2018 Fall Meeting

Presentation information

Oral presentation

II. Radiation, Accelerator, Beam and Medical Technologies » 203-1 Accelerator and Beam Acceleration Technology

[1L07-09] Beam Diagnostics and Accelerator Technology

Wed. Sep 5, 2018 2:45 PM - 3:35 PM Room L (D12 -D Building)

Chair:Takafumi Kondoh(Osaka Univ.)

3:00 PM - 3:15 PM

[1L08] Progress on Ultrasensitive Detection Techniques for Hard-to-measure Nuclide 41Ca with the 6 MV Tandem Accelerator Mass Spectrometry System

*Kimikazu Sasa1, Seiji Hosoya2, Tsutomu Takahashi1, Kenta Takano1, Yuta Ochiai1, Yasuji Oura3, Keisuke Sueki1 (1. Univ. Tsukuba, 2. QST, 3. Tokyo Metropolitan Univ.)

Keywords:Ca-41, Accelerator Mass Spectrometry (AMS), 6 MV tandem accelerator

41Ca (T1/2= 1.04 × 105 yr) is an ideal tracer on dating of the exposure age for meteorites and terrestrial surfaces. We have been developing ultrasensitive detection techniques for 41Ca-AMS with the 6 MV tandem accelerator. The ion source can extract CaF3- beams up to 500 nA from CaF2 materials. In this study, we tried to detect a charge state of 41Ca5+ with a total energy of 32.5 MeV. The beam transmission of 41Ca5+ is about 7 %. A multi-plate gas-ionization detector is employed to separate 41Ca spectrum from isobaric interferences of 41K. We can obtain a background level of 41Ca/Ca ratio to about 3 × 10−15 and a measurement precision of 3% for 9.76 × 10-12 isotopic ratio using the 6 MV AMS system.