The COSINE-100 dark matter search experiment is an array of NaI(Tl) crystal detectors located in the Yangyang Underground Laboratory (Y2L). To understand measured backgrounds in the NaI(Tl) crystals we have performed Monte Carlo simulations using the Geant4 toolkit and developed background models for each crystal that consider contributions from both internal and external sources, including cosmogenic nuclides. The background models are based on comparisons of measurement data with Monte Carlo simulations that are guided by a campaign of material assays and are used to evaluate backgrounds and identify their sources. The average background level for the six crystals (70 kg total mass) that are studied is 3.5 counts/day/keV/kg in the (2-6) keV energy interval. The dominant contributors in this energy region are found to be 210Pb and 3H.
@article{arxiv.1804.05167,
title = {Background model for the NaI(Tl) crystals in COSINE-100},
author = {P. Adhikari and G. Adhikari and E. Barbosa de Souza and N. Carlin and S. Choi and W. Q. Choi and M. Djamal and A. C. Ezeribe and C. Ha and I. S. Hahn and A. J. F. Hubbard and E. J. Jeon and J. H. Jo and H. W. Joo and W. G. Kang and M. Kauer and W. S. Kang and B. H. Kim and H. Kim and H. J. Kim and K. W. Kim and M. C. Kim and N. Y. Kim and S. K. Kim and Y. D. Kim and Y. H. Kim and V. A. Kudryavtsev and H. S. Lee and J. Lee and J. Y. Lee and M. H. Lee and D. S. Leonard and W. A. Lynch and R. H. Maruyama and F. Mouton and S. L. Olsen and H. K. Park and H. S. Park and J. S. Park and K. S. Park and W. Pettus and H. Prihtiadi and S. Ra and C. Rott and A. Scarff and N. J. C. Spooner and W. G. Thompson and L. Yang and S. H. Yong},
journal= {arXiv preprint arXiv:1804.05167},
year = {2018}
}