@article{oai:repo.qst.go.jp:00047085,
 author = {Kodaira, Satoshi and Konishi, Teruaki and Kitamura, Hisashi and Kurano, Mieko and Kawashima, Hajime and Uchihori, Yukio and Nishio, Teiji and Yasuda, Nakahiro and Ogura, Koichi and Sihver, Lembit and Benton, Eric and 小平 聡 and 小西 輝昭 and 北村 尚 and 蔵野 美恵子 and 川嶋 元 and 内堀 幸夫 and 西尾 禎治 and 安田 仲宏 and 小倉 浩一 and Ｓｉｈｖｅｒ Ｌｅｍｂｉｔ and Ｂｅｎｔｏｎ Ｅｒｉｃ},
 journal = {Nuclear Instruments and Methods in Physics Research B},
 month = {Apr},
 note = {In addition to energy loss by ionization process, protons of energy >∼50 MeV, such as those used in proton radiotherapy, can undergo nuclear interactions with nuclei of Z > 1, resulting in the production of short range (<20 μm), high-LET (linear energy transfer) target fragment particles. One of the few methods to detect these short-range particles is by means of CR-39 plastic nuclear track detector (PNTD) analyzed with an atomic force microscope (AFM). However, due to the LET-dependent angular sensitivity of CR-39 PNTD, multiple detectors exposed at a range of incident angles to the primary proton beam, must be analyzed in order to accurately determine the LET spectrum, absorbed dose and dose equivalent. The LET spectrum of 160 MeV proton-induced secondary particles was experimentally measured with CR-39 PNTDs, which were exposed at six different incident angles to take into account the intrinsic sensitivity of the critical angle for track registration. The irradiated detectors were chemically processed to remove a 1 μm thick volume of CR-39 PNTD. The measured LET range of short range tracks was from 15 keV/μm up to 1.5 MeV/μm. The absorbed dose contribution (Ds/Dp) from secondary particles to primary proton dose was ∼1%, while the dose equivalent contribution (Hs/Dp) was found to be ∼20%. Analysis of CR-39 PNTD by AFM yielded ∼60% higher value for absorbed dose compared to standard optical microscopy analysis.},
 pages = {163--168},
 title = {On the use of CR-39 PNTD with AFM analysis in measuring proton-induced target fragmentation particles},
 volume = {349},
 year = {2015}
}