WIMPs Search by Means of the Highly Segmented Scintillator

Abstract

The highly sensitive method to search for WIMPs dark matter particles is proposed. An array of thin NaI(Tl) plate has the great selectivity for distinguishing the WIMPs events and background ones. The principle of signal selection for WIMPs is described. The high sensitivity for SD (spin-dependent) type WIMPs is expected by applying multi-layer system of NaI(Tl) detector. A method of highly sensitive measurement is strongly needed to study nuclear and particle rare processes. The need for highly sensitive radiation detector has been increased in the fields of particle astrophysics and nuclear physics. Particularly, the search for dark matter candidates and the search for neutrino-less double beta decay need to select the signal events from the huge number of background ones. In the case of WIMPs search, the groups such as ELEGANT, 1 DAMA 2 applied the huge volume of NaI(Tl) scintillator. The new project with the huge volume scintillator are proposed with hundreds kg of scintillators by XMASS 3 group, ZEPLIN group 4 and so on. The many groups are trying to enhance the sensitivity by developing a large volume and low background detectors. However, to reduce the background events becomes more difficult for the larger detectors because of its poor position resolution. We propose highly selective detector system to extract the signals of WIMPs. The segmentation of a detector results good position resolution, which enhances the sensitivity for WIMPs.