Taehyun Yoon: An atom trap trace analysis (ATTA) system to measure trace contamination by Kr of XENON dark matter detector

Taehyun Yoon, Columbia University

In the XENON dark matter search experiment, trace contamination of Xe by Kr contributes background events through the beta decay of radioactive Kr-85. To achieve the required sensitivity of the detector, the contamination must be reduced below the part per trillion (ppt) level and this level must be known precisely. We have developed an atom trap trace analysis (ATTA) device using standard atom cooling and trapping techniques to detect Kr below the ppt level.