The 82nd JSAP Autumn Meeting 2021

Presentation information

Oral presentation

CS Code-sharing session » 【CS.1】 Code-sharing Session of 2.3 & 7.5

[10p-N402-1~10] CS.1 Code-sharing Session of 2.3 & 7.5

Fri. Sep 10, 2021 1:00 PM - 3:45 PM N402 (Oral)

Kimikazu Sasa(U. Tsukuba), Natsuko Fujita(JAEA)

3:00 PM - 3:15 PM

[10p-N402-8] The status of TOF-E detection system at MALT and its proceedings

〇(D)Li Zheng1, Hiroyuki Matsuzaki1, Takeyasu Yamagata1 (1.Tokyo Univ.)

Keywords:Time of flight, Monte Carlo method, Detector response

Accelerator Mass Spectrometry (AMS) is the most sensitive technique for the measurement of the actinides, particularly 236U. A Time of Flight-Energy (TOF-E) detection system is the most appropriate technique to discriminate 236U ions from 238U, 235U and other interferences. Micro Analysis Laboratory, Tandem Accelerator aims to improve the sensitivity of 236U/238U from 3×10-10 to 10-13 with the installation of TOF-E detection system.Currently, MALT has acquired start timing signal using Microchannel Plate (MCP) as start timing detector. The stop timing detector and energy detector are under construction. Prior to the construction of realistic TOF-E detection system, a (Geometry and Tracking version 4) Geant4 Monte Carlo simulation of TOF-E detection system has been completed. Two detection configurations and three thicknesses of carbon foil as electron generator have been simulated. From simulation results, it shows that the thickness of carbon foil is one key factor to efficiency and time resolution. The thinner the carbon foil, the better efficiency and time resolution. Adopting the configurations of 2.4 meters of flight path and 3 ug/cm2 of carbon foil, the flight time difference between 236U and 235U, and between 236U and 238U are, respectively, 3 ns and -6 ns and the full width at half maximum (FWHM) of 235U, 236U and 238U are identical, 1 ns. The results demonstrate that the above configuration is adequate to identify 236U from 235U, 238U. With the combination of simulation results and realistic beam experiment results, 2.63% of efficiency between start detector and silicon surface barrier detector (SBD) for U-AMS is acquired.