Development of CsI crystals for WIMP search

Abstract An experimental search for WIMP using CsI(Tl) crystals(KIMS) is being prepared at the underground laboratory, Cheongpyung, Korea. Characteristics and internal background of CsI(Tl) crystal have been investigated in detail to develop highly sensitive detector for WIMP search. The background at the underground laboratory is measured and shielding design has been done with an optimization with a MC study. The result of detector development and prospect of KIMS experiment is reported.