This array of Low Background detectors was built for the University of Washington and is used in one of the stations of the Advanced Photon Source at the Argonne National Laboratory. These detectors have been designed to measure low energy x-ray events down to 0.75 keV. This is accomplished by careful selection and design of the low background and low noise components.
Ultra-Low Background Units
The detectors used in the search for Dark Matter require special ultra low background NaI(Tl) material. The main contaminants of concern are: 238U, 40K, 232Th, 210Pb and total alpha rate. Over several years of research and development at ASI we achieved extremely radiopure material. Our ultra-low background NaI(Tl) material is called WIMPScint material. Our WIMPScint-III material is now being used in several Dark Matter experiments around the world. Refer to our data sheet for more details.
In 2019, ASI’s material have been referenced by two different international laboratories. These two customers have given us high praise in the prestigious journal, Physical Review Letters. These references are:
The University of Zaragoza ANAIS Project,
Physical Review Letters 123, 031301 (2019). First Results of the Dark Matter Annual Modulation from the ANAIS-112 Experiment.
“We would like to emphasize that the outstanding light collection measured for the nine modules is at the level of 15 photoelectrons per keV.”
The Cosine experiment, lead by the Institute for Basic Science has published two Physical Review Letters in 2019.
Physical Review Letters 122, 13180-2 (2019). First Direct Search for Inelastic Boosted Dark Matter with COSINE-100.
“COSINE-100 consists of a 106 kg array of eight ultrapure NaI(Tl) crystals….”
Physical Review Letters 122, 13180-2 (2019). The Search for a Dark Matter-Induced Annual Modulation Signal in NaI(Tl) with the COSINE-100 Experiment.
A preprint of the University of Zaragoza’s article can be found at:
and the Institute for Basic Science’s articles can be found at:
Additionally, in 2015, the quality of our material is summed up by Hyun Su Lee from the Institute of Basic Science in Korea:
“…. recently developed NaI(Tl) crystals grown by Alpha Spectra Inc. provide higher light yields and this makes it interesting to study their PSD performance and evaluate their sensitivity.” [Hyun Su Lee’s, et al., Pulse-shape discrimination between electron and nuclear recoils in a NaI(Tl) crystal, Jour. Of High Energy Physics, Aug. 2015]