Solotvina Underground Laboratory

1. Solotvina Underground Laboratory Institute for Nuclear Research (Kiev, Ukraine) http://lpd.kinr.kiev.ua

2. Solotvina Underground Laboratory was built upin 1984 on the west of Ukraine in Solotvina (Transcarpathian region)NaClsalt mine 430 m underground (1000 m w.e.) Total square  1000 m2

3. Background conditions  flux: 1.5103 m-2·d-1measured by plastic scintillator counter Termal nflux: 310-6 cm-2·s-1by 3He counter Radon:30Bq·m-3 by radon monitor (Honeywell A9000A 1006) Temperature is 241C independent of season Background of CdWO4 scintillator (44 cm) Kiev Solotvina 1000 m w.e. Solotvina in shield

4. Background measured by HP Ge detector 165 cm3 Set up with HP Ge Solotvina, 1000 m w.e. 1109 h, in shield Due to low radioactive contamination of the salt, the natural  background in the SUL is 10100 times lower than in other underground laboratories

5. Experiment to search for 2 decay of 116CdKiev-Florence collaboration Plastic active shield CdWO4 20.6 kg Copper 116CdWO4 0.33 kg Plastic light guide Quartz light guide Channel for calibration

6. Main results of116Cd  experiment 22 decay of 116Cd was observed Limits on 02 decay of 116Cd T1/20  1.723 yr at 90 % C.L. m 1.7 eV  2.510-8  2.210-6 T1/20M 0.822 yr gM  8.110-5 CAMEO project was proposed PRC 68 (2003) 035501 100 kg of 116CdWO4 scintillators allocated in a large volume of high-pure liquid  PLB 493 (2000) 216; EPJC 19 (2001) 43

7. Search for 2 decay of 160Gd was performed with the help of Gd2SiO5(Ce) crystal scintillator, 635 g, 13 949 h 2160GdQ2 = 1730 keV T1/20  1.321 yr  T1/22  1.919 yr at 90 % C.L. Yad. Fiz. 58 (1995) 195; NPA 694 (2001) 375

8. decay of 113Cd was investigated CdWO4 454 g, 433 h ½+ 0 113Cd  9/2+ 0 Q = 316 keV113In Fourth-forbidden  decay T1/2= (7.70.3)1015 yr [ Yad. Fis. 59(1995)5 ] Previous T1/2:(9.31.9)1015 yr [1]; (9.30.5 1)1015 yr [2] [1] J.Inorg.Nucl.Chem. 32(1970)2113; [2] NPB (Proc.Suppl.) 35(1994)394

9.  decay of 180W was observed 116CdWO4 330 g, 2975 h,  spectrum +0.8 –0.4 T1/2= [1.1 (stat)0.3(syst)]1018 yr Recently this result was confirmed with CaWO4 as scintillator [Yu.G.Zdesenko et al., NIMA in press] and bolometer [C.Cozzini et al., PRC 70(2004)064606] PRC 67 (2003) 014310

10. Low radioactivity technique Sensitive methods to measure radioactive contamination of scintillators were developed • Radioactive contamination of (Ca, Zn, Cd &116Cd)WO4,GSOscintillators was measured • CaWO4andZnWO4were studied as detectors to search for 2 decay processes in48Caand64Zn,and as dark matter detectors • APP (2005); NIMA (2005) in press; nucl-ex/0409014, accepted to NIMA • Study ofPbWO4, BGO, GSO,YAG:Nd, CaMoO4crystal scintillatorsto search for rare processes is in progress • nucl-ex/0412021; nucl-ex/0410021, accepted to NIM A

11. Current status of research in Solotvina Advancement of the 116Cd experiment:3-51024 yrm 0.3 eV Low counting experiments in collaboration with Roma 1 & 2 Universities and LNGS Modernization of the Solotvina Underground Laboratory will be realized in 2005 thanks to financing from the Ukrainian National Academy of Sciences

12. The Solotvina Underground Laboratory would like to participate in the ILIAS PROGRAMM