Induced Radionuclides and Their Activity Concentration in Gel Dosimeters Irradiated by Carbon Ion Beam
Radioactivity was measured in a micellar gel dosimeter, a polymer gel dosimeter, and water was irradiated by carbon ion beams at various beam energy conditions. Monte Carlo simulation was also performed to estimate the radioactivity. Short-lived positron-emitting nuclides were observed immediately a...
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MDPI AG
2022-03-01
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| Online Access: | https://www.mdpi.com/2310-2861/8/4/203 |
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| author | Masumitsu Toyohara Shinichi Minohara Yohsuke Kusano Hiroaki Gotoh Yoichiro Tanaka Masaru Yuhara Yu Yamashita Yoshiaki Shimono |
| author_facet | Masumitsu Toyohara Shinichi Minohara Yohsuke Kusano Hiroaki Gotoh Yoichiro Tanaka Masaru Yuhara Yu Yamashita Yoshiaki Shimono |
| author_sort | Masumitsu Toyohara |
| collection | DOAJ |
| description | Radioactivity was measured in a micellar gel dosimeter, a polymer gel dosimeter, and water was irradiated by carbon ion beams at various beam energy conditions. Monte Carlo simulation was also performed to estimate the radioactivity. Short-lived positron-emitting nuclides were observed immediately after irradiation, but they decayed rapidly into the background. At 24 h post-irradiation, the dominant measured radioactivity was of <sup>7</sup>Be. The simulation also showed minor activity of <sup>24</sup>Na and <sup>3</sup>H; however, they were not experimentally observed. The measured radioactivity was independent of the type of gel dosimeter under all irradiation conditions, suggesting that the radioactivity was induced by the interaction of carbon ions with water (the main component of the gel dosimeters). The ratio between the simulated and measured radioactivity was within 0.9–1.5. The activity concentration of <sup>7</sup>Be was found to be less than 1/10 of the value derived using the exemption concept proposed by the International Atomic Energy Agency. This result should be applicable to irradiated gel dosimeters containing mainly water and 0–4 wt.% C and 0–1.7 wt.% N. |
| first_indexed | 2024-03-09T10:36:30Z |
| format | Article |
| id | doaj.art-aca7a04fb8f84538913342091e0ca9c3 |
| institution | Directory Open Access Journal |
| issn | 2310-2861 |
| language | English |
| last_indexed | 2024-03-09T10:36:30Z |
| publishDate | 2022-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Gels |
| spelling | doaj.art-aca7a04fb8f84538913342091e0ca9c32023-12-01T20:55:50ZengMDPI AGGels2310-28612022-03-018420310.3390/gels8040203Induced Radionuclides and Their Activity Concentration in Gel Dosimeters Irradiated by Carbon Ion BeamMasumitsu Toyohara0Shinichi Minohara1Yohsuke Kusano2Hiroaki Gotoh3Yoichiro Tanaka4Masaru Yuhara5Yu Yamashita6Yoshiaki Shimono7Research Initiative and Promotion Organization, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, JapanKanagawa Cancer Center, Yokohama 241-8585, JapanKanagawa Cancer Center, Yokohama 241-8585, JapanDepartment of Chemistry and Life Science, Yokohama National University, Yokohama 240-8501, JapanResearch Initiative and Promotion Organization, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, JapanToshiba Energy Systems & Solutions Corporation, Kawasaki 212-8585, JapanToshiba Energy Systems & Solutions Corporation, Kawasaki 212-8585, JapanToshiba Energy Systems & Solutions Corporation, Kawasaki 212-8585, JapanRadioactivity was measured in a micellar gel dosimeter, a polymer gel dosimeter, and water was irradiated by carbon ion beams at various beam energy conditions. Monte Carlo simulation was also performed to estimate the radioactivity. Short-lived positron-emitting nuclides were observed immediately after irradiation, but they decayed rapidly into the background. At 24 h post-irradiation, the dominant measured radioactivity was of <sup>7</sup>Be. The simulation also showed minor activity of <sup>24</sup>Na and <sup>3</sup>H; however, they were not experimentally observed. The measured radioactivity was independent of the type of gel dosimeter under all irradiation conditions, suggesting that the radioactivity was induced by the interaction of carbon ions with water (the main component of the gel dosimeters). The ratio between the simulated and measured radioactivity was within 0.9–1.5. The activity concentration of <sup>7</sup>Be was found to be less than 1/10 of the value derived using the exemption concept proposed by the International Atomic Energy Agency. This result should be applicable to irradiated gel dosimeters containing mainly water and 0–4 wt.% C and 0–1.7 wt.% N.https://www.mdpi.com/2310-2861/8/4/203micellar hydrogelpolymer hydrogelcarbon ion radiotherapyradioactivityMonte Carlo simulation |
| spellingShingle | Masumitsu Toyohara Shinichi Minohara Yohsuke Kusano Hiroaki Gotoh Yoichiro Tanaka Masaru Yuhara Yu Yamashita Yoshiaki Shimono Induced Radionuclides and Their Activity Concentration in Gel Dosimeters Irradiated by Carbon Ion Beam Gels micellar hydrogel polymer hydrogel carbon ion radiotherapy radioactivity Monte Carlo simulation |
| title | Induced Radionuclides and Their Activity Concentration in Gel Dosimeters Irradiated by Carbon Ion Beam |
| title_full | Induced Radionuclides and Their Activity Concentration in Gel Dosimeters Irradiated by Carbon Ion Beam |
| title_fullStr | Induced Radionuclides and Their Activity Concentration in Gel Dosimeters Irradiated by Carbon Ion Beam |
| title_full_unstemmed | Induced Radionuclides and Their Activity Concentration in Gel Dosimeters Irradiated by Carbon Ion Beam |
| title_short | Induced Radionuclides and Their Activity Concentration in Gel Dosimeters Irradiated by Carbon Ion Beam |
| title_sort | induced radionuclides and their activity concentration in gel dosimeters irradiated by carbon ion beam |
| topic | micellar hydrogel polymer hydrogel carbon ion radiotherapy radioactivity Monte Carlo simulation |
| url | https://www.mdpi.com/2310-2861/8/4/203 |
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