[16a-D311-1~11] 2.1 Detection Devices

[16a-D311-1] Analysis of Recombination Processes in Nuclear Emulsions for Dark Matter Detection

〇Tadaaki Tani¹, Takashi Asada², Takayuki Uchida³, Tatsuhiro Naka^4,5 (1.Soc. Photogr. Imaging Jpn., 2.Napoli Univ., 3.Tokyo Polytec. Univ., 4.Toho Univ., 5.Nagoya Univ.)

Keywords:Dark matter, Nuclear emulsions, Recombination

We are trying to detect dark matter by observing a track composed of silver grains, which are converted by development from AgBrI grains (~70 nm), on which latent image centers (Agn) are formed by electron hole pairs (1800/grain) created by a nuclear recoil of a dark matter particle. In the previous paper, it was indicated through time-resolved photoconductivity that latent image formation would be disturbed by both rapid and slow recombination processes. The former takes place within 20 ns between free electrons and positive holes. The latter takes place for several days between Agn and Br2. In this paper, we have studied the latter by putting a forcus on the effect of sodium sulfite, which is expected to deactivate Br2.