暗黒物質方向探索実験における局在表面プラズモン共鳴現象を用いた飛跡解析手法の開発

摘要

WIMPs (Weakly Interacting Massive Particles) are one of the most likely dark matter candidates. Our experimental purpose is to prove the existence through the arrival direction of WIMPs by directly detecting the recoil nucleus as a track with super fine-grained emulsion. Recoil nuclei have low energy (~100 keV) and their track lengths are typically 100 nm or less. Therefore a new readout system is needed to detect such short tracks. To achieve nanomicro-metric accuracy, plasmon track analysis that combines optical property of nano-metal (called localized surface plasmon resonance) with polarization of incident light was developed. Using this, it is possible to obtain the track information beyond the optical resolution. This new readout method will greatly improve experiment performance.