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Barbagallo M, Aberle O, Alcayne V, Amaducci S, Andrzejewski J, Audouin L, Babiano-Suarez V, Bacak M, Bennett S, Berthoumieux E, Bosnar D, Brown AS, Busso M, Caamaño M, Caballero L, Calviani M, Calviño F, Cano-Ott D, Casanovas A, Cerutti F, Chiaveri E, Colonna N, Cortés GP, Cortés-Giraldo MA, Cosentino L, Cristallo S, Damone LA, Davies PJ, Diakaki M, Dietz M, Domingo-Pardo C, Dressler R, Ducasse Q, Dupont E, Durán I, Eleme Z, Fernández-Domíngez B, Ferrari A, Ferro-Gonçalves I, Finocchiaro P, Furman V, Garg R, Gawlik A, Gilardoni S, Göbel K, González-Romero E, Guerrero C, Gunsing F, Heinitz S, Heyse J, Jenkins DG, Jericha E, Jiri U, Junghans A, Kadi Y, Käppeler F, Kimura A, Knapová I, Kokkoris M, Kopatch Y, Krtička M, Kurtulgil D, Ladarescu I, Lederer-Woods C, Lerendegui-Marco J, Lonsdale SJ, Macina D, Manna A, Martínez T, Masi A, Massimi C, Mastinu PF, Mastromarco M, Maugeri E, Mazzone A, Mendoza E, Mengoni A, Michalopoulou V, Milazzo PM, Millán-Callado MA, Mingrone F, Moreno-Soto J, Musumarra A, Negret A, Ogállar F, Oprea A, Patronis N, Pavlik A, Perkowski J, Petrone C, Piersanti L, Pirovano E, Porras I, Praena J, Quesada JM, Ramos Doval D, Reifarth R, Rochman D, Rubbia C, Sabaté- Gilarte M, Saxena A, Schillebeeckx P, Schumann D, Sekhar A, Smith AG, Sosnin N, Sprung P, Stamatopoulos A, Tagliente G, Tain JL, Tarifeño-Saldivia AE, Tassan-Got L, Thomas B, Torres-Sánchez P, Tsinganis A, Urlass S, Valenta S, Vannini G, Variale V, Vaz P, Ventura A, Vescovi D, Vlachoudis V, Vlastou R, Wallner A, Woods PJ, Wright TJ, Žugec P. Measurement of the energy-differential cross-section of the 12C(n,p) 12B and 12C(n,d) 11B reactions at the n_TOF facility at CERN. EPJ WEB OF CONFERENCES 2020. [DOI: 10.1051/epjconf/202023901045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Although the 12C(n,p)12B and 12C(n,d)11B reactions are of interest in several fields of basic and applied Nuclear Physics the present knowledge of these two cross-sections is far from being accurate and reliable, with both evaluations and data showing sizable discrepancies. As part of the challenging n_TOF program on (n,cp) nuclear reactions study, the energy differential cross-sections of the 12C(n,p)12B and 12C(n,d)11 B reactions have been measured at CERN from the reaction thresholds up to 30 MeV neutron energy. Both measurements have been recently performed at the long flight-path (185 m) experimental area of the n_TOF facility at CERN using a pure (99.95%) rigid graphite target and two silicon telescopes. In this paper an overview of the experiment is presented together with a few preliminary results.
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Chadwick MB, Young PG. Calculation and Evaluation of Cross Sections and Kerma Factors for Neutrons up to 100 MeV on 16O and 14N. NUCL SCI ENG 2017. [DOI: 10.13182/nse96-a24209] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- M. B. Chadwick
- University of California, Nuclear Data Group Lawrence Livermore National Laboratory, Liver more, California 94550
| | - P. G. Young
- University of California, Theoretical Division Los Alamos National Laboratory, Los Alamos, New Mexico 87545
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3
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Chadwick MB, Young PG, Chiba S, Frankle SC, Hale GM, Hughes HG, Koning AJ, Little RC, MacFarlane RE, Prael RE, Waters LS. Cross-Section Evaluations to 150 MeV for Accelerator-Driven Systems and Implementation in MCNPX. NUCL SCI ENG 2017. [DOI: 10.13182/nse98-48] [Citation(s) in RCA: 267] [Impact Index Per Article: 38.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- M. B. Chadwick
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545
| | - P. G. Young
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545
| | - S. Chiba
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545
| | - S. C. Frankle
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545
| | - G. M. Hale
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545
| | - H. G. Hughes
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545
| | - A. J. Koning
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545
| | - R. C. Little
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545
| | | | - R. E. Prael
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545
| | - L. S. Waters
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545
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Affiliation(s)
- Jingshang Zhang
- China Institute of Atomic Energy, P.O. Box 275(41), Beijing 102413 China
| | - Yinlu Han
- China Institute of Atomic Energy, P.O. Box 275(41), Beijing 102413 China
| | - Ligang Cao
- China Institute of Atomic Energy, P.O. Box 275(41), Beijing 102413 China
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Sasaki M, Kim E, Nunomiya T, Nakamura T, Nakao N, Shibata T, Uwamino Y, Ito S, Fukumura A. Measurements of High-Energy Neutrons Penetrated Through Concrete Shields Using Self-TOF, NE213, and Activation Detectors. NUCL SCI ENG 2017. [DOI: 10.13182/nse02-a2273] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- M. Sasaki
- Tohoku University, Department of Quantum Science and Energy Engineering Aoba 01, Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - E. Kim
- Tohoku University, Department of Quantum Science and Energy Engineering Aoba 01, Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - T. Nunomiya
- Tohoku University, Department of Quantum Science and Energy Engineering Aoba 01, Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - T. Nakamura
- Tohoku University, Department of Quantum Science and Energy Engineering Aoba 01, Aramaki, Aoba-ku, Sendai 980-8579, Japan
| | - N. Nakao
- High Energy Accelerator Research Organization Oho 1-1, Tsukuba, Ibaraki 305-0801, Japan
| | - T. Shibata
- High Energy Accelerator Research Organization Oho 1-1, Tsukuba, Ibaraki 305-0801, Japan
| | - Y. Uwamino
- Institute of Physical and Chemical Research Hirosawa 2-1, Wako, Saitama 351-0198, Japan
| | - S. Ito
- Institute of Physical and Chemical Research Hirosawa 2-1, Wako, Saitama 351-0198, Japan
| | - A. Fukumura
- National Institute of Radiological Sciences Anagawa 4-9-1, Inageku, Chiba 263-8555, Japan
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6
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NAUCHI Y, BABA M, SANAMI T, IBARAKI M, IWASAKI T, HIRAKAWA N, TANAKA S, MEIGO SI, NAKASHIMA H, TAKADA H, NAKAMURA T, WATANABE Y. Measurements of (n,xp), (n,xd) Double Differential Cross Sections of Carbon and Aluminum for 65 and 75 MeV Neutrons. J NUCL SCI TECHNOL 2012. [DOI: 10.1080/18811248.1999.9726192] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Yasushi NAUCHI
- a Department of Quantum Science and Energy Engineering , Tohoku University , Aramaki , Aoba-ku , Sendai , 980-8579
| | - Mamoru BABA
- a Department of Quantum Science and Energy Engineering , Tohoku University , Aramaki , Aoba-ku , Sendai , 980-8579
| | - Toshiya SANAMI
- a Department of Quantum Science and Energy Engineering , Tohoku University , Aramaki , Aoba-ku , Sendai , 980-8579
| | - Masanobu IBARAKI
- a Department of Quantum Science and Energy Engineering , Tohoku University , Aramaki , Aoba-ku , Sendai , 980-8579
| | - Tomohiko IWASAKI
- a Department of Quantum Science and Energy Engineering , Tohoku University , Aramaki , Aoba-ku , Sendai , 980-8579
| | - Naohiro HIRAKAWA
- a Department of Quantum Science and Energy Engineering , Tohoku University , Aramaki , Aoba-ku , Sendai , 980-8579
| | - Susumu TANAKA
- b Takasaki Establishment , Japan Atomic Energy Research Institute , Watanuki-machi , Takasaki-shi , 370-1292
| | - Shin-ichiro MEIGO
- c Tokai Establishment , Japan Atomic Energy Institute , Tokai-mura , Naka-gun , Ibaraki-ken , 319-1195
| | - Hiroshi NAKASHIMA
- c Tokai Establishment , Japan Atomic Energy Institute , Tokai-mura , Naka-gun , Ibaraki-ken , 319-1195
| | - Hiroshi TAKADA
- b Takasaki Establishment , Japan Atomic Energy Research Institute , Watanuki-machi , Takasaki-shi , 370-1292
| | - Takashi NAKAMURA
- d Cyclotron Radioisotope Center , Tohoku University , Aramaki , Aoba-ku , Sendai , 980-8578
| | - Yukinobu WATANABE
- e Department of Advanced Energy Engineering Science , Kyushu University , Kasuga-Koen , Kasuga-shi , 816-8580
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HARADA M, WATANABE Y, YAMAMOTO A, YOSHIOKA S, SATO K, NAKASHIMA T, IJIRI H, YOSHIDA H, UOZUMI Y, KOORI N, MEIGO SI, IWAMOTO O, FUKAHORI T, CHIBA S. The12C(p,p′3α) Breakup Reaction Induced by 14, 18 and 26 MeV Protons. J NUCL SCI TECHNOL 2012. [DOI: 10.1080/18811248.1999.9726214] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Murphy RJ, Kozlovsky B, Share GH. Nuclear cross sections for gamma ray deexcitation line production by secondary neutrons in the Earth's atmosphere. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010ja015820] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | - B. Kozlovsky
- School of Physics and Astronomy; Tel Aviv University; Tel Aviv Israel
| | - G. H. Share
- Astronomy Department; University of Maryland; College Park Maryland USA
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Abstract
This review article provides an overview, for medical physicists, of recent work that addresses the role of nuclear reactions in proton, fast neutron, and conventional photon radiation therapy. Nuclear reaction cross sections have been evaluated, in ENDF format, for use in Monte Carlo radiation transport simulations of radiotherapy, in order to optimize the absorbed dose to a tumor. The evaluations utilize both measured cross section data as well as nuclear model calculations of direct, preequilibrium, and Hauser-Feshbach compound processes. In the case of photonuclear reactions, giant dipole resonance and quasideuteron photoabsorption mechanisms are considered.
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Bergenwall BE, Ataç A, Kullander S. Experimental kerma coefficients for carbon deduced from microscopic cross sections at 96 MeV incident neutron energy. Phys Med Biol 2004; 49:4523-42. [PMID: 15552415 DOI: 10.1088/0031-9155/49/19/006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The double-differential cross sections for (n, px), (n, dx), (n, tx), (n, 3Hex) and (n, alphax) reactions in carbon have been measured at 96 MeV incident neutron energy. The various charged particles (inclusive spectra) were identified using deltaE-E techniques. From the experimental data, energy- and angle-differential as well as production cross sections were determined, and subsequently the partial and total kerma coefficients. The deduced partial and total kerma coefficients were compared to previous experimental results and theoretical calculations. The findings indicate that the deduced kerma coefficients for the hydrogen isotopes are in good agreement with those deduced from a previous measurement, and that the kerma coefficient values, in particular of the hydrogen isotopes, are systematically higher than values obtained from recent model calculations, which consequently resulted in a total kerma coefficient which is up to 30% higher than predicted by the calculations.
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Affiliation(s)
- B E Bergenwall
- Department of Radiation Sciences, Uppsala University, Box 535, S-751 21 Uppsala, Sweden
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Miranda JG, DeLuca PM, Chadwick MB. Ion chamber gas-to-wall conversion factors for fast neutron dosimetry. RADIATION PROTECTION DOSIMETRY 2004; 110:15-25. [PMID: 15353616 DOI: 10.1093/rpd/nch184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Modern ionising photon dosimetry is essentially entirely based upon gas-filled cavity determinations. For photons, ion chamber response is largely independent of photon energy almost perfectly transforming absorbed dose in the gas to the surrounding media. Absolute uncertainties are <1-2%. For fast neutron dosimetry, this is certainly not the case. Interpretation of the response of the cavity filling material, usually a gas, to the charged particle spectrum induced in the walls and interacting with the cavity gas is fraught with uncertainties. Despite these challenges, gas filled cavities surrounded by various mixtures, compounds and elements, have proved to be essential for integral determinations of the indirectly ionising neutrons, generating dosimetric quantities, such as kerma and absorbed dose. The transformation from gas response to wall dose is material dependent and varies with neutron energy. This study discusses recent advances in cavity response interpretation using the results from complex nuclear modelling of microscopic cross sections as well as estimates of secondary particle production enabling much improved cavity gas-to-wall media conversion factors.
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Affiliation(s)
- Juan G Miranda
- 21st Century Oncology, 1176 Vegas Valley Drive, Las Vegas, NV 89113, USA
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12
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Nakamura T, Nunomiya T, Yashima H, Yonai S. Overview of recent experimental works on high energy neutron shielding. PROGRESS IN NUCLEAR ENERGY 2004. [DOI: 10.1016/s0149-1970(04)90001-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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13
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Steyn G, Cowley A, Watanabe Y, Sun W, Förtsch S, Lawrie J. Continuum Cross Sections for Proton-induced Reactions on Biologicaïly-important Target Nuclei. J NUCL SCI TECHNOL 2002. [DOI: 10.1080/00223131.2002.10875097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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14
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15
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Schrewe UJ, Newhauser WD, Brede HJ, DeLuca PM. Experimental kerma coefficients and dose distributions of C, N, O, Mg, Al, Si, Fe, Zr, A-150 plastic, Al203, AlN, SiO2 and ZrO2 for neutron energies up to 66 MeV. Phys Med Biol 2000; 45:651-83. [PMID: 10730963 DOI: 10.1088/0031-9155/45/3/307] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Low-pressure proportional counters (LPPCs) with walls made from the elements C, Mg, Al, Si, Fe and Zr and from the chemical compounds A-150 plastic, AlN, Al2O3, SiO2 and ZrO2 were used to measure neutron fluence-to-kerma conversion coefficients at energies up to 66 MeV. The LPPCs served to measure the absorbed dose deposited in the gas of a cavity surrounded by the counter walls that could be converted to the absorbed dose to the wall on the basis of the Bragg-Gray cavity theory. Numerically the absorbed doses to the walls were almost equal to the corresponding kerma values of the wall materials. The neutron fluence was determined by various experimental methods based on the reference cross sections of the 1H(n, p) scattering and/or the 238U(n, f) reactions. The measurements were performed in monoenergetic neutron fields of energies of 5 MeV, 8 MeV, 15 MeV and 17 MeV and in polyenergetic neutron beams with prominent peaks of energies of 34 MeV, 44 MeV and 66 MeV. For the measurements in the polyenergetic neutron beams, significant corrections for the contributions of the non peak energy neutrons were applied. The fluence-to kerma conversion coefficients of N and O were determined using the difference technique applied with matched pairs of LPPCs made from a chemical compound and a pure element. This paper reports experimental fluence-to-kerma conversion coefficient values of eight elements and four compounds measured for seven neutron energies, and presents a comparison with data from previous measurements and theoretical predictions. The distributions of the absorbed dose as a function of the lineal energy were measured for monoenergetic neutrons or, for polyenergetic neutron fields, deduced by applying iterative unfolding procedures in order to subtract the contributions from non-peak energy neutrons. The dose distributions provide insight into the neutron interaction processes.
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Affiliation(s)
- U J Schrewe
- Physikalisch-Technische Bundesanstalt, Braunschweig, Germany
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16
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Chadwick MB, Barschall HH, Caswell RS, DeLuca PM, Hale GM, Jones DT, MacFarlane RE, Meulders JP, Schuhmacher H, Schrewe UJ, Wambersie A, Young PG. A consistent set of neutron kerma coefficients from thermal to 150 MeV for biologically important materials. Med Phys 1999; 26:974-91. [PMID: 10436900 DOI: 10.1118/1.598601] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Neutron cross sections for nonelastic and elastic reactions on a range of elements have been evaluated for incident energies up to 150 MeV. These cross sections agree well with experimental cross section data for charged-particle production as well as neutron and photon production. Therefore they can be used to determine kerma coefficients for calculations of energy deposition by neutrons in matter. Methods used to evaluate the neutron cross sections above 20 MeV, using nuclear model calculations and experimental data, are described. Below 20 MeV, the evaluated cross sections from the ENDF/B-VI library are adopted. Comparisons are shown between the evaluated charged-particle production cross sections and measured data. Kerma coefficients are derived from the neutron cross sections, for major isotopes of H, C, N, O, Al, Si, P, Ca, Fe, Cu, W, Pb, and for ICRU-muscle, A-150 tissue-equivalent plastic, and other compounds important for treatment planning and dosimetry. Numerous comparisons are made between our kerma coefficients and experimental kerma coefficient data, to validate our results, and agreement is found to be good. An important quantity in neutron dosimetry is the kerma coefficient ratio of ICRU-muscle to A-150 plastic. When this ratio is calculated from our kerma coefficient data, and averaged over the neutron energy spectra for higher-energy clinical therapy beams [three p (68) + Be beams, and a d (48.5) + Be beam], a value of 0.94 +/- 0.03 is obtained. Kerma ratios for water to A-150 plastic, and carbon to oxygen, are also compared with measurements where available.
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Affiliation(s)
- M B Chadwick
- University of California, Los Alamos National Laboratory, New Mexico 87545, USA
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Litzenberg DW, Roberts DA, Lee MY, Pham K, Vander Molen AM, Ronningen R, Becchetti FD. On-line monitoring of radiotherapy beams: experimental results with proton beams. Med Phys 1999; 26:992-1006. [PMID: 10436901 DOI: 10.1118/1.598491] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Proton radiotherapy is a powerful tool in the local control of cancer. The advantages of proton radiotherapy over gamma-ray therapy arise from the phenomenon known as the Bragg peak. This phenomenon enables large doses to be delivered to well-defined volumes while sparing surrounding healthy tissue. To fully realize the potential of this technique the location of the high-dose volume must be controlled very accurately. An imaging system was designed and tested to monitor the positron-emitting activity created by the beam as a means of verifying the beam's range, monitoring dose, and determining tissue composition. The prototype imaging system consists of 12 pairs of cylindrical BGO detectors shielded in lead. Each crystal was 1.9 cm in diameter, 5.0 cm long, and separated by 0.5 cm from other detectors in the row. These are arranged in two rows, 60 cm apart, with the proton beam and tissue phantoms half-way between and parallel to the detector rows. Experiments were conducted with 150 MeV continuous and macro-pulsed proton beams which had beam currents ranging from 0.14 nA to 1.75 nA. The production and decay of short-lived isotopes, 15O and 14O, was studied using 1 min irradiations with a continuous beam. These isotopes provide a significant signal on short time scales, making on-line imaging possible. Macro-pulsed beams, having a period of 10 s, were used to study on-line imaging and the production and decay of long-lived isotopes, 13N, 11C, and 18F. Decay data were acquired and on-line images were obtained between beam pulses and indicate that range verification is possible, for a 150 MeV beam, after one beam pulse, to within the 1.2 cm resolution limit of the imaging system. The dose delivered to the patient may also be monitored by observing the increase in the number of coincidence events detected between successive beam pulses. Over 80% of the initial positron-emitting activity is from 15O while the remainder is primarily 11C, 13N, 14O with traces of 18F, and 10C. Radioisotopic imaging may also be performed along the beam path by fitting decay data collected after the treatment is complete. Using this technique, it is shown that variations in elemental composition in inhomogenous treatment volumes may be identified and used to locate anatomic landmarks. Radioisotopic imaging also reveals that 14O is created well beyond the Bragg peak, apparently by secondary neutrons.
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Affiliation(s)
- D W Litzenberg
- University of Michigan Medical Center, Department of Radiation Oncology, Ann Arbor, Michigan 48109, USA.
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Chadwick MB, Jones DT, Barschall HH, Caswell RS, DeLuca PM, Meulders JP, Wambersie A, Schuhmacher H, Young PG, Hale GM, Siebers JV. Nuclear data for radiotherapy: presentation of a new ICRU report and IAEA initiatives. Strahlenther Onkol 1999; 175 Suppl 2:26-9. [PMID: 10394391 DOI: 10.1007/bf03038882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
An ICRU report entitled "Nuclear Data for Neutron and Proton Radiotherapy and for Radiation Protection" is in preparation. The present paper presents an overview of this report, along with examples of some of the results obtained for evaluated nuclear cross sections and kerma coefficients. These cross sections are evaluated using a combination of measured data and the GNASH nuclear model code for elements of importance for biological, dosimetric, beam modification and shielding purposes. In the case of hydrogen both R-matrix and phase-shift scattering theories are used. In the report neutron cross sections and kerma coefficients will be presented up to 150 MeV and proton cross sections up to 250 MeV. An IAEA Consultants' Meeting was also convened to examine the "Status of Nuclear Data needed for Radiation Therapy and Existing Data Development Activities in Member States". Recommendations were made regarding future endeavours.
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HARADA M, WATANABE Y, CHIBA S, FUKAHORI T. Evaluation of Neutron Cross Sections of Carbon-12 for Energies up to 80MeV. J NUCL SCI TECHNOL 1997. [DOI: 10.1080/18811248.1997.9733638] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Medin J, Andreo P. Monte Carlo calculated stopping-power ratios, water/air, for clinical proton dosimetry (50-250 MeV). Phys Med Biol 1997; 42:89-105. [PMID: 9015811 DOI: 10.1088/0031-9155/42/1/006] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Calculations of stopping power ratios, water to air, for the determination of absorbed dose to water in clinical proton beams using ionization chamber measurements have been undertaken using the Monte Carlo method. A computer code to simulate the transport of protons in water (PETRA) has been used to calculate sw.air-data under different degrees of complexity, ranging from values based on primary protons only to data including secondary electrons and high-energy secondary protons produced in nonelastic nuclear collisions. All numerical data are based on ICRU 49 proton stopping powers. Calculations using primary protons have been compared to the simple continuous slowing-down approximation (c.s.d.a.) analytical technique used in proton dosimetry protocols, not finding significant differences that justify elaborate Monte Carlo simulations except beyond the mean range of the protons (the far side of the Bragg peak). The influence of nuclear nonelastic processes, through the detailed generation and transport of secondary protons, on the calculated stopping-power ratios has been found to be negligible. The effect of alpha particles has also been analysed, finding differences smaller than 0.1% from the results excluding them. Discrepancies of up to 0.6% in the plateau region have been found, however, when the production and transport of secondary electrons are taken into account. The large influence of nonelastic nuclear interactions on proton depth-dose distributions shows that the removal of primary protons from the incident beam decreases the peak-to-plateau ratio by a large factor, up to 40% at 250 MeV. It is therefore emphasized that nonelastic nuclear reactions should be included in Monte Carlo simulations of proton beam depth-dose distributions.
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Affiliation(s)
- J Medin
- Department of Medical Radiation Physics, Karolinska Institutet, Stockholm, Sweden.
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