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Your search keyword '"Terakawa, Atsuki"' showing total 18 results
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18 results on '"Terakawa, Atsuki"'

5. PIXE analyses of cesium in rice grains

Author

Sugai, Hiroyuki, Ishii, Keizo, Matsuyama, Shigeo, Terakawa, Atsuki, Kikuchi, Yohei, Takahashi, Hiroaki, Ishizaki, Azusa, Fujishiro, Fumito, Arai, Hirotsugu, Osada, Naoyuki, Karahashi, Masahiro, Nozawa, Yuichiro, Yamauchi, Shosei, Kikuchi, Kosuke, Koshio, Shigeki, and Watanabe, Koji

Published
2014
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7. Two-dimensional Beam Profile Monitor for Alpha Emitter

Author

Tanaka, Kazuo, Harada, Kenichi, Hayamizu, Tomohiro, Itoh, Masatoshi, Kawamura, Hirokazu, Nagahama, Hiroki, Ozawa, Naoya, Sakemi, Yasuhiro, Terakawa, Atsuki, and Uchiyama, Aiko

Subjects
Transverse profile and emittance monitors, Physics::Accelerator Physics, Physics::Atomic Physics, Accelerator Physics
Abstract

We developed two-dimensional beam profile monitors for alpha-emitters along with other larger number of ions to measure the permanent electric dipole moment of the electron using francium atoms at CYRIC in Tohoku university. Francium is produced by the fusion reaction between the oxygen beam from the cyclotron accelerator and gold target, and a far larger number of other ions such as fold or potassium are also emitted from the target. Thus it was difficult to measure the beam profile of francium hidden by these ions. We installed two beam profile monitor consisted of the micro-channel plate and phosphor screen. If we stop the beam after the beam injection to the monitor in sufficient time, we can only observe the fluorescence of the alpha particle emitted by francium atoms on the surface of the plates. By using this monitoring system, we improved the beam transport efficiency by several times and improved beam purity of francium with Wien filter., Proceedings of the 8th International Beam Instrumentation Conference, IBIC2019, Malmö, Sweden

Published
2019
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10. Elemental analysis on the particle cross-section of the radioactive cesium contaminated soil by PIXE

Author

Ohnuma, Tohru, primary, Ishii, Keizo, additional, Matsuyama, Shigeo, additional, Yamaguchi, Toshirou, additional, Arai, Hiromu, additional, Terakawa, Atsuki, additional, Arai, Hirotsugu, additional, Takyuu, Soudai, additional, Sata, Daichi, additional, Seki, Daiki, additional, Imaizumi, Kouta, additional, Suzuki, Syuuhei, additional, and Hatakeyama, Taisuke, additional

Published
2016
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12. Basic evaluation of three-dimensional position sensitive CdTe detector unit for clinical use of ultra-high resolution human PET scanner

Author

Takyu, Sodai, primary, Ishii, Keizo, additional, Kikuchi, Yohei, additional, Terakawa, Atsuki, additional, Matsuyama, Shigeo, additional, Ahmed, Abdella, additional, Matsuyama, Tetsuo, additional, Takahata, Keigo, additional, Igarashi, Shinya, additional, Sakurada, Yusuke, additional, Ito, Ryohei, additional, and Yamamoto, Yohei, additional

Published
2014
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14. Evaluating radiocesium retention ability of root-mat horizon using micro-PIXE analysis

Author

Arai, Hirotsugu, primary, Ishii, Keizo, additional, Matsuyama, Shigeo, additional, Fujishiro, Fumito, additional, Ishizaki, Azusa, additional, Osada, Naoyuki, additional, Sugai, Hiroyuki, additional, Koshio, Shigeki, additional, Kusano, Kaoru, additional, Nozawa, Yuichiro, additional, Yamauchi, Shosei, additional, Karahashi, Masahiro, additional, Oshikawa, Shun, additional, Kikuchi, Kosuke, additional, Watanabe, Koji, additional, Suziki, Yui, additional, Kikuchi, Yohei, additional, and Terakawa, Atsuki, additional

Published
2014
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16. A Study on Beam Flattening Based on Compact Double Scatterer Applicable to Rotational Beam Irradiation System in the Proton Therapy Facility at CYRIC, Tohoku University

Author

TORSHABI, Ahmad ESMAILI, primary, TERAKAWA, Atsuki, additional, ISHII, Keizo, additional, YAMAZAKI, Hiromichi, additional, MATSUYAMA, Shigeo, additional, KIKUCHI, Youhei, additional, AKIYAMA, Hisaki, additional, KOYATA, Kan, additional, TAGAWA, Atsushi, additional, ITOH, Yuki, additional, and YASUNAGA, Shigeyoshi, additional

Published
2011
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18. Experimental comparison of relative stopping power evaluation between proton CT and x-ray CT for pre-clinical proton irradiation studies of small animals.

Author

Terakawa A, Hosokawa H, Nogami M, Hitomi K, and Ishii K

Subjects
Animals, X-Rays, Phantoms, Imaging, Tomography, X-Ray Computed veterinary, Tomography, X-Ray Computed methods, Water, Protons, Proton Therapy methods
Abstract

Objective . Proton therapy experiments in small animals are useful not only for pre-clinical and translational studies, but also for the development of advanced technologies for high-precision proton therapy. While treatment planning for proton therapy is currently based on the stopping power of protons relative to water (i.e. the relative stopping power (RSP)), estimated by converting the CT number into RSP (Hounsfield unit (HU)-RSP conversion) in reconstructed x-ray computed tomography (XCT) images, the HU-RSP conversion causes uncertainties in RSP, which affect the accuracy of dose simulation in patients. Proton computed tomography (pCT) has attracted a great deal of attention due to its potential to reduce RSP uncertainties in clinical treatment planning. However, as the proton energies for irradiating small animals are much lower than those used clinically, the energy dependence of RSP may negatively affect pCT-based RSP evaluation. Here, we explored whether the low-energy pCT approach provided more accurate RSPs when planning proton therapy treatment for small animals. Approach. We evaluated the RSPs of 10 water- and tissue-equivalent materials with known constituent elements based on pCT measurements conducted at 73.6 MeV, then compared them with XCT-based and calculated RSPs to investigate energy dependence and achieve more accurate RSPs for treatment planning in small animals. Main results . Despite the low proton energy, the pCT approach for RSP evaluation yields a smaller root mean square deviation (1.9%) of RSP from the theoretical prediction, compared to conventional HU-RSP conversion with XCT (6.1%). Significance. Low-energy pCT is expected to improve the accuracy of proton therapy treatment planning in pre-clinical studies of small animals if the RSP variation that can be attributed to energy dependence is identical to the variation in the clinical proton energy region., (Creative Commons Attribution license.)

Published
2023
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