Incorporation of a bromine atom into DNA-related molecules changes their electronic properties

Hirato, Misaki*; Yokoya, Akinari*; Baba, Yuji*; Mori, Seiji*; Fujii, Kentaro*; Wada, Shinichi*; Izumi, Yudai*; Haga, Yoshinori

Physical Chemistry Chemical Physics, 25(21), p.14836 - 14847, 2023/05

https://doi.org/10.1039/D3CP01597A

Verification of dose estimation of Auger electrons emitted from Cu-64 using a combination of FNTD measurements and Monte Carlo simulations

Kusumoto, Tamon*; Matsuya, Yusuke; Baba, Kentaro*; Ogawara, Ryo*; Akselrod, M. S.*; Harrison, J.*; Fomenko, V.*; Kai, Takeshi; Ishikawa, Masayori*; Hasegawa, Sumitaka*; et al.

Radiation Measurements, 132, p.106256_1 - 106256_4, 2020/03

https://doi.org/10.1016/j.radmeas.2020.106256

Internal radiation therapy with Cu-64 concentrates energy deposition in tumor cells by virtue of released Auger electrons with low energy. In our previous study, we have attached the solutions at the surface of Fluorescent Nuclear Track Detector (FNTD) and succeeded in measuring the absorbed doses of Auger electrons registered in FNTD. However, because there are several types of radiation emitted from the source, i.e., beta rays, positron etc., the contribution degree of Auger electron to energy concentration remain uncertain. In this study, we quantitatively analyzed the spatial dose distribution in the FNTD based on Monte Carlo simulation with PHITS and GEANT4, and evaluated high dose deposited by Auger electrons. The dose distribution calculated by the PHITS code is exactly equivalent to that by Geant4. Also, the simulations are well agreement with experimental results. If the contribution of Auger electrons is ignored, the significantly high absorbed dose proximal to the source is not properly reduced. These findings demonstrate that Auger electrons work very effectively to kill cancer cells proximal to Cu-64 source while minimizing damage effects on normal cells distal to the source.

Research and development of neutron detection system using scintillator and digital-signal processing

Shinohara, Koji; Ishii, Keiichi*; Ochiai, Kentaro; Baba, Mamoru*; Sasao, Mamiko*; Kitajima, Sumio*

Plasma and Fusion Research (Internet), 8, p.1402144_1 - 1402144_9, 2013/11

https://doi.org/10.1585/pfr.8.1402144

Measurement of response on d-T neutrons of two-stage system for neutron emission profile measurement using a neutron beam at FNS

Shinohara, Koji; Ishii, Keiichi*; Ochiai, Kentaro; Baba, Mamoru*; Sasao, Mamiko*; Kitajima, Sumio*

no journal, , 

Spontaneous fission measurements using Es target

Asai, Masato; Tsukada, Kazuaki; Sato, Tetsuya; Ito, Yuta; Nishio, Katsuhisa; Makii, Hiroyuki; Hirose, Kentaro; Orlandi, R.; Suzaki, Fumi; Aoki, Ryota; et al.

no journal, , 

Fission of neutron-rich heavy-actinide nuclei exhibits extremely characteristic fission-fragment mass distributions which differ significantly from those of typical actinide nuclei. In the present study, we have succeeded in producing those neutron-rich heavy-actinide nuclei with multinucleon transfer reactions using an extremely rare and short-lived Es target bombarded with heavy-ion beam from the JAEA Tandem Accelerator. The products were mass-separated with an on-line isotope separator (ISOL), and spontaneous fission of Fm, Fm, Md, Lr was observed. Fission-fragment mass distributions and total kinetic energy distributions were obtained precisely, which provides us with important information to clarify the characteristic fission mechanism observed in this nuclear region.