1. Cristina Cozzini (Oxford), IDM 2004, Edinburgh CRESST-II background discrimination: detection of 180 W natural decay in a pure alpha spectrum Paper submitted to Physical Review C (also available on nucl-ex/0408006)

2. Cristina Cozzini (Oxford), IDM 2004, Edinburgh C. Cozzini 1, G. Angloher 2, C. Bucci 3, F. von Feilitzsch 4, D. Hauff 2, S. Henry 1, Th. Jagemann 4, J. Jochum, H. Kraus 1, B. Majorovits 1, V. Mikhailik 1, J. Ninkovic 2, F. Petricca 2, W. Potzel 4, F. Proebst 2, Y. Ramachers 1,*, W. Rau 2, M. Razeti 4, W. Seidel 2, M. Stark 4, L. Stodolsky 2, A. J. B. Tolhurst 1, W. Westphal 4, H. Wulandari 4 1. University of Oxford, U.K. 2. MPI für Physik, Munich, Germany 3. Laboratori Nazionali del Gran Sasso, Italy 4. Technische Universität München, Germany 5. Eberhard-Karls-Universität Tübingen, Germany * Permanent address: University of Warwick, U.K.

3. Cristina Cozzini (Oxford), IDM 2004, Edinburgh light reflector 300 g CaWO 4 crystal separate cryogenic light detector thermometer Superconducting film as thermometer simultaneous measurement of phonons and scintillation light to discriminate nuclear recoil signals from radioactive background CRESST PhaseII detector module

4. Cristina Cozzini (Oxford), IDM 2004, Edinburgh irradiation with e - and  with e -  und neutrons Background Suppression: 98 % 10-20 keV 99.7% 15-25 keV 99.9% > 20 keV

5. Cristina Cozzini (Oxford), IDM 2004, Edinburgh U-Th >

6. Cristina Cozzini (Oxford), IDM 2004, Edinburgh ICP-MS (inductively coupled plasma mass- spectrometry) analysis of the impurities in CaWO 4 X-ray luminescence of CaWO 4 RE- impurities in Russian (Y, Nd, Gd and Er all >1 ppm) and Pb (~1 ppm ) in Ukrainian samples Russian Ukrainian

7. Cristina Cozzini (Oxford), IDM 2004, Edinburgh 147 Sm 152 Gd 144 Nd 180 W

8. Cristina Cozzini (Oxford), IDM 2004, Edinburgh 180 W Run 28 crystal D

9. Cristina Cozzini (Oxford), IDM 2004, Edinburgh Half-life for the  -decay of 180 W obtained independently in four different runs Counts Exposure Half-life [kg days] [years] Run 28 Crystal D35±4.312.268 (1.7±0.2)  10 18 Run 27 Crystal D28.5±5.611.745 (1.9±0.4)  10 18 Run 23 Crystal E9 3.467 ≥1.1  10 18 (90% C.L.) Run 22 Crystal B4 1.140 ≥6.7  10 17 (90% C.L.)

10. Cristina Cozzini (Oxford), IDM 2004, Edinburgh Half-life for the  -decay of 180 W obtained from the total exposure (28.62 kg days) Half life T 1/2 = (1.8±0.2)  10 18 years Energy Q = (2516.4±1.1 (stat.)±1.2(sys.)) keV Previous indication (Danevich et al. Phys. Rev. C 67 (2003)) Half life T 1/2 = ( (stat.)±0.3(sys.))  10 18 years

11. Cristina Cozzini (Oxford), IDM 2004, Edinburgh Lower limits (90% C.L) for the half-life times of the non-observed  -decay on the other naturally occurring W isotopes (exposure 16.875 kg days) 182 W T 1/2 ≥ 7.7  10 21 years 183 W T 1/2 ≥ 4.1  10 21 years 184 W T 1/2 ≥ 8.9  10 21 years 186 W T 1/2 ≥ 8.2  10 21 years

12. Cristina Cozzini (Oxford), IDM 2004, Edinburgh Summary Strength of CRESST discrimination techniques High sensitivity (~1µBq/kg) Detection of the alpha decay of 180 W 182 W 183 W 184 W 186 W: improving by a factor of 50 the best previously published limits