Production of ultra-low radioactivity NaI(Tl) crystals for Dark Matter detectors

Understand

Scintillating NaI(Tl) crystals are widely used in a large variety of experimental applications.

• However, for the use as Dark Matter (DM) detectors, such crystals demand a high level of radio-purity, not achievable by means of standard industrial techniques.
• One of the main difficulties comes from the presence of potassium that always accompanies sodium in alkali halides.
• On the other hand, the arguable DM detection by DAMA experiment using NaI(Tl) scintillating crystals requires a reliable verification able to either confirm the existence of DM or rule out the DAMA claim.