1. A Search for Neutrinoless Double Beta Decay with NEMO-3 Kiyotaka Yamazaki

2. 150 Nd A source foil contains Nd 2 O 3 with 37.0±0.1g of 150 Nd (~90% of the foil) 150 Nd is a 2νββ isotope with Q ββ =3367keV -Second highest of all 2νββ isotopes (Q ββ ( 48 Ca)=4271kev)  The highest phase factor in all 2νββ isotopes.

3. Phase 1 and Phase 2 Nuclear Instruments and Methods in Physics Research A 606 (2009) 449–465 Radon diffusion through the joints of the sectors Radon-free facility was installed in September 2004 Phase1: A(Rn) = 37.7±0.1 mBq/m 3 Phase1: A(Rn) = 6.46±0.02 mBq/m 3

4. Background analysis -1e1γ channel EC (e.g. 207 Bi, 152 Eu) -daughter nucleus de-excites by emission of photon and electron is ejected via internal conversion. β-decay to an excited states (e.g. 152 Eu, 154 Eu) -daughter nucleus de-excites by emission of photon β-decay and 2 γ emission (e.g. 208 Tl) -daughter nucleus de-excites by emission of 2 photons but it is possible that one of photon is not detected.

5. Background analysis -1e1γ channel Phase 1 Phase 2 Energy Sum Energy of Electron

6. But… Nasim FATEMI-GHOMI thesis 2009 A( 208 Tl)= 0.47±0.05 mBq 924.7days 1402.1days in Total A( 208 Tl)= 1.25±0.1 mBq

7. 2e channel T 1/2 =(9.03±0.04)×10 18 years

8. Next year… Main goal is to publish all the 150 Nd results Analysis of full-set of the data Radon Problem More background analysis - with 1e, 1e2γ channel And 0νββ analysis…