D. K.; Price, W. E.; Nichols, D. K.

    1981-01-01

    A model has been developed which predicts the relative susceptibility of bipolar RAMs to heavy ion and proton upset. During the course of evaluating this model, physical and electrical variations were also evaluated indicating that the minimum internal signal level is the primary upset susceptibility indicator. Unfortunately, all of the physical and electrical variations expected during a normal product development cycle are in direct opposition to improved high-energy particle upset tolerance. Hence, a trade-off between highly susceptible, low power (medium speed) devices must be made against the less susceptible, higher power (high speed) equivalent device, taking into account the systems trade-off with respect to system power, software, error correction procedures and/or circuit redundancy.

  7. Basic Phenomena In High Energy-Density Beam Welding And Cutting

    NASA Astrophysics Data System (ADS)

    Arata, Yoshiaki

    1983-08-01

    Essential features in the dynamic behaviours of welding and cutting processes with high energy density beams are reviewed and clarified by the efficient usage of various cineradiographic diagnosises. Formation of a deep beam hole in the weld pool are described and the important effect of the front wall characters in the beam hole is demonstrated on the natures of deep penetration and defect formations such as spiking and porosity. The cutting process is also interpreted in the frame of the same physical viewpoint with the welding. A new and efficient suppression method of spiking, porosity and humping are examined and confirmed using Tandem Electron Beam developed by the author.

  8. Intestinal microbiota reduces genotoxic endpoints induced by high-energy protons.

    PubMed

    Maier, Irene; Berry, David M; Schiestl, Robert H

    2014-01-01

    Ionizing space radiation causes oxidative DNA damage and triggers oxidative stress responses, and compromised DNA repair mechanisms can lead to increased risk of carcinogenesis. Young adult mice with developed innate and adaptive immune systems that harbored either a conventional intestinal microbiota (CM) or an intestinal microbiota with a restricted microbial composition (RM) were irradiated with a total dose of 1 Gy delivered by high-energy protons (2.5 GeV/n, LET = 0.2-2 keV/μm) or silicon or iron ions (850 MeV/n, LET ≈ 50 keV/μm and 1 GeV/n, LET = 150 keV/μm, respectively). Six hours after whole-body irradiation, acute chromosomal DNA lesions were observed for RM mice but not CM mice. High-throughput rRNA gene sequencing of intestinal mucosal bacteria showed that Barnesiella intestinihominis and unclassified Bacterodiales were significantly more abundant in male RM mice than CM mice, and phylotype densities changed in irradiated mice. In addition, Helicobacter hepaticus and Bacteroides stercoris were higher in CM than RM mice. Elevated levels of persistently phosphorylated γ-H2AX were observed in RM mice exposed to high-energy protons compared to nonirradiated RM mice, and they also were associated with a decrease of the antioxidant glutathione in peripheral blood measured at four weeks after irradiation. After radiation exposure, CM mice showed lower levels of γ-H2AX phosphorylation than RM mice and an increase in specific RM-associated phylotypes, indicating a down-regulating force on DNA repair by differentially abundant phylotypes in RM versus a radiation-sensitive complex CM. PMID:24397477

  9. Isochoric Heating of Solid-Density Matter with an Ultrafast Proton Beam

    SciTech Connect

    Key, M H; Mackinnon, A J; Patel, P K; Springer, P T; Price, D F; Allen, M; Foord, M E; Cowan, T E; Ruhl, H; Stephens, R

    2003-12-22

    A new technique is described for the isochoric heating (i.e., heating at constant volume) of matter to high energy-density plasma states (>10{sup 5} J/g) on a picosecond timescale (10{sup -12} sec). An intense, collimated, ultrashort-pulse beam of protons--generated by a high-intensity laser pulse--is used to isochorically heat a solid density material to a temperature of several eV. The duration of heating is shorter than the timescale for significant hydrodynamic expansion to occur, hence the material is heated to a solid density warm dense plasma state. Using spherically-shaped laser targets a focused proton beam is produced and used to heat a smaller volume to over 20 eV. The technique described of ultrafast proton heating provides a unique method for creating isochorically heated high-energy density plasma states.

  10. EGRET High Energy Capability and Multiwavelength Flare Studies and Solar Flare Proton Spectra

    NASA Technical Reports Server (NTRS)

    Chupp, Edward L.

    1998-01-01

    The accomplishments of the participation in the Compton Gamma Ray Observatory Guest investigator program is summarized in this report. The work involved the study of Energetic Gamma Ray Experiment Telescope (EGRET)/Total Absorption Shower Counter(TASC) flare data. The specific accomplishments were the use of the accelerator neutron measurements obtained at the University of New Hampshire to verify the TASC response function and to modify the TASC fitting program to include a high energy neutron contribution, and to determine a high energy neutron contribution to the emissions from the 1991 June 11, solar flare. The next step in the analysis of this event was doing fits to the TASC energy-loss spectra as a function of time. A significant hardening of the solar proton spectrum over time was found for the flare. Further data was obtained from the Yohkoh HXT time histories and images for the 1991 October 27 flare. The results to date demonstrate that the TASC spectral analysis contributes crucial information on the particle spectrum interacting at the Sun. The report includes a paper accepted for publication, a draft of a paper to be delivered at the 26th International Cosmic Ray Conference and an abstract of a paper to be presented at the Meeting of the American Physical Society.

  11. Energy spectrum control for modulated proton beams

    SciTech Connect

    Hsi, Wen C.; Moyers, Michael F.; Nichiporov, Dmitri; Anferov, Vladimir; Wolanski, Mark; Allgower, Chris E.; Farr, Jonathan B.; Mascia, Anthony E.; Schreuder, Andries N.

    2009-06-15

    In proton therapy delivered with range modulated beams, the energy spectrum of protons entering the delivery nozzle can affect the dose uniformity within the target region and the dose gradient around its periphery. For a cyclotron with a fixed extraction energy, a rangeshifter is used to change the energy but this produces increasing energy spreads for decreasing energies. This study investigated the magnitude of the effects of different energy spreads on dose uniformity and distal edge dose gradient and determined the limits for controlling the incident spectrum. A multilayer Faraday cup (MLFC) was calibrated against depth dose curves measured in water for nonmodulated beams with various incident spectra. Depth dose curves were measured in a water phantom and in a multilayer ionization chamber detector for modulated beams using different incident energy spreads. Some nozzle entrance energy spectra can produce unacceptable dose nonuniformities of up to {+-}21% over the modulated region. For modulated beams and small beam ranges, the width of the distal penumbra can vary by a factor of 2.5. When the energy spread was controlled within the defined limits, the dose nonuniformity was less than {+-}3%. To facilitate understanding of the results, the data were compared to the measured and Monte Carlo calculated data from a variable extraction energy synchrotron which has a narrow spectrum for all energies. Dose uniformity is only maintained within prescription limits when the energy spread is controlled. At low energies, a large spread can be beneficial for extending the energy range at which a single range modulator device can be used. An MLFC can be used as part of a feedback to provide specified energy spreads for different energies.

  12. Energy spectrum control for modulated proton beams.

    PubMed

    Hsi, Wen C; Moyers, Michael F; Nichiporov, Dmitri; Anferov, Vladimir; Wolanski, Mark; Allgower, Chris E; Farr, Jonathan B; Mascia, Anthony E; Schreuder, Andries N

    2009-06-01

    In proton therapy delivered with range modulated beams, the energy spectrum of protons entering the delivery nozzle can affect the dose uniformity within the target region and the dose gradient around its periphery. For a cyclotron with a fixed extraction energy, a rangeshifter is used to change the energy but this produces increasing energy spreads for decreasing energies. This study investigated the magnitude of the effects of different energy spreads on dose uniformity and distal edge dose gradient and determined the limits for controlling the incident spectrum. A multilayer Faraday cup (MLFC) was calibrated against depth dose curves measured in water for nonmodulated beams with various incident spectra. Depth dose curves were measured in a water phantom and in a multilayer ionization chamber detector for modulated beams using different incident energy spreads. Some nozzle entrance energy spectra can produce unacceptable dose nonuniformities of up to +/-21% over the modulated region. For modulated beams and small beam ranges, the width of the distal penumbra can vary by a factor of 2.5. When the energy spread was controlled within the defined limits, the dose nonuniformity was less than +/-3%. To facilitate understanding of the results, the data were compared to the measured and Monte Carlo calculated data from a variable extraction energy synchrotron which has a narrow spectrum for all energies. Dose uniformity is only maintained within prescription limits when the energy spread is controlled. At low energies, a large spread can be beneficial for extending the energy range at which a single range modulator device can be used. An MLFC can be used as part of a feedback to provide specified energy spreads for different energies. PMID:19610318

  13. Studies and calculations of transverse emittance growth in high-energy proton storage rings

    SciTech Connect

    Mane, S.R.; Jackson, G.

    1989-03-01

    In the operation of proton-antiproton colliders, an important goal is to maximize the integrated luminosity. During such operations in the Fermilab Tevatron, the transverse beam emittances were observed to grow unexpectedly quickly, thus causing a serious reduction of the luminosity. We have studied this phenomenon experimentally and theoretically. A formula for the emittance growth rate, due to random dipole kicks, is derived. In the experiment, RF phase noise of known amplitude was deliberately injected into the Tevatron to kick the beam randomly, via dispersion at the RF cavities. Theory and experiment are found to agree reasonably well. We also briefly discuss the problem of quadrupole kicks. 14 refs., 2 figs., 3 tabs.

  14. Monte Carlo approach for hadron azimuthal correlations in high energy proton and nuclear collisions

    NASA Astrophysics Data System (ADS)

    Ayala, Alejandro; Dominguez, Isabel; Jalilian-Marian, Jamal; Magnin, J.; Tejeda-Yeomans, Maria Elena

    2012-09-01

    We use a Monte Carlo approach to study hadron azimuthal angular correlations in high-energy proton-proton and central nucleus-nucleus collisions at the BNL Relativistic Heavy Ion Collider energies at midrapidity. We build a hadron event generator that incorporates the production of 2→2 and 2→3 parton processes and their evolution into hadron states. For nucleus-nucleus collisions we include the effect of parton energy loss in the quark-gluon plasma using a modified fragmentation function approach. In the presence of the medium, for the case when three partons are produced in the hard scattering, we analyze the Monte Carlo sample in parton and hadron momentum bins to reconstruct the angular correlations. We characterize this sample by the number of partons that are able to hadronize by fragmentation within the selected bins. In the nuclear environment the model allows hadronization by fragmentation only for partons with momentum above a threshold pTthresh=2.4 GeV. We argue that one should treat properly the effect of those partons with momentum below the threshold, because their interaction with the medium may lead to showers of low-momentum hadrons along the direction of motion of the original partons as the medium becomes diluted.

  15. Proton-Beam Therapy for Olfactory Neuroblastoma

    SciTech Connect

    Nishimura, Hideki . E-mail: westvill@med.kobe-u.ac.jp; Ogino, Takashi; Kawashima, Mitsuhiko; Nihei, Keiji; Arahira, Satoko; Onozawa, Masakatsu; Katsuta, Shoichi; Nishio, Teiji

    2007-07-01

    Purpose: To analyze the feasibility and efficacy of proton-beam therapy (PBT) for olfactory neuroblastoma (ONB) as a definitive treatment, by reviewing our preliminary experience. Olfactory neuroblastoma is a rare disease, and a standard treatment strategy has not been established. Radiation therapy for ONB is challenging because of the proximity of ONBs to critical organs. Proton-beam therapy can provide better dose distribution compared with X-ray irradiation because of its physical characteristics, and is deemed to be a feasible treatment modality. Methods and Materials: A retrospective review was performed on 14 patients who underwent PBT for ONB as definitive treatment at the National Cancer Center Hospital East (Kashiwa, Chiba, Japan) from November 1999 to February 2005. A total dose of PBT was 65 cobalt Gray equivalents (Gy{sub E}), with 2.5-Gy{sub E} once-daily fractionations. Results: The median follow-up period for surviving patients was 40 months. One patient died from disseminated disease. There were two persistent diseases, one of which was successfully salvaged with surgery. The 5-year overall survival rate was 93%, the 5-year local progression-free survival rate was 84%, and the 5-year relapse-free survival rate was 71%. Liquorrhea was observed in one patient with Kadish's stage C disease (widely destroying the skull base). Most patients experienced Grade 1 to 2 dermatitis in the acute phase. No other adverse events of Grade 3 or greater were observed according to the RTOG/EORTC acute and late morbidity scoring system. Conclusions: Our preliminary results of PBT for ONB achieved excellent local control and survival outcomes without serious adverse effects. Proton-beam therapy is considered a safe and effective modality that warrants further study.

  16. Temporal relationship between high-energy proton acceleration and magnetic field changes during solar flares

    NASA Astrophysics Data System (ADS)

    Kurt, Victoria; Yushkov, Boris

    Understanding of the association of the magnetic field evolution in the corona and the temporal evolution of electromagnetic emissions produced by the accelerated particles during a solar flare can provide information about the nature of the energy-release process and its location. Recent high-spatial-resolution observations in HXR, UV and radio emissions allow one to study in detail a structure of two-ribbon flare site. According to these observations, the flare process can be divided into two different intervals with different temporal evolution of morphological structure: loop contraction during impulsive phase and subsequent loop expansion. Оn the other hand, the appearance of high-energy protons (with energy >300 MeV - an energy threshold of the pion production) in the solar atmosphere can be revealed from an emerging pion-decay component of high-energy gamma-ray emission. The present work is based on comparison of measurements of high-energy gamma-rays performed with the SONG detector onboard the CORONAS-F mission and reported observations of magnetic field evolution, such as HXR foot points (FP) separation and flare shear temporal behavior, or motion of UV/radio loops. We reliably identified the pion-decay component of gamma-ray emission in the course of five events attended with suitable spatial observations, namely, 2001 August 25, 2002 August 24, 2003 October 28, 2003 October 29, and 2005 January 20, and determined its onset time. We found that in these events the pion-decay emission occurred when the distance between conjugated foot-points of flare loops ceased to decrease and began to increase, i.e. changed from shrinkage to expansion. This result leads to the conclusion that the most efficient proton acceleration up to >300 MeV coincided in time with the radical reconfiguration of the magnetic field in the flare site. Earlier we found that the pion-decay emission onset in the 2003 October 28 flare was close to the time of maximum change rate of the

  17. Intergalactic Magnetic Field and Arrival Direction of Ultra-High-Energy Protons

    NASA Astrophysics Data System (ADS)

    Ryu, Dongsu; Das, Santabrata; Kang, Hyesung

    2010-02-01

    We studied how the intergalactic magnetic field (IGMF) affects the propagation of super-Greisen-Zatsepin-Kuz'min (GZK) protons that originate from extragalactic sources within the local GZK sphere. To this end, we set up hypothetical sources of ultra-high-energy cosmic rays (UHECRs), virtual observers, and the magnetized cosmic web in a model universe constructed from cosmological structure formation simulations. We then arranged a set of reference objects mimicking active galactic nuclei (AGNs) in the local universe, with which correlations of simulated UHECR events are analyzed. With our model IGMF, the deflection angle between the arrival direction of super-GZK protons and the sky position of their actual sources is quite large with a mean value of langθrang ~ 15° and a median value of \\tilde{θ}˜ 7°-10°. On the other hand, the separation angle between the arrival direction and the sky position of nearest reference objects is substantially smaller with langSrang ~ 3fdg5-4°, which is similar to the mean angular distance in the sky to nearest neighbors among the reference objects. This is a direct consequence of our model that the sources, observers, reference objects, and the IGMF all trace the matter distribution of the universe. The result implies that extragalactic objects lying closest to the arrival direction of UHECRs are not necessarily their actual sources. With our model for the distribution of reference objects, the fraction of super-GZK proton events, whose closest AGNs are true sources, is less than 1/3. We discussed implications of our findings for correlation studies of real UHECR events.

  18. High energy electron cooling

    SciTech Connect

    Parkhomchuk, V.

    1997-09-01

    High energy electron cooling requires a very cold electron beam. The questions of using electron cooling with and without a magnetic field are presented for discussion at this workshop. The electron cooling method was suggested by G. Budker in the middle sixties. The original idea of the electron cooling was published in 1966. The design activities for the NAP-M project was started in November 1971 and the first run using a proton beam occurred in September 1973. The first experiment with both electron and proton beams was started in May 1974. In this experiment good result was achieved very close to theoretical prediction for a usual two component plasma heat exchange.

  19. High Energy Accelerator and Colliding Beam User Group: Progress report, March 1, 1988--February 28, 1989

    SciTech Connect

    Not Available

    1988-09-01

    This report discusses work carried out by the High Energy Accelerator and Colliding Beam User Group at the University of Maryland. Particular topics discussed are: OPAL experiment at LEP; deep inelastic muon interactions; B physics with the CLEO detector at CESR; further results from JADE; and search for ''small'' violation of the Pauli principle. (LSP)

  20. TU-A-BRE-01: The Relative Biological Effectiveness of Proton Beams Relative to Photon Beams

    SciTech Connect

    Paganetti, H; Stewart, R; Carabe-Fernandez, A

    2014-06-15

    Proton therapy patients receive a 10% lower physical dose than the dose administered using photons, i.e. the proton relative biological effectiveness (RBE) is 1.1 in comparison to high-energy photons. The use of a generic, spatially invariant RBE within tumor targets and normal tissue structures disregards a large body of evidence indicating that proton RBE tends to increase with increasing linear energy transfer (LET). Because the doseaveraged proton LET in the distal edge of a spread out Bragg peak (SOBP) is larger than the LET in the plateau region or proximal edge of a SOBP, the use of a spatially invariant RBE is not well justified from a mechanistic point of view. On the other hand, the available clinical data on local tumor control rates and early or late side effects do not provide strong evidence against the continued use of a constant and spatially invariant clinical RBE. The only potential downside to the ongoing use of a constant RBE of 1.1 seems to be that we are missing a potential opportunity to enhance the therapeutic ratio, i.e., design proton therapy treatments in ways that exploit, rather than mitigate, spatial variations in proton RBE. Speakers in this symposium will: 1-review the laboratory and clinical evidence for and against the continued use of a spatially invariant RBE of 1.1, 2-examine some of the putative mechanisms connecting spatial variations in particle LET to estimates of the proton RBE at the molecular, cellular and tissue levels 3-assess the possible clinical significance of incorporating models for spatial variations in proton RBE into treatment planning systems. 4-discuss treatment planning and delivery techniques that will exploit the spatial variations of RBE within proton beams. Learning Objectives: To review laboratory and clinical evidence for and against the continued use of a constant RBE of 1.1 To understand major mechanisms connecting proton LET to RBE at the molecular, cellular and tissue levels. To quantify the

  1. Transmission calculation by empirical numerical model and Monte Carlo simulation in high energy proton radiography of thick objects

    NASA Astrophysics Data System (ADS)

    Zheng, Na; Xu, Hai-Bo

    2015-10-01

    An empirical numerical model that includes nuclear absorption, multiple Coulomb scattering and energy loss is presented for the calculation of transmission through thick objects in high energy proton radiography. In this numerical model the angular distributions are treated as Gaussians in the laboratory frame. A Monte Carlo program based on the Geant4 toolkit was developed and used for high energy proton radiography experiment simulations and verification of the empirical numerical model. The two models are used to calculate the transmission fraction of carbon and lead step-wedges in proton radiography at 24 GeV/c, and to calculate radial transmission of the French Test Object in proton radiography at 24 GeV/c with different angular cuts. It is shown that the results of the two models agree with each other, and an analysis of the slight differences is given. Supported by NSAF (11176001) and Science and Technology Developing Foundation of China Academy of Engineering Physics (2012A0202006)

  2. High-energy Laser-accelerated Electron Beams for Long-range Interrogation

    SciTech Connect

    Cunningham, Nathaniel J.; Banerjee, Sudeep; Ramanathan, Vidya; Powers, Nathan; Chandler-Smith, Nate; Umstadter, Donald; Vane, Randy; Schultz, David; Beene, James; Pozzi, Sara; Clarke, Shaun

    2009-03-10

    We are studying the use of 0.1-1.0 GeV laser-accelerated electron beams as active interrogation probes for long-standoff radiography or nuclear activation of concealed special nuclear material. Use of beams in this energy range is largely unexplored, but such beams could provide notable advantages over lower-energy beams and x-rays. High-energy laser-accelerated electrons exhibit large penetration range through air and solids, and low beam divergence for both direct beams and secondary Bremsstrahlung x-rays. We present laboratory measurements of radiography and activation, using the high-power Diodes laser system at the University of Nebraska, as well as MCNP and GEANT Monte Carlo simulation results used to aid experiment design and interpretation.

  3. High-Energy Laser-Accelerated Electron Beams for Long-Range Interrogation

    SciTech Connect

    Cummingham, N. J.; Banerjee, Sudeep; Ramanathan, Vidya; Powell, Nathan; Chandler-Smith, Nate; Vane, C Randy; Schultz, David Robert; Pozzi, Sara; Clarke, Shaun; Beene, James R; Umstadter, Donald

    2009-01-01

    We are studying the use of 0.1 1.0 GeV laser-accelerated electron beams as active interrogation probes for long-standoff radiography or nuclear activation of concealed special nuclear material. Use of beams in this energy range is largely unexplored, but such beams could provide notable advantages over lower-energy beams and x-rays. High-energy laser-accelerated electrons exhibit large penetration range through air and solids, and low beam divergence for both direct beams and secondary Bremsstrahlung x-rays. We present laboratory measurements of radiography and activation, using the high-power Diodes laser system at the University of Nebraska, as well as MCNP and GEANT Monte Carlo simulation results used to aid experiment design and interpretation.

  4. The second generation Singapore high resolution proton beam writing facilitya)

    NASA Astrophysics Data System (ADS)

    van Kan, J. A.; Malar, P.; Baysic de Vera, Armin

    2012-02-01

    A new proton beam focusing facility, designed for proton beam writing (PBW) applications has been tested. PBW allows for proximity free structuring of high aspect ratio, high-density 3D nanostructures. The new facility is designed around OM52 compact quadrupole lenses capable of operating in a variety of high demagnification configurations. Performance tests show that proton beams can be focused down to 19.0 × 29.9 nm2 and single line scans show a beam width of 12.6 nm. The ultimate goal of sub 10 nm structuring with MeV protons will be discussed.

  5. Proton Beam Focusing and Heating in Petawatt Laser-Solid Interactions

    SciTech Connect

    Snavely, R A; Gu, P; King, J; Hey, D; Akli, K; Zhang, B B; Freeman, R; Hatchett, S; Key, M H; Koch, J; Langdon, A B; Lasinsky, B; MacKinnon, A; Patel, P; Town, R; Wilks, S; Stephens, R; Tsutsumi, T; Chen, Z; Yabuuchi, T; Kurahashi, T; Sato, T; Adumi, K; Toyama, Y; Zheng, J; Kodama, R; Tanaka, K A; Yamanaka, T

    2003-08-13

    It has recently been demonstrated that femtosecond-laser generated proton beams may be focused. These protons, following expansion of the Debye sheath, emit off the inner concave surface of hemispherical shell targets irradiated at their outer convex pole. The sheath normal expansion produces a rapidly converging proton beam. Such focused proton beams provide a new and powerful means to achieve isochoric heating to high temperatures. They are potentially important for measuring the equation of state of materials at high energy density and may provide an alternative route to fast ignition. We present the first results of proton focusing and heating experiments performed at the Petawatt power level at the Gekko XII Laser Facility at ILE Osaka Japan. Solid density Aluminum slabs are placed in the proton focal region at various lengths. The degree of proton focusing is measured via XUV imaging of Planckian emission of the heated zone. Simultaneous with the XUV measurement a streaked optical imaging technique, HISAK, gave temporal optical emission images of the focal region. Results indicate excellent coupling between the laser-proton conversion and subsequent heating.

  6. Polarization beam combination technique for gain saturation effect compensation in high-energy systems

    NASA Astrophysics Data System (ADS)

    Chen, Junchi; Peng, Yujie; Su, Hongpeng; Leng, Yuxin

    2016-06-01

    To compensate for the gain saturation effect in the high-energy laser amplifier, a modified polarization beam combination (PBC) method is introduced to reshape temporal waveform of the injected laser pulse to obtain a controlled high-energy laser pulse shape after amplification. One linearly polarized beam is divided into two orthogonal polarized beams, which spatially recombine together collinearly after propagating different optical paths with relative time delay in PBC structure. The obtained beam with polarization direction being rotated by the following half wave plate is divided and combined again to reform a new beam in another modified polarization beam structure. The reformed beam is injected into three cascaded laser amplifiers. The amplified pulse shape can be controlled by the incident pulse shape and amplifier gain, which is agreeable to the simulation by the Frank-Nodvik equations. Based on the simple method, the various temporal waveform of output pulse with tunable 7 to 20 ns pulse duration can be obtained without interferometric fringes.

  7. Laser generated proton beam focusing and high temperature isochoric heating of solid matter

    SciTech Connect

    Snavely, R. A.; Hatchett, S. P.; Key, M. H.; Langdon, A. B.; Lasinski, B. F.; MacKinnon, A. J.; Patel, P.; Town, R.; Wilks, S. C.; Zhang, B.; Akli, K.; Hey, D.; King, J.; Chen, Z.; Izawa, Y.; Kitagawa, Y.; Kodama, R.; Lei, A.; Tampo, M.; Tanaka, K. A.

    2007-09-15

    The results of laser-driven proton beam focusing and heating with a high energy (170 J) short pulse are reported. Thin hemispherical aluminum shells are illuminated with the Gekko petawatt laser using 1 {mu}m light at intensities of {approx}3x10{sup 18} W/cm{sup 2} and measured heating of thin Al slabs. The heating pattern is inferred by imaging visible and extreme-ultraviolet light Planckian emission from the rear surface. When Al slabs 100 {mu}m thick were placed at distances spanning the proton focus beam waist, the highest temperatures were produced at 0.94x the hemisphere radius beyond the equatorial plane. Isochoric heating temperatures reached 81 eV in 15 {mu}m thick foils. The heating with a three-dimensional Monte Carlo model of proton transport with self-consistent heating and proton stopping in hot plasma was modeled.

  8. Controlling high harmonics generation by spatial shaping of high-energy femtosecond beam.

    PubMed

    Dubrouil, A; Mairesse, Y; Fabre, B; Descamps, D; Petit, S; Mével, E; Constant, E

    2011-07-01

    We demonstrate controlled high-order harmonic generation in gas using high-energy femtosecond pulses (50 fs-50 mJ on target) by performing spatial shaping of the terrawatt fundamental laser beam. We have developed a two optical paths mirror that can withstand high power and shape the pump beam into a quasi-flat-top profile (super Gaussian) near focus. We observe clear signatures of the spatial shaping on the harmonic beam in terms of profile, divergence, level of signal, and spectrum. The harmonic generation in neon with a quasi-flat-top beam results in a broadband extreme UV beam with extremely low divergence (~340 μrad). PMID:21725453

  9. Experimental study of magnetically confined hollow electron beams in the Tevatron as collimators for intense high-energy hadron beams

    SciTech Connect

    Stancari, G.; Annala, G.; Shiltsev, V.; Still, D.; Valishev, A.; Vorobiev, L.; /Fermilab

    2011-03-01

    Magnetically confined hollow electron beams for controlled halo removal in high-energy colliders such as the Tevatron or the LHC may extend traditional collimation systems beyond the intensity limits imposed by tolerable losses. They may also improve collimation performance by suppressing loss spikes due to beam jitter and by increasing capture efficiency. A hollow electron gun was designed and tested at Fermilab for this purpose. It was installed in one of the Tevatron electron lenses in the summer of 2010. We present the results of the first experimental tests of the hollow-beam collimation concept on 980-GeV antiproton bunches in the Tevatron.

  10. Proton-beam therapy for prostate cancer.

    PubMed

    Kagan, A Robert; Schulz, Robert J

    2010-01-01

    The treatment options for prostate cancer include prostatectomy, external-beam irradiation, brachytherapy, cryosurgery, focused ultrasound, hormonal therapy, watchful waiting, and various combinations of these modalities. Because the prostate abuts the bladder and rectum, the dose distributions of external-beam irradiations and the accuracy of their placement play crucial roles in the probability of tumor cure and the incidence of posttreatment complications. Principal among the newer radiation technologies is proton-beam therapy (PBT), whose dose distributions make it possible to deliver higher tumor doses and smaller doses to surrounding normal tissues than from x-ray systems. However, as the 10-year cause-specific survival for early-stage disease treated by radiation therapy now exceeds 90%, and with severe late toxicities in the range of 2% to 3%, randomized clinical trials provide the only means to demonstrate improved outcomes from PBT. Short of the data provided by such trials, the efficacy of PBT can be gleaned only from reports in the clinical literature, and, to date, these reports are equivocal. In view of the current health care crisis and the higher costs of PBT for prostate cancer, it is reasonable to assess the viability of this in-vogue but not-so-new technology. PMID:20890135

  11. Transverse beam shape measurements of intense proton beams using optical transition radiation

    SciTech Connect

    Scarpine, Victor E.; /Fermilab

    2012-03-01

    A number of particle physics experiments are being proposed as part of the Department of Energy HEP Intensity Frontier. Many of these experiments will utilize megawatt level proton beams onto targets to form secondary beams of muons, kaons and neutrinos. These experiments require transverse size measurements of the incident proton beam onto target for each beam spill. Because of the high power levels, most beam intercepting profiling techniques will not work at full beam intensity. The possibility of utilizing optical transition radiation (OTR) for high intensity proton beam profiling is discussed. In addition, previous measurements of OTR beam profiles from the NuMI beamline are presented.

  12. Resistivity changes in superconducting-cavity-grade Nb following high-energy proton irradiation

    SciTech Connect

    Snead, C.L. Jr.; Hanson, A.; Greene, G.A.

    1997-12-01

    Niobium superconducting rf cavities are proposed for use in the proton LINAC accelerators for spallation-neutron applications. Because of accidental beam loss and continual halo losses along the accelerator path, concern for the degradation of the superconducting properties of the cavities with accumulating damage arises. Residual-resistivity-ratio (RRR) specimens of Nb, with a range of initial RRR`s were irradiated at room temperature with protons at energies from 200 to 2000 MeV. Four-probe resistance measurements were made at room temperature and at 4.2 K both prior to and after irradiation. Nonlinear increases in resistivity simulate expected behavior in cavity material after extended irradiation, followed by periodic anneals to room temperature: For RRR = 316 material, irradiations to (2 - 3) x 10{sup 15} p/cm{sup 2} produce degradations up to the 10% level, a change that is deemed operationally acceptable. Without. periodic warming to room temperature, the accumulated damage energy would be up to a factor of ten greater, resulting in unacceptable degradations. Likewise, should higher-RRR material be used, for the same damage energy imparted, relatively larger percentage changes in the RRR will result.

  13. Production of ACTINIUM-225 via High Energy Proton Induced Spallation of THORIUM-232

    NASA Astrophysics Data System (ADS)

    Harvey, James; Nolen, Jerry A.; Kroc, Thomas; Gomes, Itacil; Horwitz, E. Philip.; McAlister, Daniel R.

    2010-06-01

    The science of cancer research is currently expanding its use of alpha particle emitting radioisotopes. Coupled with the discovery and proliferation of molecular species that seek out and attach to tumors, new therapy and diagnostics are being developed to enhance the treatment of cancer and other diseases. This latest technology is commonly referred to as Alpha Immunotherapy (AIT). Actinium-225/Bismuth-213 is a parent/daughter alpha-emitting radioisotope pair that is highly sought after because of the potential for treating numerous diseases and its ability to be chemically compatible with many known and widely used carrier molecules (such as monoclonal antibodies and proteins/peptides). The object of this effort is to refine the simulations for producing actinium-225 at proton beam energies of 400 MeV and above up to about 8 GeV. Once completed, the simulations will be experimentally verified using 400 MeV and 8 GeV protons available at Fermi National Accelerator Laboratory. Targets will be processed at Argonne National Laboratory to separate and purify the actinium-225 that will subsequently be transferred to NorthStar laboratory facilities for product quality testing and comparison to the product quality of ORNL produced actinium-225, which is currently the industry standard. The test irradiations at FNAL will produce 1-20 mCi per day which is more than sufficient for quantitative evaluation of the proposed production process.

  14. Comparative study by IBIC of Si and SiC diodes irradiated with high energy protons

    NASA Astrophysics Data System (ADS)

    Garcia Lopez, J.; Jimenez-Ramos, M. C.; Rodriguez-Ramos, M.; Ceballos, J.; Linez, F.; Raisanen, J.

    2016-04-01

    The transport properties of a series of Si and SiC diodes have been studied using the Ion Beam Induced Charge (IBIC) technique. Structural defects were induced into the samples during the irradiation with 17 MeV protons. The experimental values of the charge collection efficiency (CCE) vs bias voltages have been analyzed using a modified drift-diffusion model, which takes into account the recombination of carriers in the neutral and depletion regions. From these simulations, we have obtained the values of the carrier's lifetime for pristine and irradiated diodes, which are found to degrade faster in the case of the SiC samples. However, the decrease of the CCE at high bias voltages is more important for the Si detectors, indicative of the lower radiation hardness of this material compared to SiC. The nature of the proton-induced defects on Si wafers has been studied by Positron Annihilation Spectroscopy (PAS) and Doppler Broadening Spectroscopy (DBS). The results suggest that the main defect detected by the positrons in p-type samples is the divacancy while for n-type at least a fraction of the positron annihilate in another defect. The concentration of defects is much lower than the number of vacancies predicted by SRIM.

  15. Effects of high energy protons on the E771 silicon microstrip detector

    NASA Astrophysics Data System (ADS)

    Alexopoulos, T.; Antoniazzi, L.; Arenton, M.; Ballagh, C.; Bingham, H.; Blankman, A.; Block, M.; Boden, A.; Borodin, S.; Budagov, J.; Cao, Z. L.; Cataldi, G.; Chen, T. Y.; Clark, K.; Cline, D.; Conetti, S.; Cooper, M.; Corti, G.; Cox, B.; Creti, P.; Dukes, E.; Durandet, C.; Elia, V.; Erwin, A.; Fortney, L.; Golovatyuk, S.; Gorini, E.; Grancagnolo, F.; Haire, M.; Hanlet, P.; He, M.; Introzzi, G.; Jenkins, M.; Jennings, J.; Judd, D.; Kaeding, T.; Kononenko, W.; Kowald, W.; lanza, A.; Lau, K.; Liguori, G.; Lys, J.; Mazur, P.; McManus, A.; Misawa, S.; Mo, G.; Murphy, T.; Nelson, K.; Newcomer, M.; Panareo, M.; Ramachandran, S.; Recagni, M.; Rhoades, J.; Segal, J.; Selove, W.; Smith, R.; Spiegel, L.; Sun, J.; Tokar, S.; Torre, P.; Trischuk, J.; Trojak, T.; Tsyganov, E.; Turnbull, L.; VanBerg, R.; Wagoner, D.; Wang, C.; Wang, H. C.; Wei, C.; Yang, W.; Yao, N.; Zhang, N.; Zhang, S. N.; Zou, B.

    1993-01-01

    A silicon strip detector (SSD) system for use in very high rate experiments has been operated in Experiment E771 (Cox, 1989) at the Fermi National Accelerator laboratory. The detector electronics were designed (Swoboda, 1990; Bowden, 1990; Zimmerman, 1989; Christian, 1991) to meet the specific needs of Fermilab experiment E771 using ASIC chip sets where commercial circuits were not suitable. The electronics for the SSD were designed to operate at rates up to 60 Mhz and were operated at interaction rates up to 10 7 interaction/sec (beam rates of 2 × 10 8 proton/sec). In addition to being very fast, the detector for the 1991 run was very compact with 10000 channels of active detector in a volume fo 5cm × 5cm × 10cm. An expansion of the system to 16000 channels is planned for the next Fermilab fixed target run. The strip pitch ranged from 25 μ m in the center of the detector near the target to 100 μ m pitch at the most downstream, outer edges of the detector. The readout is a latch design with pipelined readout and appears to have single strip efficiencies of ≈ 75% even in the presence of a high radiation dose (∽ 10 14 protons/cm 2) and high leakage currents(≈ 1 nA/strip). The detector and associated amplifier electronics has presently been operated at 17° C and is designed to operate as low as 8° C.

  16. Collinear Photon Exchange in the Beam Normal Polarization Asymmetry of Elastic Electron-Proton Scattering

    SciTech Connect

    Andrei Afanasev; N.P. Merenkov

    2004-07-01

    The parity-conserving single-spin beam asymmetry of elastic electron-proton scattering is induced by an absorptive part of the two-photon exchange amplitude. We demonstrate that this asymmetry has logarithmic and double-logarithmic enhancement due to contributions of hard collinear quasi-real photons. An optical theorem is used to evaluate the asymmetry in terms of the total photoproduction cross section on the proton, predicting its magnitude at 20-30 parts per million for high electron beam energies and small scattering angles. At fixed 4-momentum transfers, the asymmetry is rising logarithmically with increasing electron beam energy, following the high-energy diffractive behavior of total photoproduction cross section on the proton.

  17. In-air ion beam analysis with high spatial resolution proton microbeam

    NASA Astrophysics Data System (ADS)

    Jakšić, M.; Chokheli, D.; Fazinić, S.; Grilj, V.; Skukan, N.; Sudić, I.; Tadić, T.; Antičić, T.

    2016-03-01

    One of the possible ways to maintain the micrometre spatial resolution while performing ion beam analysis in the air is to increase the energy of ions. In order to explore capabilities and limitations of this approach, we have tested a range of proton beam energies (2-6 MeV) using in-air STIM (Scanning Ion Transmission Microscopy) setup. Measurements of the spatial resolution dependence on proton energy have been compared with SRIM simulation and modelling of proton multiple scattering by different approaches. Results were used to select experimental conditions in which 1 micrometre spatial resolution could be obtained. High resolution in-air microbeam could be applied for IBIC (Ion Beam Induced Charge) tests of large detectors used in nuclear and high energy physics that otherwise cannot be tested in relatively small microbeam vacuum chambers.

  18. Radiation hygienization of cattle and swine slurry with high energy electron beam

    NASA Astrophysics Data System (ADS)

    Skowron, Krzysztof; Olszewska, Halina; Paluszak, Zbigniew; Zimek, Zbigniew; Kałuska, Iwona; Skowron, Karolina Jadwiga

    2013-06-01

    The research was carried out to assess the efficiency of radiation hygienization of cattle and swine slurry of different density using the high energy electron beam based on the inactivation rate of Salmonella ssp, Escherichia coli, Enterococcus spp and Ascaris suum eggs. The experiment was conducted with use of the linear electron accelerator Elektronika 10/10 in Institute of Nuclear Chemistry and Technology in Warsaw. The inoculated slurry samples underwent hygienization with high energy electron beam of 1, 3, 5, 7 and 10 kGy. Numbers of reisolated bacteria were determined according to the MPN method, using typical microbiological media. Theoretical lethal doses, D90 doses and hygienization efficiency of high energy electron beam were determined. The theoretical lethal doses for all tested bacteria ranged from 3.63 to 8.84 kGy and for A. suum eggs from 4.07 to 5.83 kGy. Salmonella rods turned out to be the most sensitive and Enterococcus spp were the most resistant to electron beam hygienization. The effectiveness or radiation hygienization was lower in cattle than in swine slurry and in thick than in thin one. Also the species or even the serotype of bacteria determined the dose needed to inactivation of microorganisms.

  19. Quarkonium production in high energy proton-nucleus collisions: CGC meets NRQCD

    NASA Astrophysics Data System (ADS)

    Kang, Zhong-Bo; Ma, Yan-Qing; Venugopalan, Raju

    2014-01-01

    We study the production of heavy quarkonium states in high energy proton-nucleus collisions. Following earlier work of Blaizot, Fujii, Gelis, and Venugopalan, we systematically include both small x evolution and multiple scattering effects on heavy quark pair production within the Color Glass Condensate (CGC) framework. We obtain for the first time expressions in the Non-Relativistic QCD (NRQCD) factorization formalism for heavy quarkonium differential cross sections as a function of transverse momentum and rapidity. We observe that the production of color singlet heavy quark pairs is sensitive to both "quadrupole" and "dipole" Wilson line correlators, whose energy evolution is described by the Balitsky-JIMWLK equations. In contrast, the color octet channel is sensitive to dipole correlators alone. In a quasi-classical approximation, our results for the color singlet channel reduce to those of Dominguez et al. [1]. We compare our results to those obtained combining the CGC with the color evaporation model and point to qualitative differences in the two approaches.

  20. EGRET High Energy Capability and Multiwavelength Flare Studies and Solar Flare Proton Spectra

    NASA Technical Reports Server (NTRS)

    Chupp, Edward L.

    1997-01-01

    UNH was assigned the responsibility to use their accelerator neutron measurements to verify the TASC response function and to modify the TASC fitting program to include a high energy neutron contribution. Direct accelerator-based measurements by UNH of the energy-dependent efficiencies for detecting neutrons with energies from 36 to 720 MeV in NaI were compared with Monte Carlo TASC calculations. The calculated TASC efficiencies are somewhat lower (by about 20%) than the accelerator results in the energy range 70-300 MeV. The measured energy-loss spectrum for 207 MeV neutron interactions in NaI were compared with the Monte Carlo response for 200 MeV neutrons in the TASC indicating good agreement. Based on this agreement, the simulation was considered to be sufficiently accurate to generate a neutron response library to be used by UNH in modifying the TASC fitting program to include a neutron component in the flare spectrum modeling. TASC energy-loss data on the 1991 June 11 flare was transferred to UNH. Also included appendix: Gamma-rays and neutrons as a probe of flare proton spectra: the solar flare of 11 June 1991.

  1. Peregrine monte carlo dose calculations for radiotherapy using clinically realistic neutron and proton beams

    SciTech Connect

    Cox, L. J., LLNL

    1997-06-16

    Lawrence Livermore National Laboratory (LLNL) has developed an all-particle Monte Carlo radiotherapy dose calculation code--PEREGRINE--for use in clinical radiation oncology. For PEREGRINE, we have assembled high-energy evaluated nuclear databases; created radiation source characterization and sampling algorithms; and simulated and characterized clinical beams for treatment with photons, neutrons and protons. Spectra are available for the Harper Hospital (Detroit, U.S.A.) Be(d,n) neutron therapy beam, the National Accelerator Centre (NAC, Faure, S.A.) Be(p,n) neutron therapy beam and many of the operating modes of the Loma Linda University Medical Center (LLUMC, Loma Linda, USA) proton treatment center. These beam descriptions are being used in PEREGRINE for Monte Carlo dose calculations on clinical configurations for comparisons to measurements. The methods of defining and sampling the beam phase space characterizations are discussed. We show calculations using these clinical beams compared to measurements in homogeneous water phantoms. The state of PEREGRINE's high energy neutron and proton transport database, PCSL, is reviewed and the remaining issues involving nuclear data needs for PEREGRINE are addressed.

  2. Beam energy tracking system on Optima XEx high energy ion implanter

    SciTech Connect

    David, Jonathan; Satoh, Shu; Wu Xiangyang; Geary, Cindy; Deluca, James

    2012-11-06

    The Axcelis Optima XEx high energy implanter is an RF linac-based implanter with 12 RF resonators for beam acceleration. Even though each acceleration field is an alternating, sinusoidal RF field, the well known phase-focusing principle produces a beam with a sharp quasi-monoenergetic energy spectrum. A magnetic energy filter after the linac further attenuates the low energy continuum in the energy spectrum often associated with RF acceleration. The final beam energy is a function of the phase and amplitude of the 12 resonators in the linac. When tuning a beam, the magnetic energy filter is set to the desired energy, and each linac parameter is tuned to maximize the transmission through the filter. Once a beam is set up, all the parameters are stored in a recipe, which can be easily tuned and has proven to be quite repeatable. The magnetic field setting of the energy filter selects the beam energy from the RF Linac accelerator, and in-situ verification of beam energy in addition to the magnetic energy filter setting has long been desired. An independent energy tracking system was developed for this purpose, using the existing electrostatic beam scanner as a deflector to construct an in-situ electrostatic energy analyzer. This paper will describe the system and performance of the beam energy tracking system.

  3. Beam structure and transverse emittance studies of high-energy ion beams

    NASA Astrophysics Data System (ADS)

    Saadatmand, K.; Johnson, K. F.; Schneider, J. D.

    1991-05-01

    A visual diagnostic technique was developed to monitor and study ion beam structure shape and size along a transport line. In this technique, a commercially available fluorescent screen is utilized in conjunction with a video camera. This visual representation of the beam structure is digitized and enhanced through use of false color coding and displayed on a TV monitor for on-line viewing. Digitized information is stored for further off-line processing (e.g., extraction of beam profiles). An optional wire grid placed upstream of the fluor screen adds the capability of transverse emittance (or angular spread) measurement to this technique. This diagnostic allows real time observation of the beam response to parameter changes (e.g., evolution of the beam structure, shifts in the beam intensity at various spatial locations within the beam perimeter, and shifts in the beam center and position).

  4. Energy Loss of High Intensity Focused Proton Beams Penetrating Metal Foils

    NASA Astrophysics Data System (ADS)

    McGuffey, C.; Qiao, B.; Kim, J.; Beg, F. N.; Wei, M. S.; Evans, M.; Fitzsimmons, P.; Stephens, R. B.; Chen, S. N.; Fuchs, J.; Nilson, P. M.; Canning, D.; Mastrosimone, D.; Foord, M. E.

    2014-10-01

    Shortpulse-laser-driven intense ion beams are appealing for applications in probing and creating high energy density plasmas. Such a beam isochorically heats and rapidly ionizes any target it enters into warm dense matter with uncertain transport and stopping properties. Here we present experimental measurements taken with the 1.25 kJ, 10 ps OMEGA EP BL shortpulse laser of the proton and carbon spectra after passing through metal foils. The laser irradiated spherically curved C targets with intensity 4×1018 W/cm2, producing proton beams with 3 MeV slope temperature and a sharp low energy cutoff at 5 MeV which has not been observed on lower energy, shorter pulse intense lasers. The beam either diverged freely or was focused to estimated 1016 p +/cm2 ps by a surrounding structure before entering the metal foils (Al or Ag and a Cu tracer layer). The proton and ion spectra were altered by the foil depending on material and whether or not the beam was focused. Transverse proton radiography probed the target with ps temporal and 10 micron spatial resolution, indicating an electrostatic field on the foil may also have affected the beam. We present complementary particle-in-cell simulations of the beam generation and transport to the foils. This work was supported by the DOE/NNSA National Laser User Facility program, Contract DE-SC0001265.

  5. High-energy Coulomb breakup of proton-dripline nuclei as a tool to study radiative-capture reactions of astrophysical interest

    NASA Astrophysics Data System (ADS)

    Sümmerer, K.

    2007-11-01

    High-energy Coulomb dissociation (CD) can be used to investigate the time-reversed process, radiative capture, for unstable nuclei where the direct capture reaction is difficult or impossible to perform. At GSI, we have run a series of CD measurements involving the proton-halo nucleus 8B which plays a major role in solar-neutrino physics. We could show that for this case CD and direct proton capture yield the same result. Theoretical guidance is necessary, however, to make sure that contributions of different electro-magnetic multipolarities and nuclear dissociation processes are well under control. Recently, we have complemented the LAND/ALADIN experimental apparatus at GSI with new Si microstrip detectors and proton-drift-chambers to continue similar studies with radioactive beams from the fragment separator FRS at GSI. The first case of astrophysical interest to be studied will be the CD of 27P. Another case will be the 2-proton breakup of 17Ne to investigate radiative two-proton capture on 15O, a process which could modify the reaction flow of the rp-process.

  6. Ratio of aerosol and gases of radioactive chlorine and particle size distribution of aerosol formed by high-energy proton irradiation.

    PubMed

    Yokoyama, S; Sato, K; Manabe, K; Noguchi, H; Kaneko, H; Oki, Y; Iida, T; Tanaka, Su

    2007-01-01

    To estimate internal doses due to the inhalation of radionuclides produced by the nuclear spallation of the air nuclei in high-energy proton accelerator facilities, the physicochemical properties of radionuclides are very important. Thus, the ratio of aerosol and gases of 38Cl and 39Cl formed by irradiating argon gas-added air with a 48 MeV proton beam has been measured. Radionuclides of 38Cl and 39Cl exist as aerosol, acid gas and non-acid gas. The percentages of activity of 38Cl and 39Cl aerosols are about 80%. The number size distributions of non-radioactive aerosol were characterised by two peaks with diameters of 10-20 nm and larger than 20 nm. As a result predicted by a simple surface model, it was found that the activity size distribution of 38Cl aerosols can be regarded as that having a single peak at 120 nm. PMID:18033760

  7. Removing THMs from drinking water using high-energy electron-beam irradiation

    SciTech Connect

    Cooper, W.J.; Cadavid, E.M.; Nickelson, M.G.; Lin, K. ); Kurucz, C.N.; Waite, T.D. )

    1993-09-01

    High-energy electron-beam irradiation was shown to be efficient for removing trihalomethanes (THMs) from drinking water. The process was demonstrated on a 1.5-MeV variable-current (0--50 mA) electron-beam system at a flow rate of 120 gpm and on a [sup 60]Co gamma source. Of the four THMs, chloroform was the most difficult, i.e., energy-intensive, to remove. The brominated THMs were much more efficiently destroyed by the process. Organically bound halogens were converted to halide anions, and no organic halogen or oxyhalogen reaction by-products were observed.

  8. Heavy ion linac as a high current proton beam injector

    NASA Astrophysics Data System (ADS)

    Barth, Winfried; Adonin, Aleksey; Appel, Sabrina; Gerhard, Peter; Heilmann, Manuel; Heymach, Frank; Hollinger, Ralph; Vinzenz, Wolfgang; Vormann, Hartmut; Yaramyshev, Stepan

    2015-05-01

    A significant part of the experimental program at Facility for Antiproton and Ion Research (FAIR) is dedicated to pbar physics requiring a high number of cooled pbars per hour. The primary proton beam has to be provided by a 70 MeV proton linac followed by two synchrotrons. The new FAIR proton linac will deliver a pulsed proton beam of up to 35 mA of 36 μ s duration at a repetition rate of 4 Hz (maximum). The GSI heavy ion linac (UNILAC) is able to deliver world record uranium beam intensities for injection into the synchrotrons, but it is not suitable for FAIR relevant proton beam operation. In an advanced machine investigation program it could be shown that the UNILAC is able to provide for sufficient high intensities of CH3 beam, cracked (and stripped) in a supersonic nitrogen gas jet into protons and carbon ions. This advanced operational approach will result in up to 3 mA of proton intensity at a maximum beam energy of 20 MeV, 1 0 0 μ s pulse duration and a repetition rate of up to 2.7 Hz delivered to the synchrotron SIS18. Recent linac beam measurements will be presented, showing that the UNILAC is able to serve as a proton FAIR injector for the first time, while the performance is limited to 25% of the FAIR requirements.

  9. Eliminating beam-hardening artifacts in high-energy industrial computed tomography(ICT)

    NASA Astrophysics Data System (ADS)

    Kang, Kejun; Zhao, Ziran; Chen, Zhiqiang; Zhang, Li

    2004-10-01

    Beam-hardening is caused by the filtering of a polychromatic X-ray beam by the objects in the scan field. In industrial field, both the X-ray source and the attenuation characteristics of the materials are different with those in medical field. Methods that work in medical field cannot give satisfying results here. The author has developed a computer software, named simulative tomographic machine (STM) platform. STM platform is designed to simulate the procedure of high-energy ICT scanning. It is also the platform for developing data process algorithm. With the STM platform, this paper presents an efficient correction technique, which can eliminate beam-hardening artifacts efficiently in high-energy ICT. The new algorithm is based on the following facts: the attenuation coefficient of each substance is precisely known; the polychromatic spectrum of accelerator can be computed with Monte Carlo (MC) method; the total photon interaction cross-section of most inspected object can be treated as constant in the energy region between 1.5 and 9MeV. The monochromatic projection can be computed from the polychromatic projection with an iterative algorithm. So we can reconstruct perfect image from the projection made only by high-energy photons.

  10. Polarized proton beam for eRHIC

    SciTech Connect

    Huang, H.; Meot, F.; Ptitsyn, V.; Roser, T.

    2015-05-03

    RHIC has provided polarized proton collisions from 31 GeV to 255 GeV in the past decade. To preserve polarization through numerous depolarizing resonances through the whole accelerator chain, harmonic orbit correction, partial snakes, horizontal tune jump system and full snakes have been used. In addition, close attentions have been paid to betatron tune control, orbit control and beam line alignment. The polarization of 60% at 255 GeV has been delivered to experiments with 1.8×1011 bunch intensity. For the eRHIC era, the beam brightness has to be maintained to reach the desired luminosity. Since we only have one hadron ring in the eRHIC era, existing spin rotator and snakes can be converted to six snake configuration for one hadron ring. With properly arranged six snakes, the polarization can be maintained at 70% at 250 GeV. This paper summarizes the effort and plan to reach high polarization with small emittance for eRHIC.

  11. SU-E-T-443: Developmental Technique for Proton Pencil Beam Measurements: Depth Dose

    SciTech Connect

    Arjomandy, B; Lee, T; Schultz, T; Hsi, W; Park, S

    2014-06-01

    Purpose: Measurements of depth dose distribution (DDD) of pencil beam in proton therapy can be challenging and time consuming. We have developed a technique that uses two Bragg peak chambers to expedite these measurements with a high accuracy. Methods and Material: We used a PTW water tank and two PTW 10.5 cm3 Bragg peak chambers; one as a field chamber and the other as a reference chamber to measure DDDs for 100–250 MeV proton pencil beams. The reference chamber was positioned outside of the water tank upstream with respect to field chamber. We used Geant4 Monte Carlo Simulation (MCS) to model the ProTom proton beam to generate DDDs. The MCS generated DDDs were used to account for halo effects of proton pencil beam that are not measureable with Bragg peak chambers. We also used PTW PEAKFINDER to measure DDDs for comparison purpose. Results: We compared measured and MCS DDDs with Continuous Slowing Down Approximation (CSDA) ranges to verify the range of proton beams that were supplied by the manufacturer. The agreements between all DDD with respect to CSDA were within ±0.5 mm. The WET for Bragg peak chamber for energies between 100–250 MeV was 12.7 ± 0.5 mm. The correction for halo effect was negligible below 150 MeV and was in order of ∼5-10% for 150–250 MeV. Conclusion: Use of Bragg Peak chamber as a reference chamber can facilitate DDD measurements in proton pencil beam with a high accuracy. Some corrections will be required to account for halo effect in case of high energy proton beams due to physical size of chamber.

  12. Detailed parametrization of neutrino and gamma-ray energy spectra from high energy proton-proton interactions

    NASA Astrophysics Data System (ADS)

    Supanitsky, A. D.

    2016-02-01

    Gamma rays and neutrinos are produced as a result of proton-proton interactions that occur in different astrophysical contexts. The detection of these two types of messengers is of great importance for the study of different physical phenomena, related to nonthermal processes, taking place in different astrophysical scenarios. Therefore, the knowledge of the energy spectrum of these two types of particles, as a function of the incident proton energy, is essential for the interpretation of the observational data. In this paper, parametrizations of the energy spectra of gamma rays and neutrinos, originated in proton-proton collisions, are presented. The energy range of the incident protons considered extends from 102 to 108 GeV . The parametrizations are based on Monte Carlo simulations of proton-proton interactions performed with the hadronic interaction models QGSJET-II-04 and EPOS-LHC, which have recently been updated with the data taken by the Large Hadron Collider.

  13. A parallel particle-in-cell model for beam-beam interaction in high energy ring colliders

    NASA Astrophysics Data System (ADS)

    Qiang, Ji; Furman, Miguel A.; Ryne, Robert D.

    2004-07-01

    In this paper we present a self-consistent simulation model of colliding beams in high energy ring colliders. The model, which is based on a particle-in-cell method, uses a new developed shifted effective Green function algorithm for the efficient calculation of the beam-beam interaction with arbitrary separation and large aspect ratio. The model uses transfer maps to treat the external focusing elements and a stochastic map to treat radiation damping and quantum excitation of the beams. In the parallel implementation we studied various strategies to deal with the particular nature of the colliding beam system - a system in which there can be significant particle movement between beam-beam collisions. We chose a particle-field decomposition approach instead of the conventional domain decomposition or particle decomposition approach. The particle-field approach leads to good load balance, reduced communication cost, and shows the best scalability on an IBM SP3 among the three parallel implementations we studied. A performance test of the beam-beam model on a Cray T3E, IBM SP3, and a PC cluster is presented. As an application, we studied the flip-flop instability in an electron-positron collider.

  14. Variable Gamma-Ray Emission Induced by Ultra-high Energy Neutral Beams: Application to 4C +21.35

    NASA Astrophysics Data System (ADS)

    Dermer, Charles D.; Murase, Kohta; Takami, Hajime

    2012-08-01

    The flat-spectrum radio quasar 4C +21.35 (PKS 1222+216) displays prominent nuclear infrared emission from ≈1200 K dust. A 70-400 GeV flare with ≈10 minute variations during half an hour of observations was found by the MAGIC telescopes, and GeV variability was observed on sub-day timescales with the Large Area Telescope on Fermi. We examine 4C +21.35, assuming that it is a source of ultra-high energy cosmic rays (UHECRs). UHECR proton acceleration in the inner jet powers a neutral beam of neutrinos, neutrons, and γ-rays from pγ photopion production. The radiative efficiency and production spectra of neutrals formed through photohadronic processes with isotropic external target photons of the broad-line region (BLR) and torus are calculated. Secondary radiations made by this process have a beaming factor vpropδ5 D, where δD is the Doppler factor. The pair-production optical depth for γ-rays and the photopion efficiency for UHECR neutrons as they pass through external isotropic radiation fields are calculated. If target photons come from the BLR and dust torus, large Doppler factors, δD >~ 100, are required to produce rapidly variable secondary radiation with isotropic luminosity >~ 1047 erg s-1 at the pc scale. The γ-ray spectra from leptonic secondaries are calculated from cascades initiated by the UHECR neutron beam at the pc-scale region and fit to the flaring spectrum of 4C +21.35. Detection of >~ 100 TeV neutrinos from 4C +21.35 or other very high energy γ-ray blazars with IceCube or KM3NeT would confirm this scenario.

  15. Dense Plasma Focus With High Energy Helium Beams for Radiological Source Replacement

    NASA Astrophysics Data System (ADS)

    Schmidt, Andrea; Ellsworth, Jennifer; Falabella, Steve; Link, Anthony; Rusnak, Brian; Sears, Jason; Tang, Vincent

    2014-10-01

    A dense plasma focus (DPF) is a compact accelerator that can produce intense high energy ion beams (multiple MeV). It could be used in place of americium-beryllium (AmBe) neutron sources in applications such as oil well logging if optimized to produce high energy helium beams. AmBe sources produce neutrons when 5.5 MeV alphas emitted from the Am interact with the Be. However, due to the very small alpha-Be cross section for alphas <2 MeV, an AmBe source replacement would have to accelerate ~0.15 μC of He to 2 + MeV in order to produce 107 neutrons per pulse. We are using our particle in cell (PIC) model in LSP of a 4 kJ dense plasma focus discharge to guide the optimization of a compact DPF for the production of high-energy helium beam. This model is fluid for the run-down phase, and then transitions to fully kinetic prior to the pinch in order to include kinetic effects such as ion beam formation and anomalous resistivity. An external pulsed-power driver circuit is used at the anode-cathode boundary. Simulations will be benchmarked to He beam measurements using filtered and time-of-flight Faraday cup diagnostics. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. This work supported by US DOE/NA-22 Office of Non-proliferation Research and Development. Computing support for this work came from the LLNL Institutional Computing Grand Challenge program.

  16. Dose conformation of intensity-modulated stereotactic photon beams, proton beams, and intensity-modulated proton beams for intracranial lesions

    SciTech Connect

    Baumert, Brigitta G. . E-mail: brigitta.baumert@maastro.nl; Norton, Ian A.; Lomax, Antony J.; Davis, J.B.

    2004-11-15

    Purpose: This study evaluates photon beam intensity-modulated stereotactic radiotherapy (IMSRT) based on dynamic leaf motion of a micromultileaf collimator (mMLC), proton beams, and intensity-modulated proton therapy (IMPT) with respect to target coverage and organs at risk. Methods and materials: Dose plans of 6 stereotactically treated patients were recalculated for IMSRT by use of the same field setup and an inverse planning algorithm. Proton and IMPT plans were calculated anew. Three different tumor shapes, multifocal, ovoid, and irregular, were analyzed, as well as dose to organs-at-risk (OAR) in the vicinity of the planning target volume (PTV). Dose distributions were calculated from beam-setup data for a manual mMLC for stereotactically guided conformal radiotherapy (SCRT), a dynamic mMLC for IMSRT, the spot-scanning technique for protons, and a modified spot-scanning technique for IMPT. SCRT was included for a part of the comparison. Criteria for assessment were PTV coverage, dose-volume histograms (DVH), volumes of specific isodoses, and the dose to OAR. Results: Dose conformation to the PTV is equally good for all three techniques and tumor shapes considered. The volumes of the 90% and 80% isodose were comparable for all techniques. For the 50% isodose volume, a divergence between the two modes was seen. In 3 cases, this volume is smaller for IMSRT, and in the 3 other cases, it is smaller for IMPT. This difference was even more pronounced for the volumes of the 30% isodose; IMPT shows further improvement over conventional protons. OAR in concavities (e.g., the brainstem) were similarly well spared by protons and IMSRT. IMPT spares critical organs best. Fewer proton beams are required to achieve similar results. Conclusions: The addition of intensity modulation improves the conformality of mMLC-based SCRT. Conformation of dose to the PTV is comparable for IMSRT, protons, and IMPT. Concerning the sparing of OAR, IMSRT is equivalent to IMPT, and IMPT is

  17. Isotope-Shift Measurement of High-energy Highly Charged Ion Beams

    NASA Astrophysics Data System (ADS)

    Ozawa, S.; Ariga, T.; Inabe, N.; Kase, M.; Tanihata, I.; Wakasugi, M.; Yano, Y.

    2001-10-01

    Isotope-shift measurement by the laser spectroscopic method was aimed to apply for radioactive isotope beams up to uranium created by projectile fragmentation at RIKEN RI beam factory (T. Katayama, et al.,): Nucl. Phys., A626, 545c (1997).to make a systematic study of the mean square nuclear charge radii. The present work was started to verify the feasibility of the method. Projectile fragments are high-energy highly charged ions and weak currents. Therefore we designed ultralow-background photon-detection system (M. Wakasugi, et al.,): Nucl. Instr. and Meth., A419, 50 (1998).for collinear laser spectroscopy of such ion beams. To demonstrate isotope-shift measurement, we measured precisely the 1s2s ^3S_1-1s2p ^3P_0,1,2 transition energy of He-like ^12C ion accelerated up to 0.9 MeV/u and ^13C ion 0.6 MeV/u. For the precision measurement, the uncertainty coming from the ambiguity in the absolute ion beam velocity was suppressed by means of that the resonance energy was measured by two laser beams which propagate in parallel and anti-parallel directions to the ion beam. As the result, isotope shifts of these transitions were obtained with the accuracy of 10 %. The lower limit of the ion-beam intensity for the measurement is estimated to be 2000 ions/s.

  18. A comparison of phantom scatter from flattened and flattening filter free high-energy photon beams

    SciTech Connect

    Richmond, Neil; Allen, Vince; Daniel, Jim; Dacey, Rob; Walker, Chris

    2015-04-01

    Flattening filter free (FFF) photon beams have different dosimetric properties from those of flattened beams. The aim of this work was to characterize the collimator scatter (S{sub c}) and total scatter (S{sub cp}) from 3 FFF beams of differing quality indices and use the resulting mathematical fits to generate phantom scatter (S{sub p}) data. The similarities and differences between S{sub p} of flattened and FFF beams are described. S{sub c} and S{sub cp} data were measured for 3 flattened and 3 FFF high-energy photon beams (Varian 6 and 10 MV and Elekta 6 MV). These data were fitted to logarithmic power law functions with 4 numerical coefficients. The agreement between our experimentally determined flattened beam S{sub p} and published data was within ± 1.2% for all 3 beams investigated and all field sizes from 4 × 4 to 40 × 40 cm{sup 2}. For the FFF beams, S{sub p} was only within 1% of the same flattened beam published data for field sizes between 6 × 6 and 14 × 14 cm{sup 2}. Outside this range, the differences were much greater, reaching − 3.2%, − 4.5%, and − 4.3% for the fields of 40 × 40 cm{sup 2} for the Varian 6-MV, Varian 10-MV, and Elekta 6-MV FFF beams, respectively. The FFF beam S{sub p} increased more slowly with increasing field size than that of the published and measured flattened beam of a similar reference field size quality index, i.e., there is less Phantom Scatter than that found with flattened beams for a given field size. This difference can be explained when the fluence profiles of the flattened and FFF beams are considered. The FFF beam has greatly reduced fluence off axis, especially as field size increases, compared with the flattened beam profile; hence, less scatter is generated in the phantom reaching the central axis.

  19. Calculation of the characteristics of clinical high-energy photon beams with EGS5-MPI

    NASA Astrophysics Data System (ADS)

    Shimizu, M.; Morishita, Y.; Kato, M.; Kurosawa, T.; Tanaka, T.; Takata, N.; Saito, N.

    2014-03-01

    A graphite calorimeter has been developed as a Japanese primary standard of absorbed dose to water in the high-energy photon beams from a clinical linac. To obtain conversion factors for the graphite calorimeter, the beam characteristics of the high-energy photon beams from the clinical linac at National Metrology Institute of Japan were calculated with the EGS5 Monte Carlo simulation code. To run the EGS5 code on High Performance Computing machines that have more than 1000 CPU cores, we developed the EGS5 parallelisation package "EGS5-MPI" by implementing a message-passing interface. We calculated the photon energy spectra, which are in good agreement with those previously calculated by D. Sheikh-Bagheri and D. W. O. Rogers (Med. Phys. 29 3). We also estimated the percentage-depth-dose distributions of photon beams from the linac using the calculated photon energy spectra. These calculated percentage-depth-dose distributions were compared with our measured distributions and were found they are in good agreement as well. We will calculate conversion factors for the graphite calorimeter using our results.

  20. Effective generation of the spread-out-Bragg peak from the laser accelerated proton beams using a carbon-proton mixed target.

    PubMed

    Yoo, Seung Hoon; Cho, Ilsung; Cho, Sungho; Song, Yongkeun; Jung, Won-Gyun; Kim, Dae-Hyun; Shin, Dongho; Lee, Se Byeong; Pae, Ki-Hong; Park, Sung Yong

    2014-12-01

    Conventional laser accelerated proton beam has broad energy spectra. It is not suitable for clinical use directly, so it is necessary for employing energy selection system. However, in the conventional laser accelerated proton system, the intensity of the proton beams in the low energy regime is higher than that in the high energy regime. Thus, to generate spread-out-Bragg peak (SOBP), stronger weighting value to the higher energy proton beams is needed and weaker weighting value to the lower energy proton beams is needed, which results in the wide range of weighting values. The purpose of this research is to investigate a method for efficient generating of the SOBP with varying magnetic field in the energy selection system using a carbon-proton mixture target. Energy spectrum of the laser accelerated proton beams was acquired using Particle-In-Cell simulations. The Geant4 Monte Carlo simulation toolkit was implemented for energy selection, particle transportation, and dosimetric property measurement. The energy selection collimator hole size of the energy selection system was changed from 1 to 5 mm in order to investigate the effect of hole size on the dosimetric properties for Bragg peak and SOBP. To generate SOBP, magnetic field in the energy selection system was changed during beam irradiation with each beam weighting factor. In this study, our results suggest that carbon-proton mixture target based laser accelerated proton beams can generate quasi-monoenergetic energy distribution and result in the efficient generation of SOBP. A further research is needed to optimize SOBP according to each range and modulated width using an optimized weighting algorithm. PMID:25154880

  1. Induction of Micronuclei in Human Fibroblasts from the Los Alamos High Energy Neutron Beam

    NASA Technical Reports Server (NTRS)

    Cox, Bradley

    2009-01-01

    The space radiation field includes a broad spectrum of high energy neutrons. Interactions between these neutrons and a spacecraft, or other material, significantly contribute to the dose equivalent for astronauts. The 15 degree beam line in the Weapons Neutron Research beam at Los Alamos Nuclear Science Center generates a neutron spectrum relatively similar to that seen in space. Human foreskin fibroblast (AG1522) samples were irradiated behind 0 to 20 cm of water equivalent shielding. The cells were exposed to either a 0.05 or 0.2 Gy entrance dose. Following irradiation, micronuclei were counted to see how the water shield affects the beam and its damage to cell nuclei. Micronuclei induction was then compared with dose equivalent data provided from a tissue equivalent proportional counter.

  2. A modular solid state detector for measuring high energy heavy ion fragmentation near the beam axis

    NASA Technical Reports Server (NTRS)

    Zeitlin, C. J.; Frankel, K. A.; Gong, W.; Heilbronn, L.; Lampo, E. J.; Leres, R.; Miller, J.; Schimmerling, W.

    1994-01-01

    A multi-element solid state detector has been designed to measure fluences of fragments produced near the beam axis by high energy heavy ion beams in thick targets. The detector is compact and modular, so as to be readily reconfigured according to the range of fragment charges and energies to be measured. Preamplifier gain settings and detector calibrations are adjustable remotely under computer control. We describe the central detector, its associated detectors and electronics, triggering scheme, data acquisition and particle identification techniques, illustrated by data taken with 600 MeV/u 56Fe beams and thick polyethylene targets at the LBL Bevalac. The applications of this work to space radiation protection are discussed.

  3. Fabrication of Pt nanoparticle incorporated polymer nanowires by high energy ion and electron beam irradiation

    NASA Astrophysics Data System (ADS)

    Tsukuda, Satoshi; Takahasi, Ryouta; Seki, Shu; Sugimoto, Masaki; Idesaki, Akira; Yoshikawa, Masahito; Tanaka, Shun-Ichiro

    2016-01-01

    Polyvinylpyrrolidone (PVP)-Pt nanoparticles (NPs) hybrid nanowires were fabricated by high energy ion beam irradiation to PVP thin films including H2PtCl6. Single ion hitting caused crosslinking reactions of PVP and reduction of Pt ions within local cylindrical area along an ion trajectory (ion track); therefore, the PVP nanowires including Pt NPs were formed and isolated on Si substrate after wet-development procedure. The number of Pt NPs was easily controlled by the mixed ratio of PVP and H2PtCl6. However, increasing the amount of H2PtCl6 led to decreasing the radial size and separation of the hybrid nanowires during the wet-development. Additional electron beam irradiation after ion beam improved separation of the nanowires and controlled radial sizes due to an increase in the density of crosslinking points inner the nanowires.

  4. Large Logarithms in the Beam Normal Spin Asymmetry of Elastic Electron--Proton Scattering

    SciTech Connect

    Andrei Afanasev; Mykola Merenkov

    2004-06-01

    We study a parity-conserving single-spin beam asymmetry of elastic electron-proton scattering induced by an absorptive part of the two-photon exchange amplitude. It is demonstrated that excitation of inelastic hadronic intermediate states by the consecutive exchange of two photons leads to logarithmic and double-logarithmic enhancement due to contributions of hard collinear quasi-real photons. The asymmetry at small electron scattering angles is expressed in terms of the total photoproduction cross section on the proton, and is predicted to reach the magnitude of 20-30 parts per million. At these conditions and fixed 4-momentum transfers, the asymmetry is rising logarithmically with increasing electron beam energy, following the high-energy diffractive behavior of total photoproduction cross section on the proton.

  5. Trap-Based Beam Formation Mechanisms and the Development of an Ultra-High-Energy-Resolution Cryogenic Positron Beam

    NASA Astrophysics Data System (ADS)

    Natisin, Michael Ryan

    The focus of this dissertation is the development of a positron beam with significantly improved energy resolution over any beam resolution previously available. While positron interactions with matter are important in a variety of contexts, the range of experimental data available regarding fundamental positron-matter interactions is severely limited as compared to analogous electron-matter processes. This difference is due largely to the difficulties encountered in creating positron beams with narrow energy spreads. Described here is a detailed investigation into the physical processes operative during positron cooling and beam formation in state-of-the-art, trap-based beam systems. These beams rely on buffer gas traps (BGTs), in which positrons are trapped and cooled to the ambient temperature (300 K) through interactions with a molecular gas, and subsequently ejected as a high resolution pulsed beam. Experimental measurements, analytic models, and simulation results are used to understand the creation and characterization of these beams, with a focus on the mechanisms responsible for setting beam energy resolution. The information gained from these experimental and theoretical studies was then used to design, construct, and operate a next-generation high-energy-resolution beam system. In this new system, the pulsed beam from the BGT is magnetically guided into a new apparatus which re-traps the positrons, cools them to 50 K, and re-emits them as a pulsed beam with superior beam characteristics. Using these techniques, positron beams with total energy spreads as low as 6.9 meV FWHM are produced. This represents a factor of ˜ 5 improvement over the previous state-of-the-art, making it the largest increase in positron beam energy resolution since the development of advanced moderator techniques in the early 1980's. These beams also have temporal spreads of 0.9 mus FWHM and radial spreads of 1 mm FWHM. This represents improvements by factors of ˜2 and 10

  6. Beam manipulation techniques, nonlinear beam dynamics, and space charge effect in high energy high power accelerators

    SciTech Connect

    Lee, S. Y.

    2014-04-07

    We had carried out a design of an ultimate storage ring with beam emittance less than 10 picometer for the feasibility of coherent light source at X-ray wavelength. The accelerator has an inherent small dynamic aperture. We study method to improve the dynamic aperture and collective instability for an ultimate storage ring. Beam measurement and accelerator modeling are an integral part of accelerator physics. We develop the independent component analysis (ICA) and the orbit response matrix method for improving accelerator reliability and performance. In collaboration with scientists in National Laboratories, we also carry out experimental and theoretical studies on beam dynamics. Our proposed research topics are relevant to nuclear and particle physics using high brightness particle and photon beams.

  7. Physics of Neutralization of Intense High-Energy Ion Beam Pulses by Electrons

    SciTech Connect

    Kaganovich, I. D.; Davidson, R. C.; Dorf, M. A.; Startsev, E. A.; Sefkow, A. B.; Lee, E. P.; Friedman, A.

    2010-04-28

    Neutralization and focusing of intense charged particle beam pulses by electrons forms the basis for a wide range of applications to high energy accelerators and colliders, heavy ion fusion, and astrophysics. For example, for ballistic propagation of intense ion beam pulses, background plasma can be used to effectively neutralize the beam charge and current, so that the self-electric and self- magnetic fields do not affect the ballistic propagation of the beam. From the practical perspective of designing advanced plasma sources for beam neutralization, a robust theory should be able to predict the self-electric and self-magnetic fields during beam propagation through the background plasma. The major scaling relations for the self-electric and self-magnetic fields of intense ion charge bunches propagating through background plasma have been determined taking into account the effects of transients during beam entry into the plasma, the excitation of collective plasma waves, the effects of gas ionization, finite electron temperature, and applied solenoidal and dipole magnetic fields. Accounting for plasma production by gas ionization yields a larger self-magnetic field of the ion beam compared to the case without ionization, and a wake of current density and self-magnetic field perturbations is generated behind the beam pulse. A solenoidal magnetic field can be applied for controlling the beam propagation. Making use of theoretical models and advanced numerical simulations, it is shown that even a small applied magnetic field of about 100G can strongly affect the beam neutralization. It has also been demonstrated that in the presence of an applied magnetic field the ion beam pulse can excite large-amplitude whistler waves, thereby producing a complex structure of self-electric and self-magnetic fields. The presence of an applied solenoidal magnetic field may also cause a strong enhancement of the radial self-electric field of the beam pulse propagating through the

  8. Physics of neutralization of intense high-energy ion beam pulses by electrons

    SciTech Connect

    Kaganovich, I. D.; Davidson, R. C.; Dorf, M. A.; Startsev, E. A.; Sefkow, A. B.; Lee, E. P.; Friedman, A.

    2010-05-15

    Neutralization and focusing of intense charged particle beam pulses by electrons form the basis for a wide range of applications to high energy accelerators and colliders, heavy ion fusion, and astrophysics. For example, for ballistic propagation of intense ion beam pulses, background plasma can be used to effectively neutralize the beam charge and current, so that the self-electric and self-magnetic fields do not affect the ballistic propagation of the beam. From the practical perspective of designing advanced plasma sources for beam neutralization, a robust theory should be able to predict the self-electric and self-magnetic fields during beam propagation through the background plasma. The major scaling relations for the self-electric and self-magnetic fields of intense ion charge bunches propagating through background plasma have been determined taking into account the effects of transients during beam entry into the plasma, the excitation of collective plasma waves, the effects of gas ionization, finite electron temperature, and applied solenoidal and dipole magnetic fields. Accounting for plasma production by gas ionization yields a larger self-magnetic field of the ion beam compared to the case without ionization, and a wake of current density and self-magnetic field perturbations is generated behind the beam pulse. A solenoidal magnetic field can be applied for controlling the beam propagation. Making use of theoretical models and advanced numerical simulations, it is shown that even a small applied magnetic field of about 100 G can strongly affect the beam neutralization. It has also been demonstrated that in the presence of an applied magnetic field the ion beam pulse can excite large-amplitude whistler waves, thereby producing a complex structure of self-electric and self-magnetic fields. The presence of an applied solenoidal magnetic field may also cause a strong enhancement of the radial self-electric field of the beam pulse propagating through the

  9. Simulations of proton beam characteristics for ELIMED Beamline

    NASA Astrophysics Data System (ADS)

    Psikal, Jan; Limpouch, Jiri; Klimo, Ondrej; Vyskocil, Jiri; Margarone, Daniele; Korn, Georg

    2016-03-01

    ELIMED Beamline should demonstrate the capability of laser-based particle accelerators for medical applications, mainly for proton radiotherapy of tumours which requires a sufficient number of accelerated protons with energy about 60 MeV at least. In this contribution, we study the acceleration of protons by laser pulse with parameters accessible for ELIMED Beamline (intensity ∼ 1022 W/cm2, pulse length ∼ 30 fs). In our two-dimensional particle-incell simulations, we observed higher energies of protons for linear than for circular polarization. Oblique incidence of the laser pulse on target does not seem to be favourable for proton acceleration at such high intensities as the accelerated protons are deflected from target normal axis and their energy and numbers are slightly decreased. The expected numbers of accelerated protons in the energy interval 60 MeV ± 5% are calculated between 109 and 1010 per laser shot with estimated proton beam divergence about 20° (FWHM).

  10. US Heavy Ion Beam Research for High Energy Density Physics Applications and Fusion

    SciTech Connect

    Davidson, R.C.; Logan, B.G.; Barnard, J.J.; Bieniosek, F.M.; Briggs, R.J.; et al.

    2005-09-19

    Key scientific results from recent experiments, modeling tools, and heavy ion accelerator research are summarized that explore ways to investigate the properties of high energy density matter in heavy-ion-driven targets, in particular, strongly-coupled plasmas at 0.01 to 0.1 times solid density for studies of warm dense matter, which is a frontier area in high energy density physics. Pursuit of these near-term objectives has resulted in many innovations that will ultimately benefit heavy ion inertial fusion energy. These include: neutralized ion beam compression and focusing, which hold the promise of greatly improving the stage between the accelerator and the target chamber in a fusion power plant; and the Pulse Line Ion Accelerator (PLIA), which may lead to compact, low-cost modular linac drivers.

  11. Superhard Coatings Synthesis Assisted by Pulsed Beams of High-Energy Gas Molecules

    NASA Astrophysics Data System (ADS)

    Metel, Alexander; Bolbukov, Vasily; Volosova, Marina; Grigoriev, Sergei; Melnik, Yury; Department of high-efficiency machining technologies Team

    2015-09-01

    For production of nanocomposite superhard (HV 5000) and fracture-tough coatings on dielectric substrates a source of metal atoms accompanied by pulsed beams of 30-keV neutral molecules was used. The source is equipped with two parallel equipotential grids placed between a magnetron target and a substrate. Negative high-voltage pulses applied to the high-transparency grids accelerate from the magnetron plasma ions, which are transformed into high-energy neutral molecules due to charge-exchange collisions with gas molecules between the grids. Mixing of the substrate and coating materials through bombardment by high-energy gas molecules results in an adequate compressive stress of the coating and interface width exceeding 1 μm, which allows deposition of 100- μm-thick coatings with a perfect adhesion. The work was supported by the Grant No. 14-29-00297 of the Russian Science Foundation.

  12. High energy Coulomb-scattered electrons for relativistic particle beam diagnostics

    NASA Astrophysics Data System (ADS)

    Thieberger, P.; Altinbas, Z.; Carlson, C.; Chasman, C.; Costanzo, M.; Degen, C.; Drees, K. A.; Fischer, W.; Gassner, D.; Gu, X.; Hamdi, K.; Hock, J.; Marusic, A.; Miller, T.; Minty, M.; Montag, C.; Luo, Y.; Pikin, A. I.; White, S. M.

    2016-04-01

    A new system used for monitoring energetic Coulomb-scattered electrons as the main diagnostic for accurately aligning the electron and ion beams in the new Relativistic Heavy Ion Collider (RHIC) electron lenses is described in detail. The theory of electron scattering from relativistic ions is developed and applied to the design and implementation of the system used to achieve and maintain the alignment. Commissioning with gold and 3He beams is then described as well as the successful utilization of the new system during the 2015 RHIC polarized proton run. Systematic errors of the new method are then estimated. Finally, some possible future applications of Coulomb-scattered electrons for beam diagnostics are briefly discussed.

  13. An online, energy-resolving beam profile detector for laser-driven proton beams.

    PubMed

    Metzkes, J; Zeil, K; Kraft, S D; Karsch, L; Sobiella, M; Rehwald, M; Obst, L; Schlenvoigt, H-P; Schramm, U

    2016-08-01

    In this paper, a scintillator-based online beam profile detector for the characterization of laser-driven proton beams is presented. Using a pixelated matrix with varying absorber thicknesses, the proton beam is spatially resolved in two dimensions and simultaneously energy-resolved. A thin plastic scintillator placed behind the absorber and read out by a CCD camera is used as the active detector material. The spatial detector resolution reaches down to ∼4 mm and the detector can resolve proton beam profiles for up to 9 proton threshold energies. With these detector design parameters, the spatial characteristics of the proton distribution and its cut-off energy can be analyzed online and on-shot under vacuum conditions. The paper discusses the detector design, its characterization and calibration at a conventional proton source, as well as the first detector application at a laser-driven proton source. PMID:27587116

  14. Generating Polarized High-Brightness Muon Beams With High-Energy Gammas

    SciTech Connect

    Yakimenko, Vitaly

    2009-01-22

    Hadron colliders are impractical at very high energies as effective interaction energy is a fraction of the energies of the beams and luminosity must rise as energy squared. Further, the prevailing gluon-gluon background radiation makes it difficult to sort out events. e{sup +}e{sup -} colliders, on other hand, are constrained at TeV energies by beamstrahlung radiation and also by cost as long linacs are required to avoid synchrotron radiation in the rings. A muon collider will have the same advantages in energy reach as an e{sup +}e{sup -} collider, but without prohibitive beamstrahlung- and synchrotron- radiation. Generation of the high-brightness polarized muon ({mu}{sup -}{mu}{sup +}) beams through gamma conversion into pairs in the nuclei field is considered in this paper. The dominant effect in the interaction of the high-energy photons with the solid target will be the production of electron-positron pairs. The low-phase space of the resulting muon beams adequately compensates for the small probability of generating a {mu}{sup -}{mu}{sup +} pair.

  15. Cross sections for proton induced high energy γ -ray emission (PIGE) in reaction 19 F(p, αγ)16 O at incident proton energies between 1.5 and 4 MeV

    NASA Astrophysics Data System (ADS)

    Cabanelas, P.; Cruz, J.; Fonseca, M.; Henriques, A.; Lourenço, F.; Luís, H.; Machado, J.; Pires Ribeiro, J.; Sánchez-Benítez, A. M.; Teubig, P.; Velho, P.; Zarza-Moreno, M.; Galaviz, D.; Jesus, A. P.

    2016-08-01

    We have studied the high energy gamma-rays produced in the reaction 19 F(p, αγ)16 O for incident proton energies from 1.5 to 4.0 MeV over NaF/Ag and CaF2/Ag thin targets in two different sets of data. Gamma-rays were detected with a High Purity Ge detector with an angle of 130° with respect to the beam axis. The cross-sections for the high energy gamma-rays of 6.129, 6.915 and 7.115 MeV have been measured for the whole group between 5 and 7.2 MeV with accuracy better than 10%. A new energy range was covered and more points are included in the cross-sections data base expanding the existing set of data. Results are in agreement with previous measurements in similar conditions.

  16. Using high-energy proton fluence to improve risk prediction for consequences of solar particle events

    NASA Astrophysics Data System (ADS)

    Kim, Myung-Hee Y.; Hayat, Matthew J.; Feiveson, Alan H.; Cucinotta, Francis A.

    2009-12-01

    The potential for exposure to large solar particle events (SPEs) with high energy levels is a major concern during interplanetary transfer and extra-vehicular activities (EVAs) on the lunar and Mars surface. Previously, we have used data from the last 5 solar cycles to estimate percentiles of dose to a typical blood-forming organ (BFO) for a hypothetical astronaut in a nominally shielded spacecraft during a 120-d lunar mission. As part of this process, we made use of complete energy spectra for 34 large historical SPEs to calculate what the BFO mGy-Eq dose would have been in the above lunar scenario for each SPE. From these calculated doses, we then developed a prediction model for BFO dose based solely on an assumed value of integrated fluence above 30 MeV ( Φ30) for an otherwise unspecified future SPE. In this study, we reasoned that since BFO dose is determined more by protons with higher energies than by those with lower energies, more accurate BFO dose prediction models could be developed using integrated fluence above 60 ( Φ60) and above 100 MeV ( Φ100) as predictors instead of Φ30. However to calculate the unconditional probability of a BFO dose exceeding a pre-specified limit ("BFO dose risk"), one must also take into account the distribution of the predictor ( Φ30,Φ60, or Φ100), as estimated from historical SPEs. But Φ60 and Φ100 have more variability, and less available historical information on which to estimate their distributions over many SPE occurrences, than does Φ30. Therefore, when estimating BFO dose risk there is a tradeoff between increased BFO dose prediction at a given energy threshold and decreased accuracy of models for describing the distribution of that threshold over future SPEs as the threshold increases. Even when taking the second of these two factors into account, we still arrived at the conclusion that overall prediction improves as the energy level threshold increases from 30 to 60 to 100 MeV. These results can be applied

  17. H- AND PROTON BEAM LOSS COMPARISON AT SNS SUPERCONDUCTING LINAC

    SciTech Connect

    Aleksandrov, Alexander V; Galambos, John D; Plum, Michael A; Shishlo, Andrei P

    2012-01-01

    A comparison of beam loss in the superconducting part (SCL) of the Spallation Neutron Source (SNS) linac for H- and protons is presented. During the experiment the nominal beam of negative hydrogen ions in the SCL was replaced by a proton beam created by insertion of a thin stripping carbon foil placed in the low energy section of the linac. The observed significant reduction in the beam loss for protons is explained by a domination of the intra beam stripping mechanism of the beam loss for H-. The details of the experiment are discussed, and a preliminary estimation of the cross section of the reaction H- + H- -> H- + H0 + e is presented. Earlier, a short description of these studies was presented in [1].

  18. Measurement of K+ production cross section by 8 GeV protons using high energy neutrino interactions in the SciBooNE detector

    SciTech Connect

    Cheng, G.

    2011-07-28

    The SciBooNE Collaboration reports K+ production cross section and rate measurements using high energy daughter muon neutrino scattering data off the SciBar polystyrene (C8H8) target in the SciBooNE detector. The K+ mesons are produced by 8 GeV protons striking a beryllium target in Fermilab Booster Neutrino Beam line (BNB). Using observed neutrino and antineutrino events in SciBooNE, we measure d2σ/dpdΩ = (5.34 ±0.76) mb/(GeV/c x sr) for p + Be =K+ + X at mean K+ energy of 3.9 GeV and angle (with respect to the proton beam direction) of 3.7 degrees, corresponding to the selected K+ sample. Compared to Monte Carlo predictions using previous higher energy K+ production measurements, this measurement, which uses the NUANCE neutrino interaction generator, is consistent with a normalization factor of 0.85 ± 0.12. This agreement is evidence that the extrapolation of the higher energy K+ measurements to an 8 GeV beam energy using Feynman scaling is valid. This measurement reduces the error on the K+ production cross section from 40% to 14%.

  19. Measurement of K+ production cross section by 8 GeV protons using high energy neutrino interactions in the SciBooNE detector

    DOE PAGESBeta

    Cheng, G.

    2011-07-28

    The SciBooNE Collaboration reports K+ production cross section and rate measurements using high energy daughter muon neutrino scattering data off the SciBar polystyrene (C8H8) target in the SciBooNE detector. The K+ mesons are produced by 8 GeV protons striking a beryllium target in Fermilab Booster Neutrino Beam line (BNB). Using observed neutrino and antineutrino events in SciBooNE, we measure d2σ/dpdΩ = (5.34 ±0.76) mb/(GeV/c x sr) for p + Be =K+ + X at mean K+ energy of 3.9 GeV and angle (with respect to the proton beam direction) of 3.7 degrees, corresponding to the selected K+ sample. Compared tomore » Monte Carlo predictions using previous higher energy K+ production measurements, this measurement, which uses the NUANCE neutrino interaction generator, is consistent with a normalization factor of 0.85 ± 0.12. This agreement is evidence that the extrapolation of the higher energy K+ measurements to an 8 GeV beam energy using Feynman scaling is valid. This measurement reduces the error on the K+ production cross section from 40% to 14%.« less

  20. Determination of the beam quality index of high-energy photon beams under nonstandard reference conditions

    SciTech Connect

    Palmans, Hugo

    2012-09-15

    Purpose: At some modern radiotherapy machines it is not possible to achieve reference conditions for the measurement of beam quality indices used in dosimetry codes of practice, such as IAEA TRS-398 and AAPM TG-51. This work aims at providing self-consistent and simpler expressions and more accurate fits for a limited range of beams of interest than have been proposed previously for deriving these beam quality indices from measurements. Methods: The starting point is a formula proposed by Sauer [Med. Phys. 36, 4168-4172 (2009)] for deriving the beam quality index used in IAEA TRS-398, TPR{sub 20,10}, from a measurement of the tissue phantom ratio at depths of 20 cm and 10 cm in water for an s Multiplication-Sign s cm{sup 2} (equivalent) square field, TPR{sub 20,10}(s). First, a self-consistent version of this formula is established followed by a simpler version by making a linear approximation. A similar approach is proposed to derive the beam quality index used in AAPM TG-51, %dd(10){sub X}, from a measurement of PDD{sub 10}(s), the percentage depth dose at 10 cm for a square field with size s. All models were fitted to subsets of relevant data from BJR supplement 25. Results: The linear models for TPR{sub 20,10}(s) and exponential models for PDD{sub 10}(s) as a function of the (equivalent) square field size can reproduce the beam quality within 0.3% and beam quality correction factors within 0.05% for square field sizes ranging from 4 cm to 12 cm and nominal photon energies from 4 MV to 12 MV. For higher energy beams the errors are only slightly worse but for %dd(10){sub X}, an additional uncertainty component has to be considered for the electron contamination correction. Conclusions: The models proposed here can be used in practical recommendations for the dosimetry of small and nonstandard fields.

  1. Multiple reflection high-energy electron diffraction beam intensity measurement system

    NASA Technical Reports Server (NTRS)

    Resh, J. S.; Jamison, K. D.; Strozier, J.; Ignatiev, A.

    1990-01-01

    A video-based analysis system for reflection high-energy electron diffraction (RHEED) is described which simultaneously measures the intensities and profiles of multiple diffraction beams. This system is used to record real-time RHEED intensity oscillations for layer-by-layer epitaxial growth. Fast Fourier transform analysis of the oscillation data is used to directly determine the growth rate and to accurately obtain phase information about the oscillations. This system is demonstrated and compared to other methods of recording RHEED oscillation data.

  2. High Energy Ion Beam Combustion Of TiO{sub 2}-B-Al Mixture

    SciTech Connect

    Rahbari, R. G.; Hamdi, M.; Yahya, R.; Yap, S. L.; Ngoi, S. K.; Wong, C. S.; Leong, L.

    2009-07-07

    High energy ion beam of a plasma focus device was used to combust TiO{sub 2}-B-Al powder mixture under quasi-adiabatic conditions. Despite uncompleted propagation of combustion wave through the sample, the microstructure of the product was completely different from that obtained from conventional bulk heating in furnace. Combustion reaction of the mixture in furnace at 700 deg. C resulted in spiral-helix motion, while plasma synthesis of the same mixture resulted in uniform self-sustaining wave propagation.

  3. Collective focusing of intense ion beam pulses for high-energy density physics applications

    SciTech Connect

    Dorf, Mikhail A.; Kaganovich, Igor D.; Startsev, Edward A.; Davidson, Ronald C.

    2011-03-15

    The collective focusing concept in which a weak magnetic lens provides strong focusing of an intense ion beam pulse carrying a neutralizing electron background is investigated by making use of advanced particle-in-cell simulations and reduced analytical models. The original analysis by Robertson [Phys. Rev. Lett. 48, 149 (1982)] is extended to the parameter regimes of particular importance for several high-energy density physics applications. The present paper investigates (1) the effects of non-neutral collective focusing in a moderately strong magnetic field; (2) the diamagnetic effects leading to suppression of the applied magnetic field due to the presence of the beam pulse; and (3) the influence of a finite-radius conducting wall surrounding the beam cross-section on beam neutralization. In addition, it is demonstrated that the use of the collective focusing lens can significantly simplify the technical realization of the final focusing of ion beam pulses in the Neutralized Drift Compression Experiment-I (NDCX-I), and the conceptual designs of possible experiments on NDCX-I are investigated by making use of advanced numerical simulations.

  4. Collective Focusing of Intense Ion Beam Pulses for High-energy Density Physics Applications

    SciTech Connect

    Dorf, Mikhail A.; Kaganovich, Igor D.; Startsev, Edward A.; Davidson, Ronald C.

    2011-04-27

    The collective focusing concept in which a weak magnetic lens provides strong focusing of an intense ion beam pulse carrying a neutralizing electron background is investigated by making use of advanced particle-in-cell simulations and reduced analytical models. The original analysis by Robertson Phys. Rev. Lett. 48, 149 (1982) is extended to the parameter regimes of particular importance for several high-energy density physics applications. The present paper investigates (1) the effects of non-neutral collective focusing in a moderately strong magnetic field; (2) the diamagnetic effects leading to suppression of the applied magnetic field due to the presence of the beam pulse; and (3) the influence of a finite-radius conducting wall surrounding the beam cross-section on beam neutralization. In addition, it is demonstrated that the use of the collective focusing lens can significantly simplify the technical realization of the final focusing of ion beam pulses in the Neutralized Drift Compression Experiment-I (NDCX-I) , and the conceptual designs of possible experiments on NDCX-I are investigated by making use of advanced numerical simulations. 2011 American Institute of Physics

  5. Numerical studies of electron acceleration behind self-modulating proton beam in plasma with a density gradient

    NASA Astrophysics Data System (ADS)

    Petrenko, A.; Lotov, K.; Sosedkin, A.

    2016-09-01

    Presently available high-energy proton beams in circular accelerators carry enough momentum to accelerate high-intensity electron and positron beams to the TeV energy scale over several hundred meters of the plasma with a density of about 1015cm-3. However, the plasma wavelength at this density is 100-1000 times shorter than the typical longitudinal size of the high-energy proton beam. Therefore the self-modulation instability (SMI) of a long (~10 cm) proton beam in the plasma should be used to create the train of micro-bunches which would then drive the plasma wake resonantly. Changing the plasma density profile offers a simple way to control the development of the SMI and the acceleration of particles during this process. We present simulations of the possible use of a plasma density gradient as a way to control the acceleration of the electron beam during the development of the SMI of a 400 GeV proton beam in a 10 m long plasma. This work is done in the context of the AWAKE project-the proof-of-principle experiment on proton driven plasma wakefield acceleration at CERN.

  6. MEIC Proton Beam Formation with a Low Energy Linac

    SciTech Connect

    Zhang, Yuhong

    2015-09-01

    The MEIC proton and ion beams are generated, accumulated, accelerated and cooled in a new green-field ion injector complex designed specifically to support its high luminosity goal. This injector consists of sources, a linac and a small booster ring. In this paper we explore feasibility of a short ion linac that injects low-energy protons and ions into the booster ring.

  7. Toward high-energy laser-driven ion beams: Nanostructured double-layer targets

    NASA Astrophysics Data System (ADS)

    Passoni, M.; Sgattoni, A.; Prencipe, I.; Fedeli, L.; Dellasega, D.; Cialfi, L.; Choi, Il Woo; Kim, I. Jong; Janulewicz, K. A.; Lee, Hwang Woon; Sung, Jae Hee; Lee, Seong Ku; Nam, Chang Hee

    2016-06-01

    The development of novel target concepts is crucial to make laser-driven acceleration of ion beams suitable for applications. We tested double-layer targets formed of an ultralow density nanostructured carbon layer (˜7 mg/cm 3 , 8 - 12 μ m -thick) deposited on a μ m -thick solid Al foil. A systematic increase in the total number of the accelerated ions (protons and C6 + ) as well as enhancement of both their maximum and average energies was observed with respect to bare solid foil targets. Maximum proton energies up to 30 MeV were recorded. Dedicated three-dimensional particle-in-cell simulations were in remarkable agreement with the experimental results, giving clear indication of the role played by the target nanostructures in the interaction process.

  8. Scaling to Ultra-High Intensities by High-Energy Petawatt Beam Combining

    SciTech Connect

    Siders, C W; Jovanovic, I; Crane, J; Rushford, M; Lucianetti, A; Barty, C J

    2006-06-23

    The output pulse energy from a single-aperture high-energy laser amplifier (e.g. fusion lasers such as NIF and LMJ) are critically limited by a number of factors including optical damage, which places an upper bound on the operating fluence; parasitic gain, which limits together with manufacturing costs the maximum aperture size to {approx} 40-cm; and non-linear phase effects which limits the peak intensity. For 20-ns narrow band pulses down to transform-limited sub-picosecond pulses, these limiters combine to yield 10-kJ to 1-kJ maximum pulse energies with up to petawatt peak power. For example, the Advanced Radiographic Capability (ARC) project at NIF is designed to provide kilo-Joule pulses from 0.75-ps to 50-ps, with peak focused intensity above 10{sup 19} W/cm{sup 2}. Using such a high-energy petawatt (HEPW) beamline as a modular unit, they discuss large-scale architectures for coherently combining multiple HEPW pulses from independent apertures, called CAPE (Coherent Addition of Pulses for Energy), to significantly increase the peak achievable focused intensity. Importantly, the maximum intensity achievable with CAPE increases non-linearly. Clearly, the total integrated energy grows linearly with the number of apertures N used. However, as CAPE combines beams in the focal plane by increasing the angular convergence to focus (i.e. the f-number decreases), the foal spot diameter scales inversely with N. Hence the peak intensity scales as N{sup 2}. Using design estimates for the focal spot size and output pulse energy (limited by damage fluence on the final compressor gratings) versus compressed pulse duration in the ARC system, Figure 2 shows the scaled focal spot intensity and total energy for various CAPE configurations from 1,2,4, ..., up to 192 total beams. They see from the fixture that the peak intensity for event modest 8 to 16 beam combinations reaches the 10{sup 21} to 10{sup 22} W/cm{sup 2} regime. With greater number of apertures, or with

  9. Compact energy selector for use with intense, short-pulse laser produced proton beams

    NASA Astrophysics Data System (ADS)

    Hazi, Andrew; Chen, Hui; Perez, Frederic; Marley, Edward; Park, Jaebum; Williams, Jackson; Vassura, Laura; Fuchs, Julien; Chen, Sophia; Shepherd, Ronnie

    2012-10-01

    Irradiation of thin solid targets with short, intense laser pulses produces energetic charged particles. The proton and ion beams generated from such laser-plasma interactions have several attractive features, but usually exhibit a broad energy distribution extending up to tens of MeV. However for some applications, such as energy-loss measurements in plasmas or injection into high-energy accelerators, quasi-mono energetic beams are preferred [1]. We have designed, built and tested a small (9 x 7 x 5 cm^3) energy selector for use with laser-produced proton beams in beam-plasma interaction experiments that utilize multiple laser beams. The device uses permanent magnets in a dipole configuration, with a fixed entrance aperture and an adjustable exit slit to select a narrow portion of the broad energy distribution in the beam. The energy selector was tested in a recent experiment at the Titan laser at Livermore. Sample data from the experiment and simulations of the device's characteristics will be presented. [4pt] [1] T. Toncian, et al., ``Ultrafast Laser--Driven Microlens to Focus and Energy-Select Mega--Electron Volt Protons,'' Science, 312, 410 (2006).

  10. Neutron productions in the fragmentation of relativistic heavy nuclei and formation of a beam of high-energy neutrons

    NASA Astrophysics Data System (ADS)

    Yurevich, V. I.

    2016-03-01

    The production of quasimonoenergetic high-energy neutrons at zero angle (0°) in the spallation of relativistic heavy nuclei is discussed by considering the example of the interaction of lead nuclei with light target nuclei. It is shown that this process can be used to generate a beam of high-energy neutrons at existing heavy ion accelerators. At the same time, itmay lead to the appearance of a parasitic neutron beam because of the interaction of the heavy-ion beam used with beam line and experimental setup materials.

  11. Beamed-Energy Propulsion (BEP): Considerations for Beaming High Energy-Density Electromagnetic Waves Through the Atmosphere

    NASA Technical Reports Server (NTRS)

    Manning, Robert M.

    2015-01-01

    A study to determine the feasibility of employing beamed electromagnetic energy for vehicle propulsion within and outside the Earth's atmosphere was co-funded by NASA and the Defense Advanced Research Projects Agency that began in June 2010 and culminated in a Summary Presentation in April 2011. A detailed report entitled "Beamed-Energy Propulsion (BEP) Study" appeared in February 2012 as NASA/TM-2012-217014. Of the very many nuances of this subject that were addressed in this report, the effects of transferring the required high energy-density electromagnetic fields through the atmosphere were discussed. However, due to the limitations of the length of the report, only a summary of the results of the detailed analyses were able to be included. It is the intent of the present work to make available the complete analytical modeling work that was done for the BEP project with regard to electromagnetic wave propagation issues. In particular, the present technical memorandum contains two documents that were prepared in 2011. The first one, entitled "Effects of Beaming Energy Through the Atmosphere" contains an overview of the analysis of the nonlinear problem inherent with the transfer of large amounts of energy through the atmosphere that gives rise to thermally-induced changes in the refractive index; application is then made to specific beamed propulsion scenarios. A brief portion of this report appeared as Appendix G of the 2012 Technical Memorandum. The second report, entitled "An Analytical Assessment of the Thermal Blooming Effects on the Propagation of Optical and Millimeter- Wave Focused Beam Waves For Power Beaming Applications" was written in October 2010 (not previously published), provides a more detailed treatment of the propagation problem and its effect on the overall characteristics of the beam such as its deflection as well as its radius. Comparisons are then made for power beaming using the disparate electromagnetic wavelengths of 1.06 microns and 2

  12. High energy conversion efficiency in laser-proton acceleration by controlling laser-energy deposition onto thin foil targets

    SciTech Connect

    Brenner, C. M.; Robinson, A. P. L.; Markey, K.; Scott, R. H. H.; Lancaster, K. L.; Musgrave, I. O.; Spindloe, C.; Winstone, T.; Wyatt, D.; Neely, D.; Gray, R. J.; McKenna, P.; Rosinski, M.; Badziak, J.; Wolowski, J.; Deppert, O.; Batani, D.; Davies, J. R.; Hassan, S. M.; Tatarakis, M.; and others

    2014-02-24

    An all-optical approach to laser-proton acceleration enhancement is investigated using the simplest of target designs to demonstrate application-relevant levels of energy conversion efficiency between laser and protons. Controlled deposition of laser energy, in the form of a double-pulse temporal envelope, is investigated in combination with thin foil targets in which recirculation of laser-accelerated electrons can lead to optimal conditions for coupling laser drive energy into the proton beam. This approach is shown to deliver a substantial enhancement in the coupling of laser energy to 5–30 MeV protons, compared to single pulse irradiation, reaching a record high 15% conversion efficiency with a temporal separation of 1 ps between the two pulses and a 5 μm-thick Au foil. A 1D simulation code is used to support and explain the origin of the observation of an optimum pulse separation of ∼1 ps.

  13. Performance of a tungsten-cerium fluoride sampling calorimeter in high-energy electron beam tests

    NASA Astrophysics Data System (ADS)

    Becker, R.; Bianchini, L.; Dissertori, G.; Djambazov, L.; Donega, M.; Lustermann, W.; Marini, A. C.; Nessi-Tedaldi, F.; Pandolfi, F.; Peruzzi, M.; Schönenberger, M.; Cavallari, F.; Dafinei, I.; Diemoz, M.; Lope, C. Jorda; Meridiani, P.; Nuccetelli, M.; Paramatti, R.; Pellegrino, F.; Micheli, F.; Organtini, G.; Rahatlou, S.; Soffi, L.; Brianza, L.; Govoni, P.; Martelli, A.; Fatis, T. Tabarelli de; Monti, V.; Pastrone, N.; Trapani, P. P.; Candelise, V.; Ricca, G. Della

    2015-12-01

    A prototype for a sampling calorimeter made out of cerium fluoride crystals interleaved with tungsten plates, and read out by wavelength-shifting fibres, has been exposed to beams of electrons with energies between 20 and 150 GeV, produced by the CERN Super Proton Synchrotron accelerator complex. The performance of the prototype is presented and compared to that of a GEANT4 simulation of the apparatus. Particular emphasis is given to the response uniformity across the channel front face, and to the prototype's energy resolution.

  14. BEAMING AND RAPID VARIABILITY OF HIGH-ENERGY RADIATION FROM RELATIVISTIC PAIR PLASMA RECONNECTION

    SciTech Connect

    Cerutti, B.; Werner, G. R.; Uzdensky, D. A.; Begelman, M. C. E-mail: greg.werner@colorado.edu E-mail: mitch@jila.colorado.edu

    2012-08-01

    We report on the first study of the angular distribution of energetic particles and radiation generated in relativistic collisionless electron-positron pair plasma reconnection using two-dimensional particle-in-cell simulations. We discover a strong anisotropy of the particles accelerated by reconnection and the associated strong beaming of their radiation. The focusing of particles and radiation increases with their energy; in this sense, this 'kinetic beaming' effect differs fundamentally from the relativistic Doppler beaming usually invoked in high-energy astrophysics, in which all photons are focused and boosted achromatically. We also present, for the first time, the modeling of the synchrotron emission as seen by an external observer during the reconnection process. The expected light curves comprise several bright symmetric sub-flares emitted by the energetic beam of particles sweeping across the line of sight intermittently, and exhibit super-fast time variability as short as about one-tenth of the system light-crossing time. The concentration of the energetic particles into compact regions inside magnetic islands and particle anisotropy explain the rapid variability. This radiative signature of reconnection can account for the brightness and variability of the gamma-ray flares in the Crab Nebula and in blazars.

  15. 1000 MeV Proton beam therapy facility at Petersburg Nuclear Physics Institute Synchrocyclotron

    NASA Astrophysics Data System (ADS)

    Abrosimov, N. K.; Gavrikov, Yu A.; Ivanov, E. M.; Karlin, D. L.; Khanzadeev, A. V.; Yalynych, N. N.; Riabov, G. A.; Seliverstov, D. M.; Vinogradov, V. M.

    2006-05-01

    Since 1975 proton beam of PNPI synchrocyclotron with fixed energy of 1000 MeV is used for the stereotaxic proton therapy of different head brain diseases. 1300 patients have been treated during this time. The advantage of high energy beam (1000 MeV) is low scattering of protons in the irradiated tissue. This factor allows to form the dose field with high edge gradients (20%/mm) that is especially important for the irradiation of the intra-cranium targets placed in immediate proximity to the life critical parts of the brain. Fixation of the 6 0mm diameter proton beam at the isodose centre with accuracy of ±1.0 mm, two-dimensional rotation technique of the irradiation provide a very high ratio of the dose in the irradiation zone to the dose at the object's surface equal to 200:1. The absorbed doses are: 120-150 Gy for normal hypophysis, 100-120 Gy for pituitary adenomas and 40-70 Gy for arterio-venous malformation at the rate of absorbed dose up to 50 Gy/min. In the paper the dynamics and the efficiency of 1000 MeV proton therapy treatment of the brain deceases are given. At present time the feasibility study is in progress with the goal to create a proton therapy on Bragg peak by means of the moderation of 1000 MeV proton beam in the absorber down to 200 MeV, energy required for radiotherapy of deep seated tumors.

  16. Remarkable new results for high-energy protons and electrons in the inner Van Allen belt regions

    NASA Astrophysics Data System (ADS)

    Baker, Daniel N.

    2016-04-01

    Early observations indicated that the Earth's Van Allen radiation belts could be separated into an inner zone dominated by high-energy protons and an outer zone dominated by high-energy electrons. Subsequent studies showed that electrons of moderate energy (less than about one megaelectronvolt) often populate both zones, with a deep 'slot' region largely devoid of particles between them. The two-belt radiation structure was explained as arising from strong electron interactions with plasmaspheric hiss just inside the plasmapause boundary with the inner edge of the outer radiation zone corresponding to the minimum plasmapause location.. Recent Van Allen Probes observations have revealed an unexpected radiation belt morphology, especially at ultrarelativistic kinetic energies (more than several megaelectronvolts). The data show an exceedingly sharp inner boundary for the ultrarelativistic electrons right at L=2.8. Additional, concurrently measured data reveal that this barrier to inward electron radial transport is likely due to scattering by powerful human electromagnetic transmitter (VLF) wave fields. We show that weak, but persistent, wave-particle pitch angle scattering deep inside the Earth's plasmasphere due to manmade signals can act to create an almost impenetrable barrier through which the most energetic Van Allen belt electrons cannot migrate. Inside of this distance, the Van Allen Probes data show that high energy (20 -100 MeV) protons have a double belt structure with a stable peak of flux at L~1.5 and a much more variable belt peaking at L~2.3.

  17. EXPERIMENTAL STUDY OF PROTON-BEAM HALO INDUCED BY BEAM MISMATCH IN LEDA.

    SciTech Connect

    Wangler, Thomas P.,; Allen, C. K.; Colestock, P. L. ,; Chan, K. D.; Crandall, K. R.; Garnett, R. W.; Gilpatrick, J. D.; Lysenko, W. P.; Qiang, J.; Schneider, J. D.; Sheffield, R. L.; Smith, H. V.; Schulze, M. E.

    2001-01-01

    We report measurements of transverse beam halo in mismatched proton beams in a 52-quadrupole FODO transport channel following the 6.7-MeV LEDA RFQ. Beam profiles in both transverse planes are measured using beam-profile diagnostic devices that consist of a movable carbon filament for measurement of the dense beam core, and scraper plates for measurement of the halo. The gradients of the first four quadrupoles can be independently adjusted to mismatch the RFQ output beam into the beam-transport channel. The properties of the measured mismatched beam profiles in the transport channel will be compared with predictions from multiparticle beam-dynamics simulations.

  18. 6-D weak-strong beam-beam simulation study of proton lifetime in presence of head-on beam-beam compensation in the RHIC

    SciTech Connect

    Luo, Y.; Fischer, W.

    2010-08-01

    In this note we summarize the calculated particle loss of a proton bunch in the presence of head-on beam-beam compensation in the Relativistic Heavy Ion Collider (RHIC). To compensate the head-on beam-beam effect in the RHIC 250 GeV polarized proton run, we are introducing a DC electron beam with the same transverse profile as the proton beam to collide with the proton beam. Such a device is called an electron lens (e-lens). In this note we first present the optics and beam parameters and the tracking setup. Then we calculate and compare the particle loss of a proton bunch with head-on beam-beam compensation, phase advance of k{pi} between IP8 and the center of the e-lens and second order chromaticity correction. We scanned the proton beam's linear chromaticity, working point and bunch intensity. We also scanned the electron beam's intensity, transverse beam size. The effect of the electron-proton transverse offset in the e-lens was studied. In the study 6-D weak-strong beam-beam interaction model a la Hirata is used for proton collisions at IP6 and IP8. The e-lens is modeled as 8 slices. Each slice is modeled with as drift - (4D beam-beam kick) - drift.

  19. Fabrication of buried channel waveguides in photosensitive glass using proton beam writing

    SciTech Connect

    Bettiol, A.A.; Venugopal Rao, S.; Teo, E.J.; Kan, J.A. van; Watt, Frank

    2006-04-24

    We report our results on the fabrication and characterization of buried, channel optical waveguides in photosensitive Foturan{sup TM} glass using a high energy proton beam. Waveguides were fabricated with varying fluence, and the propagation loss and refractive index change were measured. Near-field mode data measured at 632.8 nm showed that waveguiding could be achieved for all fluences ranging from 10{sup 14} to 10{sup 16} protons/cm{sup 2}. The maximum positive refractive index change of 1.6x10{sup -3} was measured for the highest fluence. The waveguide propagation losses measured using the scattering technique were estimated to be in the range of 8.3-12.9 dB/cm, increasing with proton fluence.

  20. Spill uniformity measurements for a raster scanned proton beam

    NASA Astrophysics Data System (ADS)

    Coutrakon, G.; Ghebremedhin, A.; Koss, P.; Evans, K.; Taylor, D.; Jenkins, G.

    2000-11-01

    The method of scanning a proton beam across a target region for radiation therapy requires a uniform beam intensity throughout the beam spill time. Achieving uniform intensity using feedback to an air core quadrapole in the Loma Linda synchrotron accelerator is described in this paper. Frequency domain transfer functions and time domain intensity ripple measurements are presented followed with results and discussion of issues requiring additional work.

  1. Spill uniformity measurements for a raster scanned proton beam

    NASA Astrophysics Data System (ADS)

    Coutrakon, G.; Ghebremedhin, A.; Johanning, J.; Koss, P.

    1997-02-01

    The method of scanning a proton beam across a target region for radiation therapy requires a uniform beam intensity throughout the beam spill time. Achieving uniform intensity using feedback to an air core quadrupole in the Loma Linda synchrotron accelerator is described in this paper. Frequency domain transfer functions and time domain intensity ripple measurements are presented followed with results and discussion of issues requiring additional work.

  2. Liquid scintillator for 2D dosimetry for high-energy photon beams

    SciTech Connect

    Poenisch, Falk; Archambault, Louis; Briere, Tina Marie; Sahoo, Narayan; Mohan, Radhe; Beddar, Sam; Gillin, Michael T.

    2009-05-15

    Complex radiation therapy techniques require dosimetric verification of treatment planning and delivery. The authors investigated a liquid scintillator (LS) system for application for real-time high-energy photon beam dosimetry. The system was comprised of a transparent acrylic tank filled with liquid scintillating material, an opaque outer tank, and a CCD camera. A series of images was acquired when the tank with liquid scintillator was irradiated with a 6 MV photon beam, and the light data measured with the CCD camera were filtered to correct for scattering of the optical light inside the liquid scintillator. Depth-dose and lateral profiles as well as two-dimensional (2D) dose distributions were found to agree with results from the treatment planning system. Further, the corrected light output was found to be linear with dose, dose rate independent, and is robust for single or multiple acquisitions. The short time needed for image acquisition and processing could make this system ideal for fast verification of the beam characteristics of the treatment machine. This new detector system shows a potential usefulness of the LS for 2D QA.

  3. Rainbow effect in channeling of high energy protons through single-wall carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Petrović, S.; Borka, D.; Nešković, N.

    2005-05-01

    We studied theoretically the angular distributions and the rainbows in the case of 1 GeV protons channeled in the ropes of (10, 10) single-wall carbon nanotubes. It was assumed that the transverse cross section of a rope could be described via a (two-dimensional) hexagonal superlattice with one nanotube per lattice point. The rope length was varied between 2.4 and 7.2 μm, corresponding to the reduced rope lengths associated with the transverse proton motion close to the centers of the regions in between three neighboring nanotubes, Λb, between 0.17 and 0.50, respectively. The angular distributions of channeled protons were generated by the computer simulation method using the numerical solution of the proton equations of motion in the transverse plane. We used the Molière's expression for the interaction potential of the proton and a carbon atom. The rainbow lines were determined numerically too. We showed that they ensured the full explanation of the angular distributions. The effect of zero-degree focusing of channeled ions for the reduced rope length Λb = 0.50 was also observed, indicating the existence of the rainbow cycles in the evolution of the angular distribution. We noted a strong influence of the rainbow effect on the effect of zero-degree focusing.

  4. Beam Optics for a Scanned Proton Beam at Loma Linda University Medical Center

    SciTech Connect

    Coutrakon, George; Hubbard, Jeff; Koss, Peter; Sanders, Ed; Panchal, Mona

    2003-08-26

    Beam scanning in proton therapy is a medical technique to lower the dose to healthy tissue while irradiating a tumor volume. Scanned proton beams for proton radiation therapy require small beam sizes at the tumor location. In beam scanning, a small beam usually less than 1 cm diameter is swept across the tumor volume with two magnets located several meters upstream of the patient. In general, all proton beams in a therapy facility must be transported from the accelerator to the treatment rooms where the scanning systems are located. This paper addresses the problem of transporting the beam without losses to the patient and achieving a small beam at the tumor location in the patient. The strengths of the beam line quadrupoles were allowed to vary to produce the desired beam sizes along the beam lines. Quadrupole strengths were obtained using the beam simulation program TRANSPORT originally from Stanford Linear Accelerator Center in Palo Alto, CA. An enhanced version of the original program by Accel Soft Inc. in San Diego, CA has been used for these studies. Beam size measurements were used for comparison with TRANSPORT to verify the predictions of TRANSPORT calculations.

  5. Beam Optics for a Scanned Proton Beam at Loma Linda University Medical Center

    NASA Astrophysics Data System (ADS)

    Coutrakon, George; Hubbard, Jeff; Koss, Peter; Sanders, Ed; Panchal, Mona

    2003-08-01

    Beam scanning in proton therapy is a medical technique to lower the dose to healthy tissue while irradiating a tumor volume. Scanned proton beams for proton radiation therapy require small beam sizes at the tumor location. In beam scanning, a small beam usually less than 1 cm diameter is swept across the tumor volume with two magnets located several meters upstream of the patient. In general, all proton beams in a therapy facility must be transported from the accelerator to the treatment rooms where the scanning systems are located. This paper addresses the problem of transporting the beam without losses to the patient and achieving a small beam at the tumor location in the patient. The strengths of the beam line quadrupoles were allowed to vary to produce the desired beam sizes along the beam lines. Quadrupole strengths were obtained using the beam simulation program TRANSPORT originally from Stanford Linear Accelerator Center in Palo Alto, CA. An enhanced version of the original program by Accel Soft Inc. in San Diego, CA has been used for these studies. Beam size measurements were used for comparison with TRANSPORT to verify the predictions of TRANSPORT calculations.

  6. J/ψ production and suppression in high-energy proton-nucleus collisions

    DOE PAGESBeta

    Ma, Yan -Qing; Venugopalan, Raju; Zhang, Hong -Fei

    2015-10-02

    In this study, we apply a color glass condensate+nonrelativistic QCD (CGC+NRQCD) framework to compute J/ψ production in deuteron-nucleus collisions at RHIC and proton-nucleus collisions at the LHC. Our results match smoothly at high p⊥ to a next-to-leading order perturbative QCD+NRQCD computation. Excellent agreement is obtained for p⊥ spectra at the RHIC and LHC for central and forward rapidities, as well as for the normalized ratio RpA of these results to spectra in proton-proton collisions. In particular, we observe that the RpA data are strongly bounded by our computations of the same for each of the individual NRQCD channels; this resultmore » provides strong evidence that our description is robust against uncertainties in initial conditions and hadronization mechanisms.« less

  7. J/ψ production and suppression in high-energy proton-nucleus collisions

    SciTech Connect

    Ma, Yan -Qing; Venugopalan, Raju; Zhang, Hong -Fei

    2015-10-02

    In this study, we apply a color glass condensate+nonrelativistic QCD (CGC+NRQCD) framework to compute J/ψ production in deuteron-nucleus collisions at RHIC and proton-nucleus collisions at the LHC. Our results match smoothly at high p⊥ to a next-to-leading order perturbative QCD+NRQCD computation. Excellent agreement is obtained for p⊥ spectra at the RHIC and LHC for central and forward rapidities, as well as for the normalized ratio RpA of these results to spectra in proton-proton collisions. In particular, we observe that the RpA data are strongly bounded by our computations of the same for each of the individual NRQCD channels; this result provides strong evidence that our description is robust against uncertainties in initial conditions and hadronization mechanisms.

  8. High-energy proton irradiation of C57Bl6 mice under hindlimb unloading

    NASA Astrophysics Data System (ADS)

    Mendonca, Marc; Todd, Paul; Orschell, Christie; Chin-Sinex, Helen; Farr, Jonathan; Klein, Susan; Sokol, Paul

    2012-07-01

    Solar proton events (SPEs) pose substantial risk for crewmembers on deep space missions. It has been shown that low gravity and ionizing radiation both produce transient anemia and immunodeficiencies. We utilized the C57Bl/6 based hindlimb suspension model to investigate the consequences of hindlimb-unloading induced immune suppression on the sensitivity to whole body irradiation with modulated 208 MeV protons. Eight-week old C57Bl/6 female mice were conditioned by hindlimb-unloading. Serial CBC and hematocrit assays by HEMAVET were accumulated for the hindlimb-unloaded mice and parallel control animals subjected to identical conditions without unloading. One week of hindlimb-unloading resulted in a persistent, statistically significant 10% reduction in RBC count and a persistent, statistically significant 35% drop in lymphocyte count. This inhibition is consistent with published observations of low Earth orbit flown mice and with crewmember blood analyses. In our experiments the cell count suppression was sustained for the entire six-week period of observation and persisted for at least 7 days beyond the period of active hindlimb-unloading. C57Bl/6 mice were also irradiated with 208 MeV Spread Out Bragg Peak (SOBP) protons at the Midwest Proton Radiotherapy Institute at the Indiana University Cyclotron Facility. We found that at 8.5 Gy hindlimb-unloaded mice were significantly more radiation sensitive with 35 lethalities out of 51 mice versus 15 out of 45 control (non-suspended) mice within 30 days of receiving 8.5 Gy of SOBP protons (p =0.001). Both control and hindlimb-unloaded stocktickerCBC analyses of 8.5 Gy proton irradiated and control mice by HEMAVET demonstrated severe reductions in WBC counts (Lymphocytes and PMNs) by day 2 post-irradiation, followed a week to ten days later by reductions in platelets, and then reductions in RBCs about 2 weeks post-irradiation. Recovery of all blood components commenced by three weeks post-irradiation. CBC analyses of 8

  9. Measurements of neutron dose equivalent for a proton therapy center using uniform scanning proton beams

    SciTech Connect

    Zheng Yuanshui; Liu Yaxi; Zeidan, Omar; Schreuder, Andries Niek; Keole, Sameer

    2012-06-15

    Purpose: Neutron exposure is of concern in proton therapy, and varies with beam delivery technique, nozzle design, and treatment conditions. Uniform scanning is an emerging treatment technique in proton therapy, but neutron exposure for this technique has not been fully studied. The purpose of this study is to investigate the neutron dose equivalent per therapeutic dose, H/D, under various treatment conditions for uniform scanning beams employed at our proton therapy center. Methods: Using a wide energy neutron dose equivalent detector (SWENDI-II, ThermoScientific, MA), the authors measured H/D at 50 cm lateral to the isocenter as a function of proton range, modulation width, beam scanning area, collimated field size, and snout position. They also studied the influence of other factors on neutron dose equivalent, such as aperture material, the presence of a compensator, and measurement locations. They measured H/D for various treatment sites using patient-specific treatment parameters. Finally, they compared H/D values for various beam delivery techniques at various facilities under similar conditions. Results: H/D increased rapidly with proton range and modulation width, varying from about 0.2 mSv/Gy for a 5 cm range and 2 cm modulation width beam to 2.7 mSv/Gy for a 30 cm range and 30 cm modulation width beam when 18 Multiplication-Sign 18 cm{sup 2} uniform scanning beams were used. H/D increased linearly with the beam scanning area, and decreased slowly with aperture size and snout retraction. The presence of a compensator reduced the H/D slightly compared with that without a compensator present. Aperture material and compensator material also have an influence on neutron dose equivalent, but the influence is relatively small. H/D varied from about 0.5 mSv/Gy for a brain tumor treatment to about 3.5 mSv/Gy for a pelvic case. Conclusions: This study presents H/D as a function of various treatment parameters for uniform scanning proton beams. For similar treatment

  10. Joining Carbon-Carbon Composites and High-Temperature Materials with High Energy Electron Beams

    NASA Technical Reports Server (NTRS)

    Goodman, Daniel; Singler, Robert

    1998-01-01

    1. Program goals addressed during this period. Experimental work was directed at formation of a low-stress bond between carbon- carbon and aluminum, with the objective of minimizing the heating of the aluminum substrate, thereby minimizing stresses resulting from the coefficient of thermal expansion (CTE) difference between the aluminum and carbon-carbon. A second objective was to form a bond between carbon-carbon and aluminum with good thermal conductivity for electronic thermal management (SEM-E) application. 2. Substrates and joining materials selected during this period. Carbon-Carbon Composite (CCC) to Aluminum. CCC (Cu coated) to Aluminum. Soldering compounds based on Sn/Pb and Sn/Ag/Cu/Bi compositions. 3. Soldering experiments performed. Conventional techniques. High Energy Electron Beam (HEEB) process.

  11. Micro-cone targets for producing high energy and low divergence particle beams

    DOEpatents

    Le Galloudec, Nathalie

    2013-09-10

    The present invention relates to micro-cone targets for producing high energy and low divergence particle beams. In one embodiment, the micro-cone target includes a substantially cone-shaped body including an outer surface, an inner surface, a generally flat and round, open-ended base, and a tip defining an apex. The cone-shaped body tapers along its length from the generally flat and round, open-ended base to the tip defining the apex. In addition, the outer surface and the inner surface connect the base to the tip, and the tip curves inwardly to define an outer surface that is concave, which is bounded by a rim formed at a juncture where the outer surface meets the tip.

  12. Characteristics of proton beams and secondary neutrons arising from two different beam nozzles

    NASA Astrophysics Data System (ADS)

    Choi, Yeon-Gyeong; Kim, Yu-Seok

    2015-10-01

    A tandem or a Van de Graaff accelerator with an energy of 3 MeV is typically used for Proton Induced X-ray Emission (PIXE) analysis. In this study, the beam line design used in the PIXE analysis, instead of the typical low-energy accelerator, was used to increase the production of isotopes from a 13-MeV cyclotron. For the PIXE analysis, the proton beam should be focused at the target through a nozzle after degrading the proton beams energy from 13 MeV to 3 MeV by using an energy degrader. Previous studies have been conducted to determine the most appropriate material for and the thickness of the energy degrader. From the energy distribution of the degraded proton beam and the neutron occurrence rate at the degrader, an aluminum nozzle of X thickness was determined to be the most appropriate nozzle construction. Neutrons are created by the collision of 3-MeV protons in the nozzle after passage through the energy degrader. In addition, a proton beam of sufficient intensity is required for a non-destructive PIXE analysis. Therefore, if nozzle design is to be optimized, the number of neutrons that arise from the collision of protons inside the nozzle, as well as the track direction of the generated secondary neutrons, must be considered, with the primary aim of ensuring that a sufficient number of protons pass through the nozzle as a direct beam. A number of laboratories are currently conducting research related to the design of nozzles used in accelerator fields, mostly medical fields. This paper presents a comparative analysis of two typical nozzle shapes in order to minimize the loss of protons and the generation of secondary neutrons. The neutron occurrence rate and the number of protons that pass through the nozzle were analyzed by using a Particle and Heavy Ion Transport code System (PHITS) program in order to identify the nozzle that generated the strongest proton beam.

  13. Single-Plane Magnetically Focused Elongated Small Field Proton Beams.

    PubMed

    McAuley, Grant A; Slater, James M; Wroe, Andrew J

    2015-08-01

    We previously performed Monte Carlo simulations of magnetically focused proton beams shaped by a single quadrapole magnet and thereby created narrow elongated beams with superior dose delivery characteristics (compared to collimated beams) suitable for targets of similar geometry. The present study seeks to experimentally validate these simulations using a focusing magnet consisting of 24 segments of samarium cobalt permanent magnetic material adhered into a hollow cylinder. Proton beams with properties relevant to clinical radiosurgery applications were delivered through the magnet to a water tank containing a diode detector or radiochromic film. Dose profiles were analyzed and compared with analogous Monte Carlo simulations. The focused beams produced elongated beam spots with high elliptical symmetry, indicative of magnet quality. Experimental data showed good agreement with simulations, affirming the utility of Monte Carlo simulations as a tool to model the inherent complexity of a magnetic focusing system. Compared to target-matched unfocused simulations, focused beams showed larger peak to entrance ratios (26% to 38%) and focused simulations showed a two-fold increase in beam delivery efficiency. These advantages can be attributed to the magnetic acceleration of protons in the transverse plane that tends to counteract the particle outscatter that leads to degradation of peak to entrance performance in small field proton beams. Our results have important clinical implications and suggest rare earth focusing magnet assemblies are feasible and could reduce skin dose and beam number while delivering enhanced dose to narrow elongated targets (eg, in and around the spinal cord) in less time compared to collimated beams. PMID:25414143

  14. Effect of Scanning Beam for Superficial Dose in Proton Therapy.

    PubMed

    Moskvin, Vadim P; Estabrook, Neil C; Cheng, Chee-Wai; Das, Indra J; Johnstone, Peter A S

    2015-10-01

    Proton beam delivery technology is under development to minimize the scanning spot size for uniform dose to target, but it is also known that the superficial dose could be as high as the dose at Bragg peak for narrow and small proton beams. The objective of this study is to explore the characteristics of dose distribution at shallow depths using Monte Carlo simulation with the FLUKA code for uniform scanning (US) and discrete spot scanning (DSS) proton beams. The results show that the superficial dose for DSS is relatively high compared to US. Additionally, DSS delivers a highly heterogeneous dose to the irradiated surface for comparable doses at Bragg peak. Our simulation shows that the superficial dose can become as high as the Bragg peak when the diameter of the proton beam is reduced. This may compromise the advantage of proton beam therapy for sparing normal tissue, making skin dose a limiting factor for the clinical use of DSS. Finally, the clinical advantage of DSS may not be essential for treating uniform dose across a large target, as in craniospinal irradiation (CSI). PMID:24945369

  15. Beam Loss Studies for the 2-MW LBNE Proton Beam Line

    SciTech Connect

    Drozhdin, A.I.; Childress, S.R.; Mokhov, N.V.; Tropin, I.S.; Zwaska, R.; /Fermilab

    2012-05-01

    Severe limits are put on allowable beam loss during extraction and transport of a 2.3 MW primary proton beam for the Long Baseline Neutrino Experiment (LBNE) at Fermilab. Detailed simulations with the STRUCT and MARS codes have evaluated the impact of beam loss of 1.6 x 10{sup 14} protons per pulse at 120 GeV, ranging from a single pulse full loss to sustained small fractional loss. It is shown that loss of a single beam pulse at 2.3 MW will result in a catastrophic event: beam pipe destruction, damaged magnets and very high levels of residual radiation inside and outside the tunnel. Acceptable beam loss limits have been determined and robust solutions developed to enable efficient proton beam operation under these constraints.

  16. Transverse beam coupling impedance of the CERN Proton Synchrotron

    NASA Astrophysics Data System (ADS)

    Persichelli, S.; Migliorati, M.; Biancacci, N.; Gilardoni, S.; Metral, E.; Salvant, B.

    2016-04-01

    Beam coupling impedance is a fundamental parameter to characterize the electromagnetic interaction of a particle beam with the surrounding environment. Synchrotron machine performances are critically affected by instabilities and collective effects triggered by beam coupling impedance. In particular, transverse beam coupling impedance is expected to impact beam dynamics of the CERN Proton Synchrotron (PS), since a significant increase in beam intensity is foreseen within the framework of the LHC Injectors Upgrade (LIU) project. In this paper we describe the study of the transverse beam coupling impedance of the PS, taking into account the main sources of geometrical impedance and the contribution of indirect space charge at different energies. The total machine impedance budget, determined from beam-based dedicated machine measurement sessions, is also discussed and compared with the theoretical model.

  17. Development and creation of conditions for the radiation of biological objects with high energy protons

    NASA Technical Reports Server (NTRS)

    Popov, V. P.; Portman, A. I.; Sychkov, M. A.; Kolodkin, A. V.; Nikl, I.

    1974-01-01

    Depth distribution of an absorbed proton radiation dose was studied by both calculation and experimental methods on a cylindrical, homogeneous plexiglass phantom that represented the geometric form of a dog. The basis of the heterogeneous phantom was the natural skeleton of a dog, muscle tissue was simulated by a mixture of paraffin and silica filler, and lung tissue by gelatine capsules.

  18. Experimental assessment of out-of-field dose components in high energy electron beams used in external beam radiotherapy.

    PubMed

    M Alabdoaburas, Mohamad; Mege, Jean-Pierre; Chavaudra, Jean; Vũ Bezin, Jérémi; Veres, Atilla; De Vathaire, Florent; Lefkopoulos, Dimitri; Diallo, Ibrahima

    2015-01-01

    The purpose of this work was to experimentally investigate the out-of-field dose in a water phantom, with several high energy electron beams used in external beam radiotherapy (RT). The study was carried out for 6, 9, 12, and 18 MeV electron beams, on three different linear accelerators, each equipped with a specific applicator. Measurements were performed in a water phantom, at different depths, for different applicator sizes, and off-axis distances up to 70 cm from beam central axis (CAX). Thermoluminescent powder dosimeters (TLD-700) were used. For given cases, TLD measurements were compared to EBT3 films and parallel-plane ionization chamber measurements. Also, out-of-field doses at 10 cm depth, with and without applicator, were evaluated. With the Siemens applicators, a peak dose appears at about 12-15 cm out of the field edge, at 1 cm depth, for all field sizes and energies. For the Siemens Primus, with a 10 × 10 cm(²) applicator, this peak reaches 2.3%, 1%, 0.9% and 1.3% of the maximum central axis dose (Dmax) for 6, 9, 12 and 18 MeV electron beams, respectively. For the Siemens Oncor, with a 10 × 10 cm(²) applicator, this peak dose reaches 0.8%, 1%, 1.4%, and 1.6% of Dmax for 6, 9, 12, and 14 MeV, respectively, and these values increase with applicator size. For the Varian 2300C/D, the doses at 12.5 cm out of the field edge are 0.3%, 0.6%, 0.5%, and 1.1% of Dmax for 6, 9, 12, and 18 MeV, respectively, and increase with applicator size. No peak dose is evidenced for the Varian applicator for these energies. In summary, the out-of-field dose from electron beams increases with the beam energy and the applicator size, and decreases with the distance from the beam central axis and the depth in water. It also considerably depends on the applicator types. Our results can be of interest for the dose estimations delivered in healthy tissues outside the treatment field for the RT patient, as well as in studies exploring RT long-term effects. PMID:26699572

  19. Mechanical Design of a High Energy Beam Absorber for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab

    SciTech Connect

    Baffes, C.; Church, M.; Leibfritz, J.; Oplt, S.; Rakhno, I.; /Fermilab

    2012-05-10

    A high energy beam absorber has been built for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab. In the facility's initial configuration, an electron beam will be accelerated through 3 TTF-type or ILC-type SRF cryomodules to an energy of 750MeV. The electron beam will be directed to one of multiple downstream experimental and diagnostic beam lines and then deposited in one of two beam absorbers. The facility is designed to accommodate up to 6 cryomodules, which would produce a 75kW beam at 1.5GeV; this is the driving design condition for the beam absorbers. The beam absorbers consist of water-cooled graphite, aluminum and copper layers contained in a helium-filled enclosure. This paper describes the mechanical implementation of the beam absorbers, with a focus on thermal design and analysis. The potential for radiation-induced degradation of the graphite is discussed.

  20. Compact disposal of high-energy electron beams using passive or laser-driven plasma decelerating stage

    SciTech Connect

    Bonatto, A.; Schroeder, C. B.; Vay, J. -L.; Geddes, C. R.; Benedetti, C.; Esarey and, E.; Leemans, W. P.

    2014-07-13

    A plasma decelerating stage is investigated as a compact alternative for the disposal of high-energy beams (beam dumps). This could benefit the design of laser-driven plasma accelerator (LPA) applications that require transportability and or high-repetition-rate operation regimes. Passive and laser-driven (active) plasma-based beam dumps are studied analytically and with particle-in-cell (PIC) simulations in a 1D geometry. Analytical estimates for the beam energy loss are compared to and extended by the PIC simulations, showing that with the proposed schemes a beam can be efficiently decelerated in a centimeter-scale distance.

  1. Characterizing a proton beam with two different methods in beam halo experiments

    NASA Astrophysics Data System (ADS)

    Jiang, Hong-Ping; Fu, Shi-Nian; Peng, Jun; Cheng, Peng; Huang, Tao; Li, Peng; Li, Fang; Li, Jian; Liu, Hua-Chang; Liu, Mei-Fei; Meng, Ming; Meng, Cai; Mu, Zhen-Cheng; Rong, Lin-Yan; Ouyang, Hua-Fu; Sun, Biao; Wang, Bo; Tian, Jian-Min; Wang, Biao; Wang, Sheng-Chang; Yao, Yuan; Xu, Tao-Guang; Xu, Xin-An; Xin, Wen-Qu; Zhao, Fu-Xiang; Zeng, Lei; Zhou, Wen-Zhong

    2014-08-01

    In beam halo experiments, it is very important to correctly characterize the RFQ output proton beam. In order to simulate the beam dynamics properly, we must first know the correct initial beam parameters. We have used two different methods, quadrupole scans and multi-wire scanners to determine the transverse phase-space properties of the proton beam. The experimental data were analyzed by fitting to the 3-D nonlinear simulation code IMPACT. For the quadrupole scan method, we found that the RMS beam radius and the measured beam-core profiles agreed very well with the simulations. For the multi-wire scanner method, we choose the case of a matched beam. By fitting the IMPACT simulation results to the measured data, we obtained the Courant-Snyder parameters and the emittance of the beam. The difference between the two methods is about eight percent, which is acceptable in our experiments.

  2. CERN antiproton target: Hydrocode analysis of its core material dynamic response under proton beam impact

    NASA Astrophysics Data System (ADS)

    Martin, Claudio Torregrosa; Perillo-Marcone, Antonio; Calviani, Marco; Muñoz-Cobo, José-Luis

    2016-07-01

    Antiprotons are produced at CERN by colliding a 26 GeV /c proton beam with a fixed target made of a 3 mm diameter, 55 mm length iridium core. The inherent characteristics of antiproton production involve extremely high energy depositions inside the target when impacted by each primary proton beam, making it one of the most dynamically demanding among high energy solid targets in the world, with a rise temperature above 2000 °C after each pulse impact and successive dynamic pressure waves of the order of GPa's. An optimized redesign of the current target is foreseen for the next 20 years of operation. As a first step in the design procedure, this numerical study delves into the fundamental phenomena present in the target material core under proton pulse impact and subsequent pressure wave propagation by the use of hydrocodes. Three major phenomena have been identified, (i) the dominance of a high frequency radial wave which produces destructive compressive-to-tensile pressure response (ii) The existence of end-of-pulse tensile waves and its relevance on the overall response (iii) A reduction of 44% in tensile pressure could be obtained by the use of a high density tantalum cladding.

  3. Dose equivalent near the bone-soft tissue interface from nuclear fragments produced by high-energy protons.

    PubMed

    Shavers, M R; Poston, J W; Cucinotta, F A; Wilson, J W

    1996-04-01

    During manned space missions, high-energy nucleons of cosmic and solar origin collide with atomic nuclei of the human body and produce a broad linear energy transfer spectrum of secondary particles, called target fragments. These nuclear fragments are often more biologically harmful than the direct ionization of the incident nucleon. That these secondary particles increase tissue absorbed dose in regions adjacent to the bone-soft tissue interface was demonstrated in a previous publication. To assess radiological risks to tissue near the bone-soft tissue interface, a computer transport model for nuclear fragments produced by high energy nucleons was used in this study to calculate integral linear energy transfer spectra and dose equivalents resulting from nuclear collisions of 1-GeV protons transversing bone and red bone marrow. In terms of dose equivalent averaged over trabecular bone marrow, target fragments emitted from interactions in both tissues are predicted to be at least as important as the direct ionization of the primary protons-twice as important, if recently recommended radiation weighting factors and "worst-case" geometry are used. The use of conventional dosimetry (absorbed dose weighted by aa linear energy transfer-dependent quality factor) as an appropriate framework for predicting risk from low fluences of high-linear energy transfer target fragments is discussed. PMID:8617586

  4. Dose equivalent near the bone-soft tissue interface from nuclear fragments produced by high-energy protons

    NASA Technical Reports Server (NTRS)

    Shavers, M. R.; Poston, J. W.; Cucinotta, F. A.; Wilson, J. W.

    1996-01-01

    During manned space missions, high-energy nucleons of cosmic and solar origin collide with atomic nuclei of the human body and produce a broad linear energy transfer spectrum of secondary particles, called target fragments. These nuclear fragments are often more biologically harmful than the direct ionization of the incident nucleon. That these secondary particles increase tissue absorbed dose in regions adjacent to the bone-soft tissue interface was demonstrated in a previous publication. To assess radiological risks to tissue near the bone-soft tissue interface, a computer transport model for nuclear fragments produced by high energy nucleons was used in this study to calculate integral linear energy transfer spectra and dose equivalents resulting from nuclear collisions of 1-GeV protons transversing bone and red bone marrow. In terms of dose equivalent averaged over trabecular bone marrow, target fragments emitted from interactions in both tissues are predicted to be at least as important as the direct ionization of the primary protons-twice as important, if recently recommended radiation weighting factors and "worst-case" geometry are used. The use of conventional dosimetry (absorbed dose weighted by aa linear energy transfer-dependent quality factor) as an appropriate framework for predicting risk from low fluences of high-linear energy transfer target fragments is discussed.

  5. Effect of Triplet Magnet Vibrations on RHIC Performance with High Energy Protons

    SciTech Connect

    Minty, M.

    2010-05-23

    In this report we present recent experimental data from the Relativistic Heavy Ion Collider (RHIC) illustrating effects resulting from {approx}10 Hz vibrations of the triplet quadrupole magnets in the interactions regions and evaluate the impact of these vibrations on RHIC collider performance. Measurements revealed modulation of the betatron tunes of appreciable magnitude relative to the total beam-beam parameter. Comparison of the discrete frequencies in the spectra of the measured beam positions and betatron tunes confirmed a common source. The tune modulations were shown to result from feed-down in the sextupole magnets in the interaction regions. In addition we show that the distortions to the closed orbit of the two counter-rotating beams produced a modulated crossing angle at the interaction point(s).

  6. External-Beam Accelerated Partial Breast Irradiation Using Multiple Proton Beam Configurations

    SciTech Connect

    Wang Xiaochun; Amos, Richard A.; Zhang Xiaodong; Taddei, Phillip J.; Woodward, Wendy A.; Hoffman, Karen E.; Yu, Tse Kuan; Tereffe, Welela; Oh, Julia; Perkins, George H.; Salehpour, Mohammad; Zhang, Sean X.; Sun, Tzou Liang; Gillin, Michael; Buchholz, Thomas A.; Strom, Eric A.

    2011-08-01

    Purpose: To explore multiple proton beam configurations for optimizing dosimetry and minimizing uncertainties for accelerated partial breast irradiation (APBI) and to compare the dosimetry of proton with that of photon radiotherapy for treatment of the same clinical volumes. Methods and Materials: Proton treatment plans were created for 11 sequential patients treated with three-dimensional radiotherapy (3DCRT) photon APBI using passive scattering proton beams (PSPB) and were compared with clinically treated 3DCRT photon plans. Monte Carlo calculations were used to verify the accuracy of the proton dose calculation from the treatment planning system. The impact of range, motion, and setup uncertainty was evaluated with tangential vs. en face beams. Results: Compared with 3DCRT photons, the absolute reduction of the mean of V100 (the volume receiving 100% of prescription dose), V90, V75, V50, and V20 for normal breast using protons are 3.4%, 8.6%, 11.8%, 17.9%, and 23.6%, respectively. For breast skin, with the similar V90 as 3DCRT photons, the proton plan significantly reduced V75, V50, V30, and V10. The proton plan also significantly reduced the dose to the lung and heart. Dose distributions from Monte Carlo simulations demonstrated minimal deviation from the treatment planning system. The tangential beam configuration showed significantly less dose fluctuation in the chest wall region but was more vulnerable to respiratory motion than that for the en face beams. Worst-case analysis demonstrated the robustness of designed proton beams with range and patient setup uncertainties. Conclusions: APBI using multiple proton beams spares significantly more normal tissue, including nontarget breast and breast skin, than 3DCRT using photons. It is robust, considering the range and patient setup uncertainties.

  7. Evaluation of risk from space radiation with high-energy heavy ion beams

    NASA Technical Reports Server (NTRS)

    Schimmerling, W.; Wilson, J. W.; Cucinotta, F.; Kim, M. H.

    1998-01-01

    The most challenging radiation in space consists of fully ionized atomic elements with high energy for which only the few lowest energy ions can be stopped in shielding materials. The health risk from exposure to these ions and their secondary radiations generated in shield materials is poorly understood since there are few human data and a systematic study in relevant animal model systems has not been made. The accuracy of risk prediction is described as the major limiting factor in the management of space radiation risk. The expected impact of systematic studies is examined using the limited available biological data and models. Given the limitations of current predictions, models must be developed that are able to incorporate the required fundamental scientific data into accurate risk estimates. The important radiation components that can be provided for laboratory testing are identified. The use of ground-based accelerator beams to simulate space radiation is explained and quantitative scientific constraints on such facilities are derived. Three facilities, one each in the United States, in Germany and in Japan, currently have the partial capability to satisfy these constraints. A facility has been proposed using the Brookhaven National Laboratory Booster Synchrotron in the United States; in conjuction with other on-site accelerators, it will be able to provide the full range of heavy ion beams and energies required.

  8. Evaluation of risk from space radiation with high-energy heavy ion beams.

    PubMed

    Schimmerling, W; Wilson, J W; Cucinotta, F; Kim, M H

    1998-07-01

    The most challenging radiation in space consists of fully ionized atomic elements with high energy for which only the few lowest energy ions can be stopped in shielding materials. The health risk from exposure to these ions and their secondary radiations generated in shield materials is poorly understood since there are few human data and a systematic study in relevant animal model systems has not been made. The accuracy of risk prediction is described as the major limiting factor in the management of space radiation risk. The expected impact of systematic studies is examined using the limited available biological data and models. Given the limitations of current predictions, models must be developed that are able to incorporate the required fundamental scientific data into accurate risk estimates. The important radiation components that can be provided for laboratory testing are identified. The use of ground-based accelerator beams to simulate space radiation is explained and quantitative scientific constraints on such facilities are derived. Three facilities, one each in the United States, in Germany and in Japan, currently have the partial capability to satisfy these constraints. A facility has been proposed using the Brookhaven National Laboratory Booster Synchrotron in the United States; in conjuction with other on-site accelerators, it will be able to provide the full range of heavy ion beams and energies required. PMID:11542638

  9. Tungsten fragmentation in nuclear reactions induced by high-energy cosmic-ray protons

    NASA Astrophysics Data System (ADS)

    Chechenin, N. G.; Chuvilskaya, T. V.; Shirokova, A. A.; Kadmenskii, A. G.

    2015-01-01

    Tungsten fragmentation arising in nuclear reactions induced by cosmic-ray protons in space-vehicle electronics is considered. In modern technologies of integrated circuits featuring a three-dimensional layered architecture, tungsten is frequently used as a material for interlayer conducting connections. Within the preequilibrium model, tungsten-fragmentation features, including the cross sections for the elastic and inelastic scattering of protons of energy between 30 and 240 MeV; the yields of isotopes and isobars; their energy, charge, and mass distributions; and recoil energy spectra, are calculated on the basis of the TALYS and EMPIRE-II-19 codes. It is shown that tungsten fragmentation affects substantially forecasts of failures of space-vehicle electronics.

  10. Tungsten fragmentation in nuclear reactions induced by high-energy cosmic-ray protons

    SciTech Connect

    Chechenin, N. G. Chuvilskaya, T. V.; Shirokova, A. A.; Kadmenskii, A. G.

    2015-01-15

    Tungsten fragmentation arising in nuclear reactions induced by cosmic-ray protons in space-vehicle electronics is considered. In modern technologies of integrated circuits featuring a three-dimensional layered architecture, tungsten is frequently used as a material for interlayer conducting connections. Within the preequilibrium model, tungsten-fragmentation features, including the cross sections for the elastic and inelastic scattering of protons of energy between 30 and 240 MeV; the yields of isotopes and isobars; their energy, charge, and mass distributions; and recoil energy spectra, are calculated on the basis of the TALYS and EMPIRE-II-19 codes. It is shown that tungsten fragmentation affects substantially forecasts of failures of space-vehicle electronics.

  11. Dynamics of RF captured cooled proton beams

    SciTech Connect

    Kells, W.; Mills, F.

    1983-01-01

    In the course of electron cooling experiments at the Electron Cooling Ring (ECR) at Fermilab, several peculiar features of the longitudinal phase space of cold protons (200 MeV) captured in RF buckets were observed. Here we present the experimental facts, present a simple theory, and summarize computer simulation results which support the theory and facts.

  12. Recent Results on High-Energy Spin Phenomena of Gluons and Sea-Quarks in Polarized Proton-Proton Collisions at Rhic at Bnl

    NASA Astrophysics Data System (ADS)

    Surrow, Bernd

    2014-01-01

    The STAR experiment at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory is carrying out a spin physics program in high-energy polarized proton collisions at √ {s} = 200 GeV and √ {s} = 500 GeV to gain a deeper insight into the spin structure and dynamics of the proton. One of the main objectives of the spin physics program at RHIC is the precise determination of the polarized gluon distribution function. The STAR detector is well suited for the reconstruction of various final states involving jets, π0, π±, e± and γ, which allows to measure several different processes. Recent results suggest a gluon spin contribution to the proton spin at the same level as the quark spin contribution itself. The production of W bosons in polarized p+p collisions at √ {s} = 500 GeV opens a new era in the study of the spin-flavor structure of the proton. W-(+) bosons are produced in \\bar {u} + d (\\bar {d} + u) collisions and can be detected through their leptonic decays, e- + \\bar {ν }e (e++ν e), where only the respective charged lepton is measured. Results of W-(+) production suggest a large asymmetry between the polarization of anti-u and anti-d quarks.

  13. Hadron Production in the Restricted Rapidity Intervals in Proton-Nucleus Interactions at High Energies

    NASA Astrophysics Data System (ADS)

    Aggarwal, Madan M.

    Data on 200 and 400 GeV proton interactions with nuclear emulsion have been analyzed. It is found that the multiplicity distributions of the shower particles in the restricted rapidity intervals are well described by the negative binomial distribution (NBD). The dependences of the NBD parameters on rapidity interval, energy and target size have been studied. The results have also been discussed in terms of Giovannini and Van Hove’s clan model of multiparticle production.

  14. Recoil-proton polarization in high-energy deuteron photodisintegration with circularly plarized photons.

    SciTech Connect

    Jiang, X.; Arrington, J.; Benmokhtar, F.; Camsonne, A.; Chen, J. P.; Holt, R. J.; Qattan, I. A.; Reimer, P. E.; Schulte, E. C.; Wijesooriya, K.; Physics; Rutgers Univ.; Univ. Blaise Pascal; Thomas Jefferson National Accelerator Facility

    2007-05-01

    We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily. Transverse polarizations are not well described, but suggest isovector dominance.

  15. Recoil-Proton Polarization in High-Energy Deuteron Photodisintegration with Circularly Polarized Photons

    SciTech Connect

    Jiang, X.; Benmokhtar, F.; Glashauser, C.; McCormick, K.; Ransome, R. D.; Arrington, J.; Holt, R. J.; Reimer, P. E.; Schulte, E. C.; Wijesooriya, K.; Camsonne, A.

    2007-05-04

    We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily. Transverse polarizations are not well described, but suggest isovector dominance.

  16. Recoil-Proton Polarization in High-Energy Deuteron Photodisintegration with Circularly Polarized Photons

    SciTech Connect

    X. Jiang; J. Arrington; F. Benmokhtar; A. Camsonne; J. P. Chen; S. Choi; E. Chudakov; F. Cusanno; A. Deur; D. Dutta; F. Garibaldi; D. Gaskell; O. Gayou; R. Gilman; C. Glashauser; D. Hamilton; O. Hansen; D. W. Higinbotham; R. J. Holt; C. W. de Jager; M. K. Jones; L. J. Kaufman; E. R. Kinney; K. Kramer; L. Lagamba; R. de Leo; J. Lerose; D. Lhuillier; R. Lindgren; N. Liyanage; K. McCormick; Z.-E. Meziani; R. Michaels; B. Moffit; P. Monaghan; S. Nanda; K. D. Paschke; C. F. Perdrisat; V. Punjabi; I. A. Qattan; R. D. Ransome; P. E. Reimer; B. Reitz; A. Saha; E. C. Schulte; R. Sheyor; K. Slifer; P. Solvignon; V. Sulkosky; G. M. Urciuoli; E. Voutier; K. Wang; K. Wijesooriya; B. Wojtsekhowski; and L. Zhu

    2007-05-01

    We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily. Transverse polarizations are not well described, but suggest isovector dominance.

  17. Angular dependence of recoil proton polarization in high-energy \\gamma d \\to p n

    SciTech Connect

    X. Jiang; J. Arrington; F. Benmokhtar; A. Camsonne; J.P. Chen; S. Choi; E. Chudakov; F. Cusanno; A. Deur; D. Dutta; F. Garibaldi; D. Gaskell; O. Gayou; R. Gilman; C. Glashauser; D. Hamilton; O. Hansen; D.W. Higinbotham; R.J. Holt; C.W. de Jager; M.K. Jones; L.J. Kaufman; E.R. Kinney; K. Kramer; L. Lagamba; R. de Leo; J. Lerose; D. Lhuillier; R. Lindgren; N. Liyanage; K. McCormick; Z.-E. Meziani; R. Michaels; B. Moffit; P. Monaghan; S. Nanda; K.D. Paschke; C.F. Perdrisat; V. Punjabi; I.A. Qattan; R.D. Ransome; P.E. Reimer; B. Reitz; A. Saha; E.C. Schulte; R. Sheyor; K. Slifer; P. Solvignon; V. Sulkosky; G.M. Urciuoli; E. Voutier; K. Wang; K. Wijesooriya; B. Wojtsekhowski; L. Zhu

    2007-02-26

    We measured the angular dependence of the three recoil proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily.. Transverse polarizations are not well described, but suggest isovector dominance.

  18. The effect of irradiation with high-energy protons on 4H-SiC detectors

    SciTech Connect

    Kazukauskas, V. Jasiulionis, R.; Kalendra, V.; Vaitkus, J.-V.

    2007-03-15

    The effect of irradiation of 4H-SiC ionizing-radiation detectors with various doses (as high as 10{sup 16} cm{sup -2}) of 24-GeV protons is studied. Isotopes of B, Be, Li, He, and H were produced in the nuclear spallation reactions of protons with carbon. Isotopes of Al, Mg, Na, Ne, F, O, and N were produced in the reactions of protons with silicon. The total amount of the produced stable isotopes varied in proportion with the radiation dose from 1.2 x 10{sup 11} to 5.9 x 10{sup 13} cm{sup -2}. It is shown that, at high radiation doses, the contact characteristics of the detectors change appreciably. The potential-barrier height increased from the initial value of 0.7-0.75 eV to 0.85 eV; the rectifying characteristics of the Schottky contacts deteriorated appreciably. These effects are attributed to the formation of a disordered structure of the material as a result of irradiation.

  19. Beam acceleration through proton radio frequency quadrupole accelerator in BARC

    NASA Astrophysics Data System (ADS)

    Bhagwat, P. V.; Krishnagopal, S.; Mathew, J. V.; Singh, S. K.; Jain, P.; Rao, S. V. L. S.; Pande, M.; Kumar, R.; Roychowdhury, P.; Kelwani, H.; Rama Rao, B. V.; Gupta, S. K.; Agarwal, A.; Kukreti, B. M.; Singh, P.

    2016-05-01

    A 3 MeV proton Radio Frequency Quadrupole (RFQ) accelerator has been designed at the Bhabha Atomic Research Centre, Mumbai, India, for the Low Energy High Intensity Proton Accelerator (LEHIPA) programme. The 352 MHz RFQ is built in 4 segments and in the first phase two segments of the LEHIPA RFQ were commissioned, accelerating a 50 keV, 1 mA pulsed proton beam from the ion source, to an energy of 1.24 MeV. The successful operation of the RFQ gave confidence in the physics understanding and technology development that have been achieved, and indicate that the road forward can now be traversed rather more quickly.

  20. Dense Monoenergetic Proton Beams from Chirped Laser-Plasma Interaction

    NASA Astrophysics Data System (ADS)

    Galow, Benjamin J.; Salamin, Yousef I.; Liseykina, Tatyana V.; Harman, Zoltán; Keitel, Christoph H.

    2011-10-01

    Interaction of a frequency-chirped laser pulse with single protons and a hydrogen gas target is studied analytically and by means of particle-in-cell simulations, respectively. The feasibility of generating ultraintense (107 particles per bunch) and phase-space collimated beams of protons (energy spread of about 1%) is demonstrated. Phase synchronization of the protons and the laser field, guaranteed by the appropriate chirping of the laser pulse, allows the particles to gain sufficient kinetic energy (around 250 MeV) required for such applications as hadron cancer therapy, from state-of-the-art laser systems of intensities of the order of 1021W/cm2.

  1. Velocity Distributions and Proton Beam Production in the Solar Wind

    SciTech Connect

    Pierrard, Viviane; Voitenko, Yuriy

    2010-03-25

    Helios, Ulysses, and Wind spacecraft have observed the velocity distribution functions (VDFs) of solar wind particles deviating significantly from Maxwellians. We review recent models using different approximations and mechanisms that determine various observed characteristics of the VDFs for the electrons, protons and minor ions. A new generation mechanism is proposed for super-Alfvenic proton beams and tails that are often observed in the fast solar wind. The mechanism is based on the proton trapping and acceleration by kinetic Alfven waves (KAWs), which carry a field-aligned potential well propagating with super-Alfven velocities.

  2. How proton pulse characteristics influence protoacoustic determination of proton-beam range: simulation studies.

    PubMed

    Jones, Kevin C; Seghal, Chandra M; Avery, Stephen

    2016-03-21

    The unique dose deposition of proton beams generates a distinctive thermoacoustic (protoacoustic) signal, which can be used to calculate the proton range. To identify the expected protoacoustic amplitude, frequency, and arrival time for different proton pulse characteristics encountered at hospital-based proton sources, the protoacoustic pressure emissions generated by 150 MeV, pencil-beam proton pulses were simulated in a homogeneous water medium. Proton pulses with Gaussian widths ranging up to 200 μs were considered. The protoacoustic amplitude, frequency, and time-of-flight (TOF) range accuracy were assessed. For TOF calculations, the acoustic pulse arrival time was determined based on multiple features of the wave. Based on the simulations, Gaussian proton pulses can be categorized as Dirac-delta-function-like (FWHM < 4 μs) and longer. For the δ-function-like irradiation, the protoacoustic spectrum peaks at 44.5 kHz and the systematic error in determining the Bragg peak range is <2.6 mm. For longer proton pulses, the spectrum shifts to lower frequencies, and the range calculation systematic error increases (⩽ 23 mm for FWHM of 56 μs). By mapping the protoacoustic peak arrival time to range with simulations, the residual error can be reduced. Using a proton pulse with FWHM = 2 μs results in a maximum signal-to-noise ratio per total dose. Simulations predict that a 300 nA, 150 MeV, FWHM = 4 μs Gaussian proton pulse (8.0 × 10(6) protons, 3.1 cGy dose at the Bragg peak) will generate a 146 mPa pressure wave at 5 cm beyond the Bragg peak. There is an angle dependent systematic error in the protoacoustic TOF range calculations. Placing detectors along the proton beam axis and beyond the Bragg peak minimizes this error. For clinical proton beams, protoacoustic detectors should be sensitive to <400 kHz (for -20 dB). Hospital-based synchrocyclotrons and cyclotrons are promising sources of proton pulses for generating clinically measurable protoacoustic

  3. Commissioning of polarized-proton and antiproton beams at Fermilab

    SciTech Connect

    Yokosawa, A.

    1988-05-04

    The author described the polarized-proton and polarized-antiproton beams up to 200 GeV/c at Fermilab. The beam line, called MP, consists of the 400-m long primary and 350-m long secondary beam line followed by 60-m long experimental hall. We discuss the characteristics of the polarized beams. The Fermilab polarization projects are designated at E-581/704 initiated and carried out by an international collaboration, Argonne (US), Fermilab (US), Kyoto-Kyushu-Hiroshima-KEK (Japan), LAPP (France), Northwestern University (US), Los Alamos Laboratory (US), Rice (US), Saclay (France), Serpukhov (USSR), INFN Trieste (Italy), and University of Texas (US).

  4. Future of high energy physics

    SciTech Connect

    Panofsky, W.K.H.

    1984-06-01

    A rough overview is given of the expectations for the extension of high energy colliders and accelerators into the xtremely high energy range. It appears likely that the SSC or something like it will be the last gasp of the conventional method of producing high energy proton-proton collisions using synchrotron rings with superconducting magnets. It is likely that LEP will be the highest energy e+e/sup -/ colliding beam storage ring built. The future beyond that depends on the successful demonstrations of new technologies. The linear collider offers hope in this respect for some extension in energy for electrons, and maybe even for protons, but is too early to judge whether, by how much, or when such an extension will indeed take place.

  5. Micro-patterns fabrication using focused proton beam lithography

    NASA Astrophysics Data System (ADS)

    Cutroneo, M.; Havranek, V.; Mackova, A.; Semian, V.; Torrisi, L.; Calcagno, L.

    2016-03-01

    Proton beam writing technique was recently introduced at 3MV Tandetron accelerator at Nuclear Physics Institute in Rez (Czech Republic). It has been used, to produce three-dimensional (3D) micro-structures in poly(methylmethacrylate) by 2.0 MeV and 2.6 MeV protons micro-beam. Micro-channels (52 μm × 52 μm) have been realized. After chemical etching, the quality of the bottom and side walls of the produced structures in PMMA were analyzed using Scanning Transmission Ion Microscopy (STIM).

  6. A pencil beam approach to proton computed tomography

    SciTech Connect

    Rescigno, Regina Bopp, Cécile; Rousseau, Marc; Brasse, David

    2015-11-15

    Purpose: A new approach to proton computed tomography (pCT) is presented. In this approach, protons are not tracked one-by-one but a beam of particles is considered instead. The elements of the pCT reconstruction problem (residual energy and path) are redefined on the basis of this new approach. An analytical image reconstruction algorithm applicable to this scenario is also proposed. Methods: The pencil beam (PB) and its propagation in matter were modeled by making use of the generalization of the Fermi–Eyges theory to account for multiple Coulomb scattering (MCS). This model was integrated into the pCT reconstruction problem, allowing the definition of the mean beam path concept similar to the most likely path (MLP) used in the single-particle approach. A numerical validation of the model was performed. The algorithm of filtered backprojection along MLPs was adapted to the beam-by-beam approach. The acquisition of a perfect proton scan was simulated and the data were used to reconstruct images of the relative stopping power of the phantom with the single-proton and beam-by-beam approaches. The resulting images were compared in a qualitative way. Results: The parameters of the modeled PB (mean and spread) were compared to Monte Carlo results in order to validate the model. For a water target, good agreement was found for the mean value of the distributions. As far as the spread is concerned, depth-dependent discrepancies as large as 2%–3% were found. For a heterogeneous phantom, discrepancies in the distribution spread ranged from 6% to 8%. The image reconstructed with the beam-by-beam approach showed a high level of noise compared to the one reconstructed with the classical approach. Conclusions: The PB approach to proton imaging may allow technical challenges imposed by the current proton-by-proton method to be overcome. In this framework, an analytical algorithm is proposed. Further work will involve a detailed study of the performances and limitations of

  7. Collimation of laser-produced proton beam

    NASA Astrophysics Data System (ADS)

    Takano, M.; Nagashima, T.; Izumiyama, T.; Gu, Y. J.; Barada, D.; Kong, Q.; Wang, P. X.; Ma, Y. Y.; Wang, W. M.; Kawata, S.

    2016-03-01

    In intense laser plasma interaction for particle acceleration several issues remain to be solved. In this paper we focus on a collimation of ion beam, which is produced by a laser plasma interaction. In this study, the ion beam is collimated by a thin film target. When an intense short pulse laser illuminates a target, target electrons are accelerated, and create an electron cloud that generates a sheath electric field at the target surface. Such the ion acceleration mechanism is called the target normal sheath acceleration (TNSA). The TNSA field would be used for the ion beam collimation by the electric field. We have successfully obtained a collimated beam in our particle-in-cell simulations.

  8. CLUST - EVAP Monte Carlo Simulation Applications for Determining Effective Energy Deposition in Silicon by High Energy Protons

    NASA Technical Reports Server (NTRS)

    ONeill, Pat M.

    2000-01-01

    The CLUST-EVAP is a Monte Carlo simulation of the interaction of high energy (25 - 400 MeV) protons with silicon nuclei. The initial nuclear cascade stage is modeled using the CLUST model developed by Indiana University over 30 years ago. The second stage, in which the excited nucleus evaporates particles in random directions, is modeled according to the evaporation algorithm provided by H. H. K. Tang of IBM. Using the CLUST-EVAP code to model fragment produ6tion and the Vavilov-Landau theory to model fluctuations in direct ionization in thin silicon layers, we have predicted energy deposition in silicon components for various geometrical configurations. We have compared actual measurements with model predictions for geometry's such as single, thin silicon particle detectors, telescopic particle detectors flown in space to measure the environment, and thin sensitive volumes of modern micro-electronic components. We have recently compared the model predictions with actual measurements made by the DOSTEL spectrometer flown in the Shuttle payload bay on STS-84. The model faithfully reproduces the features and aids in interpretation of flight results of this instrument. We have also applied the CLUST-EVAP model to determine energy deposition in the thin sensitive volumes of modern micro-electronic components. We have accessed the ability of high energy (200 MeV) protons to induce latch-up in certain devices that are known to latch up in heavy ion environments. However, some devices are not nearly as susceptible to proton induced latch-up as expected according to their measured heavy ion latch-up cross sections. The discrepancy is believed to be caused by the limited range of the proton-silicon interaction fragments. The CLUST-EV AP model was used to determine a distribution of these fragments and their range and this is compared to knowledge of the ranges required based on the known device structure. This information is especially useful in accessing the risk to on

  9. Fermilab Proton Beam for Mu2e

    SciTech Connect

    Syphers, M.J.; /Fermilab

    2009-10-01

    Plans to use existing Fermilab facilities to provide beam for the Muon to Electron Conversion Experiment (Mu2e) are under development. The experiment will follow the completion of the Tevatron Collider Run II, utilizing the beam lines and storage rings used today for antiproton accumulation without considerable reconfiguration. The proposed Mu2e operating scenario is described as well as the accelerator issues being addressed to meet the experimental goals.

  10. Particle selection and beam collimation system for laser-accelerated proton beam therapy.

    PubMed

    Luo, Wei; Fourkal, Eugene; Li, Jinsheng; Ma, Chang-Ming

    2005-03-01

    In a laser-accelerated proton therapy system, the initial protons have broad energy and angular distributions, which are not suitable for direct therapeutic applications. A compact particle selection and collimation device is needed to deliver small pencil beams of protons with desired energy spectra. In this work, we characterize a superconducting magnet system that produces a desired magnetic field configuration to spread the protons with different energies and emitting angles for particle selection. Four magnets are set side by side along the beam axis; each is made of NbTi wires which carry a current density of approximately 10(5) A/cm2 at 4.2 K, and produces a magnetic field of approximately 4.4 T in the corresponding region. Collimation is applied to both the entrance and the exit of the particle selection system to generate a desired proton pencil beam. In the middle of the magnet system, where the magnetic field is close to zero, a particle selection collimator allows only the protons with desired energies to pass through for therapy. Simulations of proton transport in the presence of the magnetic field show that the selected protons have successfully refocused on the beam axis after passing through the magnetic field with the optimal magnet system. The energy spread for any given characteristic proton energy has been obtained. It is shown that the energy spread is a function of the magnetic field strength and collimator size and reaches the full width at half maximum of 25 MeV for 230 MeV protons. Dose distributions have also been calculated with the GEANT3 Monte Carlo code to study the dosimetric properties of the laser-accelerated proton beams for radiation therapy applications. PMID:15839352

  11. Reply to comment on 'Proton beam monitor chamber calibration'.

    PubMed

    Gomà, Carles; Lorentini, Stefano; Meer, David; Safai, Sairos

    2016-09-01

    This reply shows that the discrepancy of about 3% between Faraday cup dosimetry and reference dosimetry using a cylindrical ionization chamber found in Gomà (2014 Phys. Med. Biol. 59 4961-71) seems to be due to an overestimation of the beam quality correction factors tabulated in IAEA TRS-398 for the cylindrical chamber used, rather than to 'unresolved problems with Faraday cup dosimetry', as suggested by Palmans and Vatnitsky (2016 Phys. Med. Biol. 61 6585-93). Furthermore, this work shows that a good agreement between reference dosimetry and Faraday cup dosimetry is possible, provided accurate beam quality correction factors for proton beams are used. The review on W air values presented by Palmans and Vatnitsky is believed to be inaccurate, as it is based on the imprecise assumption of ionization chamber perturbation correction factors in proton beams being equal to unity. PMID:27535895

  12. High energy proton radiation damage to (AlGa)As-G aAs solar cells

    NASA Technical Reports Server (NTRS)

    Loo, R.; Goldhammer, L.; Kamath, S.; Knechtli, R. C.

    1979-01-01

    Twelve 2 + 2 sq cm (AlGa)As-GaAs solar cells were fabricated and were subjected to 15.4 and 40 MeV of proton irradiation. The results showed that the GaAs cells degrade considerably less than do conventional and developmental K7 silicon cells. The detailed characteristics of the GaAs and silicon cells, both before and after irradiation, are described. Further optimization of the GaAs cells seems feasible, and areas for future work are suggested.

  13. Impact of 7-TeV/c large hadron collider proton beam on a copper target

    NASA Astrophysics Data System (ADS)

    Tahir, N. A.; Goddard, B.; Kain, V.; Schmidt, R.; Shutov, A.; Lomonosov, I. V.; Piriz, A. R.; Temporal, M.; Hoffmann, D. H. H.; Fortov, V. E.

    2005-04-01

    The large hadron collider (LHC) will allow for collision between two 7TeV/c proton beams, each comprising 2808 bunches with 1.1×1011 protons per bunch, traveling in opposite direction. The bunch length is 0.5ns and two neighboring bunches are separated by 25ns so that the duration of the entire beam is about 89μs. The beam power profile in the transverse direction is a Gaussian with a standard deviation of 0.2mm. The energy stored in each beam is about 350MJ that is sufficient to melt 500kg of copper. In case of a failure in the machine protection systems, the entire beam could impact directly onto an accelerator equipment. A first estimate of the scale of damage resulting from such a failure has been assessed for a solid copper target hit by the beam by carrying out three-dimensional energy deposition calculations and two-dimensional numerical simulations of the hydrodynamic and thermodynamic response of the target. This work has shown that the penetration depth of the LHC protons will be between 10 and 40m in solid copper. These calculations show that material conditions obtained in the target are similar to those planned for beam impact at dedicated accelerators designed to study the physics of high-energy-density states of matter, for example, the Facility for Antiprotons and Ion Research at the Gesellschaft für Schwerionenforschung, Darmstadt [W. F. Henning, Nucl. Instrum Methods Phys. Res. B 214, 211 (2004)].

  14. Improved beam spot measurements in the 2nd generation proton beam writing system

    NASA Astrophysics Data System (ADS)

    Yao, Yong; van Mourik, Martin W.; Santhana Raman, P.; van Kan, Jeroen A.

    2013-07-01

    Nanosized ion beams (especially proton and helium) play a pivotal role in the field of ion beam lithography and ion beam analysis. Proton beam writing has shown lithographic details down to the 20 nm level, limited by the proton beam spot size. Introducing a smaller spot size will allow smaller lithographic features. Smaller probe sizes, will also drastically improve the spatial resolution for ion beam analysis techniques. Among many other requirements, having an ideal resolution standard, used for beam focusing and a reliable focusing method, is an important pre-requisite for sub-10 nm beam spot focusing. In this paper we present the fabrication processes of a free-standing resolution standard with reduced side-wall projection and high side-wall verticality. The resulting grid is orthogonal (90.0° ± 0.1), has smooth edges with better than 6 nm side-wall projection. The new resolution standard has been used in focusing a 2 MeV H2+ beam in the 2nd generation PBW system at Center for Ion Beam Applications, NUS. The beam size has been characterized using on- and off-axis scanning transmission ion microscopy (STIM) and ion induced secondary electron detection, carried out with a newly installed micro channel plate electron detector. The latter has been shown to be a realistic alternative to STIM measurements, as the drawback of PIN diode detector damage is alleviated. With these improvements we show reproducible beam focusing down to 14 nm.

  15. Acceleration of Ultra-Low Emittance Proton and Ion Beams with High Intensity Lasers

    NASA Astrophysics Data System (ADS)

    Cowan, Thomas E.

    2002-11-01

    Intense beams of several MeV protons and ions, generated by the interaction of high-intensity short pulse lasers with thin foils, have been observed by many researchers in recent years.(S.P. Hatchett et al., Phys. Plasmas 7, 2076 (2000); T.E. Cowan et al., Nucl. Inst. Meth. A 455, 130 (2000); R.A. Snavely et al., Phys. Rev. Lett. 85, 2945 (2000); S.C. Wilks et al., Phys. Plasmas 8, 532 (2000); E. Clark et al., Phys. Rev. Lett. 84, 670 (2000).) In experiments performed at the 100 TW LULI laser, we have succeeded to control the ion acceleration process to produce ultra high quality proton beams, whose transverse emittance is <0.006 π mm-mrad (rms-normalized), a factor of 100 lower than is typical of conventional RF linear accelerators. Within the envelope of the entire beam, we could focus individual proton beamlets to 100 nm spatial scales. This required control of the laser-plasma interaction, of the transport of MA currents of relativistic electrons through the target substrate, and of the surface topology and source material layering on the target foil rear-surface.(M. Roth et al., Phys. Rev. ST Accel. Beams 5, 061002 (2002).) By varying the source material, we also accelerated light ion beams, such as He-like fluorine, to over 5 MeV/nucleon.(M. Hegelich et al., Phys. Rev. Lett. 89, 085002 (2002).) From PIC simulations we understand the highest-energy and lowest-divergence proton acceleration as a transient laser-driven virtual cathode effect occurring at the target rear-surface. We have also confirmed the acceleration of ions from the front surface (A. Maksimchuk et al., Phys. Rev. Lett. 84, 4108 (2000).), which we find exhibits an intense low-energy component, but only a tenuous high-energy component, in agreement with PIC simulations. This work was performed with corporate support of General Atomics.

  16. Beam collimation and energy spectrum compression of laser-accelerated proton beams using solenoid field and RF cavity

    NASA Astrophysics Data System (ADS)

    Teng, J.; Gu, Y. Q.; Zhu, B.; Hong, W.; Zhao, Z. Q.; Zhou, W. M.; Cao, L. F.

    2013-11-01

    This paper presents a new method of laser produced proton beam collimation and spectrum compression using a combination of a solenoid field and a RF cavity. The solenoid collects laser-driven protons efficiently within an angle that is smaller than 12 degrees because it is mounted few millimeters from the target, and collimates protons with energies around 2.3 MeV. The collimated proton beam then passes through a RF cavity to allow compression of the spectrum. Particle-in-cell (PIC) simulations demonstrate the proton beam transport in the solenoid and RF electric fields. Excellent energy compression and collection efficiency of protons are presented. This method for proton beam optimization is suitable for high repetition-rate laser acceleration proton beams, which could be used as an injector for a conventional proton accelerator.

  17. Prospects at high energies

    SciTech Connect

    Quigg, C.

    1988-11-01

    I discuss some possibilities for neutrino experiments in the fixed-target environment of the SPS, Tevatron, and UNK, with their primary proton beams of 0.4, 0.9, and 3.0 TeV. The emphasis is on unfinished business: issues that have been recognized for some time, but not yet resolved. Then I turn to prospects for proton-proton colliders to explore the 1-TeV scale. I review the motivation for new physics in the neighborhood of 1 TeV and mention some discovery possibilities for high-energy, high-luminosity hadron colliders and the implications they would have for neutrino physics. I raise the possibility of the direct study of neutrino interactions in hadron colliders. I close with a report on the status of the SSC project. 38 refs., 17 figs.

  18. ALPtraum: ALP production in proton beam dump experiments

    NASA Astrophysics Data System (ADS)

    Döbrich, Babette; Jaeckel, Joerg; Kahlhoefer, Felix; Ringwald, Andreas; Schmidt-Hoberg, Kai

    2016-02-01

    With their high beam energy and intensity, existing and near-future proton beam dumps provide an excellent opportunity to search for new very weakly coupled particles in the MeV to GeV mass range. One particularly interesting example is a so-called axion-like particle (ALP), i.e. a pseudoscalar coupled to two photons. The challenge in proton beam dumps is to reliably calculate the production of the new particles from the interactions of two composite objects, the proton and the target atoms. In this work we argue that Primakoff production of ALPs proceeds in a momentum range where production rates and angular distributions can be determined to sufficient precision using simple electromagnetic form factors. Reanalysing past proton beam dump experiments for this production channel, we derive novel constraints on the parameter space for ALPs. We show that the NA62 experiment at CERN could probe unexplored parameter space by running in `dump mode' for a few days and discuss opportunities for future experiments such as SHiP.

  19. Nuclear Data for Proton Beam Radiotherapy

    SciTech Connect

    Melo Rego, Maria Eugenia de; Carlson, B. V.

    2009-06-03

    The need for a program of work focused on the nuclear data evaluation of charged-particle reactions has arisen recently due to their increasing use in cancer therapy. This project, as part of that program, has as its main goal the selection and comparison of nuclear data for nuclear reactions induced by protons at low to intermediate energies (E<250 MeV). The methodology of selection was based on the data base EXFOR and the compilations of radionuclide production cross sections of N. Sobolevsky. For the purpose of comparison and evaluation, theoretical calculations with the reaction model code EMPIRE-II are being used.

  20. FIDDLING CARBON STRINGS WITH POLARIZED PROTON BEAMS.

    SciTech Connect

    HUANG, H.; KURITA, K.

    2006-05-01

    An innovative polarimeter based on proton carbon elastic scattering in the Coulomb Nuclear Interference (CNI) region was first tested in the Brookhaven AGS successfully. CNI Polarimeters were then installed in the AGS and both RHIC rings. The polarimeter consists of ultra-thin carbon targets and silicon strip detectors. The waveform digitizers are used for signal readout, which allows deadtime-less data processing on the fly. Polarimeters are crucial instrumentation for the RHIC spin physics program. This paper summarizes the polarimeter design issues and operation results.

  1. The influence of the Earth's magnetosphere on the high-energy solar protons

    NASA Technical Reports Server (NTRS)

    Bazilevskaya, G. A.; Makhmutov, V. S.; Charakhchyan, T. N.

    1985-01-01

    In the Earth's polar regions the intensity of the solar protons with the energy above the critical energy of geomagnetic cutoff is the same as in the interplanetary space. The penumbra in the polar regions is small and the East-West effect is also small. However the geomagnetic cutoff rigidity R sub c in polar regions is difficult to calculate because it is not sufficient to include only the internal sources of the geomagnetic field. During the magneto-quiescent periods the real value of R sub c can be less by 0.1 GV than the calculated value because of the external sources. During the geomagnetic storms the real value of R sub c is still lower.

  2. Pyrolysis of complex organics following high-energy proton irradiation of a simple inorganic gas mixture

    NASA Astrophysics Data System (ADS)

    Takano, Yoshinori; Marumo, Katsumi; Yabashi, Suguru; Kaneko, Takeo; Kobayashi, Kensei

    2004-08-01

    Complex organics formed by 3MeV proton irradiation of a simple inorganic gas mixture with a composition representative of the primitive earth atmosphere (carbon monoxide, nitrogen, and water) were characterized by application of Curie-point pyrolysis. Pyrolysis products consisted of a wide variety of organic compounds including amide compounds, heterocyclic, and polycyclic aromatic hydrocarbons. The present data showed that primary and primitive organic matter serving as "precursors" to fundamental building blocks associated with life might have been formed in a gaseous mixture of a similar composition to that of the primitive earth atmosphere. Large numbers of endogenous organic compounds and protocatalysis components produced by cosmic rays may have contributed significantly to the early stages of chemical evolution on the primitive earth.

  3. EPR/alanine dosimetry for two therapeutic proton beams

    NASA Astrophysics Data System (ADS)

    Marrale, Maurizio; Carlino, Antonio; Gallo, Salvatore; Longo, Anna; Panzeca, Salvatore; Bolsi, Alessandra; Hrbacek, Jan; Lomax, Tony

    2016-02-01

    In this work the analysis of the electron paramagnetic resonance (EPR) response of alanine pellets exposed to two different clinical proton beams employed for radiotherapy is performed. One beam is characterized by a passive delivery technique and is dedicated to the eyes treatment (OPTIS2 beam line). Alanine pellets were irradiated with a 70 MeV proton beam corresponding to 35 mm range in eye tissue. We investigated how collimators with different sizes and shape used to conform the dose to the planned target volume influence the delivered dose. For this purpose we performed measurements with varying the collimator size (Output Factor) and the results were compared with those obtained with other dosimetric techniques (such as Markus chamber and diode detector). This analysis showed that the dosimeter response is independent of collimator diameter if this is larger than or equal to 10 mm. The other beam is characterized by an active spot-scanning technique, the Gantry1 beam line (maximum energy 230 MeV), and is used to treat deep-seated tumors. The dose linearity of alanine response in the clinical dose range was tested and the alanine dose response at selected locations in depth was measured and compared with the TPS planned dose in a quasi-clinical scenario. The alanine response was found to be linear in the dose in the clinical explored range (from 10 to 70 Gy). Furthermore, a depth dose profile in a quasi-clinical scenario was measured and compared to the dose computed by the Treatment Planning System PSIPLAN. The comparison of calibrated proton alanine measurements and TPS dose shows a difference under 1% in the SOBP and a "quenching" effect up to 4% in the distal part of SOBP. The positive dosimetric characteristics of the alanine pellets confirm the feasibility to use these detectors for "in vivo" dosimetry in clinical proton beams.

  4. Characterization of uniform scanning proton beams with analytical models

    NASA Astrophysics Data System (ADS)

    Demez, Nebi

    Tissue equivalent phantoms have an important place in radiation therapy planning and delivery. They have been manufactured for use in conventional radiotherapy. Their tissue equivalency for proton beams is currently in active investigation. The Bragg-Kleeman rule was used to calculate water equivalent thickness (WET) for available tissue equivalent phantoms from CIRS (Norfolk, VA, USA). WET's of those phantoms were also measured using proton beams at Hampton University Proton Therapy Institute (HUPTI). WET measurements and calculations are in good agreement within ˜1% accuracy except for high Z phantoms. Proton beams were also characterized with an analytical proton dose calculation model, Proton Loss Model (PLM) [26], to investigate protons interactions in water and those phantoms. Depth-dose and lateral dose profiles of protons in water and in those phantoms were calculated, measured, and compared. Water Equivalent Spreadness (WES) was also investigated for those phantoms using the formula for scattering power ratio. Because WES is independent of incident energy of protons, it is possible to estimate spreadness of protons in different media by just knowing WES. Measurements are usually taken for configuration of the treatment planning system (TPS). This study attempted to achieve commissioning data for uniform scanning proton planning with analytical methods, PLM, which have been verified with published measurements and Monte Carlo calculations. Depth doses and lateral profiles calculated by PLM were compared with measurements via the gamma analysis method. While gamma analysis shows that depth doses are in >90% agreement with measured depth doses, the agreement falls to <80% for some lateral profiles. PLM data were imported into the TPS (PLM-TPS). PLM-TPS was tested with different patient cases. The PLM-TPS treatment plans for 5 prostate cases show acceptable agreement. The Planning Treatment Volume (PTV) coverage was 100 % with PLM-TPS except for one case in

  5. MOSFET sensitivity dependence on integrated dose from high-energy photon beams.

    PubMed

    Tanyi, James A; Krafft, Shane P; Hagio, Tomoe; Fuss, Martin; Salter, Bill J

    2008-01-01

    The ability of a commercially available dual bias, dual MOSFET dosimetry system to measure therapeutic doses reproducibly throughout its vendor-defined dose-based lifetime has been evaluated by characterizing its sensitivity variation to integrated/cumulative doses from,high-energy (6 and 15 MV) photon radiotherapy beams. The variation of sensitivity as a function of total integrated dose was studied for three different dose-per-fraction levels; namely, 50, 200, and 1200 cGy/fraction. In standard sensitivity mode (i.e., measurements involving dose-per-fraction levels > or =100 cGy), the response of the MOSFET system to identical irradiations increased with integrated dose for both energies investigated. Dose measurement reproducibility for the low (i.e., 50 cGy) dose fractions was within 2.1% (if the system was calibrated before each in-phantom measurement) and 3.1% [if the system was calibrated prior to first use, with no intermediate calibration(s)]. Similarly, dose measurement reproducibility was between 2.2% and 6.6% for the conventional (i.e., 200 cGy) dose fractions and between 1.8% and 7.9% for escalated (i.e., 1200 cGy) dose fractions. The results of this study suggest that, due to the progressively increasing sensitivity resulting from the dual-MOSFET design, frequent calibrations are required to achieve measurement accuracy of < or =3% (within one standard deviation). PMID:18293559

  6. Monte Carlo simulation and parameterized treatment on the effect of nuclear elastic scattering in high-energy proton radiography

    NASA Astrophysics Data System (ADS)

    Xu, Hai-Bo; Zheng, Na

    2015-07-01

    A version of Geant4 has been developed to treat high-energy proton radiography. This article presents the results of calculations simulating the effects of nuclear elastic scattering for various test step wedges. Comparisons with experimental data are also presented. The traditional expressions of the transmission should be correct if the angle distribution of the scattering is Gaussian multiple Coulomb scattering. The mean free path (which depends on the collimator angle) and the radiation length are treated as empirical parameters, according to transmission as a function of thickness obtained by simulations. The results can be used in density reconstruction, which depends on the transmission expressions. Supported by NSAF (11176001) and Science and Technology Developing Foundation of China Academy of Engineering Physics (2012A0202006)

  7. Assessing Antibody Microarray for Space Missions: Effect of Long-term Storage, Gamma radiation and High Energy proton radiation

    NASA Astrophysics Data System (ADS)

    de Diego-Castilla, G.; Parro, V.

    2012-09-01

    Fluorescent antibody microarray has been proposed for Molecular biomarker detector in planetary exploration [1]. A number of different environmental stresses may affect the antibody performance, such as temperatures variations, highly penetrating radiation and high energy particles. Here we have tested the effect of gamma radiation, proton radiation and longterm storage on the microarray immunoassay and fluorocromes. Although different antibodies might have different susceptibilities we conclude that there was not significant reduction in the functionality of antibodies printed on the microarray and the fluorescent tracers antibodies, even in a extreme case of receiving a radiation dose 3000-fold than a biochip would receive in a trip mission to Mars. In summary, antibodies are suitable for use in planetary exploration purposes.

  8. Stability Issues of the Mu2e Proton Beam

    SciTech Connect

    Ng, K.Y.; /Fermilab

    2009-05-01

    Stability issues of the mu2e proton beam are discussed. These include space-charge distortion of bunch shape, microwave instabilities, mode-coupling instabilities, head-tail instabilities, as well as electron-cloud effects. We have studied several beam stability issues of the proton beam heading to the target for the mu2e experiment. We find bunch-shape distortions driven by the space charge force is reasonably small, and longitudinal microwave instability will unlikely to occur. Electron-cloud buildup, with density up to {rho}{sub e} {approx} 2 x 10{sup 12} m{sup -3} in the Accumulator, can probably drive head-tail instabilities. However, these, together with the instabilities driven by the resistive-wall impedance can be avoided by restricting the chromaticity to larger than {approx} 0.2. TMCI will not occur even when the electron-cloud wake is included.

  9. The generation of proton beams in two-ribbon flares

    NASA Technical Reports Server (NTRS)

    Martens, P. C. H.

    1988-01-01

    It is shown that, in the current sheet at the top of the arcade of postflare loops in a two-ribbon solar flare, particle beams are generated by direct electric-field acceleration. The acceleration process is completely collisionless and is limited only by the gyromotion along the component of the magnetic field perpendicular to the sheet. This mechanism is similar to the particle acceleration in the geomagnetic tail. Neutral beams emanate from the sheet with almost zero pitch angle, making protons the main carriers of the beam energy. Approximately 10 to the 35th protons/sec are generated with a typical energy of 200 keV. Their energy distribution is a single power law, with an upper and lower energy cut-off. Such a population is capable of simultaneously generating the observed impulsive-phase hard X-rays and the gamma rays.

  10. Dose error analysis for a scanned proton beam delivery system

    NASA Astrophysics Data System (ADS)

    Coutrakon, G.; Wang, N.; Miller, D. W.; Yang, Y.

    2010-12-01

    All particle beam scanning systems are subject to dose delivery errors due to errors in position, energy and intensity of the delivered beam. In addition, finite scan speeds, beam spill non-uniformities, and delays in detector, detector electronics and magnet responses will all contribute errors in delivery. In this paper, we present dose errors for an 8 × 10 × 8 cm3 target of uniform water equivalent density with 8 cm spread out Bragg peak and a prescribed dose of 2 Gy. Lower doses are also analyzed and presented later in the paper. Beam energy errors and errors due to limitations of scanning system hardware have been included in the analysis. By using Gaussian shaped pencil beams derived from measurements in the research room of the James M Slater Proton Treatment and Research Center at Loma Linda, CA and executing treatment simulations multiple times, statistical dose errors have been calculated in each 2.5 mm cubic voxel in the target. These errors were calculated by delivering multiple treatments to the same volume and calculating the rms variation in delivered dose at each voxel in the target. The variations in dose were the result of random beam delivery errors such as proton energy, spot position and intensity fluctuations. The results show that with reasonable assumptions of random beam delivery errors, the spot scanning technique yielded an rms dose error in each voxel less than 2% or 3% of the 2 Gy prescribed dose. These calculated errors are within acceptable clinical limits for radiation therapy.

  11. Self-pinched transport of an intense proton beam

    SciTech Connect

    Ottinger, P. F.; Young, F. C.; Stephanakis, S. J.; Rose, D. V.; Neri, J. M.; Weber, B. V.; Myers, M. C.; Hinshelwood, D. D.; Mosher, D.; Olson, C. L.

    2000-01-01

    Ion beam self-pinched transport (SPT) experiments have been carried out using a 1.1-MeV, 100-kA proton beam. A Rutherford scattering diagnostic and a LiF nuclear activation diagnostic measured the number of protons within a 5 cm radius at 50 cm into the transport region that was filled with low-pressure helium. Time-integrated signals from both diagnostics indicate self-pinching of the ion beam in a helium pressure window between 35 and 80 mTorr. Signals from these two diagnostics are consistent with ballistic transport at pressures above and below this SPT pressure window. Interferometric measurements of electron densities during beam injection into vacuum are consistent with ballistic transport with co-moving electrons. Interferometric measurements for beam injection into helium show that the electron density increases quadratically with pressure through the SPT window and roughly linearly with pressure above the SPT window. The ionization fraction of the helium plateaus at about 1.5% for pressures above 80 mTorr. In the SPT window, the electron density is 3 to 20 times the beam density. Numerical simulations of these beam transport experiments produce results that are in qualitative agreement with the experimental measurements. (c) 2000 American Institute of Physics.

  12. On the nucleon effective mass role to the high energy proton spallation reactions

    NASA Astrophysics Data System (ADS)

    Santos, B. M.; Pinheiro, A. R. C.; Gonçalves, M.; Duarte, S. B.; Cabral, R. G.

    2016-04-01

    We explore the effect of the nucleon effective mass to the dynamic evolution of the rapid phase of proton-nucleus spallation reactions. The analysis of the relaxation time for the non-equilibrium phase is studied by variations in the effective mass parameter. We determine the final excitation energy of the hot residual nucleus at the end of cascade phase and the de-excitation of the nuclear system is carried out considering the competition of particle evaporation and fission processes. It was shown that the excitation energy depends of the hot compound residual nucleus at the end of the rapid phase on the changing effective mass. The multiplicity of particles was also analyzed in cascade and evaporation phase of the reaction. The use of nucleon effective mass during cascade phase can be considered as an effect of the many-body nuclear interactions not included explicitly in a treatment to the nucleon-nucleon interaction inside the nucleus. This procedure represents a more realistic scenario to obtain the neutron multiplicity generated in this reaction, which is a benchmark for the calculation of the neutronic in the ADS reactors.

  13. [Indralin--a novel effective radioprotector during irradiation by high-energy protons].

    PubMed

    Shashkov, V S; Efimov, V I; Vasin, M V; Antipov, V V; Iliukhin, A V; Vlasov, P A; Karsanova, S K; Grigor'ev, Iu G; Ushakov, I B

    2010-01-01

    Experiments with 120 mongrel dogs were aimed at the assessment of radio protective strength of indralin and local shielding of the pelvic marrow from 2.5 Gy, and also their concurrent use for the dogs irradiated by protons (240 MeV) at absolutely lethal and over-lethal 4 Gy and 5 Gy. Clinical observations, hematological investigations and ECG analysis of survived animals were conducted 4.5 years post the irradiation. Dogs that remained healthy following 3.5 to 4.5 years since the irradiation were sacrificed for pathomorphological investigations. The radioprotective effect of local shielding against 4 Gy was weak while this effect of intramuscular indralin (10, 20, 40 mg/kg of body) was significant reaching 50 to 67.7%. The concurrent use of two methods had, apparently, potentiated the 100% radioprotection of the animals irradiated by overlethal 5 Gy. Blood investigations of the survived dogs every 2-4 months evidenced that complete recovery of the total leukocyte count had taken 9 to 13 months. Also, dogs' pregnancy in 9-10 months since the beginning of irradiation pointed to maintenance of fertility and the ability to parturiate 2 or 3 times yielding 5-6 live cubs. Necropsy of the dogs did not reveal gross macroscopic structural changes of visceral organs or tissues. Seven out of 27 sacrificed dogs had benign tumors infrequent in intact dogs at this age. PMID:20803992

  14. High energy density proton exchange membrane fuel cell with dry reactant gases

    SciTech Connect

    Srinivasan, S.; Gamburzev, S.; Velev, O.A.

    1996-12-31

    Proton exchange membrane fuel cells (PEMFC) require careful control of humidity levels in the cell stack to achieve a high and stable level of performance. External humidification of the reactant gases, as in the state-of-the-art PEMFCs, increases the complexity, the weight, and the volume of the fuel cell power plant. A method for the operation of PEMFCs without external humidification (i.e., self-humidified PEMFCs) was first developed and tested by Dhar at BCS Technology. A project is underway in our Center to develop a PEMFC cell stack, which can work without external humidification and attain a performance level of a current density of 0.7 A/cm{sup 2} at a cell potential of 0.7 V, with hydrogen/air as reactants at 1 atm pressure. In this paper, the results of our efforts to design and develop a PEMFC stack requiring no external humidification will be presented. This paper focuses on determining the effects of type of electrodes, the methods of their preparation, as well as that of the membrane and electrode assembly (MEA), platinum loading and types of electrocatalyst on the performance of the PEMFC will be illustrated.

  15. High energy efficiency and high power density proton exchange membrane fuel cells: Electrode kinetics and mass transport

    NASA Technical Reports Server (NTRS)

    Srinivasan, Supramaniam; Velev, Omourtag A.; Parthasathy, Arvind; Manko, David J.; Appleby, A. John

    1991-01-01

    The development of proton exchange membrane (PEM) fuel cell power plants with high energy efficiencies and high power densities is gaining momentum because of the vital need of such high levels of performance for extraterrestrial (space, underwater) and terrestrial (power source for electric vehicles) applications. Since 1987, considerable progress has been made in achieving energy efficiencies of about 60 percent at a current density of 200 mA/sq cm and high power densities (greater than 1 W/sq cm) in PEM fuel cells with high (4 mg/sq cm) or low (0.4 mg/sq cm) platinum loadings in electrodes. The following areas are discussed: (1) methods to obtain these high levels of performance with low Pt loading electrodes - by proton conductor impregnation into electrodes, localization of Pt near front surface; (2) a novel microelectrode technique which yields electrode kinetic parameters for oxygen reduction and mass transport parameters; (3) demonstration of lack of water transport from anode to cathode; (4) modeling analysis of PEM fuel cell for comparison with experimental results and predicting further improvements in performance; and (5) recommendations of needed research and development for achieving the above goals.

  16. Macroparticle simulation studies of a proton beam haloexperiment

    SciTech Connect

    Qiang, J.; Colestock, P.L.; Gilpatrick, D.; Smith, H.V.; Wangler,T.P.; Schulze, M.E.

    2002-09-12

    We report macroparticle simulations for comparison withmeasured results from a proton beam-halo experiment in a 52-quadrupoleperiodic-focusing channel. An important issue is that the inputphase-space distribution is not experimentally known. Three differentinitial distributions with different shapes predict different beamprofiles in the transport system. Simulations have been fairly successfulin reproducing the core of the measured matched-beam profiles and thetrend of emittance growth as a function of mismatch factor, butunderestimate the growth rate of halo and emittance for mismatched beams.In this study, we find that knowledge of the Courant-Snyder parametersand emittances of the input beam is not sufficient for reliableprediction of the halo. Input distributions iwth greater population inthe tails produce larger rates of emittance growth, a result that isqualitatively consistent with the particle-core model of halo formationin mismatched beams.

  17. Preliminary results of proton beam characterization for a facility of broad beam in vitro cell irradiation

    NASA Astrophysics Data System (ADS)

    Wéra, A.-C.; Donato, K.; Michiels, C.; Jongen, Y.; Lucas, S.

    2008-05-01

    The interaction of charged particles with living matter needs to be well understood for medical applications. Particularly, it is useful to study how ion beams interact with tissues in terms of damage, dose released and dose rate. One way to evaluate the biological effects induced by an ion beam is by the irradiation of cultured cells at a particle accelerator, where cells can be exposed to different ions at different energies and flux. In this paper, we report the first results concerning the characterization of a broad proton beam obtained with our 2 MV tandem accelerator. For broad beam in vitro cell irradiation, the beam has to be stable over time, uniform over a ∼0.5 cm2 surface, and a dose rate ranging from 0.1 to 10 Gy/min must be achievable. Results concerning the level of achievement of these requirements are presented in this paper for a 1 MeV proton beam.

  18. Contributions from Ultraviolet Spectroscopy to the Prediction of High-energy Proton Hazards from CME Shocks

    NASA Astrophysics Data System (ADS)

    Lin, J.; Raymond, J. C.; Cranmer, S. R.; Kohl, J. L.

    2004-05-01

    A significant potential hazard to astronauts and their equipment in interplanetary space is the relativistic proton flux produced by coronal mass ejections (CMEs) and solar flares. The longest-duration phase of solar energetic particle (SEP) activity is believed to come from the CME shock as it propagates through the extended corona and heliosphere. Ultraviolet spectroscopy by SOHO has revealed a means for: (1) detecting and characterizing CME shocks in the corona, and (2) determining the plasma conditions in the pre-CME corona which are needed to understand the formation and evolution of shocks. Such remote sensing - combined with models of SEP acceleration and transport - can be used to predict the strength, duration, and production sites of the radiation. This poster describes the specific means by which ultraviolet spectroscopy and other remote-sensing data can be used to determine the inputs and boundary conditions for individual events (such as the October-November 2003 storms) in existing SEP model codes. We also discuss an additional potential source of SEP radiation associated with electric fields in the current sheets that form in flare regions in the wake of CME. Both observations and model calculations show that the reconnection-induced electric field can reach a maximum strength of a few V/cm within tens of minutes after the onset of the eruption, then decreases gradually over several hours. SEPs produced in these regions may account for X-rays and γ -rays observed prior to the formation of CME shocks. Ultraviolet spectroscopy has been shown to provide constraints on the plasma properties in all of the above CME features. This work is supported by NASA under grant NAG5-12865 to the Smithsonian Astrophysical Observatory, by Agenzia Spaziale Italiana, and by the Swiss contribution to ESA's PRODEX program.

  19. Performance of the KTeV high-energy neutral kaon beam at Fermilab

    SciTech Connect

    Bocean, V.

    1998-06-01

    The performance of the primary and secondary beams for the KTeV experiments E832 and E799-II is reviewed. The beam was commissioned in the summer of 1996 and initially operated for approximately one year. The report includes results on the primary beam, target station including primary beam dump and muon sweeping system, neutral beam collimation system, and alignment.

  20. A search for proton beams during flares on AU Microscopii

    NASA Technical Reports Server (NTRS)

    Robinson, R. D.; Carpenter, K. G.; Woodgate, B. E.; Maran, S. P.

    1993-01-01

    We report the results of a coordinated observing campaign on the active M dwarf star AU Mic. The purpose of the campaign was to search for evidence of proton beams during the impulsive phase of stellar flares and to determine whether the energy contained in these beams represented a significant fraction of the energy budget of the flare. During a total of 3.5 hr of monitoring a small flare was observed simultaneously by the HST, IUE, and the AAT. This event, which had a total optical + UV emission of 1.3 x 10 exp 32 ergs, occurred during the decay phase of a much larger event and showed no evidence for a proton beam with an energy greater than a few times 10 exp 29 ergs/s. This is comparable to the maximum energy flux released by the flare, though this energy release rate must occur over a time interval much shorter than that of the impulsive phase itself. We conclude that the proton beams may be capable of transporting some energy during the impulsive phase of a flare, but that they are unlikely to be the major contributor, at least for this particular event.

  1. Proton beam generation of oblique whistler waves

    NASA Technical Reports Server (NTRS)

    Wong, H. K.; Goldstein, M. L.

    1988-01-01

    It is known that ion beams are capable of generating whistler waves that propagate parallel to the mean magnetic field. Such waves may have been observed both upstream of the earth's bow shock and in the vicinity of comets. Previous analyses are extended to include propagation oblique to the mean magnetic field. The instability is generated by the perpendicular component of free energy in the ions, which can arise either via a temperature anisotropy or via a gyrating distribution. In the former case, the generation of whistler waves is confined to a fairly narrow cone of propagation directions centered about parallel propagation; in the latter case, the maximum growth of the instability can occur at fairly large obliquities (theta equal to about 50 deg).

  2. TH-C-BRD-04: Beam Modeling and Validation with Triple and Double Gaussian Dose Kernel for Spot Scanning Proton Beams

    SciTech Connect

    Hirayama, S; Takayanagi, T; Fujii, Y; Fujimoto, R; Fujitaka, S; Umezawa, M; Nagamine, Y; Hosaka, M; Yasui, K; Toshito, T

    2014-06-15

    Purpose: To present the validity of our beam modeling with double and triple Gaussian dose kernels for spot scanning proton beams in Nagoya Proton Therapy Center. This study investigates the conformance between the measurements and calculation results in absolute dose with two types of beam kernel. Methods: A dose kernel is one of the important input data required for the treatment planning software. The dose kernel is the 3D dose distribution of an infinitesimal pencil beam of protons in water and consists of integral depth doses and lateral distributions. We have adopted double and triple Gaussian model as lateral distribution in order to take account of the large angle scattering due to nuclear reaction by fitting simulated inwater lateral dose profile for needle proton beam at various depths. The fitted parameters were interpolated as a function of depth in water and were stored as a separate look-up table for the each beam energy. The process of beam modeling is based on the method of MDACC [X.R.Zhu 2013]. Results: From the comparison results between the absolute doses calculated by double Gaussian model and those measured at the center of SOBP, the difference is increased up to 3.5% in the high-energy region because the large angle scattering due to nuclear reaction is not sufficiently considered at intermediate depths in the double Gaussian model. In case of employing triple Gaussian dose kernels, the measured absolute dose at the center of SOBP agrees with calculation within ±1% regardless of the SOBP width and maximum range. Conclusion: We have demonstrated the beam modeling results of dose distribution employing double and triple Gaussian dose kernel. Treatment planning system with the triple Gaussian dose kernel has been successfully verified and applied to the patient treatment with a spot scanning technique in Nagoya Proton Therapy Center.

  3. Generation of high-energy mono-energetic heavy ion beams by radiation pressure acceleration of ultra-intense laser pulses

    NASA Astrophysics Data System (ADS)

    Wu, D.; Qiao, B.; McGuffey, C.; He, X. T.; Beg, F. N.

    2014-12-01

    Generation of high-energy mono-energetic heavy ion beams by radiation pressure acceleration (RPA) of intense laser pulses is investigated. Different from previously studied RPA of protons or light ions, the dynamic ionization of high-Z atoms can stabilize the heavy ion acceleration. A self-organized, stable RPA scheme specifically for heavy ion beams is proposed, where the laser peak intensity is required to match with the large ionization energy gap when the successive ionization state passes the noble gas configurations [such as removing an electron from the helium-like charge state ( Z - 2 ) + to ( Z - 1 ) + ]. Two-dimensional particle-in-cell simulations show that a mono-energetic Al13+ beam with peak energy 1.0 GeV and energy spread of only 5% can be obtained at intensity of 7 × 10 20 W / cm 2 through the proposed scheme. A heavier, mono-energetic, ion beam (Fe26+) can attain a peak energy of 17 GeV by increasing the intensity to 10 22 W / cm 2 .

  4. Generation of high-energy mono-energetic heavy ion beams by radiation pressure acceleration of ultra-intense laser pulses

    SciTech Connect

    Wu, D.; Qiao, B.; McGuffey, C.; Beg, F. N.; He, X. T.

    2014-12-15

    Generation of high-energy mono-energetic heavy ion beams by radiation pressure acceleration (RPA) of intense laser pulses is investigated. Different from previously studied RPA of protons or light ions, the dynamic ionization of high-Z atoms can stabilize the heavy ion acceleration. A self-organized, stable RPA scheme specifically for heavy ion beams is proposed, where the laser peak intensity is required to match with the large ionization energy gap when the successive ionization state passes the noble gas configurations [such as removing an electron from the helium-like charge state (Z−2){sup +} to (Z−1){sup +}]. Two-dimensional particle-in-cell simulations show that a mono-energetic Al{sup 13+} beam with peak energy 1.0 GeV and energy spread of only 5% can be obtained at intensity of 7×10{sup 20} W/cm{sup 2} through the proposed scheme. A heavier, mono-energetic, ion beam (Fe{sup 26+}) can attain a peak energy of 17 GeV by increasing the intensity to 10{sup 22} W/cm{sup 2}.

  5. A beam optics study of the biomedical beam line at a proton therapy facility

    NASA Astrophysics Data System (ADS)

    Yun, Chong Cheoul; Kim, Jong-Won

    2007-10-01

    A biomedical beam line has been designed for the experimental area of a proton therapy facility to deliver mm to sub-mm size beams in the energy range of 20-50 MeV using the TRANSPORT/TURTLE beam optics codes and a newly-written program. The proton therapy facility is equipped with a 230 MeV fixed-energy cyclotron and an energy selection system based on a degrader and slits, so that beam currents available for therapy decrease at lower energies in the therapeutic beam energy range of 70-230 MeV. The new beam line system is composed of an energy-degrader, two slits, and three quadrupole magnets. The minimum beam sizes achievable at the focal point are estimated for the two energies of 50 and 20 MeV. The focused FWHM beam size is approximately 0.3 mm with an expected beam current of 20 pA when the beam energy is reduced to 50 MeV from 100 MeV, and roughly 0.8 mm with a current of 10 pA for a 20 MeV beam.

  6. Comments on Injector Proton Beam Study in Run 2014

    SciTech Connect

    Zhang, S. Y.

    2014-09-15

    During the entire period of injector proton study in run 2014, it seems that the beam transverse emittance out of Booster is larger than that in run 2013. The emittance measured at the BtA transfer line and also the transmission from Booster late to AGS late are presented for this argument. In addition to this problem, it seems that the multiturn Booster injection, which defines the transverse emittance, needs more attention. Moreover, for high intensity operations, the space charge effect may be already relevant in RHIC polarized proton runs. With the RHIC proton intensity improvement in the next several years, higher Booster input intensity is needed, therefore, the space charge effect at the Booster injection and early ramp may become a new limiting factor.

  7. Analysis ob beam losses at PSR (Proton Storage Ring)

    SciTech Connect

    Macek, R.J.; Fitzgerald, D.H.; Hutson, R.L.; Plum, M.A.; Thiessen, H.A.

    1988-01-01

    Beam losses and the resulting component activation at the Los Alamos Proton Storage Ring (PSR) have limited operating currents to about 30..mu..A average at a repetition rate of 15 Hz. Loss rates were found to be approximately proportional to the circulating current and can be understood by a detailed accounting of emittance growth in the two step injection process along with Coulomb scattering of the stored beam during multiple traversals of the injection foil. Calculations and simulations of the losses are in reasonable agreement with measurements.

  8. Proton beam therapy for locally advanced lung cancer: A review

    PubMed Central

    Schild, Steven E; Rule, William G; Ashman, Jonathan B; Vora, Sujay A; Keole, Sameer; Anand, Aman; Liu, Wei; Bues, Martin

    2014-01-01

    Protons interact with human tissue differently than do photons and these differences can be exploited in an attempt to improve the care of lung cancer patients. This review examines proton beam therapy (PBT) as a component of a combined modality program for locally advanced lung cancers. It was specifically written for the non-radiation oncologist who desires greater understanding of this newer treatment modality. This review describes and compares photon (X-ray) radiotherapy (XRT) to PBT. The physical differences of these beams are described and the clinical literature is reviewed. Protons can be used to create treatment plans delivering significantly lower doses of radiation to the adjacent organs at risk (lungs, esophagus, and bone marrow) than photons. Clinically, PBT combined with chemotherapy has resulted in low rates of toxicity compared to XRT. Early results suggest a possible improvement in survival. The clinical results of proton therapy in lung cancer patients reveal relatively low rates of toxicity and possible survival benefits. One randomized study is being performed and another is planned to clarify the clinical differences in patient outcome for PBT compared to XRT. Along with the development of better systemic therapy, newer forms of radiotherapy such as PBT should positively impact the care of lung cancer patients. This review provides the reader with the current status of this new technology in treating locally advanced lung cancer. PMID:25302161

  9. Proteomic Analysis of Proton Beam Irradiated Human Melanoma Cells

    PubMed Central

    Kedracka-Krok, Sylwia; Jankowska, Urszula; Elas, Martyna; Sowa, Urszula; Swakon, Jan; Cierniak, Agnieszka; Olko, Pawel; Romanowska-Dixon, Bozena; Urbanska, Krystyna

    2014-01-01

    Proton beam irradiation is a form of advanced radiotherapy providing superior distributions of a low LET radiation dose relative to that of photon therapy for the treatment of cancer. Even though this clinical treatment has been developing for several decades, the proton radiobiology critical to the optimization of proton radiotherapy is far from being understood. Proteomic changes were analyzed in human melanoma cells treated with a sublethal dose (3 Gy) of proton beam irradiation. The results were compared with untreated cells. Two-dimensional electrophoresis was performed with mass spectrometry to identify the proteins. At the dose of 3 Gy a minimal slowdown in proliferation rate was seen, as well as some DNA damage. After allowing time for damage repair, the proteomic analysis was performed. In total 17 protein levels were found to significantly (more than 1.5 times) change: 4 downregulated and 13 upregulated. Functionally, they represent four categories: (i) DNA repair and RNA regulation (VCP, MVP, STRAP, FAB-2, Lamine A/C, GAPDH), (ii) cell survival and stress response (STRAP, MCM7, Annexin 7, MVP, Caprin-1, PDCD6, VCP, HSP70), (iii) cell metabolism (TIM, GAPDH, VCP), and (iv) cytoskeleton and motility (Moesin, Actinin 4, FAB-2, Vimentin, Annexin 7, Lamine A/C, Lamine B). A substantial decrease (2.3 x) was seen in the level of vimentin, a marker of epithelial to mesenchymal transition and the metastatic properties of melanoma. PMID:24392146

  10. Thermal hydraulic studies of spallation target for one-way coupled Indian accelerator driven systems with low energy proton beam

    NASA Astrophysics Data System (ADS)

    Mantha, V.; Mohanty, A. K.; Satyamurthy, P.

    2007-02-01

    BARC has recently proposed a one-way coupled ADS reactor. This reactor requires typically 1 GeV proton beam with 2 mA of current. Approximately 8 kW of heat is deposited in the window of the target. Circulating liquid metal target (lead/lead-bismuth{eutectic) has to extract this heat and this is a critical R&D problem to be solved. At present there are very few accelerators, which can give few mA and high-energy proton beam. However, accelerators with low energy and hundreds of micro-ampere current are commercially available. In view of this, it is proposed in this paper to simulate beam window heating of 8 kW in the target with low-energy proton beam. Detailed thermal analysis in the spallation and window region has been carried out to study the capability of heat extraction by circulating LBE for a typical target loop with a proton beam of 30 MeV energy and current of 0.267 mA. The heat deposition study is carried out using FLUKA code and flow analysis by CFD code. The detailed analysis of this work is presented in this paper.

  11. Cost-Effectiveness of Proton Beam Therapy for Intraocular Melanoma

    PubMed Central

    Moriarty, James P.; Borah, Bijan J.; Foote, Robert L.; Pulido, Jose S.; Shah, Nilay D.

    2015-01-01

    Purpose Proton beam therapy is a commonly accepted treatment for intraocular melanomas, but the literature is lacking in descriptions of patient preferences of clinical outcomes and economic impact. In addition, no economic evaluations have been published regarding the incremental cost-effectiveness of proton beam therapy compared with enucleation or plaque brachytherapy, typical alternative treatments. We, therefore, conducted a cost-utility analysis of these three approaches for the treatment of intraocular melanomas. Materials and Methods A Markov model was constructed. Model parameters were identified from the published literature and publicly available data sources. Cost-effectiveness of each treatment was calculated in 2011 US Dollars per quality-adjusted life-year. Incremental cost-effectiveness ratios were calculated assuming enucleation as reference. One-way sensitivity analyses were conducted on all model parameters. A decision threshold of $50,000/quality-adjusted life-year was used to determine cost-effectiveness. Results Enucleation had the lowest costs and quality-adjusted life-years, and plaque brachytherapy had the highest costs and quality-adjusted life-years. Compared with enucleation, the base-case incremental cost-effectiveness ratios for plaque brachytherapy and proton beam therapy were $77,500/quality-adjusted life-year and $106,100/quality-adjusted life-year, respectively. Results were highly sensitive to multiple parameters. All three treatments were considered optimal, and even dominant, depending on the values used for sensitive parameters. Conclusion Base-case analysis results suggest enucleation to be optimal. However, the optimal choice was not robust to sensitivity analyses and, depending on the assumption, both plaque brachytherapy and proton beam therapy could be considered cost-effective. Future clinical studies should focus on generating further evidence with the greatest parameter uncertainty to inform future cost

  12. Proton Beam Therapy for Aged Patients With Hepatocellular Carcinoma

    SciTech Connect

    Hata, Masaharu Tokuuye, Koichi; Sugahara, Shinji; Tohno, Eriko; Nakayama, Hidetsugu; Fukumitsu, Nobuyoshi; Mizumoto, Masashi; Abei, Masato; Shoda, Junichi; Minami, Manabu; Akine, Yasuyuki

    2007-11-01

    Purpose: To investigate the safety and efficacy of proton beam therapy for aged patients with hepatocellular carcinoma (HCC). Methods and Materials: Twenty-one patients aged {>=}80 years with HCC underwent proton beam therapy. At the time of irradiation, patient age ranged from 80 to 85 years (median, 81 years). Hepatic tumors were solitary in 17 patients and multiple in 4. Tumor size ranged from 10 to 135 mm (median, 40 mm) in maximum diameter. Ten, 5, and 6 patients received proton beam irradiation with total doses of 60 Gy in 10 fractions, 66 Gy in 22 fractions, and 70 Gy in 35 fractions, respectively, according to tumor location. Results: All irradiated tumors were controlled during the follow-up period of 6-49 months (median, 16 months). Five patients showed new hepatic tumors outside the irradiated volume, 2-13 months after treatment, and 1 of them also had lung metastasis. The local progression-free and disease-free rates were 100% and 72% at 3 years, respectively. Of 21 patients, 7 died 6-49 months after treatment; 2 patients each died of trauma and old age, and 1 patient each died of HCC, pneumonia, and arrhythmia. The 3-year overall, cause-specific, and disease-free survival rates were 62%, 88%, and 51%, respectively. No therapy-related toxicity of Grade {>=} 3 but thrombocytopenia in 2 patients was observed. Conclusions: Proton beam therapy seems to be tolerable, effective, and safe for aged patients with HCC. It may contribute to prolonged survival due to tumor control.

  13. Proton beam scattering system optimization for clinical and research applications

    SciTech Connect

    Wroe, A. J.; Schulte, R. W.; Slater, J. D.; Barnes, S.; McAuley, G.; Slater, J. M.

    2013-04-15

    Purpose: To develop and test a method for optimizing and constructing a dual scattering system in passively scattered proton therapy. Methods: A beam optics optimization algorithm was developed to optimize the thickness of the first scatterer (S1) and the profile (of both the high-Z material and Lexan) of the second scatterer (S2) to deliver a proton beam matching a given set of parameters, including field diameter, fluence, flatness, and symmetry. A new manufacturing process was also tested that allows the contoured second scattering foil to be created much more economically and quickly using Cerrobend casting. Two application-specific scattering systems were developed and tested using both experimental and Monte Carlo techniques to validate the optimization process described. Results: A scattering system was optimized and constructed to deliver large uniform irradiations of radiobiology samples at low dose rates. This system was successfully built and tested using film and ionization chambers. The system delivered a uniform radiation field of 50 cm diameter (to a dose of {+-}7% of the central axis) while the depth dose profile could be tuned to match the specifications of the particular investigator using modulator wheels and range shifters. A second scattering system for intermediate field size (4 cm < diameter < 10 cm) stereotactic radiosurgery and radiation therapy (SRS and SRT) treatments was also developed and tested using GEANT4. This system improved beam efficiency by over 70% compared with existing scattering systems while maintaining field flatness and depth dose profile. In both cases the proton range uniformity across the radiation field was maintained, further indicating the accuracy of the energy loss formalism in the optimization algorithm. Conclusions: The methods described allow for rapid prototyping of scattering foils to meet the demands of both research and clinical beam delivery applications in proton therapy.

  14. Capacitive beam position monitors for the low-β beam of the Chinese ADS proton linac

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Wu, Jun-Xia; Zhu, Guang-Yu; Jia, Huan; Xue, Zong-Heng; Zheng, Hai; Xie, Hong-Ming; Kang, Xin-Cai; He, Yuan; Li, Lin; Denard, Jean Claude

    2016-02-01

    Beam Position Monitors (BPMs) for the low-β beam of the Chinese Accelerator Driven Subcritical system (CADS) Proton linac are of the capacitive pick-up type. They provide higher output signals than that of the inductive type. This paper will describe the design and tests of the capacitive BPM system for the low-β proton linac, including the pick-ups, the test bench and the read-out electronics. The tests done with an actual proton beam show a good agreement between the measurements and the simulations in the time domain. Supported by National Natural Science Foundation of China (11405240) and “Western Light” Talents Training Program of Chinese Academy of Sciences

  15. Radiobiological study by using laser-driven proton beams

    SciTech Connect

    Yogo, A.; Nishikino, M.; Mori, M.; Ogura, K.; Sagisaka, A.; Orimo, S.; Nishiuchi, M.; Pirozhkov, A. S.; Ikegami, M.; Tampo, M.; Sakaki, H.; Suzuki, M.; Daito, I.; Kiriyama, H.; Okada, H.; Kanazawa, S.; Kondo, S.; Shimomura, T.; Nakai, Y.; Kawachi, T.

    2009-07-25

    Particle acceleration driven by high-intensity laser systems is widely attracting interest as a potential alternative to conventional ion acceleration, including ion accelerator applications to tumor therapy. Recent works have shown that a high intensity laser pulse can produce single proton bunches of a high current and a short pulse duration. This unique feature of laser-ion acceleration can lead to progress in the development of novel ion sources. However, there has been no experimental study of the biological effects of laser-driven ion beams. We describe in this report the first demonstrated irradiation effect of laser-accelerated protons on human lung cancer cells. In-vitro A549 cells are irradiated with a proton dose of 20 Gy, resulting in a distinct formation of gamma-H2AX foci as an indicator of DNA double-strand breaks. This is a pioneering result that points to future investigations of the radiobiological effects of laser-driven ion beams. The laser-driven ion beam is apotential excitation source for time-resolved determination of hydroxyl (OH) radical yield, which will explore relationship between the fundamental chemical reactions of radiation effects and consequent biological processes.

  16. Radiobiological study by using laser-driven proton beams

    NASA Astrophysics Data System (ADS)

    Yogo, A.; Sato, K.; Nishikino, M.; Mori, M.; Teshima, T.; Numasaki, H.; Murakami, M.; Demizu, Y.; Akagi, S.; Nagayama, S.; Ogura, K.; Sagisaka, A.; Orimo, S.; Nishiuchi, M.; Pirozhkov, A. S.; Ikegami, M.; Tampo, M.; Sakaki, H.; Suzuki, M.; Daito, I.; Oishi, Y.; Sugiyama, H.; Kiriyama, H.; Okada, H.; Kanazawa, S.; Kondo, S.; Shimomura, T.; Nakai, Y.; Tanoue, M.; Sugiyama, H.; Sasao, H.; Wakai, D.; Kawachi, T.; Nishimura, H.; Bolton, P. R.; Daido, H.

    2009-07-01

    Particle acceleration driven by high-intensity laser systems is widely attracting interest as a potential alternative to conventional ion acceleration, including ion accelerator applications to tumor therapy. Recent works have shown that a high intensity laser pulse can produce single proton bunches of a high current and a short pulse duration. This unique feature of laser-ion acceleration can lead to progress in the development of novel ion sources. However, there has been no experimental study of the biological effects of laser-driven ion beams. We describe in this report the first demonstrated irradiation effect of laser-accelerated protons on human lung cancer cells. In-vitro A549 cells are irradiated with a proton dose of 20 Gy, resulting in a distinct formation of γ-H2AX foci as an indicator of DNA double-strand breaks. This is a pioneering result that points to future investigations of the radiobiological effects of laser-driven ion beams. The laser-driven ion beam is apotential excitation source for time-resolved determination of hydroxyl (OH) radical yield, which will explore relationship between the fundamental chemical reactions of radiation effects and consequent biological processes.

  17. Proton beam writing of submicrometer structures at LIPSION

    NASA Astrophysics Data System (ADS)

    Menzel, F.; Spemann, D.; Petriconi, S.; Lenzner, J.; Butz, T.

    2007-07-01

    We report on the current status of proton beam writing (PBW) at LIPSION. At present, minimal feature sizes of 130 nm were obtained in SU-8. For this purpose 10 μm thick SU-8 was irradiated with 2.25 MeV protons under STIM conditions (˜1 fA) using a dedicated scan program. These structures have an aspect ratio of 77. However, artefacts from beam spot fluctuations and instabilities due to their large height are noticeable. Furthermore, Ni grids of different sizes and pitches were produced by electroplating. The corresponding templates were written in a negative resist called ma-N 440, which can be removed much more easily compared to SU-8 after the plating step and therefore offers the advantage of a large area Ni grow and a better control of the plating current density. This results in a higher quality concerning the homogeneity of the Ni-layer. In addition, an experimental setup for the electrochemical etching of silicon was constructed and Si structures were created by proton beam writing of Si, reaching minimal lateral dimensions of 1.2 μm.

  18. Beam optics of the 2 MeV proton injection line at the LLUMC proton accelerator

    NASA Astrophysics Data System (ADS)

    Coutrakon, G.; Hubbard, J.; Sanders, E.

    2005-12-01

    Simulations of the beam optics of the LLUMC proton accelerator injection line have been modeled using the computer codes Parmila [Los Alamos Nat'l Lab, Internal Report LA-UR-98-4478, Los Alamos Accelerator Code Group, Los Alamos, NM] and Trace 3D [Distributed by AccelSoft Inc, P.O. Box 2813. Del Mar, CA 92014, United States]. These simulations give reasonable agreement with the known accelerator dispersion, beam energy spread and optimal debuncher setting. The purpose of this paper is to understand the beam losses and show where improvements can be made, if required, in the future. It has previously been found [G. Coutrakon et al., J. Med. Phys. 20 (11) (1994) 1691] that most intensity losses in the synchrotron can be ascribed to the narrow energy acceptance of the synchrotron. While the present intensity of the accelerator is quite adequate for patient treatments, future plans to treat larger fields will make higher intensity more desirable. A simulation has been performed which adds a second debuncher, or energy compactor, which shows a reduction in energy spread by a factor of two yielding a factor of two increase in the available intensity. The present intensity of 2.5 × 1010 protons per pulse with 34% of the injected intensity captured in the ring can possibly be improved to 5 × 1010 protons per pulse by capturing 68% of the injected beam intensity. These results are discussed in this paper.

  19. Production of high-brightness CW proton beams with very high proton fractions

    SciTech Connect

    Spence, D.; McMichael, G.; Lykke, K.R.; Schneider, J.D.; Sherman, J.; Stevens, R. Jr.; Hodgkins, D.

    1995-12-01

    This paper demonstrates a new technique to significantly enhance the proton fraction of an ion beam extracted from a plasma ion source. We employ a magnetically confined microwave driven source, though the technique is not source-specific and can probably be applied equally effectively to other plasma sources such as Penning and multicusp types. Specifically, we dope the plasma with about 1% H{sub 2}O, which increases the proton fraction of a 45 keV 45 mA beam from 75 to 90% with 375W 2.45 GHz power to the source and from 84% to 92% for 500W when the source is operated under nonresonant conditions. Much of the remaining fraction of the beam comprises a heavy mass ion we believe to be N{sup +} impurity ions resulting from the conditions under which the experiments were performed. If so, this impurity can be easily removed and much higher proton fractions could be expected. Preliminary measurements show the additive has no adverse effect on the emittance of the extracted beam, and source stability is greatly improved.

  20. Report of the Snowmass T4 working group on particle sources: Positron sources, anti-proton sources and secondary beams

    SciTech Connect

    N. Mokhov et al.

    2002-12-05

    This report documents the activities of the Snowmass 2001 T4 Particle Sources Working Group. T4 was charged with examining the most challenging aspects of positron sources for linear colliders and antiproton sources for proton-antiproton colliders, and the secondary beams of interest to the physics community that will be available from the next generation of high-energy particle accelerators. The leading issues, limiting technologies, and most important R and D efforts of positron production, antiproton production, and secondary beams are discussed in this paper. A listing of T4 Presentations is included.

  1. Direct-current proton-beam measurements at Los Alamos

    SciTech Connect

    Sherman, Joseph; Stevens, Ralph R.; Schneider, J. David; Zaugg, Thomas

    1995-09-15

    Recently, a CW proton accelerator complex was moved from Chalk River Laboratories (CRL) to Los Alamos National Laboratory. This includes a 50-keV dc proton injector with a single-solenoid low-energy beam transport system (LEBT) and a CW 1.25-MeV, 267-MHz radiofrequency quadrupole (RFQ). The move was completed after CRL had achieved 55-mA CW operation at 1.25 MeV using 250-kW klystrode tubes to power the RFQ. These accelerator components are prototypes for the front end of a CW linac required for an accelerator-driven transmutation linac, and they provide early confirmation of some CW accelerator components. The injector (ion source and LEBT) and emittance measuring unit are installed and operational at Los Alamos. The dc microwave ion source has been operated routinely at 50-keV, 75-mA hydrogen-ion current. This ion source has demonstrated very good discharge and H2 gas efficiencies, and sufficient reliability to complete CW RFQ measurements at CRL. Proton fraction of 75% has been measured with 550-W discharge power. This high proton fraction removes the need for an analyzing magnet. Proton LEBT emittance measurements completed at Los Alamos suggest that improved transmission through the RFQ may be achieved by increasing the solenoid focusing current. Status of the final CW RFQ operation at CRL and the installation of the RFQ at Los Alamos will be given.

  2. Direct-current proton-beam measurements at Los Alamos

    SciTech Connect

    Sherman, J.; Stevens, R.R.; Schneider, J.D.; Zaugg, T.

    1994-08-01

    Recently, a CW proton accelerator complex was moved from Chalk River Laboratories (CRL) to Los Alamos National Laboratory. This includes a 50-keV dc proton injector with a single-solenoid low-energy beam transport system (LEBT) and a CW 1.25-MeV, 267-MHz radiofrequency quadrupole (RFQ). The move was completed after CRL had achieved 55-mA CW operation at 1.25 MeV using 250-kW klystrode tubes to power the RFQ. These accelerator components are prototypes for the front end of a CW linac required for an accelerator-driven transmutation linac, and they provide early confirmation of some CW accelerator components. The injector (ion source and LEBT) and emittance measuring unit are installed and operational at Los Alamos. The dc microwave ion source has been operated routinely at 50-keV, 75-mA hydrogen-ion current. This ion source has demonstrated very good discharge and H{sub 2} gas efficiencies, and sufficient reliability to complete CW RFQ measurements at CRL. Proton fraction of 75% has been measured with 550-W discharge power. This high proton fraction removes the need for an analyzing magnet. Proton LEBT emittance measurements completed at Los Alamos suggest that improved transmission through the RFQ may be achieved by increasing the solenoid focusing current. Status of the final CW RFQ operation at CRL and the installation of the RFQ at Los Alamos is given.

  3. EMERGING TECHNOLOGY BULLETIN: REMOVAL OF PHENOL FROM AQUEOUS SOLUTIONS USING HIGH ENERGY ELECTRON BEAM IRRADIATION

    EPA Science Inventory

    Irradiation of aqueous solutions with high-energy electrons results in the formation of the aqueous electron, hydrogen radical, H-, and the hydroxyl radical, OH-. These reactive transient species initiate chemical reactions capable of destroying organic compounds in aqueous solut...

  4. Preplasma effects on the generation of high-energy protons in ultraintense laser interaction with foil targets

    SciTech Connect

    Zheng, F. L.; Huang, T. W.; Wu, S. Z.; Zhang, H.; He, X. T.; Institute of Applied Physics and Computational Mathematics, Beijing 100088 ; Yu, M. Y.; Institut für Theoretische Physik I, Ruhr-Universität Bochum, D-44780 Bochum ; Zhou, C. T.; Institute of Applied Physics and Computational Mathematics, Beijing 100088; Science College, National University of Defense Technology, Changsha 410073

    2013-12-15

    It is shown that the intense quasistatic electric and magnetic fields self-generated near the axis of the laser-driven channel in an appropriately profiled preplasma during ultraintense laser interaction with a thin target can create dense relativistic electron bunches. The latter easily penetrate through the target and can greatly enhance the sheath field at the rear, resulting in significant increase in the laser-to-ion energy conversion efficiency and the maximum energy of the target normal sheath accelerated ions. Particle-in-cell simulations show that with a hydrogen targets a proton beam of peak energy ∼38 MeV and energy conversion efficiency ≥6.5% can be produced by a linearly polarized 5 × 10{sup 19} W/cm{sup 2} laser. An analytical model is also proposed and its results agree well with those of the simulations.

  5. Preplasma effects on the generation of high-energy protons in ultraintense laser interaction with foil targets

    NASA Astrophysics Data System (ADS)

    Zheng, F. L.; Wu, S. Z.; Zhang, H.; Huang, T. W.; Yu, M. Y.; Zhou, C. T.; He, X. T.

    2013-12-01

    It is shown that the intense quasistatic electric and magnetic fields self-generated near the axis of the laser-driven channel in an appropriately profiled preplasma during ultraintense laser interaction with a thin target can create dense relativistic electron bunches. The latter easily penetrate through the target and can greatly enhance the sheath field at the rear, resulting in significant increase in the laser-to-ion energy conversion efficiency and the maximum energy of the target normal sheath accelerated ions. Particle-in-cell simulations show that with a hydrogen targets a proton beam of peak energy ˜38 MeV and energy conversion efficiency ≥6.5% can be produced by a linearly polarized 5 × 1019 W/cm2 laser. An analytical model is also proposed and its results agree well with those of the simulations.

  6. Beam tube vacuum in future superconducting proton colliders

    SciTech Connect

    Turner, W.

    1994-10-01

    The beam tube vacuum requirements in future superconducting proton colliders that have been proposed or discussed in the literature -- SSC, LHC, and ELN -- are reviewed. The main beam tube vacuum problem encountered in these machines is how to deal with the magnitude of gas desorption and power deposition by synchrotron radiation while satisfying resistivity, impedance, and space constraints in the cryogenic environment of superconducting magnets. A beam tube vacuum model is developed that treats photodesorption of tightly bound H, C, and 0, photodesorption of physisorbed molecules, and the isotherm vapor pressure of H{sub 2}. Experimental data on cold tube photodesorption experiments are reviewed and applied to model calculations of beam tube vacuum performance for simple cold beam tube and liner configurations. Particular emphasis is placed on the modeling and interpretation of beam tube photodesorpiion experiments at electron synchrotron light sources. The paper also includes discussion of the constraints imposed by beam image current heating, the growth rate of the resistive wall instability, and single-bunch instability impedance limits.

  7. Beam tube vacuum in future superconducting proton colliders

    NASA Astrophysics Data System (ADS)

    Turner, William C.

    1995-02-01

    The beam tube vacuum requirements in future superconducting proton colliders that have been proposed or discussed in the literature—SSC, LHC, and ELN—are reviewed. The main beam tube vacuum problem encountered in these machines is how to deal with the magnitude of gas desorption and power deposition by synchrotron radiation while satisfying resistivity, impedance, and space constraints in the cryogenic environment of superconducting magnets. A beam tube vacuum model is developed that treats photodesorption of tightly bound H, C, and O, photodesorption of physisorbed molecules, and the isotherm vapor pressure of H2. Experimental data on cold tube photodesorption experiments are reviewed and applied to model calculations of beam tube vacuum performance for simple cold beam tube and liner configurations. Particular emphasis is placed on the modeling and interpretation of beam tube photodesorption experiments at electron synchrotron light sources. The paper also includes discussion of the constraints imposed by beam image current heating, the growth rate of the resistive wall instability, and single-bunch instability impedance limits.

  8. Macro Monte Carlo for dose calculation of proton beams.

    PubMed

    Fix, Michael K; Frei, Daniel; Volken, Werner; Born, Ernst J; Aebersold, Daniel M; Manser, Peter

    2013-04-01

    Although the Monte Carlo (MC) method allows accurate dose calculation for proton radiotherapy, its usage is limited due to long computing time. In order to gain efficiency, a new macro MC (MMC) technique for proton dose calculations has been developed. The basic principle of the MMC transport is a local to global MC approach. The local simulations using GEANT4 consist of mono-energetic proton pencil beams impinging perpendicularly on slabs of different thicknesses and different materials (water, air, lung, adipose, muscle, spongiosa, cortical bone). During the local simulation multiple scattering, ionization as well as elastic and inelastic interactions have been taken into account and the physical characteristics such as lateral displacement, direction distributions and energy loss have been scored for primary and secondary particles. The scored data from appropriate slabs is then used for the stepwise transport of the protons in the MMC simulation while calculating the energy loss along the path between entrance and exit position. Additionally, based on local simulations the radiation transport of neutrons and the generated ions are included into the MMC simulations for the dose calculations. In order to validate the MMC transport, calculated dose distributions using the MMC transport and GEANT4 have been compared for different mono-energetic proton pencil beams impinging on different phantoms including homogeneous and inhomogeneous situations as well as on a patient CT scan. The agreement of calculated integral depth dose curves is better than 1% or 1 mm for all pencil beams and phantoms considered. For the dose profiles the agreement is within 1% or 1 mm in all phantoms for all energies and depths. The comparison of the dose distribution calculated using either GEANT4 or MMC in the patient also shows an agreement of within 1% or 1 mm. The efficiency of MMC is up to 200 times higher than for GEANT4. The very good level of agreement in the dose comparisons

  9. Macro Monte Carlo for dose calculation of proton beams

    NASA Astrophysics Data System (ADS)

    Fix, Michael K.; Frei, Daniel; Volken, Werner; Born, Ernst J.; Aebersold, Daniel M.; Manser, Peter

    2013-04-01

    Although the Monte Carlo (MC) method allows accurate dose calculation for proton radiotherapy, its usage is limited due to long computing time. In order to gain efficiency, a new macro MC (MMC) technique for proton dose calculations has been developed. The basic principle of the MMC transport is a local to global MC approach. The local simulations using GEANT4 consist of mono-energetic proton pencil beams impinging perpendicularly on slabs of different thicknesses and different materials (water, air, lung, adipose, muscle, spongiosa, cortical bone). During the local simulation multiple scattering, ionization as well as elastic and inelastic interactions have been taken into account and the physical characteristics such as lateral displacement, direction distributions and energy loss have been scored for primary and secondary particles. The scored data from appropriate slabs is then used for the stepwise transport of the protons in the MMC simulation while calculating the energy loss along the path between entrance and exit position. Additionally, based on local simulations the radiation transport of neutrons and the generated ions are included into the MMC simulations for the dose calculations. In order to validate the MMC transport, calculated dose distributions using the MMC transport and GEANT4 have been compared for different mono-energetic proton pencil beams impinging on different phantoms including homogeneous and inhomogeneous situations as well as on a patient CT scan. The agreement of calculated integral depth dose curves is better than 1% or 1 mm for all pencil beams and phantoms considered. For the dose profiles the agreement is within 1% or 1 mm in all phantoms for all energies and depths. The comparison of the dose distribution calculated using either GEANT4 or MMC in the patient also shows an agreement of within 1% or 1 mm. The efficiency of MMC is up to 200 times higher than for GEANT4. The very good level of agreement in the dose comparisons

  10. High-energy negative ion beam obtained from pulsed inductively coupled plasma for charge-free etching process

    NASA Astrophysics Data System (ADS)

    Vozniy, O. V.; Yeom, G. Y.

    2009-06-01

    Negative ions in conventional inductively coupled plasma are often more chemically active than positive ions (for example, in CF4 or SF6 plasmas), but inconveniently they are trapped inside the sheath and cannot be used for high-energy surface etching in sources with a grid-type acceleration system. In this work we describe a method of positive and negative ion extraction that allows the energy and flux of oppositely charged particles to be varied independently. Then by scattering the ions off from a metal surface, it is possible to form a high-energy beam of neutrals from the negative ions by using the low-energy positive component of the beam current for better charge compensation.

  11. Dose error analysis for a scanned proton beam delivery system.

    PubMed

    Coutrakon, G; Wang, N; Miller, D W; Yang, Y

    2010-12-01

    All particle beam scanning systems are subject to dose delivery errors due to errors in position, energy and intensity of the delivered beam. In addition, finite scan speeds, beam spill non-uniformities, and delays in detector, detector electronics and magnet responses will all contribute errors in delivery. In this paper, we present dose errors for an 8 × 10 × 8 cm(3) target of uniform water equivalent density with 8 cm spread out Bragg peak and a prescribed dose of 2 Gy. Lower doses are also analyzed and presented later in the paper. Beam energy errors and errors due to limitations of scanning system hardware have been included in the analysis. By using Gaussian shaped pencil beams derived from measurements in the research room of the James M Slater Proton Treatment and Research Center at Loma Linda, CA and executing treatment simulations multiple times, statistical dose errors have been calculated in each 2.5 mm cubic voxel in the target. These errors were calculated by delivering multiple treatments to the same volume and calculating the rms variation in delivered dose at each voxel in the target. The variations in dose were the result of random beam delivery errors such as proton energy, spot position and intensity fluctuations. The results show that with reasonable assumptions of random beam delivery errors, the spot scanning technique yielded an rms dose error in each voxel less than 2% or 3% of the 2 Gy prescribed dose. These calculated errors are within acceptable clinical limits for radiation therapy. PMID:21076200

  12. Nonlinear optical beam manipulation and high energy beam propagation through the atmosphere; Proceedings of the Meeting, Los Angeles, CA, Jan. 18-20, 1989

    NASA Astrophysics Data System (ADS)

    Fisher, Robert A.; Wilson, Leroy E.

    Various papers on nonlinear optical beam manipulation and high-energy beam propagation through the atmosphere are presented. Individual topics addressed include: suppression of Raman amplification using large Stokes seeds, review of multiple-short-pulse SBS experiments and theory, laser-induced gratings for beam manipulation in a gas, considerations for computing realistic atmospheric distortion parameter profiles, effect of turbulent diffusion on laser propagation, use of multiple photon processes in krypton for laser guiding of electron beams, effect of ionization on intense electron beam propagation in low-pressure media, lidar measurements of the troposphere and middle atmosphere, seasonal and diurnal changes in cloud obscuration to visible and IR energy transmission, new cloud composite climatologies using meteorological satellite imagery, effect of neutral atmospheric structure on beam propagation, small-scale electron density fluctuations in a disturbed ionospheric environment, and SDIO radio frequency communications in a structured environment.

  13. Reflection high-energy electron diffraction beam-induced structural and property changes on WO{sub 3} thin films

    SciTech Connect

    Du, Y. Varga, T.; Zhang, K. H. L.; Chambers, S. A.

    2014-08-04

    Reduction of transition metal oxides can greatly change their physical and chemical properties. Using deposition of WO{sub 3} as a case study, we demonstrate that reflection high-energy electron diffraction (RHEED), a surface-sensitive tool widely used to monitor thin-film deposition processes, can significantly affect the cation valence and physical properties of the films through electron-beam induced sample reduction. The RHEED beam is found to increase film smoothness during epitaxial growth of WO{sub 3}, as well as change the electronic properties of the film through preferential removal of surface oxygen.

  14. Reflection High-Energy Electron Diffraction Beam-Induced Structural and Property Changes on WO3 Thin Films

    SciTech Connect

    Du, Yingge; Zhang, Hongliang; Varga, Tamas; Chambers, Scott A.

    2014-08-08

    Reduction of transition metal oxides can greatly change their physical and chemical properties. Using deposition of WO3 as a case study, we demonstrate that reflection high-energy electron diffraction (RHEED), a surface-sensitive tool widely used to monitor thin-film deposition processes, can significantly affect the cation valence and physical properties of the films through electron-beam induced sample reduction. The RHEED beam is found to increase film smoothness during epitaxial growth of WO3, as well as change the electronic properties of the film through preferential removal of surface oxygen.

  15. Study of the heating of tokamaks by high energy ion beams. Quarterly report, September 29, 1980-December 31, 1980

    SciTech Connect

    Drummond, W.E.

    1981-01-01

    This research program encompasses a number of design studies for a steady state (or long pulse) Auto-Resonant Accelerator (ARA) capable of producing intense beams of high energy ions suitable for the heating of large tokamak devices. The different research topics addressed therefore range over a number of questions related to the design of the individual elements of the accelerator itself, but they include, as well, studies of the transport of the ion beam from the accelerator to the tokamak, and the injection and stripping of these ions in the tokamak and their subsequent energy deposition in the tokamak plasma.

  16. High energy accelerator and colliding beam user group. Progress report, March 1, 1983-February 29, 1984

    SciTech Connect

    Not Available

    1983-01-01

    Topics covered in this research summary include: status of the OPAL collaboration at LEP, CERN; two-photon physics at PLUTO; search for new particles at JADE; neutrinoless double beta decay at DESY; Fermilab jet experiment; neutrino deuterium experiment in the 15 foot bubble chamber at Fermilab; deep inelastic muon experiment at Fermilab; new experiments at the proton-antiproton collider; neutrino-electron scattering at Los Alamos; parity violation in proton-proton scattering; an upgrade of laboratory and computer facilities; and a study of bismuth germanate as a durable scintillation crystal. (GHT)

  17. High energy micro electron beam generation using chirped laser pulse in the presence of an axial magnetic field

    SciTech Connect

    Akou, H. Hamedi, M.

    2015-10-15

    In this paper, the generation of high-quality and high-energy micro electron beam in vacuum by a chirped Gaussian laser pulse in the presence of an axial magnetic field is numerically investigated. The features of energy and angular spectra, emittances, and position distribution of electron beam are compared in two cases, i.e., in the presence and absence of an external magnetic field. The electron beam is accelerated with higher energy and qualified in spatial distribution in the presence of the magnetic field. The presence of an axial magnetic field improves electron beam spatial quality as well as its gained energy through keeping the electron motion parallel to the direction of propagation for longer distances. It has been found that a 64 μm electron bunch with about MeV initial energy becomes a 20 μm electron beam with high energy of the order of GeV, after interacting with a laser pulse in the presence of an external magnetic field.

  18. Proton Beam Therapy for Hepatocellular Carcinoma Located Adjacent to the Alimentary Tract;Proton beam therapy; Hepatocellular carcinoma; Gastrointestinal bleeding

    SciTech Connect

    Nakayama, Hidetsugu; Sugahara, Shinji; Fukuda, Kuniaki; Abei, Masato; Shoda, Junichi; Sakurai, Hideyuki; Tsuboi, Koji; Matsuzaki, Yasushi; Tokuuye, Koichi

    2011-07-15

    Purpose: To evaluate the safety and effectiveness of proton beam therapy for hepatocellular carcinoma (HCC) located adjacent to the alimentary tract. Patients and Methods: Forty-seven patients (median age, 69 years; range, 43-82 years) who had HCC located within 2 cm of the alimentary tract underwent proton beam therapy. Liver damage according to the Child-Pugh classification was Class A in 35 patients, Class B in 9, and Class C in 3. Treatment protocols of the early 16 patients and the late 31 patients were 72.6 GyE in 22 fractions and 77 GyE in 35 fractions, respectively. Results: During the median follow-up period of 23 months, 24 patients died; the remaining 23 patients were alive until September 2008. The median overall survival was 33.9 months (95% confidence interval [CI], 10.8-57.0 months). Actuarial overall and local progression-free survival rates at 3 years were 50.0% and 88.1%, respectively. Grade 2 and 3 alimentary tract hemorrhage was observed in 3 (6.4%) and 1 (2.1%) patients, respectively. Conclusions: Our proton beam therapy strategy for HCC located adjacent to the alimentary tract seems to be effective but should be performed with caution.

  19. An MCNPX Monte Carlo model of a discrete spot scanning proton beam therapy nozzle

    SciTech Connect

    Sawakuchi, Gabriel O.; Mirkovic, Dragan; Perles, Luis A.; Sahoo, Narayan; Zhu, X. Ron; Ciangaru, George; Suzuki, Kazumichi; Gillin, Michael T.; Mohan, Radhe; Titt, Uwe

    2010-09-15

    Purpose: The purposes of this study were to validate a discrete spot scanning proton beam nozzle using the Monte Carlo (MC) code MCNPX and use the MC validated model to investigate the effects of a low-dose envelope, which surrounds the beam's central axis, on measurements of integral depth dose (IDD) profiles. Methods: An accurate model of the discrete spot scanning beam nozzle from The University of Texas M. D. Anderson Cancer Center (Houston, Texas) was developed on the basis of blueprints provided by the manufacturer of the nozzle. The authors performed simulations of single proton pencil beams of various energies using the standard multiple Coulomb scattering (MCS) algorithm within the MCNPX source code and a new MCS algorithm, which was implemented in the MCNPX source code. The MC models were validated by comparing calculated in-air and in-water lateral profiles and percentage depth dose profiles for single pencil beams with their corresponding measured values. The models were then further tested by comparing the calculated and measured three-dimensional (3-D) dose distributions. Finally, an IDD profile was calculated with different scoring radii to determine the limitations on the use of commercially available plane-parallel ionization chambers to measure IDD. Results: The distance to agreement, defined as the distance between the nearest positions of two equivalent distributions with the same value of dose, between measured and simulated ranges was within 0.13 cm for both MCS algorithms. For low and intermediate pencil beam energies, the MC simulations using the standard MCS algorithm were in better agreement with measurements. Conversely, the new MCS algorithm produced better results for high-energy single pencil beams. The IDD profile calculated with cylindrical tallies with an area equivalent to the area of the largest commercially available ionization chamber showed up to 7.8% underestimation of the integral dose in certain depths of the IDD profile

  20. Beam profile measurement and evaluation of far field high energy laser

    NASA Astrophysics Data System (ADS)

    Yang, Pengling; Feng, Guobin; Wang, Zhenbao; Wang, Ping; Wu, Yong; Zhang, Jianmin; Cheng, Shaowu; Feng, Gang; Wang, Fei; Shao, Bibo

    2015-05-01

    The far field beam profile is of significant importance to the analysis of the atmospheric propagation effect and evaluation of the beam control capability, tracking and aiming precision of laser system. In the paper, technology of laser beam measurement such as mid-infrared laser detection at wide temperature range, power density attenuation, photoelectric and calorimetric compound method for laser measurement, synchronous detecting of multi-channel pulsed signal are introduced. A series of instrumented target with detector array are developed for laser beam power density distribution measurement at far field. The power in the bucket, strehl ratio, centroid and jitter of beam can be calculated from the measured results.

  1. Adventures in Gaseous Positronics - An Ultra-High-Energy-Resolution Cryogenic Beam

    NASA Astrophysics Data System (ADS)

    Natisin, Mike

    2016-05-01

    While positron interactions with matter are important in a variety of contexts, many important experiments have been inhibited due to the difficulties encountered in creating beams with narrow energy spreads. This talk focuses on the development of a pulsed positron beam with a total energy spread of 7 meV FWHM; this represents a factor of five improvement over the previous state-of-the-art. Current positron atomic physics experiments rely on high quality beams from buffer gas traps. Although widely used, the physical phenomena operative in beam formation had not previously been fully investigated, and understanding these processes proved crucial to improving beam quality. Experimental measurements and simulation results of positron cooling and beam formation are discussed, with an emphasis on beam energy resolution. Using these results, a new cryogenic, trap-based beam system was built. Positrons are cooled to 50 K using a CO buffer gas, resulting in beams with total energy spreads as low as 6.9 meV FWHM, sub-microsecond temporal spreads and beam diameters as small as 1 mm. Details of this beam system, as well as new experiments that will be enabled by it, will be discussed. Work supported by NSF Grant PHY-1401794.

  2. Dose rate and beam profile measurement of proton beam using a flat panel detector

    NASA Astrophysics Data System (ADS)

    Park, Jeong-Min

    2015-10-01

    A 20-MeV or 100-MeV proton beam is provided to users for their proton beam irradiation experiments at KOrea Multi-Purpose Accelerator Complex. Radiochromic film (Gafchromic / HDV2) has been used to measure the dose rate and the profile of an incident proton beam during irradiation experiments. However, such measurements using radiochromic film have some inconveniences because an additional scanning process of is required to quantify the film's image. Therefore, we tried to measure the dose rate and beam profile by using a flat panel detector (FPD), which was developed for X-ray radiography as a substitute for radiochromic film because the FPD can measure the beam profile and the dose rate directly through a digitized image with a high spatial resolution. In this work, we investigated the feasibility of using a FPD as a substitute for radiochromic film. The preliminary results for the beam profile and the dose rate measured by using the flat panel detector are reported in the paper.

  3. Quenching correction for volumetric scintillation dosimetry of proton beams

    PubMed Central

    Robertson, Daniel; Mirkovic, Dragan; Sahoo, Narayan; Beddar, Sam

    2013-01-01

    Purpose Volumetric scintillation dosimetry has the potential to provide fast, high-resolution, three-dimensional radiation dosimetry. However, scintillators exhibit a nonlinear response at the high linear energy transfer (LET) values characteristic of proton Bragg peaks. The purpose of this study was to develop a quenching correction method for volumetric scintillation dosimetry of proton beams. Methods Scintillation light from a miniature liquid scintillator detector was measured along the central axis of a 161.6-MeV proton pencil beam. Three-dimensional dose and LET distributions were calculated for 85.6-, 100.9-, 144.9-, and 161.6-MeV beams using a validated Monte Carlo model. LET values were also calculated using an analytical formula. A least-squares fit to the data established the empirical parameters of a quenching correction model. The light distribution in a tank of liquid scintillator was measured with a CCD camera at all four beam energies. The quenching model and LET data were used to correct the measured light distribution. Results The calculated and measured Bragg peak heights agreed within ±3% for all energies except 85.6 MeV, where the agreement was within ±10%. The quality of the quenching correction was poorer for sharp low-energy Bragg peaks because of blurring and detector size effects. The corrections performed using analytical LET values resulted in doses within 1% of those obtained using Monte Carlo LET values. Conclusion The proposed method can correct for quenching with sufficient accuracy for dosimetric purposes. The required LET values may be computed effectively using Monte Carlo or analytical methods. Future detectors should improve blurring correction methods and optimize the pixel size to improve accuracy for low-energy Bragg peaks. PMID:23257200

  4. Resist materials for proton beam writing: A review

    NASA Astrophysics Data System (ADS)

    van Kan, J. A.; Malar, P.; Wang, Y. H.

    2014-08-01

    Proton beam writing (PBW) is a lithographic technique that has been developed since the mid 1990s, initially in Singapore followed by several groups around the world. MeV protons while penetrating materials will maintain a practically straight path. During the continued slowing down of a proton in material it will mainly interact with substrate electrons and transfer a small amount of energy to each electron, the induced secondary electrons will modify the molecular structure of resist within a few nanometers around the proton track. The recent demonstration of high aspect ratio sub 20 nm lithography in HSQ shows the potential of PBW. To explore the full capabilities of PBW, the understanding of the interaction of fast protons with different resist materials is important. Here we give an update of the growing number of resist materials that have been evaluated for PBW. In particular we evaluate the exposure and development strategies for the most promising resist materials like PMMA, HSQ, SU-8 and AR-P and compare their characteristics with respect to properties such as contrast and sensitivity. Besides an updated literature survey we also present new findings on AR-P and PMGI resists. Since PBW is a direct write technology it is important to look for fast ways to replicate micro and nanostructures. In this respect we will discuss the suitability and performance of several resists for Ni electroplating for mold fabrication in nano imprint technologies. We will summarize with an overview of proton resist characteristics like sensitivity, contrast, aspect ratio and suitability for electroplating.

  5. Modern applications of high energy ion beams: From "single-event burnout" to human eye cancer treatment

    NASA Astrophysics Data System (ADS)

    Homeyer, H.; Mahnke, H.-E.

    1996-12-01

    Energetic ion beams, originally the domain of nuclear physics, become increasingly important tools in many other fields of research and development. The choice of ion species and ion energy allows an enormously wide variation of the penetration depth and of the amount of the electronic stopping power. These features are utilized to modify or damage materials and living tissues in a specific way. Materials modification with energetic ion beams is one of the central aims of research and development at the ion beam laboratory, ISL-Berlin, a center for ion-beam applications at the Hahn-Meitner-Institut Berlin. In particular, energetic protons will be used for eye cancer treatment. Selected topics such as the "single-event burnout" of high power diodes and the eye cancer therapy setup will be presented in detail.

  6. Development of an efficient scanning and purging magnet system for IMRT with narrow high energy photon beams

    NASA Astrophysics Data System (ADS)

    Andreassen, Björn; Svensson, Roger; Holmberg, Rickard; Danared, Håkan; Brahme, Anders

    2009-12-01

    Due to the clinical advantages of Intensity Modulated Radiation Therapy (IMRT) high flexibility and accuracy in intensity modulated dose delivery is desirable to really maximize treatment outcome. Although it is possible to deliver IMRT by using broad beams in combination with dynamic multileaf collimation the process is rather time consuming and inefficient. By using narrow scanned high energy photon beams the treatment outcome can be improved, the treatment time reduced and accurate 3D in vivo dose delivery monitoring is possible by PET-CT based dose delivery imaging of photo nuclear reactions in human tissues. Narrow photon beams can be produced by directing a low emittance high energy electron beam on a thin target, and then cleaning the therapeutic photon beam from transmitted high energy electrons, and photon generated charged leptons, with a dedicated purging magnet placed directly downstream of the target. To have an effective scanning and purging magnet system the purging magnet should be placed immediately after the bremsstrahlung target to deflect the transmitted electrons to an efficient electron stopper. In the static electron stopper the electrons should be safely collected independent of the desired direction of the therapeutic scanned photon beam. The SID (Source to Isocenter Distance) should preferably be short while retaining the ability to scan over a large area on the patient and consequently there are severe requirements both on the strength and the geometry of the scanning and purging magnets. In the present study an efficient magnet configuration with a purging and scanning magnet assembly is developed for electron energies in the 50-75 MeV range and a SID of 75 cm. For a bremsstrahlung target of 3 mm Be these electron energies produce a photon beam of 25-17 mm FWHM (Full Width Half Maximum) at a SID of 75 cm. The magnet system was examined both in terms of the efficiency in scanning the narrow bremsstrahlung beam and the deflection of

  7. Attenuation of ambient dose equivalent from neutrons by thick concrete, cast iron and composite shields for high energy proton, 3He, 48Ca and 238U ions on Cu targets for shielding design

    NASA Astrophysics Data System (ADS)

    Iwamoto, Yosuke; Ronningen, R. M.

    2011-02-01

    Data on neutron dose attenuation by thick concrete, cast iron, and cast iron plus concrete composite shields for heavy ions and protons having high energies (200-1000 MeV/u) are necessary for shielding designs of high-powered heavy ion accelerator facilities. Neutron production source terms, shield material attenuation lengths, and neutron dose rate reduction effectiveness of the bulk shielding in the angular range from 0° to 125° were determined by the Particle and Heavy Ion Transport Code (PHITS) for beams of 300 and 550 MeV/u 48Ca ions, 200 and 400 MeV/u 238U ions, 800 MeV/u 3He and 1 GeV protons. Calculated results of interaction lengths of concrete and cast iron were also compared with similar work performed by Agosteo et al., and to experimental and other calculated data on interaction lengths. The agreement can be regarded as acceptable.

  8. LATTICES FOR HIGH-POWER PROTON BEAM ACCELERATION AND SECONDARY BEAM COLLECTION AND COOLING.

    SciTech Connect

    WANG, S.; WEI, J.; BROWN, K.; GARDNER, C.; LEE, Y.Y.; LOWENSTEIN, D.; PEGGS, S.; SIMOS, N.

    2006-06-23

    Rapid cycling synchrotrons are used to accelerate high-intensity proton beams to energies of tens of GeV for secondary beam production. After primary beam collision with a target, the secondary beam can be collected, cooled, accelerated or decelerated by ancillary synchrotrons for various applications. In this paper, we first present a lattice for the main synchrotron. This lattice has: (a) flexible momentum compaction to avoid transition and to facilitate RF gymnastics (b) long straight sections for low-loss injection, extraction, and high-efficiency collimation (c) dispersion-free straights to avoid longitudinal-transverse coupling, and (d) momentum cleaning at locations of large dispersion with missing dipoles. Then, we present a lattice for a cooler ring for the secondary beam. The momentum compaction across half of this ring is near zero, while for the other half it is normal. Thus, bad mixing is minimized while good mixing is maintained for stochastic beam cooling.

  9. A longitudinal bunch rotation and acceleration scheme for a short bunch and high energy spread muon beam

    NASA Astrophysics Data System (ADS)

    Scrivens, R.

    2000-08-01

    A neutrino factory for νμ would require a high-power proton beam bombarding a target to produce pions that decay to muons which can be accelerated. Such a proton driver could be realized with a high-power linac, which could produce short bunches in the interaction point. If the bunch structure could be maintained to the input of a linear accelerator, the re-bunching of muons would be avoided. A preliminary design of the longitidinal beam dynamics for the acceleration of short muon bunches with a large-energy spread will be presented. Muons bunches are assumed at the linac input to consist of a phase space occupying a region from 200-400 MeV with a bunch length of 24 ps. They are captured and accelerated to 1 GeV with a resulting bunch length of 100 ps. Seventy five percent of the muons are transported within these limits.

  10. Exploring the Origin of High-Energy Particle Beams in the Atmosphere

    NASA Astrophysics Data System (ADS)

    Chilingarian, Ashot A.

    2014-11-01

    High-energy processes in the magnetosphere and atmosphere such as thunderstorm ground enhancements (TGEs), terrestrial gamma ray flashes (TGFs), and transient luminous events (TLEs) and recently discovered relativistic electron acceleration in the Earth's outer radiation belt trigger various dynamic processes in the Earth's environments and have broad astrophysical relevance. Investigation of the accelerated structures in the geospace plasmas can shed light on particle acceleration to much higher energy in the similar structures of space plasmas in the most distant objects in the universe. The Earth's broad environment is a real laboratory for high-energy astrophysics.

  11. Surface, structural and tensile properties of proton beam irradiated zirconium

    NASA Astrophysics Data System (ADS)

    Rafique, Mohsin; Chae, San; Kim, Yong-Soo

    2016-02-01

    This paper reports the surface, structural and tensile properties of proton beam irradiated pure zirconium (99.8%). The Zr samples were irradiated by 3.5 MeV protons using MC-50 cyclotron accelerator at different doses ranging from 1 × 1013 to 1 × 1016 protons/cm2. Both un-irradiated and irradiated samples were characterized using Field Emission Scanning Electron Microscope (FESEM), X-ray Diffraction (XRD) and Universal Testing Machine (UTM). The average surface roughness of the specimens was determined by using Nanotech WSxM 5.0 develop 7.0 software. The FESEM results revealed the formation of bubbles, cracks and black spots on the samples' surface at different doses whereas the XRD results indicated the presence of residual stresses in the irradiated specimens. Williamson-Hall analysis of the diffraction peaks was carried out to investigate changes in crystallite size and lattice strain in the irradiated specimens. The tensile properties such as the yield stress, ultimate tensile stress and percentage elongation exhibited a decreasing trend after irradiation in general, however, an inconsistent behavior was observed in their dependence on proton dose. The changes in tensile properties of Zr were associated with the production of radiation-induced defects including bubbles, cracks, precipitates and simultaneous recovery by the thermal energy generated with the increase of irradiation dose.

  12. Shielding measurements for a 230 MeV proton beam

    SciTech Connect

    Siebers, J.V.

    1990-01-01

    Energetic secondary neutrons produced as protons interact with accelerator components and patients dominate the radiation shielding environment for proton radiotherapy facilities. Due to the scarcity of data describing neutron production, attenuation, absorbed dose, and dose equivalent values, these parameters were measured for 230 MeV proton bombardment of stopping length Al, Fe, and Pb targets at emission angles of 0{degree}, 22{degree}, 45{degree}, and 90{degree} in a thick concrete shield. Low pressure tissue-equivalent proportional counters with volumes ranging from 1 cm{sup 3} to 1000 cm{sup 3} were used to obtain microdosimetric spectra from which absorbed dose and radiation quality are deduced. Does equivalent values and attenuation lengths determined at depth in the shield were found to vary sharply with angle, but were found to be independent of target material. Neutron dose and radiation length values are compared with Monte Carlo neutron transport calculations performed using the Los Alamos High Energy Transport Code (LAHET). Calculations used 230 MeV protons incident upon an Fe target in a shielding geometry similar to that used in the experiment. LAHET calculations overestimated measured attenuation values at 0{degree}, 22{degree}, and 45{degree}, yet correctly predicted the attenuation length at 90{degree}. Comparison of the mean radiation quality estimated with the Monte Carlo calculations with measurements suggest that neutron quality factors should be increased by a factor of 1.4. These results are useful for the shielding design of new facilities as well as for testing neutron production and transport calculations.

  13. Dynamics of R.F. Captured Electron Cooled Proton Beams

    SciTech Connect

    Kells, W.; Mills, F.;

    1983-01-01

    In the course of electron cooling experiments at the Electron Cooling Ring (ECR) at Fermilab, several peculiar features of the longitudinal phase space of cold protons (200 MeV) captured in R.F. buckets were observed. Here we present the experimental facts, present a simple theory, and summarize computer simulation results which support the theory and facts. The experimental apparatus and measurement techniques have been described elsewhere. R.F. bunching was achieved with a single PPA, loaded cavity gap driven at harmonic number 6({approx} 7.56 MHz) of the revolution frequency. R.F. voltage could be developed across this gap sufficient to entirely capture even the uncooled circulating proton beam ({delta}p/p FWHM = 0.17%).

  14. Reactions induced by beams of neutron and proton halo nuclei

    NASA Astrophysics Data System (ADS)

    Penionzhkevich, Yu. E.

    1997-02-01

    Within the collaboration Dubna-GANIL (Caen, France) - IPN (Orsay, France) - NPI (Rez, Czech Republic) - IAP (Bucharest, Romania) at GANIL and the Dubna U400M accelerator, experiments have been carried out to study elastic scattering, fusion and fission using secondary ion beams of 6He, 11Li and 8B. The fission cross-section for the 6He isotopes has been found to be significantly higher than for the 4He nuclei. This enhancement depends mainly on the entrance channel and it is connected with the neutron skin of the 6He nuclei. Also, investigation of the elastic scattering of 11Li (neutron halo), 7Be and 8B (proton halo) has been performed. The microscopic analysis supports the existence of a neutron halo in 11Li and the proton skin in 8B and 7Be. Perspectives for investigations in this field at the Laboratory of Nuclear Reactions JINR are also discussed.

  15. SQUID-based beam position monitoring for proton EDM experiment

    NASA Astrophysics Data System (ADS)

    Haciomeroglu, Selcuk

    2014-09-01

    One of the major systematic errors in the proton EDM experiment is the radial B-field, since it couples the magnetic dipole moment and causes a vertical spin precession. For a proton with EDM at the level of 10-29 e.cm, 0.22 pG of B-field and 10.5 MV/m of E-field cause same vertical spin precession. On the other hand, the radial B-field splits the counter-rotating beams depending on the vertical focusing strength in the ring The magnetic field due to this split modulated at a few kHz can be measured by a SQUID-magnetometer. This measurement requires the B-field to be kept less than 1 nT everywhere around the ring using shields of mu-metal and aluminum layers. Then, the SQUID measurements involve noise from three sources: outside the shields, the shields themselves and the beam. We study these three sources of noise using an electric circuit (mimicking the beam) inside a magnetic shielding room which consists two-layers of mu-metal and an aluminum layer.

  16. Varying stopping and self-focusing of intense proton beams as they heat solid density matter

    NASA Astrophysics Data System (ADS)

    Kim, J.; McGuffey, C.; Qiao, B.; Wei, M. S.; Grabowski, P. E.; Beg, F. N.

    2016-04-01

    Transport of intense proton beams in solid-density matter is numerically investigated using an implicit hybrid particle-in-cell code. Both collective effects and stopping for individual beam particles are included through the electromagnetic fields solver and stopping power calculations utilizing the varying local target conditions, allowing self-consistent transport studies. Two target heating mechanisms, the beam energy deposition and Ohmic heating driven by the return current, are compared. The dependences of proton beam transport in solid targets on the beam parameters are systematically analyzed, i.e., simulations with various beam intensities, pulse durations, kinetic energies, and energy distributions are compared. The proton beam deposition profile and ultimate target temperature show strong dependence on intensity and pulse duration. A strong magnetic field is generated from a proton beam with high density and tight beam radius, resulting in focusing of the beam and localized heating of the target up to hundreds of eV.

  17. Stereotactic proton beam therapy for intracranial arteriovenous malformations

    SciTech Connect

    Vernimmen, Frederik J.A.I. . E-mail: fv@sun.ac.za; Slabbert, Jacobus P.; Wilson, Jennifer A.; Fredericks, Shaheeda

    2005-05-01

    Purpose: To investigate hypofractionated stereotactic proton therapy of predominantly large intracranial arteriovenous malformations (AVMs) by analyzing retrospectively the results from a cohort of patients. Methods and Materials: Since 1993, a total of 85 patients with vascular lesions have been treated. Of those, 64 patients fulfilled the criteria of having an arteriovenous malformation and sufficient follow-up. The AVMs were grouped by volume: <14 cc (26 patients) and {>=}14 cc (38 patients). Treatment was delivered with a fixed horizontal 200 MeV proton beam under stereotactic conditions, using a stereophotogrammetric positioning system. The majority of patients were hypofractionated (2 or 3 fractions), and the proton doses are presented as single-fraction equivalent cobalt Gray equivalent doses (SFEcGyE). The overall mean minimum target volume dose was 17.37 SFEcGyE, ranging from 10.38-22.05 SFEcGyE. Results: Analysis by volume group showed obliteration in 67% for volumes <14 cc and 43% for volumes {>=}14 cc. Grade IV acute complications were observed in 3% of patients. Transient delayed effects were seen in 15 patients (23%), becoming permanent in 3 patients. One patient also developed a cyst 8 years after therapy. Conclusions: Stereotactic proton beam therapy applied in a hypofractionated schedule allows for the safe treatment of large AVMs, with acceptable results. It is an alternative to other treatment strategies for large AVMs. AVMs are likely not static entities, but probably undergo vascular remodeling. Factors influencing angiogenesis could play a new role in a form of adjuvant therapy to improve on the radiosurgical results.

  18. Effects of a realistic adaptive optics system on the atmospheric propagation of a high energy laser beam

    NASA Astrophysics Data System (ADS)

    Digumarthi, Ramji V.; Mehta, Naresh C.; Blankinship, Ross M.

    1990-05-01

    An adaptive optics (AO) correction system is generally required to compensate for beam degradations caused by interactions between a high energy laser (HEL) beam and the atmosphere. The GRAND propagation code includes a model of a realistic AO system representing many features of a state-of-the-art beam control system. This AO system includes models of a wavefront sensor, a tilt mirror, a focus (secondary) mirror, and a woofer-tweeter deformable mirror arrangement. This paper reports the results of a study to assess the impact of the realistic AO system on the correctability of HEL-atmosphere interactions. The GRAND code results compare the performance of the low-pass filter model and the realistic AO system model in the presence of turbulence and moderate-to-severe thermal blooming. In addition, the effects of low frequency Kolmogorov turbulence were studied in terms of its impact on the AO system requirements.

  19. High-energy-density electron beam from interaction of two successive laser pulses with subcritical-density plasma

    NASA Astrophysics Data System (ADS)

    Wang, J. W.; Yu, W.; Yu, M. Y.; Xu, H.; Ju, J. J.; Luan, S. X.; Murakami, M.; Zepf, M.; Rykovanov, S.

    2016-02-01

    It is shown by particle-in-cell simulations that a narrow electron beam with high energy and charge density can be generated in a subcritical-density plasma by two consecutive laser pulses. Although the first laser pulse dissipates rapidly, the second pulse can propagate for a long distance in the thin wake channel created by the first pulse and can further accelerate the preaccelerated electrons therein. Given that the second pulse also self-focuses, the resulting electron beam has a narrow waist and high charge and energy densities. Such beams are useful for enhancing the target-back space-charge field in target normal sheath acceleration of ions and bremsstrahlung sources, among others.

  20. Pitfalls of tungsten multileaf collimator in proton beam therapy

    SciTech Connect

    Moskvin, Vadim; Cheng, Chee-Wai; Das, Indra J.

    2011-12-15

    Purpose: Particle beam therapy is associated with significant startup and operational cost. Multileaf collimator (MLC) provides an attractive option to improve the efficiency and reduce the treatment cost. A direct transfer of the MLC technology from external beam radiation therapy is intuitively straightforward to proton therapy. However, activation, neutron production, and the associated secondary cancer risk in proton beam should be an important consideration which is evaluated. Methods: Monte Carlo simulation with FLUKA particle transport code was applied in this study for a number of treatment models. The authors have performed a detailed study of the neutron generation, ambient dose equivalent [H*(10)], and activation of a typical tungsten MLC and compared with those obtained from a brass aperture used in a typical proton therapy system. Brass aperture and tungsten MLC were modeled by absorber blocks in this study, representing worst-case scenario of a fully closed collimator. Results: With a tungsten MLC, the secondary neutron dose to the patient is at least 1.5 times higher than that from a brass aperture. The H*(10) from a tungsten MLC at 10 cm downstream is about 22.3 mSv/Gy delivered to water phantom by noncollimated 200 MeV beam of 20 cm diameter compared to 14 mSv/Gy for the brass aperture. For a 30-fraction treatment course, the activity per unit volume in brass aperture reaches 5.3 x 10{sup 4} Bq cm{sup -3} at the end of the last treatment. The activity in brass decreases by a factor of 380 after 24 h, additional 6.2 times after 40 days of cooling, and is reduced to background level after 1 yr. Initial activity in tungsten after 30 days of treating 30 patients per day is about 3.4 times higher than in brass that decreases only by a factor of 2 after 40 days and accumulates to 1.2 x 10{sup 6} Bq cm{sup -3} after a full year of operation. The daily utilization of the MLC leads to buildup of activity with time. The overall activity continues to increase

  1. The NuMI proton beam at Fermilab successes and challenges

    SciTech Connect

    Childress, S.; /Fermilab

    2008-11-01

    The NuMI beam at Fermilab has delivered over 5 x 10{sup 20} 120 GeV protons to the neutrino production target since the start for MINOS [1] neutrino oscillation experiment operation in 2005. We report on proton beam commissioning and operation status, including successes and challenges with this beam.

  2. Fabrication of phosphor micro-grids using proton beam lithography.

    SciTech Connect

    Rossi, Paolo; Antolak, Arlyn J.; Provencio, Paula Polyak; Doyle, Barney Lee; Malmqvist, Klas; Hearne, Sean Joseph; Nilsson, Christer; Kristiansson, Per; Wegden, Marie; Elfman, Mikael; Pallon, Jan; Auzelyte, Vaida

    2005-07-01

    A new nuclear microscopy technique called ion photon emission microscopy or IPEM was recently invented. IPEM allows analysis involving single ions, such as ion beam induced charge (IBIC) or single event upset (SEU) imaging using a slightly modified optical microscope. The spatial resolution of IPEM is currently limited to more than 10 {micro}m by the scattering and reflection of ion-induced photons, i.e. light blooming or spreading, in the ionoluminescent phosphor layer. We are developing a 'Microscopic Gridded Phosphor' (also called Black Matrix) where the phosphor nanocrystals are confined within the gaps of a micrometer scale opaque grid, which limits the amount of detrimental light blooming. MeV-energy proton beam lithography is ideally suited to lithographically form masks for the grid because of high aspect ratio, pattern density and sub-micron resolution of this technique. In brief, the fabrication of the grids was made in the following manner: (1) a MeV proton beam focused to 1.5-2 {micro}m directly fabricated a matrix of pillars in a 15 {micro}m thick SU-8 lithographic resist; (2) 7:1 aspect ratio pillars were then formed by developing the proton exposed area; (3) Ni (Au) was electrochemically deposited onto Cu-coated Si from a sulfamate bath (or buffered CN bath); (4) the SU-8 pillars were removed by chemical etching; finally (5) the metal micro-grid was freed from its substrate by etching the underlying Cu layer. Our proposed metal micro-grids promise an order-of-magnitude improvement in the resolution of IPEM.

  3. Recent developments of SOLEROO: Australia's first high energy radioactive Ion Beam capability

    NASA Astrophysics Data System (ADS)

    Carter, I. P.; Dasgupta, M.; Hinde, D. J.; Luong, D. H.; Williams, E.; Ramachandran, K.; Cook, K. J.; Muirhead, A. G.; Marshall, S.; Tunningley, T.

    2015-04-01

    The first measurements of the Australian National University's new radioactive ion beam capability were carried out using elastic scattering of a 8Li radioactive beam from a 197Au target. The purpose of this experiment was to test the radioactive ion beam capability as a complete system, which uses a pair of twin position-sensitive parallel plate avalanche counters as tracking detectors along with a highly pixelated double sided Si detector array. The tracking detector system allows us to have extremely high purity secondary radioactive ion beams by electronically tagging the reaction products of interest, thus allowing complete separation from the unwanted contaminant beam species of similar mass and charge. Here, some recent developments and characteristics of this system are presented.

  4. Prompt neutrino results from a proton beam dump experiment

    NASA Astrophysics Data System (ADS)

    Berge, P.; Dydak, F.; Guyot, C.; Hagelberg, R.; Merlo, J. P.; Ranjard, F.; Rothberg, J.; Steinberger, J.; Taureg, H.; von Rüden, W.; Wahl, H.; Williams, R. W.; Wotschack, J.; Blümer, H.; Buchholz, P.; Duda, J.; Eisele, F.; Kleinknecht, K.; Knobloch, J.; Pollmann, D.; Pszola, B.; Renk, B.; Belusević, R.; Falkenburg, B.; Flottmann, T.; de Groot, J. G. H.; Geweniger, C.; Hepp, V.; Keilwerth, H.; Tittel, K.; Debu, P.; Para, A.; Perez, P.; Peyaud, B.; Rander, J.; Schuller, J. P.; Turlay, R.; Abramowicz, H.; Królikowski, J.

    1992-06-01

    A study of prompt neutrino events from 400 GeV protons on a beam-dump is presented. The ratio of electron- to muon-neutrino rates is 0.86±0.14, in agreement with e-μ universality. The anti-neutrino to neutrino flux ratio isbar v_μ /v_μ = 0.81 ± 0.19. The absolute rates and distributions observed are shown to be in quantitative agreement with the known properties of charmedquark production in hadron collisions.

  5. Supine proton beam craniospinal radiotherapy using a novel tabletop adapter.

    PubMed

    Buchsbaum, Jeffrey C; Besemer, Abby; Simmons, Joseph; Hoene, Ted; Simoneaux, Victor; Sandefur, Amy; Wolanski, Mark; Li, Zhao; Cheng, Chee-Wei

    2013-01-01

    To develop a device that allows supine craniospinal proton and photon therapy to the vast majority of proton and photon facilities currently experiencing limitations as a result of couch design issues. Plywood and carbon fiber were used for the development of a prototype unit. Once this was found to be satisfactory after all design issues were addressed, computer-assisted design (CAD) was used and carbon fiber tables were built to our specifications at a local manufacturer of military and racing car carbon fiber parts. Clinic-driven design was done using real-time team discussion for a prototype design. A local machinist was able to construct a prototype unit for us in <2 weeks after the start of our project. Once the prototype had been used successfully for several months and all development issues were addressed, a custom carbon fiber design was developed in coordination with a carbon fiber manufacturer in partnership. CAD methods were used to design the units to allow oblique fields from head to thigh on patients up to 200 cm in height. Two custom-designed carbon fiber craniospinal tabletop designs now exist: one long and one short. Four are in successful use in our facility. Their weight tolerance is greater than that of our robot table joint (164 kg). The long unit allows for working with taller patients and can be converted into a short unit as needed. An affordable, practical means of doing supine craniospinal therapy with protons or photons can be used in most locations via the use of these devices. This is important because proton therapy provides a much lower integral dose than all other therapy methods for these patients and the supine position is easier for patients to tolerate and for anesthesia delivery. These units have been successfully used for adult and pediatric supine craniospinal therapy, proton therapy using oblique beams to the low pelvis, treatment of various spine tumors, and breast-sparing Hodgkin's therapy. PMID:22951538

  6. Supine proton beam craniospinal radiotherapy using a novel tabletop adapter

    SciTech Connect

    Buchsbaum, Jeffrey C.; Besemer, Abby; Simmons, Joseph; Hoene, Ted; Simoneaux, Victor; Sandefur, Amy; Wolanski, Mark; Li, Zhao; Cheng, Chee-Wei

    2013-04-01

    To develop a device that allows supine craniospinal proton and photon therapy to the vast majority of proton and photon facilities currently experiencing limitations as a result of couch design issues. Plywood and carbon fiber were used for the development of a prototype unit. Once this was found to be satisfactory after all design issues were addressed, computer-assisted design (CAD) was used and carbon fiber tables were built to our specifications at a local manufacturer of military and racing car carbon fiber parts. Clinic-driven design was done using real-time team discussion for a prototype design. A local machinist was able to construct a prototype unit for us in <2 weeks after the start of our project. Once the prototype had been used successfully for several months and all development issues were addressed, a custom carbon fiber design was developed in coordination with a carbon fiber manufacturer in partnership. CAD methods were used to design the units to allow oblique fields from head to thigh on patients up to 200 cm in height. Two custom-designed carbon fiber craniospinal tabletop designs now exist: one long and one short. Four are in successful use in our facility. Their weight tolerance is greater than that of our robot table joint (164 kg). The long unit allows for working with taller patients and can be converted into a short unit as needed. An affordable, practical means of doing supine craniospinal therapy with protons or photons can be used in most locations via the use of these devices. This is important because proton therapy provides a much lower integral dose than all other therapy methods for these patients and the supine position is easier for patients to tolerate and for anesthesia delivery. These units have been successfully used for adult and pediatric supine craniospinal therapy, proton therapy using oblique beams to the low pelvis, treatment of various spine tumors, and breast-sparing Hodgkin's therapy.

  7. The effects of the RHIC E-lenses magnetic structure layout on the proton beam trajectory

    SciTech Connect

    Gu, X.; Pikin, A.; Luo, Y.; Okamura, M.; Fischer, W.; Gupta, R.; Hock, J.; Raparia, D.

    2011-03-28

    We are designing two electron lenses (E-lens) to compensate for the large beam-beam tune spread from proton-proton interactions at IP6 and IP8 in the Relativistic Heavy Ion Collider (RHIC). They will be installed in RHIC IR10. First, the layout of these two E-lenses is introduced. Then the effects of e-lenses on proton beam are discussed. For example, the transverse fields of the e-lens bending solenoids and the fringe field of the main solenoids will shift the proton beam. For the effects of the e-lens on proton beam trajectory, we calculate the transverse kicks that the proton beam receives in the electron lens via Opera at first. Then, after incorporating the simplified E-lens lattice in the RHIC lattice, we obtain the closed orbit effect with the Simtrack Code.

  8. A dc arc plasma torch as a tailored heat source for thermohydraulic simulation of proton beam target interaction in ADSS

    NASA Astrophysics Data System (ADS)

    Ghorui, S.; Sahasrabudhe, S. N.; Murthy, P. S. S.; Das, A. K.

    2006-11-01

    Currently, research on accelerator driven subcritical systems (ADSS) is gaining significance due to their high safety levels and extremely attractive potential in terms of both thorium utilization and nuclear waste transmutation. While high energy and high current proton beams are being built worldwide, intensive efforts are being undertaken in parallel towards the development of complex lead bismuth eutectic target systems. The major focus is directed towards understanding of the material compatibility and detailed thermohydraulic simulation of the liquid metal flow. The requisite heat flux is being deposited using innovative and easily controllable heat sources. This paper presents an experimental and simulation study to explore the potential of using dc arc plasma torches as a tailored heat source for thermohydraulic simulation of proton beam-target interaction in such systems.

  9. High energy accelerator and colliding beam user group: Progress report, March 1, 1987-February 29, 1988

    SciTech Connect

    Not Available

    1987-09-01

    Progress is reported on the OPAL experiment at LEP, including construction and assembly of the hadron calorimeter and development of OPAL software. Progress on the JADE experiment, which examines e/sup +/e/sup -/ interactions at PETRA, and of the PLUTO collaboration are also discussed. Experiments at Fermilab are reported, including deep inelastic muon scattering at TeV II, the D0 experiment at TeV I, and hadron jet physics. Neutrino-electron elastic scattering and a search for point-sources of ultra-high energy cosmic rays are reported. Other activities discussed include polarization in electron storage rings, participation in studies for the SSC and LEP 200, neutron-antineutron oscillations, and the work of the electronics support group. High energy physics computer experience is also discussed. 158 refs. (LEW)

  10. Characterization of the proton beam at the output of the 6.7MeV LEDA RFQ.

    SciTech Connect

    Allen, C. K.; Colestock, P. L. ,; Gilpatrick, J. D.; Lysenko, W. P.; Rybarcyk, L. J.; Schneider, J. D.; Sheffield, R. L.; Smith, H. V.; Wangler, Thomas P.,; Crandall, K. R.; Chan, D.; Garnett, R. W.; Schulze, M. E.

    2001-01-01

    The present configuration of the Low-Energy Demonstration Accelerator (LEDA) consists of a 75-keV proton injector, a 6.7-MeV 350-MHz cw radio-frequency quadrupole (RFQ) with associated high-power and lowlevel rf systems, a 52-magnet periodic lattice followed by a short high-energy beam transport (HEBT) and highpower (670-kW cw) beam stop. The rms beam emittance was measured prior to the installation of the 52-magnet lattice, based on wire-scanner measurements of the beam profile at a single location in the HEBT. New measurements with additional diagnostic hardware have been performed to determine the rms transverse beam properties of the beam at the output of the 6.7-MeV LEDA RFQ. The 52-magnet periodic lattice also includes ten beam position monitors (BPMs) evenly spaced in pairs of two. The BPMs provide a measure of the bunched beam current that exhibits nulls at different locations in the lattice. Model predictions of the locations of the nulls and the strength of the bunched beam current are made to determine what information this data can provide regarding the longitudinal beam emittance.

  11. Measurement of high energy x-ray beam penumbra with Gafchromic trade mark sign EBT radiochromic film

    SciTech Connect

    Cheung Tsang; Butson, Martin J.; Yu, Peter K. N.

    2006-08-15

    High energy x-ray beam penumbra are measured using Gafchromic trade mark sign EBT film. Gafchromic trade mark sign EBT, due to its limited energy dependence and high spatial resolution provide a high level of accuracy for dose assessment in penumbral regions. The spatial resolution of film detector systems is normally limited by the scanning resolution of the densitometer. Penumbral widths (80%/20%) measured at D{sub max} were found to be 2.8, 3.0, 3.2, and 3.4 mm ({+-}0.2 mm) using 5, 10, 20, and 30 cm square field sizes, respectively, for a 6 MV linear accelerator produced x-ray beam. This is compared to 3.2 mm{+-}0.2 mm (Kodak EDR2) and 3.6 mm{+-}0.2 mm (Kodak X-Omat V) at 10 cmx10 cm measured using radiographic film. Using a zero volume extrapolation technique for ionization chamber measurements, the 10 cmx10 cm field penumbra at D{sub max} was measured to be 3.1 mm, a close match to Gafchromic trade mark sign EBT results. Penumbral measurements can also be made at other depths, including the surface, as the film does not suffer significantly from dosimetric variations caused by changing x-ray energy spectra. Gafchromic trade mark sign EBT film provides an adequate measure of penumbral dose for high energy x-ray beams.

  12. Effect of the electron lenses on the RHIC proton beam closed orbit

    SciTech Connect

    Gu, X.; Luo, Y.; Pikin, A.; Okamura, M.; Fischer, W.; Montag, C.; Gupta, R.; Hock, J.; Jain, A.; Raparia, D.

    2011-02-01

    We are designing two electron lenses (E-lens) to compensate for the large beam-beam tune spread from proton-proton interactions at IP6 and IP8 in the Relativistic Heavy Ion Collider (RHIC). They will be installed at RHIC IR10. The transverse fields of the E-lenses bending solenoids and the fringe field of the main solenoids will shift the proton beam. We calculate the transverse kicks that the proton beam receives in the electron lens via Opera. Then, after incorporating the simplified E-lens lattice in the RHIC lattice, we obtain the closed orbit effect with the Simtrack Code.

  13. Effect of strong solenoidal focusing on beam emittance of low-energy intense proton beam in the SARAF LEBT

    NASA Astrophysics Data System (ADS)

    Shor, A.; Weissman, L.

    2016-07-01

    Influence of strong solenoidal beam focusing on beam emittance was studied at the SARAF LEBT beam line using 5 mA 20 keV proton quasi-DC beams. The measurements show that within the experimental uncertainties, emittance does not change over the whole focusing range. Detailed beam dynamics simulations were performed to achieve better understanding of the experimental results. The experimental and simulation results are fully consistent with the assumption of nearly full space charge neutralization for the quasi-DC proton beam.

  14. Dosimetry for ocular proton beam therapy at the Harvard Cyclotron Laboratory based on the ICRU Report 59.

    PubMed

    Newhauser, W D; Burns, J; Smith, A R

    2002-09-01

    The Massachusetts General Hospital, the Harvard Cyclotron Laboratory (HCL), and the Massachusetts Eye and Ear Infirmary have treated almost 3000 patients with ocular disease using high-energy external-beam proton radiation therapy since 1975. The absorbed dose standard for ocular proton therapy beams at HCL was based on a fluence measurement with a Faraday cup (FC). A majority of proton therapy centers worldwide, however, use an absorbed dose standard that is based on an ionization chamber (IC) technique. The ion chamber calibration is deduced from a measurement in a reference 60Co photon field together with a calculated correction factor that takes into account differences in a chamber's response in 60Co and proton fields. In this work, we implemented an ionization chamber-based absolute dosimetry system for the HCL ocular beamline based on the recommendations given in Report 59 by the International Commission on Radiation Units and Measurements. Comparative measurements revealed that the FC system yields an absorbed dose to water value that is 1.1% higher than was obtained with the IC system. That difference is small compared with the experimental uncertainties and is clinically insignificant. In June of 1998, we adopted the IC-based method as our standard practice for the ocular beam. PMID:12349914

  15. Experimental analysis of general ion recombination in a liquid-filled ionization chamber in high-energy photon beams

    SciTech Connect

    Chung, Eunah; Seuntjens, Jan; Davis, Stephen

    2013-06-15

    Purpose: To study experimentally the general ion recombination effect in a liquid-filled ionization chamber (LIC) in high-energy photon beams. Methods: The general ion recombination effect on the response of a micro liquid ion chamber (microLion) was investigated with a 6 MV photon beam in normal and SRS modes produced from a Varian{sup Registered-Sign} Novalis Tx{sup TM} linear accelerator. Dose rates of the linear accelerator were set to 100, 400, and 1000 MU/min, which correspond to pulse repetition frequencies of 60, 240, and 600 Hz, respectively. Polarization voltages applied to the microLion were +800 and +400 V. The relative collection efficiency of the microLion response as a function of dose per pulse was experimentally measured with changing polarization voltage and pulse repetition frequencies and was compared with the theoretically calculated value. Results: For the 60 Hz pulse repetition frequency, the experimental relative collection efficiency was not different from the theoretical one for a pulsed beam more than 0.3% for both polarization voltages. For a pulsed radiation beam with a higher pulse repetition frequency, the experimental relative collection efficiency converged to the theoretically calculated efficiency for continuous beams. This result indicates that the response of the microLion tends toward the response to a continuous beam with increasing pulse repetition frequency of a pulsed beam because of low ion mobility in the liquid. Conclusions: This work suggests an empirical method to correct for differences in general ion recombination of a LIC between different radiation fields. More work is needed to quantitatively explain the LIC general ion recombination behavior in pulsed beams generated from linear accelerators.

  16. A diamond detector in the dosimetry of high-energy electron and photon beams

    NASA Astrophysics Data System (ADS)

    Laub, Wolfram U.; Kaulich, Theodor W.; Nüsslin, Fridtjof

    1999-09-01

    A diamond detector type 60003 (PTW Freiburg) was examined for the purpose of dosimetry with 4-20 MeV electron beams and 4-25 MV photon beams. Results were compared with those obtained by using a Markus chamber for electron beams and an ionization chamber for photon beams. Dose distributions were measured in a water phantom with the detector connected to a Unidos electrometer (PTW Freiburg). After a pre-irradiation of about 5 Gy the diamond detector shows a stability in response which is better than that of an ionization chamber. The current of the diamond detector was measured under variation of photon beam dose rate between 0.1 and 7 Gy min-1. Different FSDs were chosen. Furthermore the pulse repetition frequency and the depth of the detector were changed. The electron beam dose rate was varied between 0.23 and 4.6 Gy min-1 by changing the pulse-repetition frequency. The response shows no energy dependence within the covered photon-beam energy range. Between 4 MeV and 18 MeV electron beam energy it shows only a small energy dependence of about 2%, as expected from theory. For smaller electron energies the response increases significantly and an influence of the contact material used for the diamond detector can be surmised. A slight sublinearity of the current and dose rate was found. Detector current and dose rate are related by the expression ipropto(dotD)Delta, where i is the detector current, (dotD) is the dose rate and Delta is a correction factor of approximately 0.963. Depth-dose curves of photon beams, measured with the diamond detector, show a slight overestimation compared

  17. Fabrication of a microreactor by proton beam writing technique

    NASA Astrophysics Data System (ADS)

    Huszank, R.; Szilasi, S. Z.; Vad, K.; Rajta, I.

    2009-06-01

    Microreactors are innovative and promising tools in technology nowadays because of their advantages compared to the conventional-scale reactors. These advantages include vast improvements in surface to volume ratio, energy efficiency, reaction speed and yield and increased control of reaction conditions, to name a few examples. The high resolution capability of the micromachining technique utilizing accelerated ion beams in the fabrication technology of microreactors has not yet been taken advantage of. In this work we present the design of a prototype micro-electrochemical cell of 1.5 μL volume (2.5 × 2.5 × 0.240 mm) created with a 3 MeV proton microbeam. The cell can be separated into two half-cells with a suitable membrane applicable to galvanic or fuel cells as well. We deposited gold electrodes on both of the half-cells. The operability of the device was demonstrated by electric current flow between the two electrodes in this micro-electrochemical cell containing a simple electrolyte solution. We used a polycapillary film to separate the two half-cells, hindering the mixing of the anolyte and catholyte solutions. As a result of the minimal mixing caused by the polycapillary film, this cell design can be suitable for electro-synthesis. Due to the high resolution of proton beam writing, it is planned to reduce the dimensions of this kind of microreactor.

  18. Greyscale proton beam writing in p-type Gallium Arsenide

    NASA Astrophysics Data System (ADS)

    Diering, D.; Spemann, D.; Lenzner, J.; Müller, St.; Böntgen, T.; von Wenckstern, H.

    2013-07-01

    Proton beam writing (PBW) is a well known method for micromachining, e.g. of semiconductors. Up to now, only few indication is given on how the resulting structure height in micromachined semiconductors can be controlled by means of fluence variation. This approach for 3D-microstructuring, called Greyscale PBW, was already successfully demonstrated for negative photoresists. In this study (1 0 0) p-type Gallium Arsenide (GaAs) was irradiated with 2.28 MeV protons and fluences in the range from 1.2×1014 H+ cm-2 to 1.0×1018 H+ cm-2 at the ion beam laboratory LIPSION and subsequently electrochemically etched with 10%-KOH. A linear dependency of structure height on ion fluence was established. In this way, pyramid-like structures as well as concave-shaped structures could be created. GaAs showed a lateral anisotropic etch behaviour during the development step with preferential etching along the [0 1 1] directions. On some structures the surface roughness and the change of conductivity were investigated by atomic force and scanning capacitance microscopy, respectively. The rms roughness of the surface of the structures was 5.4 nm and 10.6 nm for a fluence of 7.8×1015 H+ cm-2 and 1.2×1017 H+ cm-2, respectively. We observed an increasing etching rate for fluences larger than 1016 H+ cm-2.

  19. On the dehydration mechanism of Mg(OH){sub 2} by a high-energy electron beam

    SciTech Connect

    Su Dong; Jiang, Nan; Spence, John C. H.; He Feng; Petuskey, William T.

    2008-09-15

    The dehydration process in Mg(OH){sub 2} induced by high-energy electron irradiation is studied by in situ electron energy loss spectroscopy. During dehydration, both the low energy-loss spectra and the Mg L{sub 23} edge show the existence of partially oxidized Mg- or O-deficient MgO in the dehydrated products, which is not seen in the thermally dehydrated MgO. This indicates that the dehydration mechanism under the electron beam may be different from the mechanism involved in a thermal process.

  20. High energy electron beams characterization using CaSO4:Dy+PTFE phosphors for clinical therapy applications.

    PubMed

    Rivera, T; Espinoza, A; Von, S M; Alvarez, R; Jiménez, Y

    2012-07-01

    In the present work high energy electron beam dosimetry from linear accelerator (LINACs) for clinical applications using dysprosium doped calcium sulfate embedded in polytetrafluorethylene (CaSO4:Dy+PTFE) was studied. The irradiations were carried out using high electron beams (6 to 18 MeV) from a linear accelerator (LINAC) Varian, CLINAC 2300C/D, for clinical practice purpose. The electron irradiations were obtained using the water solid in order to guarantee electronic equilibrium conditions (EEC). Field shaping for electron beams was obtained with electron cones. Glow curve and other thermoluminescent characteristics of CaSO4:Dy+PTFE were conducted under high electrons beams irradiations. The TL response of the pellets showed an intensity peak centered at around 215 °C. TL response of CaSO4:Dy+PTFE as a function of high electron absorbed dose showed a linearity in a wide range. To obtain reproducibility characteristic, a set of pellets were exposed repeatedly for the same electron absorbed dose. The results obtained in this study can suggest the applicability of CaSO4:Dy+PTFE pellets for high electron beam dosimetry, provided fading is correctly accounted for. PMID:22182630

  1. High Energy Accelerator and Colliding Beam User Group. Progress report, May 1, 1980--March 31, 1981

    SciTech Connect

    Snow, G.A.

    1980-12-01

    The major activities of the High Energy Physics Group at the University of Maryland during the current contract period have been: analysis of e{sup +}e{sup {minus}} events from the PLUTO detector at PETRA, design and construction of modifications to PLUTO for 2{gamma} physics, analyses of {nu}{sub {mu}}D{sub 2} bubble chamber pictures from Fermilab, completion of the {nu}{sub {mu}}e elastic scattering experiment at Fermilab, development and demonstration of an ultra cold neutron source produced by Doppler shifting, testing of equipment for the hadron jet experiment at Fermilab that is about to begin, and planning for large projects in the future.

  2. Spectral reconstruction of high energy photon beams for kernel based dose calculations.

    PubMed

    Hinson, William H; Bourland, J Daniel

    2002-08-01

    A kernel-based dose computation method with finite-size pencil beams (FSPBs) requires knowledge of the photon spectrum. Published methods of indirect spectral measurements using transmission measurements through beam attenuators use mathematical fits with a large number of parameters and constraints. In this study, we examine a simple strategy for fitting transmission data that models important physical characteristics of photon beams produced in clinical linear accelerators. The shape of an unattenuated bremsstrahlung spectrum is known, varying linearly from a maximum at zero energy to a value of zero at a maximum energy. This unattenuated spectrum is altered primarily by absorption of low energy photons by the flattening filter, causing the true spectrum to roll off to zero at low photon energies. A fitting equation models this behavior and has these advantages over previous methods: (1) the equation describes the shape of a bremsstrahlung spectrum based on physical expectations; and (2) only three fit parameters are required with a single constraint. Results for 4 MV and 6 MV accelerators for central axis and off-axis beams show good agreement with the maximum, average and modal energies for known spectra. Previously published models, representations of beam fluence (energy fluence, dN/dE), experimental methods, and the fitting process are discussed. PMID:12201426

  3. The electric field induced by high-energy solar electron beams

    NASA Astrophysics Data System (ADS)

    Reid, Hamish; Kontar, Eduard

    2016-07-01

    Solar electron beam responsible for type III emission generate Langmuir waves as they propagate out from the Sun. The Langmuir waves are observed through in-situ electric field measurements. The increase in the electric field is not observed to be smoothly distributed as the electron beam passes spacecraft but is spikey, with the waves occurring in discrete clumps. The clumpy behaviour is commonly attributed to the turbulent nature of the solar wind electron density modulating the effective growth rate of Langmuir waves from the propagating electron beam. Exactly how the intensity of the density turbulence modulates the induced electric field distribution is known quantitatively. Using quasilinear simulations we investigate how increasing the level of density turbulence in the solar wind plasma changes the distribution of the beam-driven electric field distribution. For plasma conditions indicative of 1 AU we demonstrate how the electric field distribution that is peaked at the maximum electric field for unperturbed plasma, spreads out more uniformly in magnitude as density turbulence increases, and is also able to reach higher electric fields. We show how the electric field distribution changes as an electron beam travels through plasma from the Sun to the Earth through the inner heliosphere. Our simulations provide predictions of the radial behaviour that the upcoming Solar Orbiter and Solar Probe Plus spacecraft will detect as they travel towards the Sun.

  4. Variation of sensitometric curves of radiographic films in high energy photon beams.

    PubMed

    Danciu, C; Proimos, B S; Rosenwald, J C; Mijnheer, B J

    2001-06-01

    Film dosimetry is an important tool for the verification of irradiation techniques. The shape of the sensitometric curve depends on the type of film as well as on the irradiation and processing conditions. Existing data concerning the influence of irradiation geometry on the sensitometric curve are conflicting. In particular the variation of optical density, OD, with field size and depth in a phantom shows large differences in magnitude between various authors. This variation, as well as the effect of beam energy and film plane orientation on OD, was therefore investigated for two types of film, Kodak X-Omat V and Agfa Structurix D2. Films were positioned in a solid phantom, either perpendicular or (almost) parallel to the beam axis, and irradiated to different dose levels using various photon beams (Co-60, 6 MV, 15 MV, 18 MV, 45 MV). It was found that the sensitometric curves of the Kodak film derived at different depths are almost identical for the four x-ray beams. For the Kodak film the differences in OD with depth are less than 2%, except for the Co-60 beam, where the difference is about 4% at 10 cm depth for a 15 cm x 15 cm field. The slope of the sensitometric curve of the Agfa film is somewhat more dependent on photon beam energy, depth and field size. The sensitometric curves of both types of film are almost independent of the film plane orientation, except for shallow depths. For Co-60 and for the same dose, the Kodak and Agfa films gave at dose maximum an OD lower by 4% and 6%, respectively, for the parallel compared to the perpendicular geometry. Good dosimetric results can be obtained if films from the same batch are irradiated with small to moderate field sizes (up to about 15 cm x 15 cm), at moderate depths (up to about 15 cm), using a single calibration curve, e.g., for a 10 cm x 10 cm field. PMID:11439493

  5. Early and delayed reproductive death in human cells exposed to high energy iron-ion beams

    NASA Astrophysics Data System (ADS)

    Bettega, D.; Calzolari, P.; Doneda, L.; Durante, M.; Tallone, L.

    For radiation protection of the astronauts it is important to know both the acute and the late effects of charged particles. Iron is the most abundant high charge and energy (HZE) specie in galactic cosmic radiation. (HZE) ions are considered to be the major contributors to equivalent dose in space, but the Relative Biological Effectiveness of HZE particles has large uncertainties, expecially for late effects. We have determined early and delayed reproductive death in human fibroblast cells (AG1522) exposed to iron ion beams of energies between 0.2 and 1 GeV/n. The cells were irradiated at the HIMAC accelerator in Chiba (0.2 and 0.5 GeV/n) and at the AGS accelerator at the NASA Space Radiation Laboratory in Brookhaven (1 GeV/n). For each beam the dose--effect curves were measured at least twice in the dose range between 0.5 and 2 Gy. 60 Co gamma rays were used as reference radiation. The following results were obtained: 1) the 1 GeV/n beam effectiveness for inactivation of the AG1522 cells is higher than that of any other beam. 2) the progeny of the irradiated cells show the presence of delayed damage in the form of reproductive death for all the beams with the 1 GeV/n being the most effective. 3) the relative biological effectiveness of the iron beams is higher for delayed compared to early reproductive death. A comparison with preliminary results obtained with 970 MeV/n Ti and 490 MeV/n Si ions will be also reported .

  6. Plasma effects on extragalactic ultra-high-energy cosmic ray hadron beams in cosmic voids

    SciTech Connect

    Krakau, S.; Schlickeiser, R. E-mail: rsch@tp4.rub.de

    2014-07-01

    The linear instability of an ultrarelativistic hadron beam (Γ {sub b} ≈ 10{sup 6}) in the unmagnetized intergalactic medium (IGM) is investigated with respect to the excitation of collective electrostatic and aperiodic electromagnetic fluctuations. This analysis is important for the propagation of extragalactic ultrarelativistic cosmic rays (E > 10{sup 15} eV) from their distant sources to Earth. We calculate minimum instability growth times that are orders of magnitude shorter than the cosmic ray propagation time in the IGM. Due to nonlinear effects, especially the modulation instability, the cosmic ray beam stabilizes and can propagate with nearly no energy loss through the IGM.

  7. High energy metal ion implantation using `Magis`, a novel, broad-beam, Marx-generator-based ion source

    SciTech Connect

    Anders, A.; Brown, I.G.; Dickinson, M.R.; MacGill, R.A.

    1996-08-01

    Ion energy of the beam formed by an ion source is proportional to extractor voltage and ion charge state. Increasing the voltage is difficult and costly for extraction voltage over 100 kV. Here we explore the possibility of increasing the charge states of metal ions to facilitate high-energy, broad beam ion implantation at a moderate voltage level. Strategies to enhance the ion charge state include operating in the regimes of high-current vacuum sparks and short pulses. Using a time-of-flight technique we have measured charge states as high as 7+ (73 kA vacuum spark discharge) and 4+ (14 kA short pulse arc discharge), both for copper, with the mean ion charge states about 6.0 and 2.5, respectively. Pulsed discharges can conveniently be driven by a modified Marx generator, allowing operation of ``Magis`` with a single power supply (at ground potential) for both plasma production and ion extraction.

  8. Resistance of Bacillus subtilis spores to 12C ion beams, stimulation of high-energy charged particles in space

    NASA Astrophysics Data System (ADS)

    Zhang, Li; Dang, Bingrong; Li, Junxiong; Chen, Jinsong; Liu, Mei; Liu, Zhiheng; Zhang, Lixin

    To monitor the response of live microbes in space radiation environment with high-energy charged particles, we carry out ground stimulation radiation experiments. Spores of Bacillus (CGMCC 1.1849) species are one of the model systems used for astro- and radiobiological studies. (12) C ion beams served as stimulated space radiation from 5gry, 10gry, 20gry, 40gry, to 80gry at a rate of 15gry/min Death rates are measured and mutant strains are isolated. Five representative strains are analyzed for their corresponding gene sequences, protein sequences and gene expression index of DNA repair system gene recA and recO. The statistic results showed the strains resistance to (12) C ion beams radiation is partially due to the increase of gene expression index of recA and recO. In conclusion, our research provide a surrogate system to monitor the live microbial response in resistant to space radiation environment.

  9. Do you want to build such a machine? : Designing a high energy proton accelerator for Argonne National Laboratory.

    SciTech Connect

    Paris, E.

    2004-04-05

    Argonne National Laboratory's efforts toward researching, proposing and then building a high-energy proton accelerator have been discussed in a handful of studies. In the main, these have concentrated on the intense maneuvering amongst politicians, universities, government agencies, outside corporations, and laboratory officials to obtain (or block) approval and/or funds or to establish who would have control over budgets and research programs. These ''top-down'' studies are very important but they can also serve to divorce such proceedings from the individuals actually involved in the ground-level research which physically served to create theories, designs, machines, and experiments. This can lead to a skewed picture, on the one hand, of a lack of effect that so-called scientific and technological factors exert and, on the other hand, of the apparent separation of the so-called social or political from the concrete practice of doing physics. An exception to this approach can be found in the proceedings of a conference on ''History of the ZGS'' held at Argonne at the time of the Zero Gradient Synchrotron's decommissioning in 1979. These accounts insert the individuals quite literally as they are, for the most part, personal reminiscences of those who took part in these efforts on the ground level. As such, they are invaluable raw material for historical inquiry but generally lack the rigor and perspective expected in a finished historical work. The session on ''Constructing Cold War Physics'' at the 2002 annual History of Science Society Meeting served to highlight new approaches circulating towards history of science and technology in the post-WWII period, especially in the 1950s. There is new attention towards the effects of training large numbers of scientists and engineers as well as the caution not to equate ''national security'' with military preparedness, but rather more broadly--at certain points--with the explicit ''struggle for the hearts and minds of

  10. High energy electron beam curing of epoxy resin systems incorporating cationic photoinitiators

    DOEpatents

    Janke, C.J.; Lopata, V.J.; Havens, S.J.; Dorsey, G.F.; Moulton, R.J.

    1999-03-02

    A mixture of epoxy resins such as a semi-solid triglycidyl ether of tris (hydroxyphenyl) methane and a low viscosity bisphenol A glycidyl ether and a cationic photoinitiator such as a diaryliodonium salt is cured by irradiating with a dosage of electron beams from about 50 to about 150 kGy, forming a cross-linked epoxy resin polymer.

  11. High energy electron beam curing of epoxy resin systems incorporating cationic photoinitiators

    DOEpatents

    Janke, Christopher J.; Lopata, Vincent J.; Havens, Stephen J.; Dorsey, George F.; Moulton, Richard J.

    1999-01-01

    A mixture of epoxy resins such as a semi-solid triglycidyl ether of tris (hydroxyphenyl) methane and a low viscosity bisphenol A glycidyl ether and a cationic photoinitiator such as a diaryliodonium salt is cured by irradiating with a dosage of electron beams from about 50 to about 150 kGy, forming a cross-linked epoxy resin polymer.

  12. Compact Undulator for the Cornell High Energy Synchrotron Source: Design and Beam Test Results

    NASA Astrophysics Data System (ADS)

    Temnykh, A.; Dale, D.; Fontes, E.; Li, Y.; Lyndaker, A.; Revesz, P.; Rice, D.; Woll, A.

    2013-03-01

    We developed, built and beam tested a novel, compact, in-vacuum undulator magnet based on an adjustable phase (AP) scheme. The undulator is 1 m long with a 5mm gap. It has a pure permanent magnet structure with 24.4mm period and 1.1 Tesla maximum peak field. The device consists of two planar magnet arrays mounted on rails inside of a rectangular box-like frame with 156 mm × 146 mm dimensions. The undulator magnet is enclosed in a 273 mm (10.75") diameter cylindrical vacuum vessel with a driver mechanism placed outside. In May 2012 the CHESS Compact Undulator (CCU) was installed in Cornell Electron Storage Ring and beam tested. During four weeks of dedicated run we evaluated undulator radiation properties as well as magnetic, mechanical and vacuum properties of the undulator magnet. We also studied the effect of the CCU on storage ring beam. The spectral characteristics and intensity of radiation were found to be in very good agreement with expected. The magnet demonstrated reproducibility of undulator parameter K at 1.4 × 10-4 level. It was also found that the undulator K. parameter change does not affect electron beam orbit and betatron tunes.

  13. A Toroidal Charge Monitor for High-Energy Picosecond Electron Beams

    SciTech Connect

    Simmons, Robert H.; Ng, Johnny S.T.

    2007-03-28

    A monitor system suitable for the accurate measurement of the total charge of a 2-ps 28.5 GeV electron beam over a large dynamic range is described. Systematic uncertainties and results on absolute calibration, resolution, and long-term stability are presented.

  14. Quasi-monoenergetic proton beam from a proton-layer embedded metal foil irradiated by an intense laser pulse

    NASA Astrophysics Data System (ADS)

    Kim, Kyung Nam; Lee, Kitae; Kumar, Manoj; Kim, Ha-Na; Park, Seong Hee; Jeong, Young Uk; Vinokurov, Nikolay; Kim, Yong Gi

    2016-03-01

    A target structure, ion-layer embedded foil (ILEF) is proposed for producing a quasi-monoenergetic proton beam by utilizing a bulk electrostatic field, which is generated by irradiating the target with an ultra-intense laser pulse, inside the plasma. Compared with the case of a single metal foil in which the proton layer is initially present on the surface, in the ILEF target, the proton layer is initially located inside a metal foil. A two-dimensional particle-in-cell (PIC) simulation shows that the target generates a proton beam with a narrow energy spread. With a laser intensity of 2 × 1019 W/cm2, a 22-MeV proton beam with an energy spread of 8% at the full-width-half-maximum (FWHM) is obtained when the proton layer is located at 0.4 μm inside the rear surface of a 2.4 μm-thick copper foil. When the proton layer moves toward the front side, a proton beam with a flat-top energy distribution ranging from 15 MeV to 35 MeV is obtained. Further, with a higher laser intensity of 1021 W/cm2, a proton beam with the maximum energy of 345 MeV and FWHM energy spread of 7.2% is obtained. The analysis of the PIC simulation with an aid of a fluid analysis shows that the spectrum is affected by the initial position of the proton layer, its initial spread during the formation of the sheath field, and the space charge effect.

  15. Transport of intense proton beam in the presence of subdominant species in a low energy beam transport system

    NASA Astrophysics Data System (ADS)

    Babu, P. Sing; Goswami, A.; Pandit, V. S.

    2016-04-01

    The dynamics of space-charge-dominated low energy proton beam in the presence of H2+ and H3+ beams has been studied in a solenoid based transport system using particle-in-cell (PIC) simulation method. Multispecies envelope equation and random search technique have been used to transport and match the primary beam considering two options. The PIC simulation shows the formation of hollow distribution of H2+ and H3+ beams around the proton beam in the first case where the waist of the proton beam is formed in between the solenoids and it is absent in the second case where the beam size is kept large in between the solenoids. Separation of hollow distribution appears more distinct as the proton fraction is increased and is almost independent of the combination of H2+ and H3+ beams for a given proton fraction. This effect helps to reject the unwanted species more effectively. The evolution of rms size and emittance of the proton beam has been studied in the presence of a circular aperture using KV and Gaussian distributions for the species in both the cases.

  16. Status of and prospects for proton beam utilization at the KOMAC

    NASA Astrophysics Data System (ADS)

    Kim, Kye-Ryung

    2015-02-01

    The 1st proton beam utilization experiment using the 100-MeV proton accelerator at the Korea Multi-purpose Accelerator Complex (KOMAC) was successfully conducted on July 22, 2013. Forty-eight proposals for the second half year's beam times were submitted, and 37 proposals were selected. The beam time was allocated by the PAC (Program Advisory Committee), which was composed of experts recommended by the KOPUA (Korea Proton Accelerator User Association). For proton beam utilization, the KOMAC constructed two target rooms, TR23 and TR103, for the 20-MeV and 100-MeV proton beam last year, and an operation license was issued by the KINS (Korea Institute of Nuclear Safety) in July, before the beam service started. Proton beams can be utilized in various application fields, such as nano-, bio-, space, semiconductor, and nuclear technologies, medical sciences, nuclear physics, and so on. Especially, the demands for high-dose irradiation with proton beams are increasing for nuclear- and fusion-material tests and radio-isotope production. In this paper, we review the achievements during last ten years and report the status of and the future prospects for beam utilization of the 100-MeV proton accelerator at the KOMAC.

  17. LD-pumped erbium and neodymium lasers with high energy and output beam quality

    NASA Astrophysics Data System (ADS)

    Kabanov, Vladimir V.; Bezyazychnaya, Tatiana V.; Bogdanovich, Maxim V.; Grigor'ev, Alexandr V.; Lebiadok, Yahor V.; Lepchenkov, Kirill V.; Ryabtsev, Andrew G.; Ryabtsev, Gennadii I.; Shchemelev, Maxim A.

    2013-05-01

    Physical and fabrication peculiarities which provide the high output energy and beam quality for the diode pumped erbium glass and Nd:YAG lasers are considered. Developed design approach allow to make passively Q-switched erbium glass eye-safe portable laser sources with output energy 8 - 12 mJ (output pulse duration is less than 25 ns, pulse repetition rate up to 5 Hz) and beam quality M2 less than 1.3. To reach these values the erbium laser pump unit parameters were optimized also. Namely, for the powerful laser diode arrays the optimal near-field fill-factor, output mirror reflectivity and heterostructure properties were determined. Construction of advanced diode and solid-state lasers as well as the optical properties of the active element and the pump unit make possible the lasing within a rather wide temperature interval (e.g. from minus forty till plus sixty Celsius degree) without application of water-based chillers. The transversally pumped Nd:YAG laser output beam uniformity was investigated depending on the active element (AE) pump conditions. In particular, to enhance the pump uniformity within AE volume, a special layer which practically doesn't absorb the pump radiation but effectively scatters the pump and lasing beams, was used. Application of such layer results in amplified spontaneous emission suppression and improvement of the laser output beam uniformity. The carried out investigations allow us to fabricate the solid-state Nd:YAG lasers (1064 nm) with the output energy up to 420 mJ at the pulse repetition rate up to 30 Hz and the output energy up to 100 mJ at the pulse repetition rate of of 100 Hz. Also the laser sources with following characteristics: 35 mJ, 30 Hz (266 nm); 60 mJ, 30 Hz (355 nm); 100 mJ, 30 Hz (532 nm) were manufactured on the base of the developed Nd:YAG quantrons.

  18. Dosimetric properties of high energy current (HEC) detector in keV x-ray beams

    NASA Astrophysics Data System (ADS)

    Zygmanski, Piotr; Shrestha, Suman; Elshahat, Bassem; Karellas, Andrew; Sajo, Erno

    2015-04-01

    We introduce a new x-ray radiation detector. The detector employs high-energy current (HEC) formed by secondary electrons consisting predominantly of photoelectrons and Auger electrons, to directly convert x-ray energy to detector signal without externally applied power and without amplification. The HEC detector is a multilayer structure composed of thin conducting layers separated by dielectric layers with an overall thickness of less than a millimeter. It can be cut to any size and shape, formed into curvilinear surfaces, and thus can be designed for a variety of QA applications. We present basic dosimetric properties of the detector as function of x-ray energy, depth in the medium, area and aspect ratio of the detector, as well as other parameters. The prototype detectors show similar dosimetric properties to those of a thimble ionization chamber, which operates at high voltage. The initial results obtained for kilovoltage x-rays merit further research and development towards specific medical applications.

  19. On the retention of high-energy protons and nuclei with charges Z or equal to 2 in large solar flares after the process of their acceleration

    NASA Technical Reports Server (NTRS)

    Volodichev, N. N.; Kuzhevsky, B. M.; Nechaev, O. Y.; Savenko, I. A.

    1985-01-01

    Data which suggest that the protons with energies of up to several GeV should be retained on the Sun after the process of their acceleration are presented. The protons are on the average retained for 15 min, irrespectively of the solar flare heliolatitude and of the accelerated particle energy ranging from 100 MeV to several GeV. It is suggested that the particles are retained in a magnetic trap formed in a solar active region. No Z or = 2 nuclei of solar origin during large solar flares. The absence of the 500 MeV/nucleon nuclei with Z or = 2 may be due to their retention in the magnetic trap which also retains the high-energy protons. During the trapping time the approx. 500 MeV/nucleon nuclei with Z or = 2 may escape due to nuclear interactions and ionization loss.

  20. Proton-beam driven fast ignition of inertially confined fuels: Reduction of the ignition energy by the use of two proton beams with radially shaped profiles

    SciTech Connect

    Temporal, M.; Honrubia, J. J.; Atzeni, S.

    2008-05-15

    Fast ignition of a spherical compressed deuterium-tritium assembly induced by the energy deposition of laser-accelerated proton beams is considered. An efficient way to reduce the ignition energy consists of using a two proton beams scheme [M. Temporal, Phys Plasmas 13, 122704 (2006)]. For a uniformly compressed fuel at 500 g/cm{sup 3} irradiated by proton beams with Maxwellian energy distribution with a temperature of 4 MeV, the ignition energy is 10 kJ using only one proton beam and reduces to a total of 8 kJ with the two-beam scheme. Further reduction of the ignition energy is found by using a first beam with annular radial profile and a second beam with the uniform radial profile. It is found that the first beam causes some additional fuel compression and confinement that decrease the total beam energy required for the ignition to 6 kJ, which is 40% smaller than in the case of a single beam with uniform radial profile.

  1. High Energy Laboratory Astrophysics Experiments using electron beam ion traps and advanced light sources

    NASA Astrophysics Data System (ADS)

    Brown, Gregory V.; Beiersdorfer, Peter; Bernitt, Sven; Eberle, Sita; Hell, Natalie; Kilbourne, Caroline; Kelley, Rich; Leutenegger, Maurice; Porter, F. Scott; Rudolph, Jan; Steinbrugge, Rene; Traebert, Elmar; Crespo-Lopez-Urritia, Jose R.

    2015-08-01

    We have used the Lawrence Livermore National Laboratory's EBIT-I electron beam ion trap coupled with a NASA/GSFC microcalorimeter spectrometer instrument to systematically address problems found in the analysis of high resolution X-ray spectra from celestial sources, and to benchmark atomic physics codes employed by high resolution spectral modeling packages. Our results include laboratory measurements of transition energies, absolute and relative electron impact excitation cross sections, charge exchange cross sections, and dielectronic recombination resonance strengths. More recently, we have coupled to the Max-Plank Institute for Nuclear Physics-Heidelberg's FLASH-EBIT electron beam ion trap to third and fourth generation advanced light sources to measure photoexcitation and photoionization cross sections, as well as, natural line widths of X-ray transitions in highly charged iron ions. Selected results will be presented.

  2. Sci—Thur PM: Planning and Delivery — 02: Treatment planning workflow for very high-energy electron beam radiotherapy

    SciTech Connect

    Bazalova, Magdalena; Qu, Bradley; Palma, Bianey; Maxim, Peter; Loo, Billy; Hårdemark, Bjorn; Hynning, Elin

    2014-08-15

    Purpose: To develop treatment planning workflow for rapid radiotherapy delivered with very-high energy electron (VHEE) scanning beam. Methods: VHEE radiotherapy treatment planning was performed by linking Monte Carlo (MC) dose calculations with inverse optimization in a research version of RayStation. In order to study a number of treatment parameters, a Matlab graphical user interface (GUI) for calculation of VHEE beamlet dose was developed. Through the GUI, EGSnrc MC simulations were run for a number of beam energies, number of beams, beamlet spot and grid sizes, and machine bore sizes. VHEE plans for a pediatric patient with a 4.3 cm{sup 3} brain target optimized with spot-scanning algorithm in RayStation were compared to the clinically delivered 6 MV VMAT plan. Results and Discussion: VHEE beam energy had the largest effect on the quality of dose distributions. For the same target dose, the mean doses to critical organs decreased by 10–15% when planned with 100 MeV compared to 60 MeV. VHEE plans calculated with 36 beams outperformed plans calculated with 13 and 17 beams. While beamlet spacing and bore size had a small effect on VHEE dose distributions, 0.1-3mm beamlet sizes resulted in identical dose distributions. Critical organ doses were by up to 70% lower in the best VHEE plan compared to the clinical 6 MV VMAT plan. Conclusions: We have developed a GUI for MC beamlet generation for treatment planning of VHEE radiotherapy. We have demonstrated that pediatric VHEE plans resulted in significant critical organ dose sparing compared to the clinical VMAT plan.

  3. Lateral damage in graphene carved by high energy focused gallium ion beams

    SciTech Connect

    Liao, Zhongquan; Zhang, Tao; Jordan, Rainer; Gall, Martin; Rosenkranz, Rüdiger; Dianat, Arezoo; Cuniberti, Gianaurelio; and others

    2015-07-06

    Raman mapping is performed to study the lateral damage in supported monolayer graphene carved by 30 keV focused Ga{sup +} beams. The evolution of the lateral damage is tracked based on the profiles of the intensity ratio between the D (1341 cm{sup −1}) and G (1582 cm{sup −1}) peaks (I{sub D}/I{sub G}) of the Raman spectra. The I{sub D}/I{sub G} profile clearly reveals the transition from stage 2 disorder into stage 1 disorder in graphene along the direction away from the carved area. The critical lateral damage distance spans from <1 μm up to more than 30 μm in the experiment, depending on the parameters used for carving the graphene. The wide damage in the lateral direction is attributed to the deleterious tail of unfocused ions in the ion beam probe. The study raises the attention on potential sample damage during direct patterning of graphene nanostructures using the focused ion beam technique. Minimizing the total carving time is recommended to mitigate the lateral damage.

  4. Proton beam writing of three-dimensional nanostructures in hydrogen silsesquioxane.

    PubMed

    van Kan, Jeroen A; Bettiol, Andrew A; Watt, Frank

    2006-03-01

    Proton beam writing (p-beam writing) is a promising new direct-write lithographic technique for three-dimensional nanofabrication. In p-beam writing a megaelectronvolt proton beam is focused to a sub-100-nm spot size and scanned over a suitable resist material. Unlike electrons, when a proton beam interacts with resist it follows an almost straight path resulting in high aspect ratio structures with vertical, smooth sidewalls. The secondary electrons induced by the primary proton beam have low energy and therefore limited range, resulting in minimal proximity effects. Hydrogen silsesquioxane has been identified as a superior resist for p-beam writing, allowing the production of high-aspect-ratio structures down to 22 nm. PMID:16522066

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

    SciTech Connect

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

    2007-01-15

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

  6. Proton beam shaped by "particle lens" formed by laser-driven hot electrons

    NASA Astrophysics Data System (ADS)

    Zhai, S. H.; Shen, B. F.; Wang, W. P.; Zhang, H.; He, S. K.; Lu, F.; Zhang, F. Q.; Deng, Z. G.; Dong, K. G.; Wang, S. Y.; Zhou, K. N.; Xie, N.; Wang, X. D.; Zhang, L. G.; Huang, S.; Liu, H. J.; Zhao, Z. Q.; Gu, Y. Q.; Zhang, B. H.; Xu, Z. Z.

    2016-05-01

    Two-dimensional tailoring of a proton beam is realized by a "particle lens" in our experiment. A large quantity of electrons, generated by an intense femtosecond laser irradiating a polymer target, produces an electric field strong enough to change the trajectory and distribution of energetic protons flying through the electron area. The experiment shows that a strip pattern of the proton beam appears when hot electrons initially converge inside the plastic plate. Then the shape of the proton beam changes to a "fountain-like" pattern when these hot electrons diffuse after propagating a distance.

  7. Proton Beams Inhibit Proliferation of Breast Cancer Cells by Altering DNA Methylation Status

    PubMed Central

    Kim, Byungtak; Bae, Hansol; Lee, Hyunkyung; Lee, Seungyeon; Park, Jeong Chan; Kim, Kye Ryung; Kim, Sun Jung

    2016-01-01

    Proton beam therapy has been gaining popularity in the management of a wide spectrum of cancers. However, little is known about the effect of proton beams on epigenetic alterations. In this study, the effects of proton beams on DNA methylation were evaluated in the breast cell lines MCF-10A and MCF-7. Pyrosequencing analysis of the long interspersed element 1 (LINE1) gene indicated that a few specific CpG sites were induced to be hypermethylated by proton beam treatment from 64.5 to 76.5% and from 57.7 to 60.0% (p < 0.05) in MCF-10A and MCF-7, respectively. Genome-wide methylation analysis identified “Developmental Disorder, Hereditary Disorder, Metabolic Disease” as the top network in the MCF-7 cell line. The proliferation rate significantly decreased in proton beam-treated cells, as judged by colony formation and cell proliferation assay. Upon treatment with the proton beam, expression of selected genes (MDH2, STYXL1, CPE, FAM91A1, and GPR37) was significantly changed in accordance with the changes of methylation level. Taken together, the findings demonstrate that proton beam-induced physiological changes of cancer cells via methylation modification assists in establishing the epigenetic basis of proton beam therapy for cancer. PMID:26918048

  8. Ciliochoroidal melanomas treated with a narrow medical proton beam

    SciTech Connect

    Brovkina, A.F.; Zarubei, G.D.

    1986-03-01

    We treated 63 patients with intraocular melanomas by means of a narrow medical proton beam. Tumors were irradiated with 2,500 rad at each of four to five sessions, with an interval of one to two days between sessions. The melanomas ranged in diameter from 8 to 20 mm and were from 3.0 to 13.7 mm in thickness. Patients were followed up for three months to seven years. In 11 cases, the tumor was fully resorbed. Complications included radiation cataract, postradiation glaucoma, radiation retinopathy, and exudative retinal detachment. In 12 cases, enucleation was performed because tumor growth persisted. Four patients died during follow-up period because of metastasis. The eye was preserved in 47 cases.

  9. Improving Outcomes for Esophageal Cancer using Proton Beam Therapy.

    PubMed

    Chuong, Michael D; Hallemeier, Christopher L; Jabbour, Salma K; Yu, Jen; Badiyan, Shahed; Merrell, Kenneth W; Mishra, Mark V; Li, Heng; Verma, Vivek; Lin, Steven H

    2016-05-01

    Radiation therapy (RT) plays an essential role in the management of esophageal cancer. Because the esophagus is a centrally located thoracic structure there is a need to balance the delivery of appropriately high dose to the target while minimizing dose to nearby critical structures. Radiation dose received by these critical structures, especially the heart and lungs, may lead to clinically significant toxicities, including pneumonitis, pericarditis, and myocardial infarction. Although technological advancements in photon RT delivery like intensity modulated RT have decreased the risk of such toxicities, a growing body of evidence indicates that further risk reductions are achieved with proton beam therapy (PBT). Herein we review the published dosimetric and clinical PBT literature for esophageal cancer, including motion management considerations, the potential for reirradiation, radiation dose escalation, and ongoing esophageal PBT clinical trials. We also consider the potential cost-effectiveness of PBT relative to photon RT. PMID:27084662

  10. Three-dimensional metamaterials fabricated using Proton Beam Writing

    NASA Astrophysics Data System (ADS)

    Bettiol, A. A.; Turaga, S. P.; Yan, Y.; Vanga, S. K.; Chiam, S. Y.

    2013-07-01

    Proton Beam Writing (PBW) is a direct write lithographic technique that has recently been applied to the fabrication of three dimensional metamaterials. In this work, we show that the unique capabilities of PBW, namely the ability to fabricate arrays of high resolution, high aspect ratio microstructures in polymer or replicated into metal, is well suited to metamaterials research. We have also developed a novel method for selectively electroless plating silver directly onto polymer structures that were fabricated using PBW. This method opens up new avenues for utilizing PBW for making metamaterials and other sub-wavelength metallic structures. Several potential applications of three dimensional metamaterials fabricated using PBW are discussed, including sensing and negative refractive index materials.

  11. Single cell electroporation using proton beam fabricated biochips

    NASA Astrophysics Data System (ADS)

    Homhuan, S.; Zhang, B.; Sheu, F.-S.; Bettiol, A. A.; Watt, F.

    2010-05-01

    We report the design and fabrication of a novel single cell electroporation biochip fabricated by the Proton Beam Writing technique (PBW), a new technique capable of direct-writing high-aspect-ratio nano and microstructures. The biochip features nickel micro-electrodes with straight-side walls between which individual cells are positioned. By applying electrical impulses across the electrodes, SYTOX® Green nucleic acid stain is incorporated into mouse neuroblastoma (N2a) cells. When the stain binds with DNA inside the cell nucleus, green fluorescence is observed upon excitation from a halogen lamp. Three parameters; electric field strength, pulse duration, and the number of pulses have been considered and optimized for the single cell electroporation. The results show that our biochip gives successfully electroporated cells . This single cell electroporation system represents a promising method for investigating the introduction of a wide variety of fluorophores, nanoparticles, quantum dots, DNAs and proteins into cells.

  12. Equation Of State Measurements of Warm Dense Copper Heated By Laser Accelerated Proton Beams

    NASA Astrophysics Data System (ADS)

    Dyer, Gilliss; Feldman, Samuel; Kuk, Donghoon; Wagner, Craig; Gaul, Erhard; Donovan, Michael; Martinez, Mikael; Borger, Teddy; Spinks, Michael; Jiang, Sheng; Aymond, Franki; Akli, Kramer; Ditmire, Todd

    2014-10-01

    We report equation of state (EOS) measurements of solid density transition metals heated to temperatures of 1 to 50 eV by laser accelerated pulsed proton beams. Matter at these densities and temperatures, referred to as warm dense matter (WDM), will exhibit long-range coupling, partial ionization and thermal energies comparable to the Fermi energy, making theoretical predictions of state properties very challenging. Mbar pressures likewise make such states difficult to study in the lab. In this work we use a terawatt or petawatt laser to accelerate MeV protons from a source foil, which then heat an adjacent sample foil. We probe the sample foil on a picosecond timescale using streaked optical pyrometery, time resolved interferometry, and XUV imaging. Previously we and various other groups have applied these techniques to the study of aluminum, one of the best-understood metals from the standpoint of high energy density equations of state. Here we present measurements of Cu, Cr, and Ag. Transition metals such as these are of particular interest because of modeling challenges posed by a partially filled d - orbital.

  13. Microdosimetric relative biological effectiveness of therapeutic proton beams.

    PubMed

    Tung, Chuan-Jong

    2015-01-01

    When compared to photon beams, particle beams have distinct spatial distributions on the energy depositions in both the macroscopic and microscopic volumes. In a macroscopic volume, the absorbed dose distribution shows a rapid increase near the particle range, that is, Bragg peak, as particle penetrates deep inside the tissue. In a microscopic volume, individual particle deposits its energy along the particle track by producing localized ionizations through the formation of clusters. These highly localized clusters can induce complex types of deoxyribonucleic acid (DNA) damage which are more difficult to repair and lead to higher relative biological effectiveness (RBE) as compared to photons. To describe the biological actions, biophysical models on a microscopic level have been developed. In this review, microdosimetric approaches are discussed for the determination of RBE at different depths in a patient under particle therapy. These approaches apply the microdosimetric lineal energy spectra obtained from measurements or calculations. Methods to determine these spectra will be focused on the tissue equivalent proportional counter and the Monte Carlo program. Combining the lineal energy spectrum and the biological model, RBE can be determined. Three biological models are presented. A simplified model applies the dose-mean lineal energy and the measured RBE (linear energy transfer) data. A more detailed model makes use of the full lineal energy spectrum and the biological weighting function spectrum. A comprehensive model calculates the spectrum-averaged yields of DNA damages caused by all primary and secondary particles of a particle beam. Results of these models are presented for proton beams. PMID:26459792

  14. Exit Dose Measurement in Therapeutic High Energy Photon Beams and Cobalt-60 Gamma Rays

    NASA Astrophysics Data System (ADS)

    Sathiyan, S.; Ravikumar, M.

    2007-01-01

    To estimate the skin dose to the patient from the treatment planning, the knowledge about exit dose is essential, which is calculated from the percentage depth dose. In this study 6 MV and 18 MV beams from linear accelerator and cobalt-60 beams were used. The ionometric measurements were carried out with parallel plate chamber of sensitive volume 0.16 cc. Parallel plate chamber was fitted in to 30 x 30 cm2 polystyrene phantom at a fixed FSD with the measuring entrance window facing farther from the source. The field size for this measuring condition was maintained at 10 x 10 cm2. The ionization measurements were also carried out by changing the thickness of the polystyrene phantom at the entrance side of the point of measurement. In order to find out the variation of relative exit dose (RED) with field size the measurements were carried out without and with the full back-scattering material (27.2 gm/cm2) placed beyond the entrance window of the chamber. The measurements were also done for the entrance polystyrene phantom thicknesses of 10, 20 and 30 cm for the field size ranging from 5 x 5 cm2 to 30 x 30 cm2. The dose at the exit surface with no backscatter material is about 4.4%, 3.7% and 5.8% less than the dose with the full backscatter material present beyond the point of measurement for 6 MV, 18 MV X-rays and cobalt-60 gamma rays. The reduction in exit dose does not depend much of the phantom thickness through which the beam traverses before exiting at the chamber side. Dose enhancements of about 1.03 times were observed for a field size of 5 x 5 cm2 for 6 MV, 18 MV X-rays and cobalt-60 gamma rays. The dose enhancement factor (DEF) values were noticed to vary with field size beyond 15 x 15 cm2 for all the energies studied. Also it can be observed that the dose enhancement factor (DEF) values do not depend on the thickness of the phantom material through which the beam has traversed. The DEF values were found to vary marginally for different phantom material

  15. Use of proton beams with breast prostheses and tissue expanders

    SciTech Connect

    Moyers, Michael F.; Mah, Dennis; Boyer, Sean P.; Chang, Chang; Pankuch, Mark

    2014-04-01

    Since the early 2000s, a small but rapidly increasing number of patients with breast cancer have been treated with proton beams. Some of these patients have had breast prostheses or tissue expanders in place during their courses of treatment. Procedures must be implemented to plan the treatments of these patients. The density, kilovoltage x-ray computed tomography numbers (kVXCTNs), and proton relative linear stopping powers (pRLSPs) were calculated and measured for several test sample devices. The calculated and measured kVXCTNs of saline were 1% and 2.4% higher than the values for distilled water while the calculated RLSP for saline was within 0.2% of the value for distilled water. The measured kVXCTN and pRLSP of the silicone filling material for the test samples were approximately 1120 and 0.935, respectively. The conversion of kVXCTNs to pRLSPs by the treatment planning system standard tissue conversion function is adequate for saline-filled devices but for silicone-filled devices manual reassignment of the pRLSPs is required.

  16. Dosimetric properties of high energy current (HEC) detector in keV x-ray beams.

    PubMed

    Zygmanski, Piotr; Shrestha, Suman; Elshahat, Bassem; Karellas, Andrew; Sajo, Erno

    2015-04-01

    We introduce a new x-ray radiation detector. The detector employs high-energy current (HEC) formed by secondary electrons consisting predominantly of photoelectrons and Auger electrons, to directly convert x-ray energy to detector signal without externally applied power and without amplification. The HEC detector is a multilayer structure composed of thin conducting layers separated by dielectric layers with an overall thickness of less than a millimeter. It can be cut to any size and shape, formed into curvilinear surfaces, and thus can be designed for a variety of QA applications. We present basic dosimetric properties of the detector as function of x-ray energy, depth in the medium, area and aspect ratio of the detector, as well as other parameters. The prototype detectors show similar dosimetric properties to those of a thimble ionization chamber, which operates at high voltage. The initial results obtained for kilovoltage x-rays merit further research and development towards specific medical applications. PMID:25789488

  17. An Experiment To Demonstrate Spacecraft Power Beaming and Solar Cell Annealing Using High-Energy Lasers

    NASA Astrophysics Data System (ADS)

    Luce, Richard; Michael, Sherif

    2003-05-01

    Satellite lifetime is often limited by degradation of the electrical power subsystem, e.g. radiation-damaged solar arrays or failed batteries. Being able to beam power from terrestrial sites could alleviate this limitation, extending the lifetime of billions of dollars of satellite assets, as well as providing additional energy for electric propulsion that can be used for stationkeeping and orbital changes. In addition, laboratory research at the Naval Postgraduate School (NPS) has shown the potential to anneal damaged solar cells using lasers. This paper describes that research and a proposed Maui experiment to demonstrate the relevant concepts by lasing PANSAT, an NPS-built and operated spacecraft.

  18. Comparative Studies of Hard X-Ray Spectral Evolution in Solar Flares with High-Energy Proton Events Observed at Earth

    NASA Astrophysics Data System (ADS)

    Kiplinger, Alan L.

    1995-11-01

    This paper presents the results of two extensive studies of hard X-ray spectral evolution in solar flares and their associations with energetic interplanetary proton events. The focus of this work is to establish the degree to which events that display progressively hardening hard X-ray spectra, at any time and over all observable timescales, are associated with high-energy interplanetary proton events. The first study examined a sample of 152 hard X-ray flares well observed with the HXRBS instrument on the Solar Maximum Mission (SMM). The study showed that 22 events revealed a progressive spectral hardening either over flux peaks (i.e., a soft-hard- harder spectral evolution) or during flux decays and that 18 of these 22 events (82%) had associated 10 MeV proton events or enhancements. Conversely, the absence of spectral hardening is associated with the absence of interplanetary protons with 124 of the 130 remaining flares (95.4%). Since the hard X-ray counting rate threshold of the first study was sufficiently high (5000 counts s-1) to exclude many flares (more than 36%) associated with the largest interplanetary proton events, a second study was conducted using 193 less intense HXRBS events (a one out of three sample) and their associations with only large proton events. This study also identifies events with progressive spectral hardening. It also employs selection criteria suggested by the results of the first study to "predict" which flares would or would not have associated large proton events. This prescription for "predicting" proton events did so correctly for four large (SESC qualified) proton events, missed none, and produced only one "false alarm" in which the criteria were met but only a small proton event was seen at earth. Thus, a correct "prediction" was made for all but one of the 193 events. The results of the first study are then combined with the weighted results of the one out of three study, using the same selection criteria, to project

  19. Electron beam effective source surface distances for a high energy linear accelerator.

    PubMed

    Sharma, S C; Johnson, M W

    1991-06-01

    The design of the Varian Clinac 1800 linear accelerator electron applicator system does not allow clearance for all head and neck patients to be treated at the standard calibration distance of 100 cm. Discrepancies have been found between dose calculations using the inverse square law for extended distances and their measured data. A 4 X 4 cm2 applicator at an energy of 9 MeV, for example, had dose differences of 13 and 23% at distances of 105 and 110 cm SSD. Because of these discrepancies, effective source surface distances (SSDeff) were determined for all the standard electron energies and applicators of a Clinac 1800. These effective source surface distances ranged from 41.6 cm to 92.6 cm for the 4 X 4 cm2 cone/6 MeV electron beam through the 25 X 25 cm2 cone/20 MeV electron beam. A summary of these distances and an analysis of the clinical use of both a best fit SSDeff and a common SSDeff for patient dosimetry calculations is presented. PMID:1907830

  20. Induction of Cell Death through Alteration of Oxidants and Antioxidants in Epithelial Cells Exposed to High Energy Protons

    NASA Technical Reports Server (NTRS)

    Ramesh, Govindarajan; Wu, Honglu

    2012-01-01

    Radiation affects several cellular and molecular processes including double strand breakage, modifications of sugar moieties and bases. In outer space, protons are the primary radiation source which poses a range of potential health risks to astronauts. On the other hand, the use of proton radiation for tumor radiation therapy is increasing as it largely spares healthy tissues while killing tumor tissues. Although radiation related research has been conducted extensively, the molecular toxicology and cellular mechanisms affected by proton radiation remain poorly understood. Therefore, in the present study, we irradiated rat epithelial cells (LE) with different doses of protons and investigated their effects on cell proliferation and cell death. Our data showed an inhibition of cell proliferation in proton irradiated cells with a significant dose dependent activation and repression of reactive oxygen species (ROS) and antioxidants, glutathione and superoxide dismutase respectively as compared to control cells. In addition, apoptotic related genes such as caspase-3 and -8 activities were induced in a dose dependent manner with corresponding increased levels of DNA fragmentation in proton irradiated cells than control cells. Together, our results show that proton radiation alters oxidant and antioxidant levels in the cells to activate apoptotic pathway for cell death.

  1. Induction of Cell Death Through Alteration of Oxidants and Antioxidants in Epithelial Cells Exposed to High Energy Protons

    NASA Astrophysics Data System (ADS)

    Ramesh, Govindarajan; Wu, Honglu

    2012-07-01

    Radiation affects several cellular and molecular processes including double strand breakage, modifications of sugar moieties and bases. In outer space, protons are the primary radiation source which poses a range of potential health risks to astronauts. On the other hand, the use of proton radiation for tumor radiation therapy is increasing as it largely spares healthy tissues while killing tumor tissues. Although radiation related research has been conducted extensively, the molecular toxicology and cellular mechanisms affected by proton radiation remain poorly understood. Therefore, in the present study, we irradiated rat epithelial cells (LE) with different doses of protons and investigated their effects on cell proliferation and cell death. Our data showed an inhibition of cell proliferation in proton irradiated cells with a significant dose dependent activation and repression of reactive oxygen species (ROS) and antioxidants, glutathione and superoxide dismutase respectively as compared to control cells. In addition, apoptotic related genes such as caspase-3 and -8 activities were induced in a dose dependent manner with corresponding increased levels of DNA fragmentation in proton irradiated cells than control cells. Together, our results show that proton radiation alters oxidant and antioxidant levels in the cells to activate apoptotic pathway for cell death.

  2. Fusion Energy and Stopping Power in a Degenerate DT Pellet Driven by a Laser-Accelerated Proton Beam

    NASA Astrophysics Data System (ADS)

    Mehrangiz, M.; Ghasemizad, A.; Jafari, S.; Khanbabaei, B.

    2016-06-01

    In this paper, we have improved the fast ignition scheme in order to have more authority needed for high-energy-gain. Due to the more penetrability and energy deposition of the particle beams in fusion targets, we employ a laser-to-ion converter foil as a scheme for generating energetic ion beams to ignite the fusion fuel. We find the favorable intensity and wavelength of incident laser by evaluating the laser-proton conversion gain. By calculating the source-target distance, proton beam power and energy are estimated. Our analysis is generalized to the plasma degeneracy effects which can increase the fusion gain several orders of magnitude by decreasing the ion-electron collisions in the plasma. It is found that the wavelength of 0.53 μm and the intensity of about 1020 W/cm2, by saving about 10% conversion coefficient, are the suitable measured values for converting a laser into protons. Besides, stopping power and fusion burn calculations have been done in degenerate and non-degenerate plasma mediums. The results indicate that in the presence of degeneracy, the rate of fusion enhances. Supported by the Research Council of University of Guilan

  3. MO-H-19A-01: FEATURED PRESENTATION - Treatment Planning Tool for Radiotherapy with Very High-Energy Electron Beams

    SciTech Connect

    Bazalova, M; Qu, B; Palma, B; Loo, B; Maxim, P; Hynning, E; Hardemark, B

    2014-06-15

    Purpose: To develop a tool for treatment planning optimization for fast radiotherapy delivered with very high-energy electron beams (VHEE) and to compare VHEE plans to state-of-the-art plans for challenging pelvis and H'N cases. Methods: Treatment planning for radiotherapy delivered with VHEE scanning pencil beams was performed by integrating EGSnrc Monte Carlo (MC) dose calculations with spot scanning optimization run in a research version of RayStation. A Matlab GUI for MC beamlet generation was developed, in which treatment parameters such as the pencil beam size and spacing, energy and number of beams can be selected. Treatment planning study for H'N and pelvis cases was performed and the effect of treatment parameters on the delivered dose distributions was evaluated and compared to the clinical treatment plans. The pelvis case with a 691cm3 PTV was treated with 2-arc 15MV VMAT and the H'N case with four PTVs with total volume of 531cm3 was treated with 4-arc 6MV VMAT. Results: Most studied VHEE plans outperformed VMAT plans. The best pelvis 80MeV VHEE plan with 25 beams resulted in 12% body dose sparing and 8% sparing to the bowel and right femur compared to the VMAT plan. The 100MeV plan was superior to the 150MeV plan. Mixing 100 and 150MeV improved dose sparing to the bladder by 7% compared to either plan. Plans with 16 and 36 beams did not significantly affect the dose distributions compared to 25 beam plans. The best H'N 100MeV VHEE plan decreased mean doses to the brainstem, chiasm, and both globes by 10-42% compared to the VMAT plan. Conclusion: The pelvis and H'N cases suggested that sixteen 100MeV beams might be sufficient specifications of a novel VHEE treatment machine. However, optimum machine parameters will be determined with the presented VHEE treatment-planning tool for a large number of clinical cases. BW Loo and P Maxim received research support from RaySearch Laboratories. E Hynning and B Hardemark are employees of RaySearch Laboratories.

  4. Dose-volume delivery guided proton therapy using beam on-line PET system

    SciTech Connect

    Nishio, Teiji; Ogino, Takashi; Nomura, Kazuhiro; Uchida, Hiroshi

    2006-11-15

    Proton therapy is one form of radiotherapy in which the irradiation can be concentrated on a tumor using a scanned or modulated Bragg peak. Therefore, it is very important to evaluate the proton-irradiated volume accurately. The proton-irradiated volume can be confirmed by detection of pair annihilation gamma rays from positron emitter nuclei generated by the target nuclear fragment reaction of irradiated proton nuclei and nuclei in the irradiation target using a positron emission tomography (PET) apparatus, and dose-volume delivery guided proton therapy (DGPT) can thereby be achieved using PET images. In the proton treatment room, a beam ON-LINE PET system (BOLPs) was constructed so that a PET apparatus of the planar-type with a high spatial resolution of about 2 mm was mounted with the field of view covering the isocenter of the beam irradiation system. The position and intensity of activity were measured using the BOLPs immediately after the proton irradiation of a gelatinous water target containing {sup 16}O nuclei at different proton irradiation energy levels. The change of the activity-distribution range against the change of the physical range was observed within 2 mm. The experiments of proton irradiation to a rabbit and the imaging of the activity were performed. In addition, the proton beam energy used to irradiate the rabbit was changed. When the beam condition was changed, the difference between the two images acquired from the measurement of the BOLPs was confirmed to clearly identify the proton-irradiated volume.

  5. Monte Carlo comparison of x-ray and proton CT for range calculations of proton therapy beams.

    PubMed

    Arbor, N; Dauvergne, D; Dedes, G; Létang, J M; Parodi, K; Quiñones, C T; Testa, E; Rit, S

    2015-10-01

    Proton computed tomography (CT) has been described as a solution for imaging the proton stopping power of patient tissues, therefore reducing the uncertainty of the conversion of x-ray CT images to relative stopping power (RSP) maps and its associated margins. This study aimed to investigate this assertion under the assumption of ideal detection systems. We have developed a Monte Carlo framework to assess proton CT performances for the main steps of a proton therapy treatment planning, i.e. proton or x-ray CT imaging, conversion to RSP maps based on the calibration of a tissue phantom, and proton dose simulations. Irradiations of a computational phantom with pencil beams were simulated on various anatomical sites and the proton range was assessed on the reference, the proton CT-based and the x-ray CT-based material maps. Errors on the tissue's RSP reconstructed from proton CT were found to be significantly smaller and less dependent on the tissue distribution. The imaging dose was also found to be much more uniform and conformal to the primary beam. The mean absolute deviation for range calculations based on x-ray CT varies from 0.18 to 2.01 mm depending on the localization, while it is smaller than 0.1 mm for proton CT. Under the assumption of a perfect detection system, proton range predictions based on proton CT are therefore both more accurate and more uniform than those based on x-ray CT. PMID:26378805

  6. Monte Carlo comparison of x-ray and proton CT for range calculations of proton therapy beams

    NASA Astrophysics Data System (ADS)

    Arbor, N.; Dauvergne, D.; Dedes, G.; Létang, J. M.; Parodi, K.; Quiñones, C. T.; Testa, E.; Rit, S.

    2015-10-01

    Proton computed tomography (CT) has been described as a solution for imaging the proton stopping power of patient tissues, therefore reducing the uncertainty of the conversion of x-ray CT images to relative stopping power (RSP) maps and its associated margins. This study aimed to investigate this assertion under the assumption of ideal detection systems. We have developed a Monte Carlo framework to assess proton CT performances for the main steps of a proton therapy treatment planning, i.e. proton or x-ray CT imaging, conversion to RSP maps based on the calibration of a tissue phantom, and proton dose simulations. Irradiations of a computational phantom with pencil beams were simulated on various anatomical sites and the proton range was assessed on the reference, the proton CT-based and the x-ray CT-based material maps. Errors on the tissue’s RSP reconstructed from proton CT were found to be significantly smaller and less dependent on the tissue distribution. The imaging dose was also found to be much more uniform and conformal to the primary beam. The mean absolute deviation for range calculations based on x-ray CT varies from 0.18 to 2.01 mm depending on the localization, while it is smaller than 0.1 mm for proton CT. Under the assumption of a perfect detection system, proton range predictions based on proton CT are therefore both more accurate and more uniform than those based on x-ray CT.

  7. Measurements of yields of fission products in the reaction of {sup 238}U with high-energy p, d and n beams

    SciTech Connect

    Nolen, J.A.; Ahmad, I.; Back, B.B.

    1995-08-01

    An experiment was performed at the Michigan State University cyclotron to determine the yields of neutron-rich fission products in the reaction of {sup 238}U with 100-MeV neutrons, 200-MeV deuterons and 200-MeV protons. Several 1-mm-thick {sup 238}U foils were irradiated for 100-second intervals sequentially for each configuration and the ten spectra were added for higher statistics. The three successive spectra, each for a 40 s period, were accumulated for each sample. Ten foils were irradiated. Successive spectra allowed us to determine approximate half-lives of the gamma peaks. Several arrangements, which were similar to the setup we plan to use in our radioactive beam proposal, were used for the production of fission products. For the high-energy neutron irradiation, U foils were placed after a 5-inch-long, 1-inch-diameter Be cylinder which stopped the 200-MeV deuteron beam generating 100-MeV neutrons. Arrangements for deuteron irradiation included direct irradiation of U foils, placing U foils after different lengths of (0.5 inch, 1.0 inch and 1.5 inch) 2-inch diameter U cylinder. Since the deuteron range in uranium is 17 mm, some of the irradiations were due to the secondary neutrons from the deuteron-induced fission of U. Similar arrangements were also used for the 200-MeV proton irradiation of the {sup 238}U foils. In all cases, several neutron-rich fission products were identified and their yields determined. In particular, we were able to observe Sn in all the runs and determine its yield. The data show that with our proposed radioactive device we will be able to produce more than 10{sup 12} {sup 132}Sn atoms per second in the target. Assuming an overall efficiency of 1 %, we will be able to deliver one particle nanoampere of {sup 132}Sn beam at a target location. Detailed analysis of the {gamma}-ray spectra is in progress.

  8. Determination of Endpoint Energy and Bremsstrahlung Spectra for High-Energy Radiation-Therapy Beams

    NASA Astrophysics Data System (ADS)

    Landry, Danny Joe

    Few attempts have been made to experimentally determine thick-target bremsstrahlung spectra of megavoltage therapy beams. For spectral studies using the Compton scattering technique, sodium iodine (NaI) detectors with relatively poor energy resolution have been used. Other experimental techniques for determining spectra are generally not suited for a clinical environment with the inherent time and space constraints. To gather more spectral information than previously obtained in the region near the endpoint energy, the use of a high-resolution intrinsic-germanium (Ge) detector was proposed. A response function matrix was determined from experimentally obtained pulse height distributions on the multichannel analyzer. The distributions were for nine various monoenergetic sources between 280 adn 1525 keV. The response function was used to convert the measured pulse height distributions to photon flux spectra using an iterative approximation technique with a computer. Photon flux spectra from the Sagittaire Linear Accelerator were obtained at average-electron endpoint energies of 15, 20, and 25 MeV. Two spectra were measured at the 25 MeV setting; one spectrum was measured along the central axis and one spectrum at 4(DEGREES) off axis. Photon spectra were also obtained for a Van de Graaff generator at the nominal endpoint energies of 2.2, 2.35, and 2.5 MeV. The results for both the linac and the Van de Graaff generator were compared with theoretical spectra and previously measured spectra where available. Also, photon spectra from a Theratron-80 (('60)Co) unit were determined for three field sizes and for a 10 x 10 cm. field with a lucite tray or a 45(DEGREES) wedge in the beam. The resulting spectra were compared to previously measured ('60)Co spectra.

  9. Efficiency improvements for ion chamber calculations in high energy photon beams.

    PubMed

    Wulff, J; Zink, K; Kawrakow, I

    2008-04-01

    This article presents the implementation of several variance reduction techniques that dramatically improve the simulation efficiency of ion chamber dose and perturbation factor calculations. The cavity user code for the EGSnrc Monte Carlo code system is extended by photon cross-section enhancement (XCSE), an intermediate phase-space storage (IPSS) technique, and a correlated sampling (CS) scheme. XCSE increases the density of photon interaction sites inside and in the vicinity of the chamber and results-in combination with a Russian Roulette game for electrons that cannot reach the cavity volume-in an increased efficiency of up to a factor of 350 for calculating dose in a Farmer type chamber placed at 10 cm depth in a water phantom. In combination with the IPSS and CS techniques, the efficiency for the calculation of the central electrode perturbation factor Pcel can be increased by up to three orders of magnitude for a single chamber location and by nearly four orders of magnitude when considering the Pcel variation with depth or with distance from the central axis in a large field photon beam. The intermediate storage of the phase-space properties of particles entering a volume that contains many possible chamber locations leads to efficiency improvements by a factor larger than 500 when computing a profile of chamber doses in the field of a linear accelerator photon beam. All techniques are combined in a new EGSnrc user code egs_chamber. Optimum settings for the variance reduction parameters are investigated and are reported for a Farmer type ion chamber. A few example calculations illustrating the capabilities of the egs_chamber code are presented. PMID:18491527

  10. Efficiency improvements for ion chamber calculations in high energy photon beams

    SciTech Connect

    Wulff, J.; Zink, K.; Kawrakow, I.

    2008-04-15

    This article presents the implementation of several variance reduction techniques that dramatically improve the simulation efficiency of ion chamber dose and perturbation factor calculations. The cavity user code for the EGSnrc Monte Carlo code system is extended by photon cross-section enhancement (XCSE), an intermediate phase-space storage (IPSS) technique, and a correlated sampling (CS) scheme. XCSE increases the density of photon interaction sites inside and in the vicinity of the chamber and results - in combination with a Russian Roulette game for electrons that cannot reach the cavity volume - in an increased efficiency of up to a factor of 350 for calculating dose in a Farmer type chamber placed at 10 cm depth in a water phantom. In combination with the IPSS and CS techniques, the efficiency for the calculation of the central electrode perturbation factor P{sub cel} can be increased by up to three orders of magnitude for a single chamber location and by nearly four orders of magnitude when considering the P{sub cel} variation with depth or with distance from the central axis in a large field photon beam. The intermediate storage of the phase-space properties of particles entering a volume that contains many possible chamber locations leads to efficiency improvements by a factor larger than 500 when computing a profile of chamber doses in the field of a linear accelerator photon beam. All techniques are combined in a new EGSnrc user code egs{sub c}hamber. Optimum settings for the variance reduction parameters are investigated and are reported for a Farmer type ion chamber. A few example calculations illustrating the capabilities of the egs{sub c}hamber code are presented.

  11. Diamond detector in absorbed dose measurements in high-energy linear accelerator photon and electron beams.

    PubMed

    Ravichandran, Ramamoorthy; Binukumar, John Pichy; Al Amri, Iqbal; Davis, Cheriyathmanjiyil Antony

    2016-01-01

    Diamond detectors (DD) are preferred in small field dosimetry of radiation beams because of small dose profile penumbras, better spatial resolution, and tissue-equivalent properties. We investigated a commercially available 'microdiamond' detector in realizing absorbed dose from first principles. A microdiamond detector, type TM 60019 with tandem electrometer is used to measure absorbed doses in water, nylon, and PMMA phantoms. With sensitive volume 0.004 mm3, radius 1.1mm, thickness 1 x10(-3) mm, the nominal response is 1 nC/Gy. It is assumed that the diamond detector could collect total electric charge (nC) developed during irradiation at 0 V bias. We found that dose rate effect is less than 0.7% for changing dose rate by 500 MU/min. The reproducibility in obtaining readings with diamond detector is found to be ± 0.17% (1 SD) (n = 11). The measured absorbed doses for 6 MV and 15 MV photons arrived at using mass energy absorption coefficients and stop-ping power ratios compared well with Nd, water calibrated ion chamber measured absorbed doses within 3% in water, PMMA, and nylon media. The calibration factor obtained for diamond detector confirmed response variation is due to sensitivity due to difference in manufacturing process. For electron beams, we had to apply ratio of electron densities of water to carbon. Our results qualify diamond dosimeter as a transfer standard, based on long-term stability and reproducibility. Based on micro-dimensions, we recommend these detectors for pretreatment dose verifications in small field irradiations like stereotactic treatments with image guidance. PMID:27074452

  12. Clinical results of proton beam therapy for advanced neuroblastoma

    PubMed Central

    2013-01-01

    Purpose To evaluate the efficacy of proton beam therapy (PBT) for pediatric patients with advanced neuroblastoma. Methods PBT was conducted at 21 sites in 14 patients with neuroblastoma from 1984 to 2010. Most patients were difficult to treat with photon radiotherapy. Two and 6 patients were classified into stages 3 and 4, respectively, and 6 patients had recurrent disease. Seven of the 8 patients who received PBT as the initial treatment were classified as the high risk group. Twelve patients had gross residual disease before PBT and 2 had undergone intraoperative radiotherapy before PBT. Five patients received PBT for multiple sites, including remote metastases. Photon radiotherapy was used in combination with PBT for 3 patients. The PBT doses ranged from 19.8 to 45.5 GyE (median: 30.6 GyE). Results Seven patients are alive with no evidence of disease, 1 is alive with disease progression, and 6 died due to the tumor. Recurrence in the treatment field was not observed and the 3-year locoregional control rate was 82%. Severe acute radiotoxicity was not observed, but 1 patient had narrowing of the aorta and asymptomatic vertebral compression fracture at 28 years after PBT, and hair loss was prolonged in one patient. Conclusion PBT may be a better alternative to photon radiotherapy for children with advanced neuroblastoma, and may be conducted safely for patients with neuroblastoma that is difficult to manage using photon beams. PMID:23758770

  13. Spectroscopic characterization of high-energy and high fluence rate photon beams

    NASA Astrophysics Data System (ADS)

    Bartol, Laura J.

    High-energy, high fluence rate photon sources are used in radiation oncology for the treatment of a variety of disease sites. Common dosimetry methods for characterizing these sources use energy-integrating devices; however, the most descriptive characterization of these sources are performed with devices that preserve the energy-specific information in the source output. This work used Monte-Carlo- (MC-) and measurement-based spectroscopic methods to characterize two therapeutic-level megavoltage photon sources. MC simulations were performed using the MCNP5 transport code and measurements were performed with a Compton-scattering (CS) technique. Because MC was used extensively in this work, some general MCNP5 investigations were performed to benchmark the techniques used. Limitations in the advanced variance reduction techniques, Doppler-broadening model, and use of phase space files were investigated. Based on the results of these investigations, recommendations were made for using each technique. The validity of the CS technique for use with megavoltage systems was demonstrated using MC simulations of a 6 MV linear accelerator field and measurements of a high dose rate 192Ir source. Following these initial demonstrations, the spectrum of a 60Co teletherapy unit was characterized. Simulations were performed to determine the spectrum's sensitivity to the source model. Multiple measurements were completed using a reverse-electrode germanium (REGe) detector with the CS spectrometry technique. The CS spectra were corrected for detector response and the CS geometry using a novel detector response function that was calculated using MCNP5. The detector response was unfolded using the Gold deconvolution method. Comparisons of the simulated and measured spectra showed agreement in terms of the peak positions, mean spectrum energy, and relative fluences under specific portions of the spectra. The spectrum of a 6 MV photon field from a Varian Clinac iX linear accelerator was

  14. TRANSVERSE ELECTRON-PROTON TWO-STREAM INSTABILITY IN A BUNCHED BEAM

    SciTech Connect

    Wang, T. F.; Channell, Paul J.; Macek, R. J.; Davidson, Ronald C.

    2001-01-01

    For intense proton beams, the focus of recent two-stream instability analyses has been on the transverse instability observed in the Proton Storage Ring (PSR) at Los Alamos National Laboratory. The PSR stores a long proton bunch with a near triangular line density profile for a duration of about one millisecond. The instability is observed as rapidly growing transverse oscillations of the stored beam, usually occuring when the beam intensity reaches 2.5 x 10{sup 13} ppp or higher, causing fast beam loss. Experimental results support the conjecture that the instability in PSR is due to the two-stream interaction between the circulating proton beam and the electrons created in the ring, i.e., the so called e-p instability. However, the understanding of the physics of this instability is usually based on the theory developed for a continuous beam of uniform line density. Although computer simulations have been implemented or are being developed to study the e-p instability in bunched beams, a companion analytical theory still remains to be developed. The present work is an attempt to investigate the transverse e-p instability in a proton bunch using an analytical approach based on the centroid model built on the 'one-pass' interaction between the protons and the electrons. This paper is an analytical investigation of the transverse electron-proton (e-p) two-stream instability in a proton bunch propagating through a stationary electron background. The equations of motion, including the effect of damping, are derived for the centroids of the proton beam and the electron cloud. An approach is developed to solve the coupled linear centroid equations in the time domain describing the e-p instability in proton bunches with nonuniform line densities. Examples are presented for proton line densities corresponding to uniform and parabolic profiles.

  15. Pore structure modification of diatomite as sulfuric acid catalyst support by high energy electron beam irradiation and hydrothermal treatment

    NASA Astrophysics Data System (ADS)

    Li, Chong; Zhang, Guilong; Wang, Min; Chen, Jianfeng; Cai, Dongqing; Wu, Zhengyan

    2014-08-01

    High energy electron beam (HEEB) irradiation and hydrothermal treatment (HT), were applied in order to remove the impurities and enlarge the pore size of diatomite, making diatomite more suitable to be a catalyst support. The results demonstrated that, through thermal, charge, impact and etching effects, HEEB irradiation could make the impurities in the pores of diatomite loose and remove some of them. Then HT could remove rest of them from the pores and contribute significantly to the modification of the pore size distribution of diatomite due to thermal expansion, water swelling and thermolysis effects. Moreover, the pore structure modification improved the properties (BET (Brunauer-Emmett-Teller) specific surface area, bulk density and pore volume) of diatomite and the catalytic efficiency of the catalyst prepared from the treated diatomite.

  16. Micro-nanopores fabricated by high-energy electron beam irradiation: suitable structure for controlling pesticide loss.

    PubMed

    Xiang, Yubin; Wang, Ning; Song, Jimei; Cai, Dongqing; Wu, Zhengyan

    2013-06-01

    Pesticide sprayed onto crop leaves tends to be washed off by rainwater and discharge into the environment through leaching and runoff, resulting in severe pollution to both soil and water. Here, to control pesticide loss, we developed a loss-control pesticide (LCP) by adding modified natural nanoclay (diatomite) through high-energy electron beam (HEEB) to traditional pesticide. After HEEB treatment, the originally clogged pores in diatomite opened, resulting in plenty of micro-nanopores in diatomite, which are beneficial for the pesticide molecules to access and be adsorbed. This pesticide-diatomite complex tended to be retained by the rough surface of crop leaves, displaying a high adhesion performance onto the leaves, so that the pesticide loss reduced, sufficient pesticide for crops was supplied, and the pollution risk of the pesticide could be substantially lowered. PMID:23672373

  17. High Energy Density Physics Research Using Intense Heavy Ion Beam at FAIR: The HEDgeHOB Program

    NASA Astrophysics Data System (ADS)

    Tahir, N. A.; Shutov, A.; Piriz, A. R.; Deutsch, C.; Stöhlker, Th.

    2016-03-01

    International project, Facility for Antiprotons and Ion Research (FAIR), has entered in its construction phase at Darmstadt. It is expected that the new powerful heavy ion synchrotron, SIS100 will deliver a strongly bunched intense beam of energetic uranium ions that will provide the scientists with an efficient and novel tool to research High Energy Density (HED) Physics in the laboratory. Over the past 15 years, substantial theoretical work has been done to design numerous experiments that can be done at this facility in this field. This work has resulted in an extensive scientific proposal named HEDgeHOB, that includes experiment proposals addressing various aspects of HED matter, for example, planetary physics, equation of state, hydrodynamic instabilities and others. In this paper we present a summary of this work.

  18. Numerical Modeling of Complex Targets for High-Energy- Density Experiments with Ion Beams and other Drivers

    DOE PAGESBeta

    Koniges, Alice; Liu, Wangyi; Lidia, Steven; Schenkel, Thomas; Barnard, John; Friedman, Alex; Eder, David; Fisher, Aaron; Masters, Nathan

    2016-03-01

    We explore the simulation challenges and requirements for experiments planned on facilities such as the NDCX-II ion accelerator at LBNL, currently undergoing commissioning. Hydrodynamic modeling of NDCX-II experiments include certain lower temperature effects, e.g., surface tension and target fragmentation, that are not generally present in extreme high-energy laser facility experiments, where targets are completely vaporized in an extremely short period of time. Target designs proposed for NDCX-II range from metal foils of order one micron thick (thin targets) to metallic foam targets several tens of microns thick (thick targets). These high-energy-density experiments allow for the study of fracture as wellmore » as the process of bubble and droplet formation. We incorporate these physics effects into a code called ALE-AMR that uses a combination of Arbitrary Lagrangian Eulerian hydrodynamics and Adaptive Mesh Refinement. Inclusion of certain effects becomes tricky as we must deal with non-orthogonal meshes of various levels of refinement in three dimensions. A surface tension model used for droplet dynamics is implemented in ALE-AMR using curvature calculated from volume fractions. Thick foam target experiments provide information on how ion beam induced shock waves couple into kinetic energy of fluid flow. Although NDCX-II is not fully commissioned, experiments are being conducted that explore material defect production and dynamics.« less

  19. Numerical Modeling of Complex Targets for High-Energy- Density Experiments with Ion Beams and other Drivers

    NASA Astrophysics Data System (ADS)

    Koniges, Alice; Liu, Wangyi; Lidia, Steven; Schenkel, Thomas; Barnard, John; Friedman, Alex; Eder, David; Fisher, Aaron; Masters, Nathan

    2016-03-01

    We explore the simulation challenges and requirements for experiments planned on facilities such as the NDCX-II ion accelerator at LBNL, currently undergoing commissioning. Hydrodynamic modeling of NDCX-II experiments include certain lower temperature effects, e.g., surface tension and target fragmentation, that are not generally present in extreme high-energy laser facility experiments, where targets are completely vaporized in an extremely short period of time. Target designs proposed for NDCX-II range from metal foils of order one micron thick (thin targets) to metallic foam targets several tens of microns thick (thick targets). These high-energy-density experiments allow for the study of fracture as well as the process of bubble and droplet formation. We incorporate these physics effects into a code called ALE-AMR that uses a combination of Arbitrary Lagrangian Eulerian hydrodynamics and Adaptive Mesh Refinement. Inclusion of certain effects becomes tricky as we must deal with non-orthogonal meshes of various levels of refinement in three dimensions. A surface tension model used for droplet dynamics is implemented in ALE-AMR using curvature calculated from volume fractions. Thick foam target experiments provide information on how ion beam induced shock waves couple into kinetic energy of fluid flow. Although NDCX-II is not fully commissioned, experiments are being conducted that explore material defect production and dynamics.

  20. Mechanical properties improvement of pulsed laser-deposited hydroxyapatite thin films by high energy ion-beam implantation

    NASA Astrophysics Data System (ADS)

    Nelea, V.; Pelletier, H.; Müller, D.; Broll, N.; Mille, P.; Ristoscu, C.; Mihailescu, I. N.

    2002-01-01

    Major problems in the hydroxyapatite (HA), Ca 5(PO 4) 3OH, thin films processing still keep the poor mechanical properties and the lack in density. We present a study on the feasibility of high energy ion-beam implantation technique to densify HA bioceramic films. Crystalline HA films were grown by pulsed laser deposition (PLD) method using an excimer KrF ∗ laser ( λ=248 nm, τ FWHM≥20 ns). The films were deposited on Ti-5Al-2.5Fe alloys substrates previously coated with a ceramic TiN buffer layer. After deposition the films were implanted with Ar + ions at high energy. Optical microscopy (OM), white light confocal microscopy (WLCM), grazing incidence X-ray diffraction (GIXRD) and Berkovich nanoindentation in normal and scratch options have been applied for the characterization of the obtained structures. We put into evidence an enhancement of the mechanical characteristics after implantation, while GIXRD measurements confirm that the crystalline structure of HA phase is preserved. The improvement in mechanical properties is an effect of a densification after ion treatment as a result of pores elimination and grains regrowth.

  1. Dose-calculation algorithms in the context of inhomogeneity corrections for high energy photon beams

    SciTech Connect

    Papanikolaou, Niko; Stathakis, Sotirios

    2009-10-15

    Radiation therapy has witnessed a plethora of innovations and developments in the past 15 years. Since the introduction of computed tomography for treatment planning there has been a steady introduction of new methods to refine treatment delivery. Imaging continues to be an integral part of the planning, but also the delivery, of modern radiotherapy. However, all the efforts of image guided radiotherapy, intensity-modulated planning and delivery, adaptive radiotherapy, and everything else that we pride ourselves in having in the armamentarium can fall short, unless there is an accurate dose-calculation algorithm. The agreement between the calculated and delivered doses is of great significance in radiation therapy since the accuracy of the absorbed dose as prescribed determines the clinical outcome. Dose-calculation algorithms have evolved greatly over the years in an effort to be more inclusive of the effects that govern the true radiation transport through the human body. In this Vision 20/20 paper, we look back to see how it all started and where things are now in terms of dose algorithms for photon beams and the inclusion of tissue heterogeneities. Convolution-superposition algorithms have dominated the treatment planning industry for the past few years. Monte Carlo techniques have an inherent accuracy that is superior to any other algorithm and as such will continue to be the gold standard, along with measurements, and maybe one day will be the algorithm of choice for all particle treatment planning in radiation therapy.

  2. High energy electron-beam irradiation effects in Si-SiOx structures

    NASA Astrophysics Data System (ADS)

    Nesheva, D.; Dzhurkov, V.; Šćepanović, M.; Bineva, I.; Manolov, E.; Kaschieva, S.; Nedev, N.; Dmitriev, S. N.; Popović, Z. V.

    2016-02-01

    Homogeneous SiOx films (x=1.3, 200 nm and 1000 nm thick) and composite a-Si-SiOy films (y ∼ 1.80) containing amorphous Si nanoparticles have been prepared on crystalline (c-Si) substrate. A part of the films was irradiated at temperature below 50°C by 20 MeV electrons with two different fluences (7.2x1014 and 1.44x1015 el.cm-2). Atomic force microscopy (AFM), Raman spectroscopy and capacitance (conductance) - voltage (C(G)-V) measurements on Al/c-Si/SiOx/Al or Al/c-Si/(a-Si-SiOy)/Al structures were used to get information about the irradiation induced changes in the surface morphology, the phase composition in the film bulk and at the Si-SiOx interface. The AFM results show that the electron irradiation decreases the film surface roughness of the films annealed at 250°C. The Raman scattering data imply appearance of amorphous silicon phase and some structural changes in the oxide matrix of the homogeneous SiOx films. In the composite films electron beam stimulated decrease of the defects at the a-Si/SiOy interface has been assumed. The initial C(G)-V results speak about electron induced formation of electrically active defects in the SiOy matrix of the composite films.

  3. MTBE and priority contaminant treatment with high energy electron beam injection

    NASA Astrophysics Data System (ADS)

    Cooper, William J.; Nickelsen, Michael G.; Mezyk, Stephen P.; Leslie, Greg; Tornatore, Paul M.; Hardison, Wayne; Hajali, Paris A.

    2002-11-01

    A study was conducted to examine the removal of methyl tert-butyl ether (MTBE) and 15 other organic compounds, as well as perchlorate ion, in waters of different quality. The 15 organic compounds consisted of halogenated solvents (chlorination), disinfection by-products, pesticides, and nitrosodimethylamine (NDMA). These studies were conducted using a pilot scale 20 kW mobile electron beam system at Water Factory 21, Orange County, CA where wastewater is treated and re-injected into the ground as a barrier to salt water intrusion. Future applications for this treated water include water reuse. Ground water and treated wastewater, after having gone through a reverse osmosis-polishing step (RO permeate), were used to prepare mixtures of the compounds. Using fundamental radiation chemistry, it was possible to examine the factors effecting removal efficiency of all the compounds as well as MTBE destruction and reaction by-product formation and removal. All of the organic compounds were destroyed in the studies and we also observed the destruction of perchlorate ion in one of the waters.

  4. A telescope proton recoil spectrometer for fast neutron beam-lines

    NASA Astrophysics Data System (ADS)

    Cazzaniga, C.; Rebai, M.; Tardocchi, M.; Croci, G.; Nocente, M.; Ansell, S.; Frost, C. D.; Gorini, G.

    2015-07-01

    Fast neutron measurements were performed on the VESUVIO beam-line at the ISIS spallation source using a new telescope proton recoil spectrometer. Neutrons interact on a plastic target. Proton production is mainly due to elastic scattering on hydrogen nuclei and secondly due to interaction with carbon nuclei. Recoil protons are measured by a proton spectrometer, which uses in coincidence a 2.54 cm thick YAP scintillator and a 500μm thick silicon detector, measuring the full proton recoil energy and the partial deposited energy in transmission, respectively. Recoil proton spectroscopy measurements (up to Ep = 60MeV) have been interpreted by using Monte Carlo simulations of the beam-line. This instrument is of particular interest for the characterization of the ChipIr beam-line at ISIS, which was designed to feature an atmospheric-like neutron spectrum for the irradiation of micro-electronics.

  5. High energy neutron radiography

    SciTech Connect

    Gavron, A.; Morley, K.; Morris, C.; Seestrom, S.; Ullmann, J.; Yates, G.; Zumbro, J.

    1996-06-01

    High-energy spallation neutron sources are now being considered in the US and elsewhere as a replacement for neutron beams produced by reactors. High-energy and high intensity neutron beams, produced by unmoderated spallation sources, open potential new vistas of neutron radiography. The authors discuss the basic advantages and disadvantages of high-energy neutron radiography, and consider some experimental results obtained at the Weapons Neutron Research (WNR) facility at Los Alamos.

  6. Scaling of cross sections for K-electron capture by high-energy protons and alpha-particles from the multielectron atoms

    NASA Technical Reports Server (NTRS)

    Omidvar, K.

    1976-01-01

    Electron capture by protons from H, He, and the K-shell of Ar, and alpha particles from He are considered. It is shown that when a certain function of the experimental cross sections is plotted versus the inverse of the collision energy, at high energies the function falls on a straight line. At lower energies the function concaves up or down, depending on the charge of the projectile, the effective charge and the ionization potential of the electron that is being captured. The plot can be used to predict cross sections where experimental data are not available, and as a guide in future experiments. High energy scaling formulas for K-electron capture by low-charge projectiles are given.

  7. Assessment of small volume ionization chambers as reference dosimeters in high-energy photon beams

    NASA Astrophysics Data System (ADS)

    Le Roy, M.; de Carlan, L.; Delaunay, F.; Donois, M.; Fournier, P.; Ostrowsky, A.; Vouillaume, A.; Bordy, J. M.

    2011-09-01

    LNE-LNHB is involved in a European project aiming at establishing absorbed dose-to-water standards for photon-radiation fields down to 2 × 2 cm2. This requires the calibration of reference ionization chambers of small volume. Twenty-four ionization chambers of eight different types with volume ranging from 0.007 to 0.057 cm3 were tested in a 60Co beam. For each chamber, two major characteristics were investigated: (1) the stability of the measured current as a function of the irradiation time under continuous irradiation. At LNE-LNHB, the variation of the current should be less than ±0.1% in comparison with its first value (over a 16 h irradiation time); (2) the variation of the ionization current with the applied polarizing voltage and polarity. Leakage currents were also measured. Results show that (1) every tested PTW (31015, 31016 and 31014) and Exradin A1SL chambers demonstrate a satisfying stability under irradiation. Other types of chambers have a stability complying with the stability criterion for some or none of them. (2) IBA CC01, IBA CC04 and Exradin A1SL show a proper response as a function of applied voltage for both polarities. PTW, Exradin A14SL and Exradin A16 do not. Only three types of chambers were deemed suitable as reference chambers according to LNE-LNHB requirements and specifications from McEwen (2010 Med. Phys. 37 2179-93): Exradin A1SL chambers (3/3), IBA CC04 (2/3) and IBA CC01 (1/3). The Exradin A1SL type with an applied polarizing voltage of 150 V was chosen as an LNE-LNHB reference chamber type in 2 × 2 cm2 radiation fields.

  8. Improve beam quality of laser proton acceleration with funnel-shaped-hole target

    NASA Astrophysics Data System (ADS)

    Yang, Peng; Fan, Da Peng; Li, Yu Xiao

    2016-03-01

    Improve beam quality of laser proton acceleration using a funnel-shaped-hole target is demonstrated through particle simulations. When an intense short pulse laser illuminates a thin foil target with a hole at the rear surface, the proton beam divergence is suppressed compared with that obtained in a traditional flat target. In this paper, a funnel-shaped-hole target is proposed to improve the proton beam quality. Using two-dimensional particle-in-cell (PIC) simulations, three different shapes of target (funnel-shaped-hole target, cylinder-shaped-hole target and flat target) are simulated and compared. The funnel-shaped hole in the rear surface of the target helps to focus the electron cloud significantly and improve the maximum proton energy and suppress the proton beam divergence. Different thicknesses of the new target are also simulated, and the effects of thickness on the divergence angle and proton spectra are investigated. The optimal size of the new target is obtained and the quality of the proton beam is improved significantly. The funnel-shaped-hole target serves as a new method to improve the proton beam quality in laser-plasma interactions.

  9. Treatment planning for radiotherapy with very high-energy electron beams and comparison of VHEE and VMAT plans

    SciTech Connect

    Bazalova-Carter, Magdalena; Qu, Bradley; Palma, Bianey; Jensen, Christopher; Maxim, Peter G. E-mail: BWLoo@Stanford.edu; Loo, Billy W. E-mail: BWLoo@Stanford.edu; Hårdemark, Björn; Hynning, Elin

    2015-05-15

    Purpose: The aim of this work was to develop a treatment planning workflow for rapid radiotherapy delivered with very high-energy electron (VHEE) scanning pencil beams of 60–120 MeV and to study VHEE plans as a function of VHEE treatment parameters. Additionally, VHEE plans were compared to clinical state-of-the-art volumetric modulated arc therapy (VMAT) photon plans for three cases. Methods: VHEE radiotherapy treatment planning was performed by linking EGSnrc Monte Carlo (MC) dose calculations with inverse treatment planning in a research version of RayStation. In order to study the effect of VHEE treatment parameters on VHEE dose distributions, a MATLAB graphical user interface (GUI) for calculation of VHEE MC pencil beam doses was developed. Through the GUI, pediatric case MC simulations were run for a number of beam energies (60, 80, 100, and 120 MeV), number of beams (13, 17, and 36), pencil beam spot (0.1, 1.0, and 3.0 mm) and grid (2.0, 2.5, and 3.5 mm) sizes, and source-to-axis distance, SAD (40 and 50 cm). VHEE plans for the pediatric case calculated with the different treatment parameters were optimized and compared. Furthermore, 100 MeV VHEE plans for the pediatric case, a lung, and a prostate case were calculated and compared to the clinically delivered VMAT plans. All plans were normalized such that the 100% isodose line covered 95% of the target volume. Results: VHEE beam energy had the largest effect on the quality of dose distributions of the pediatric case. For the same target dose, the mean doses to organs at risk (OARs) decreased by 5%–16% when planned with 100 MeV compared to 60 MeV, but there was no further improvement in the 120 MeV plan. VHEE plans calculated with 36 beams outperformed plans calculated with 13 and 17 beams, but to a more modest degree (<8%). While pencil beam spacing and SAD had a small effect on VHEE dose distributions, 0.1–3 mm pencil beam sizes resulted in identical dose distributions. For the 100 MeV VHEE pediatric

  10. Particle in cell simulation of laser-accelerated proton beams for radiation therapy.

    PubMed

    Fourkal, E; Shahine, B; Ding, M; Li, J S; Tajima, T; Ma, C M

    2002-12-01

    In this article we present the results of particle in cell (PIC) simulations of laser plasma interaction for proton acceleration for radiation therapy treatments. We show that under optimal interaction conditions protons can be accelerated up to relativistic energies of 300 MeV by a petawatt laser field. The proton acceleration is due to the dragging Coulomb force arising from charge separation induced by the ponderomotive pressure (light pressure) of high-intensity laser. The proton energy and phase space distribution functions obtained from the PIC simulations are used in the calculations of dose distributions using the GEANT Monte Carlo simulation code. Because of the broad energy and angular spectra of the protons, a compact particle selection and beam collimation system will be needed to generate small beams of polyenergetic protons for intensity modulated proton therapy. PMID:12512712

  11. High-Energy-Resolution Inelastic Electron and Proton Scattering and the Multiphonon Nature of Mixed-Symmetry 2{sup +} States in {sup 94}Mo

    SciTech Connect

    Burda, O.; Kuhar, M.; Lenhardt, A.; Neumann-Cosel, P. von; Ponomarev, V. Yu.; Richter, A.; Wambach, J.; Botha, N.; Fearick, R. W.; Carter, J.; Sideras-Haddad, E.; Foertsch, S. V.; Neveling, R.; Smit, F. D.; Fransen, C.; Fujita, H.; Holt, J. D.; Pietralla, N.; Scholten, O.

    2007-08-31

    High-energy-resolution inelastic electron scattering (at the S-DALINAC) and proton scattering (at iThemba LABS) experiments permit a thorough test of the nature of proposed one- and two-phonon symmetric and mixed-symmetric 2{sup +} states of the nucleus {sup 94}Mo. The combined analysis reveals the one-phonon content of the mixed-symmetry state and its isovector character suggested by microscopic nuclear model calculations. The purity of two-phonon 2{sup +} states is extracted.

  12. The quantification of wound healing as a method to assess late radiation damage in primate skin exposed to high-energy protons

    NASA Astrophysics Data System (ADS)

    Cox, A. B.; Lett, J. T.

    In an experiment examining the effects of space radiations on primates, different groups of rhesus monkeys (Macaca mulatta) were exposed to single whole-body doses of 32- or 55-MeV protons. Survivors of those exposures, together with age-matched controls, have been monitored continuously since 1964 and 1965. Late effects of nominal proton doses ranging from 2-6 Gray have been measured in vitro using skin fibroblasts from the animals. A logical extension of that study is reported here, and it involves observations of wound healing after 3-mm diameter dermal punches were removed from the ears (pinnae) of control and irradiated monkeys. Tendencies in the reduction of competence to repair cutaneous wound have been revealed by the initial examinations of animals that received doses greater than 2 Gy more than 2 decades earlier. These trends indicate that this method of assessing radiation damage to skin exposed to high-energy radiations warrants further study.

  13. Note: Proton microbeam formation with continuously variable kinetic energy using a compact system for three-dimensional proton beam writing

    SciTech Connect

    Ohkubo, T. Ishii, Y.

    2015-03-15

    A compact focused gaseous ion beam system has been developed to form proton microbeams of a few hundreds of keV with a penetration depth of micrometer range in 3-dimensional proton beam writing. Proton microbeams with kinetic energies of 100-140 keV were experimentally formed on the same point at a constant ratio of the kinetic energy of the object side to that of the image side. The experimental results indicate that the beam diameters were measured to be almost constant at approximately 6 μm at the same point with the kinetic energy range. These characteristics of the system were experimentally and numerically demonstrated to be maintained as long as the ratio was constant.

  14. A beam intensity monitor for the Loma Linda cancer therapy proton accelerator

    SciTech Connect

    Coutrakon, G.; Miller, D. ); Kross, B.J.; Anderson, D.F. ); DeLuca, P. Jr.; Siebers, J. )

    1991-07-01

    A beam intensity monitor was tested in a 230-MeV proton beam at the Loma Linda Proton Therapy Accelerator during its commissioning at Fermi National Accelerator Laboratory. The intensity monitor was designed to regulate the beam intensity extracted from the proton synchrotron. The proton beam is tunable between 70 and 250 MeV with an adjustable intensity between 10{sup 10} and 10{sup 11} protons per spill. A beam spill is typically 1 s long with a 2-s repetition period. The intensity monitor must be radiation hard, expose minimum mass to the beam, and measure intensity to 1% in 1-ms time intervals. To this end, a 5-cm-thick xenon gas scintillator optically coupled to a photomultiplier tube (PMT) was tested to measure its response to the proton beam. The gas cell was operated at 1.2 atm of pressure and has 12.7-{mu}m-thick titanium entrance and exit foils. The total mass exposed to the beam is 0.14 g/cm{sup 2} and is dominated by the titanium windows. This mass corresponds to a range attenuation equal to 1.4 mm of water. The energy lost to the xenon gas is about 70 keV per proton. Each passing proton will produce approximately 2000 photons. With a detection efficiency on the order of 0.05% for this UV light, one would anticipate over 10{sup 10} photoelectrons per second. In a 1-ms time bin there will be approximately 10{sup 7} photoelectrons. This yields a resolution limited by systematics. For unregulated 0.4-s proton spills, we observe a response bandwidth in excess of 10{sup 4} Hz. While signal-to-noise and linearity were not easily measured, we estimate as few as 10{sup 3} protons can be observed suggesting a dynamic range in excess of 10{sup 5} is available.

  15. A beam intensity monitor for the Loma Linda cancer therapy proton accelerator.

    PubMed

    Coutrakon, G; Miller, D; Kross, B J; Anderson, D F; DeLuca, P; Siebers, J

    1991-01-01

    A beam intensity monitor was tested in a 230-MeV proton beam at the Loma Linda Proton Therapy Accelerator during its commissioning at Fermi National Accelerator Laboratory. The intensity monitor was designed to regulate the beam intensity extracted from the proton synchrotron. The proton beam is tunable between 70 and 250 MeV with an adjustable intensity between 10(10) and 10(11) protons per spill. A beam spill is typically 1 s long with a 2-s repetition period. The intensity monitor must be radiation hard, expose minimum mass to the beam, and measure intensity to 1% in 1-ms time intervals. To this end, a 5-cm-thick xenon gas scintillator optically coupled to a photomultiplier tube (PMT) was tested to measure its response to the proton beam. The gas cell was operated at 1.2 atm of pressure and has 12.7-microns-thick titanium entrance and exit foils. The total mass exposed to the beam is 0.14 g/cm2 and is dominated by the titanium windows. This mass corresponds to a range attenuation equal to 1.4 mm of water. The energy lost to the xenon gas is about 70 keV per proton. Each passing proton will produce approximately 2000 photons. With a detection efficiency on the order of 0.05% for this UV light, one would anticipate over 10(10) photoelectrons per second. In a 1-ms time bin there will be approximately 10(7) photoelectrons. This yields a resolution limited by systematics. For unregulated 0.4-s proton spills, we observe a response bandwidth in excess of 10(4) Hz. While signal-to-noise and linearity were not easily measured, we estimate as few as 10(3) protons can be observed suggesting a dynamic range in excess of 10(5) is available. PMID:1656180

  16. High Energy Laboratory Astrophysics using an X-Ray Microcalorimeter with an Electron Beam Ion Trap

    NASA Astrophysics Data System (ADS)

    Porter, Frederick

    Since the summer of 2000 we have successfully deployed a high-resolution x-ray microcalorimeter spectrometer, based on the spaceflight XRS instrument, at the Electron Beam Ion Trap (EBIT) facility at the Lawrence Livermore National Laboratory. Over the last 15 years, this highly successful partnership has made fundamental measurements in laboratory astrophysics including the measurements of the absolute cross sections of all the Fe L shell transitions from Fe XVII to Fe XXIV, line ratios in Fe and Ni L shell transitions, measurements of Fe K shell emission over a wide range of electron energies, and direct measurements of charge exchange emission from highly ionized Fe, O, N, and most recently L shell S, using a variety of donor gases. This work has resulted in the publication of over 40 peer-reviewed articles with many more either submitted or in preparation. The newest addition to the facility, the ECS microcalorimeter spectrometer, developed under this program, has performed flawlessly as a facility-class instrument since 2007. We propose here to continue our highly successful partnership and deploy new technology to resolve lines in the important 1/4 keV band that encompasses the M-shell iron emission and the L shell emission, including charge exchange, of many of the lower-Z elements, such as Si, S, Mg, Ne, Ca, and Ar. This work is highly relevant to NASA objectives as it allows for the unambiguous connection between spectroscopic observations with Chandra, XMM, Astro-H, and future spectrometers aboard missions like Athena, and the physics occurring in the cosmological source. Our program aids these measurements by benchmarking the spectroscopic synthesis models used to interpret all x-ray observations. Without laboratory measurements to support these models, it is not a priori certain that the models are correct, and the observational data correctly interpreted. This is especially true for charge exchange measurements, where there are substantially

  17. Study of the penumbra for high-energy photon beams with Gafchromic™ EBT2 films

    NASA Astrophysics Data System (ADS)

    Oh, Se An; Kang, Min Kyu; Yea, Ji Woon; Kim, Sung Kyu; Oh, Young Kee

    2012-06-01

    The penumbra has a major impact on obtaining uniformity of isodose distributions in radiation therapy. The penumbra phenomena of intensity-modulated radiation therapy (IMRT) techniques using multi-leaf collimators (MLCs) has an impact on the dose distributions in the border of the target volumes and the MLC. The aim of this study was to determine the impact of high photon energy (6 MV, 10 MV) on the penumbra for various depths and field sizes by using the Pencil Beam Convolution algorithms (eclipse 8.6) and self-developing Gafchromic™ EBT2 film. For dose calculations and EBT2 measurements, we used an acryl phantom with dimensions 20 × 20 × 20 cm3. The 200 cGy dose was delivered to the central depth (10 cm) of the acryl phantom. The result of this study was that increased energy, field size and depth are rise to an increased penumbra (20% ˜ 80%) width. For a 6 MV photon energy, the penumbra widths (20%-80%) at 1.5 cm, 5 cm, and 10 cm depths were 4.2 mm, 4.4 mm, and 5.7 mm for the eclipse calculations and 2.9 mm, 4.1 mm, and 4.2 mm for the EBT2 film measurements for 10 × 10 cm2 field sizes, respectively. For a 10 MV photon energy, the penumbra widths were 4.5 mm, 4.7 mm, and 6.2 mm for eclipse calculations and 4.1 mm, 4.6 mm, and 4.9 mm for EBT2 film measurements, respectively. As the field size was changed to 3 cm, 5 cm, 7 cm, 10 cm, and 15 cm, the penumbra widths changed to 5.1 mm, 5.3 mm, 5.6 mm, 5.9 mm, and 6.1 mm for eclipse calculations and 2.9 mm, 3.3 mm, 3.6 mm, 4.2 mm, and 5.1 mm for EBT2 measurements, respectively, for 10 cm depths for 6 MV photon energies. In this study, compared to the 10 MV photon energy, the 6 MV photon energy was preferred in treatments such as the 3D conformal radiation therapy and the IMRT for critical organs near the target volume.

  18. Perturbation correction factors for the NACP-02 plane-parallel ionization chamber in water in high-energy electron beams.

    PubMed

    Verhaegen, F; Zakikhani, R; Dusautoy, A; Palmans, H; Bostock, G; Shipley, D; Seuntjens, J

    2006-03-01

    Recent dosimetry protocols for clinical high-energy electron beams recommend measurements of absorbed dose-to-water with a plane-parallel or cylindrical ionization chamber. For well-guarded plane-parallel ionization chambers, the ionization chamber perturbation factor in water, p(Q), has a recommended value of unity in all protocols. This assumption was investigated in detail in this study for one of the recommended ionization chambers in the protocols: the Scanditronix NACP-02 plane-parallel ionization chamber. Monte Carlo (MC) simulations of the NACP-02 ionization chamber with the EGSnrc code were validated against backscatter experiments. MC simulations were then used to calculate p(wall), p(cav) and p(Q) perturbation factors and water-to-air Spencer-Attix stopping powers in 4-19 MeV electron beams of a calibration laboratory (NPL), and in 6-22 MeV clinical electron beams from a Varian CL2300 accelerator. Differences between calculated and the currently recommended (Burns et al 1996 Med. Phys. 23 383-8) stopping powers, water-to-air, were found to be limited to 0.9% at depths between the reference depth z(ref) and the depth where the dose has decreased to 50% of the maximum dose, R50. p(wall) was found to exceed unity by 2.3% in the 4 MeV NPL calibration beam at z(ref). For higher energy electron beams p(wall) decreased to a value of about 1%. Combined with a p(cav) about 1% below unity for all energies at z(ref), this was found to cause p(Q) to exceed unity significantly for all energies. In clinical electron beams all three perturbation factors were found to increase with depth. Our findings indicate that the perturbation factors have to be taken into account in calibration procedures and for clinical depth dose measurements with the NACP-02 ionization chamber. PMID:16481689

  19. Maximum proton kinetic energy and patient-generated neutron fluence considerations in proton beam arc delivery radiation therapy

    PubMed Central

    Sengbusch, E.; Pérez-Andújar, A.; DeLuca, P. M.; Mackie, T. R.

    2009-01-01

    energy from 250 to 200 MeV decreases the total neutron energy fluence produced by stopping a monoenergetic pencil beam in a water phantom by a factor of 2.3. It is possible to significantly lower the requirements on the maximum kinetic energy of a compact proton accelerator if the ability to treat a small percentage of patients with rotational therapy is sacrificed. This decrease in maximum kinetic energy, along with the corresponding decrease in neutron production, could lower the cost and ease the engineering constraints on a compact proton accelerator treatment facility. PMID:19291975

  20. Maximum proton kinetic energy and patient-generated neutron fluence considerations in proton beam arc delivery radiation therapy.

    PubMed

    Sengbusch, E; Pérez-Andújar, A; DeLuca, P M; Mackie, T R

    2009-02-01

    proton kinetic energy from 250 to 200 MeV decreases the total neutron energy fluence produced by stopping a monoenergetic pencil beam in a water phantom by a factor of 2.3. It is possible to significantly lower the requirements on the maximum kinetic energy of a compact proton accelerator if the ability to treat a small percentage of patients with rotational therapy is sacrificed. This decrease in maximum kinetic energy, along with the corresponding decrease in neutron production, could lower the cost and ease the engineering constraints on a compact proton accelerator treatment facility. PMID:19291975