[20p-PB5-1~85] 2 Ionizing Radiation (Poster)

[20p-PB5-69] Advanced detection method of semiconductor detector for nuclear fission and its applications

〇Mirei Takeyama¹, Daiya Kaji², Koji Morimoto², Yasuo Wakabayashi², Fuyuki Tokanai¹, Kosuke Morita^2,3 (1.Yamagata Univ. Center for AMS, 2.RIKEN Nishina Center, 3.Kyusyu Univ.)

Keywords:silicon semiconductor detector, spontaneous fission, superheavy element

The elements with atomic number Z≥104 are called superheavy elements (SHEs). We have been investigating the physical and chemical properties of the SHEs using a gas-filled recoil ion separator (GARIS) installed at the RIKEN Linear Accelerator (RILAC) facility. Following the successful discovery of element ²⁷⁸Nh, the search for element 119 and beyond, which is uncharted territory, using the hot-fusion reaction was set as our next challenge. Prior to taking up the new challenge, we first investigated the response of the detection system to spontaneous fission (SF) events. The system consists of five silicon semiconductor detectors (SSDs). The identification of the SF to discriminate background events is primary importance since the decay chains originating from these SHEs synthesized with hot-fusion reactions are terminated by SF through consecutive alpha emission. We carried out the performance test of the system by directly impinging the SF source into the SSD. Furthermore, we have investigated the results by comparing with those obtained by a computer simulation using the particle and heavy ion transport code system (PHITS).