Telescope Germanium Vertical

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Telescope Germanium Vertical
V. Egorov
T G V
status report

• JINR Dubna, Russia
• CSNSM Orsay, France
• CTU Prague, Czech Republic
• RRC - Kurchatov Institute Moscow, Russia
• CU Bratislava, Slovakia

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Double Beta Spectrometers
TGV
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Nuclei - candidates
0.187
1.25
2 X-rays
0.25 106/g
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TGV-1 (1994 2000) results
T1/2 (2?2?) (2.9?7.5)1019 y T1/2 (2?0?) ? ?
1.51021 y (90CL)
Zero
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Telescope Germanium Vertical (TGV-2)

• 32 HPGe planar detectors ?60 mm 6 mm
• with sensitive volume 20.4 cm2 6 mm
• Total sensitive volume 400 cm3
• Total mass of detectors 3 kg
• Total area of samples 330 cm2
• Total mass of samples 10 ? 25 g
• Total efficiency 50 ? 60
  
• E-resolution 3 ? 4 keV _at_ 60Co
• LE-threshold 5 ? 6 keV
• Double EC (2005-2006)
• - 12 samples of 106Cd
  10 g 106Cd ( 50 µm )

UThlt0.1 ppb
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TGV-2 (2000 )
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Suppression of low energy noise with
primitive Fourier analysis
High freq. noise E1 gt E2 Real signal
E1 E2 Low freq. noise E1 lt E2
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Low frequency (microphonic)
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?
GEMMA
BTW
search for the Neutrino Magnetic Moment
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Results of one-year (2005) measurement

• 2?EC/EC (0?0,g.s.) decay of Cd-106
• Experiment
• T1/2 1.8 x 1020 y (95CL) (TGV-2)
• T1/2 5.8 x 1017 y (90CL) (F.Danevich
  et.al.)
• T1/2 1.5 x 1017 y (68CL) (H.Kiel et.al.)
• Theory
• T1/2 1.0 x 1020 y (J.Suhonen)
• T1/2 8.7 x 1020 y (M.Hirsch)
• T1/2 4.4 x 1021 y (F.Simkovich)

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Gas-tight cup of the cryostat (ultra-pure
Al, made by CANBERRA) has a weld seam here
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Drastic solution
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110
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Comparision of results

• 2?EC/EC (0?0,g.s.) decay of Cd-106
• Experiment
• T1/2 1.8 x 1020 y (95CL) (TGV-2)
• T1/2 5.8 x 1017 y (90CL) (F.Danevich
  et.al.)
• T1/2 1.5 x 1017 y (68CL) (H.Kiel et.al.)
• Theory
• T1/2 1.0 x 1020 y (J.Suhonen)
• T1/2 8.7 x 1020 y (M.Hirsch)
• T1/2 4.4 x 1021 y (F.Simkovich)

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Muon Capture Rates for Double Beta
Decay
?CR42?

• ( PSI experiment R02-02 )

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?CR42?
(d,2He) PR C70(2004)
OMC
?
??
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Ordinary Muon Capture (OMC)
?CR42?

• Electron Capture
• e- (A,Z) ? (A, Z-1) ?e
• Q
  me ? 0.5 MeV
• Muon Capture
• ?- (A,Z) ? (A, Z-1) ??
• Q m?
  ? 100 MeV

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?CR42?
OMC
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Set-up
?CR42?
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Observables measured

• ?-radiation energy (30 .. 8000 keV)
• Time between the µ-Stop and the
  ?-emission (0 .. 1000 ns)

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Time after the Muon Stop ns
Energy of gamma-rays keV
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Data Analysis

• Time evolution of the ?-lines intensity
• Muon Life Time in the given isotope
• µ-Capture Rate in the given isotope

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?CR42?
Total ?-Capture Rates
48Ca 5992 ns
40Ca 3622 ns
48Ti 3601 ns
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Data Analysis

• Intensity of the ?-lines in the
• intermediate nucleus
• Detailed balance of the ?-intensities
• Partial µ-capture rates to the (1), (2) and
  other (low) excited states of the intermediate
  nucleus

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?CR42?
OMC
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Data Analysis

• Intensity of the ?-lines of the other daughter
  nuclei
• Yield of the different daughter nuclei
• Branching of the reactions
• (µ,?) (µ,? n) (µ,? 2n) (µ,? p)
• Population of high-excited states in the
  intermediate nucleus

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?-lines observed with 76Se target
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BTW µ stopped in Argon
(Could be important for GERDA)
?capture(1.1650.013) 1/µs
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Status of the µCR42ß experiment