Performance of an ultra-pure NaI(Tl) detector produced by an indigenously-developed purification method and crystal growth for the COSINE-200 experiment

The COSINE-100 experiment has been operating with 106 kg of low-background NaI(Tl) detectors to test the results from DAMA/LIBRA experiment, which claims have observed dark matter. However, since background crystals used in is 2–3 times higher than that DAMA detectors, no conclusion regarding claimed observation could be reached. Therefore, we plan upgrade current next phase, COSINE-200, by using ultra-low detectors. basic principle was already proved commercially available Astro-grade NaI powder Sigma-Aldrich (now Merck) company. developed a mass production process ultra-pure at Center for Underground Physics (CUP) Institute Basic Science (IBS), Korea, direct purification raw powder. We produce more 1,000 COSINE-200 experiment. With our crystal grower installed CUP, successfully grown technique assembled detector. In this article, report performance detector produced IBS, Korea.