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A Search for Neutrinoless Double Beta Decay with NEMO-3. Kiyotaka Yamazaki. 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 2 νββ isotope with Q ββ =3367keV -Second highest of all 2 νββ isotopes (Q ββ ( 48 Ca)=4271kev) - PowerPoint PPT Presentation
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A Search for Neutrinoless Double Beta Decay with NEMO-3
Kiyotaka Yamazaki
150Nd
A source foil contains Nd2O3 with 37.0±0.1g of 150Nd (~90% of the foil)
150Nd is a 2νββ isotope with Qββ=3367keV -Second highest of all 2νββ isotopes (Qββ (48Ca)=4271kev)
The highest phase factor in all 2νββ isotopes.
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/m3
Phase1: A(Rn) = 6.46±0.02 mBq/m3
Background analysis -1e1γ channel
EC (e.g. 207Bi, 152Eu) -daughter nucleus de-excites by emission of photon and electron is ejected via internal conversion. β-decay to an excited states (e.g. 152Eu, 154Eu) -daughter nucleus de-excites by emission of photon
β-decay and 2γ emission (e.g. 208Tl) -daughter nucleus de-excites by emission of 2 photons but it is possible that one of photon is not detected.
Background analysis -1e1γ channel
Phase 1 Phase 2
Energy Sum
Energy ofElectron
But…
Nasim FATEMI-GHOMI thesis 2009
A(208Tl)= 0.47±0.05 mBq
924.7days
1402.1days in Total
A(208Tl)= 1.25±0.1 mBq
2e channel
T1/2=(9.03±0.04)×1018 years
Next year…
• Main goal is to publish all the 150Nd results
• Analysis of full-set of the data• Radon Problem• More background analysis
- with 1e, 1e2γ channel• And 0νββ analysis…