An innovative technique for the investigation of the 4-fold forbidden beta-decay of $^{50}$V

Understand

For the first time a Vanadium-based crystal was operated as cryogenic particle detector.

• The scintillating low temperature calorimetric technique was used for the characterization of a 22 g YVO$_4$ crystal aiming at the investigation of the 4-fold forbidden non-unique $\beta^-$ decay of $^{50}$V.
• The excellent bolometric performance of the compound together with high light output of the crystal makes it an outstanding technique for the study of such elusive rate process.
• The internal radioactive contaminations of the crystal are also investigated showing that an improvement on the current status of material selection and purification are needed, $^{235/238}$U and $^{232}$Th are measured at the level of 28 mBq/kg, 1.3 Bq/kg and 28 mBq/kg, respectively.