Initial performance of the UltraLo-1800 alpha particle detector at the 700 m deep Yangyang underground laboratory in Korea is described. The ionization detector uses Argon as a counting gas for measuring alpha events of a sample. We present initial calibration results and low-activity sample measurements based on the detector's pulse discrimination method and a hardware veto. A likelihood analysis that shows a separation of a bulk component from a surface component with a contamination depth from 210Po alpha particles using simulated models is presented.
@article{arxiv.1805.09947,
title = {Initial performance of the high sensitivity alpha particle detector at the Yangyang underground laboratory},
author = {C. Ha and G. Adhikari and P. Adhikari and E. J. Jeon and W. G. Kang and B. H. Kim and H. Kim and Y. D. Kim and Y. H. Kim and H. S. Lee and J. H. Lee and M. H. Lee and D. S. Leonard and S. L. Olsen and J. S. Park and S. H. Yong and Y. S. Yoon},
journal= {arXiv preprint arXiv:1805.09947},
year = {2018}
}