Measurement of proton-induced target fragmentation cross sections in carbon

• Published in: Nuclear physics. A Vol. 946; pp. 104 - 116
• Main Authors: Matsushita, K., Nishio, T., Tanaka, S., Tsuneda, M., Sugiura, A., Ieki, K.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2016
• Subjects: Cross section; Fragmentation reaction; PET; Positron emitter; Proton therapy; Fragmentation reaction; Proton therapy; Cross section; PET; Positron emitter
• ISSN: 0375-9474
• DOI: 10.1016/j.nuclphysa.2015.11.007

In proton therapy, positron emitter nuclei are generated via the target nuclear fragmentation reactions between irradiated proton and nuclei constituting a human body. The proton-irradiated volume can be confirmed with measurement of annihilation γ-rays from the generated positron emitter nuclei. To achieve the high accuracy of proton therapy, in vivo dosimetry, i.e., evaluation of the irradiated dose during the treatment is important. To convert the measured activity distribution to irradiated dose, cross-sectional data for positron emitter production is necessary, which is currently insufficient in the treatment area. The purpose of this study is to collect cross-sectional data of C12(p,pn)C11 and C12(p,p2n)C10 reactions between the incident proton and carbon nuclei, which are important target nuclear fragmentation reactions, to estimate the range and exposure dose distribution in the patient's body. Using planar-type PET capable of measuring annihilation γ-rays at high positional resolution and thick polyethylene target, we measured cross-sectional data in continuous wide energy range. The cross section of C12(p,pn)C11 is in good agreement with existing experimental data. The cross section of C12(p,p2n)C10 is reported for the first data in the low-energy range of 67.6–10.5 MeV near the Bragg peak of proton beam. •Cross sections for C11 and C10 productions in proton-induced target fragmentation were measured.•Cross sections of C12(p,pn)11C were in good agreement with previous studies.•The first data of cross sections of C12(p,p2n)10C for range of 67.6–10 MeV were obtained.•Cross sections of continuous energy were measured using planar-type PET and thick target.