Abstract Highly radiopure NaI(Tl) was developed to search for particle candidates of dark matter. Optimized methods were combined reduce various radioactive impurities. $^{40}$K effectively reduced by the recrystallization method. The progenies decay chains uranium and thorium appropriate resins. concentration natural potassium in crystal 20 ppb. Concentrations alpha-ray emitters successfully r...

COSINE-200 is the next phase experiment of ongoing COSINE-100 that aims to unambiguously verify annual modulation signals observed by DAMA and reach world competitive sensitivity on low-mass dark matter search. To achieve physics goal COSINE-200, successful production low-background NaI(Tl) detectors crucial it must begin from mass ultra-low background NaI powder. A clean facility for mass-prod...

This paper describes the liquid scintillator veto system for COSINE-100 dark matter experiment and its performance. The detector consists of eight NaI(Tl) crystals immersed in 2200~L linear alkylbenzene-based scintillator. tags between 65 75\% internal $^{40}$K background 2--6 keV energy region. We also describe model scintillator, which is primarily used to assess calibration threshold.

Abstract The JRC applied six measurement techniques to standardise the activity of an 241 Am solution in frame 2003 key comparison CCRI(II)-K2.Am-241. methods used were alpha-particle counting at a defined small solid angle, high-efficiency particle and photon with windowless 4π CsI(Tl) sandwich spectrometer, alpha pressurised proportional counter, alpha-gamma coincidence sum counter NaI(Tl) we...

For nearly two decades the DAMA Collaboration has been observing a modulating signal compatible with that expected from dark matter presence in our galaxy. However, interpretations of this standard assumptions for particles are strongly ruled out by large number other experiments. This tension can be relaxed somewhat making more tailored choices model and properties interest, but expanding mode...

Natural radionuclides present in soil as well as certain anthropogenic radionuclides released to the environment are the major contributors to terrestrial outdoor exposures. In the assessment of human exposures from environmental radioactivity, besides the conventional method of soil and vegetation sampling combined with laboratory based analyses of environmental media, the other choice would b...