Development of radiopure cadmium tungstate crystal scintillators from enriched [sup 106]Cd and [sup 116]Cd to search for double beta decay

Improvement of radiopurity level of enriched 116CdWO4 and ZnWO4 crystal scintillators by recrystallization

“…1 and No. 2 was estimated from the experimental data of the Aurora experiment [1,6,7], while the radioactive contamination of the crystal sample No. 3 was measured by HPGe detector [1] and also in the present work by scintillation counting method (see Sections 3 and 4).…”

Status and Perspectives of 2ϵ, ϵβ+ and 2β+ Decays

“…Moreover, low background crystal scintillators are being used for a long time in rare α and β decays (see e.g., [78]). Hoverer, a very wide choice of scintillators is available for DBD experiments, such as CdWO 4 (due to 106 Cd, 108 Cd, 114 Cd, 116 Cd, 180 W, 186 W), CaMoO 4 (due to 100 Mo), and their enrichments (such as 106 Cd, 116 Cd and 100 Mo) [31,[79][80][81][82][83][84] [51][52][53]58,[91][92][93][94][95][96][97][98][99][100][101][102][103][104]. Moreover, as other example, rare-earth-doped scintillators (CaF 2 (Eu), LaCl 3 (Ce), etc.)…”

“…or scintillators, such as CdWO 4 and CaWO 4 , are used to study very specific nuclear rare processes [105][106][107][108]. Extensive literature on historical benchmarks and the industrial production of crystals is available, see, e.g., [51,52,58,[85][86][87][88][89][90][91][92][93][94][95][96][97][98][99][100][101][102][103][105][106][107][108][109][110][111][112][113][114][115][116][117][118][119].…”

Enriched Crystal Scintillators for 2β Experiments

“…The scintillating detectors shown good optical and scintillation properties obtained thanks to the deep purification of 116 Cd and W, and the advantage of the low-thermal-gradient Czochralski technique to grow the crystal. The experiment with two cadmium tungsten crystal scintillators has been run in the low background DAMA/R&D set-up at the LNGS with several upgrades to improve the detector background counting rate and energy resolution [92][93][94]. The radioactive contamination by radionuclides from U/Th chains and K of the scintillating elements increases longitudinal during the crystal growth that shows a segregation of radio-impurities: The conic part of the boule, the beginning of the crystal growth, appeared the cleanest one.…”