ec/ec process measurement in tgv experiment
DESCRIPTION
For TGV collaboration: JINR Dubna, Russia CTU Prague, Czech Republic CSNSM Orsay, France RRC - Kurchatov Institute Moscow, Russia CU Bratislava, Slovakia. EC/EC process measurement in TGV experiment. P. Č erm á k IEAP CTU in Prague. Outline. TGV I TGV II - PowerPoint PPT PresentationTRANSCRIPT
P. Cermak Rez near Prague, December 2005
EC/EC process measurement in TGV
experiment
For TGV collaboration:
JINR Dubna, RussiaCTU Prague, Czech Republic
CSNSM Orsay, FranceRRC - Kurchatov Institute Moscow, Russia
CU Bratislava, Slovakia
P. ČermákIEAP CTU in Prague
P. Cermak Rez near Prague, December 2005
Outline
● TGV I TGV II● TGV II measurements overview● Data processing ● Example● Summary
P. Cermak Rez near Prague, December 2005
TGV
• Telescope Germanium Vertical (stack of 16 (32) HPGe detectors)
• aims at the study of double beta processes of 48Ca and 106Cd (double beta decay, double electron capture)
• started in 1996
• located in Modane Underground Laboratory (France)
P. Cermak Rez near Prague, December 2005
TGV I
yT 193.33.1
22/1 10)2.4(
● 16 HPGe detectors of planar type, diameter 40mm, thickness 6mm
● 8x 48Ca foils
● 8x Ca-natural foils
~ 1.35 x 1022 of 48Ca atoms (1.08 g)
)%90(105.1 2102/1 CLyT
P. Cermak Rez near Prague, December 2005
TGV I
open cryostat assembled cryostat, PAs
P. Cermak Rez near Prague, December 2005
TGV II
• to improve 48Ca result obtained
by TGV I
• to investigate processes in 106Cd
(to focus on EC/EC
channel)
),(22 10646
10648 raysXPdCde e
purpose:
2EC/EC:
keVEkeVkeV XECEC 2519:ROI,2778Q /
P. Cermak Rez near Prague, December 2005
TGV II spectrometer
Dewar
cryostatPbCu
borated polyethylene
PA
SM
1m
P. Cermak Rez near Prague, December 2005
Detector part of the TGV II
32 HPGe planar detectors 60 mm x 6 mm with sensitive volume: 20.4 cm2 x 6 mm Total sensitive volume: 400 cm3
Total mass of detectors: 3 kg Total area of samples : 330 cm2
Total mass of sample(s) : 10 25 g E-resolution : 3 4 keV @ 60Co LE-threshold : down to 10 keV Double beta emitters: - samples of 48Ca:
CaF2 + CH2 ( 75 mg / cm2 ) - samples of 106Cd:
106Cd (~ 50 µm )
U+Th<0.1 ppb
P. Cermak Rez near Prague, December 2005
TGV II
pedestal open cryostat
P. Cermak Rez near Prague, December 2005
TGV II
assembled cryostat, PAs
P. Cermak Rez near Prague, December 2005
Run overview
• 12/03 – 2/04… background, empty cryostat, 1363 hours• 3/04 – 5/04… 13x 106Cd + 3x Cd-nat., 1768 hours
113mCd,
14 years,
Q=590 keV
P. Cermak Rez near Prague, December 2005
● 5/04 – 6/04… 12x 106Cd + 4x Cd-nat., 328 hours● 6/04 – 10/04… 12x 106Cd + 4x Cd-nat., 2033 hours● 11/04 – 1/05… 16x Cd-nat., 903 hours● 2/05 – …… 12x 106Cd + 4x Cd-nat., new sources:
106Cd ... 75.00% 112Cd ... 6.18%108Cd ... 0.80% 113Cd ... 2.77%110Cd ... 4.47% 114Cd ... 6.18%111Cd ... 3.55% 116Cd ... 1.05%
Run overview (2)
P. Cermak Rez near Prague, December 2005
Data processing
1. What we look for: X-rays @21keV from 106Pd
P. Cermak Rez near Prague, December 2005
Data processing (2)2. What we have: X-rays @23keV from 106Cd
106Cd, 3736 hours
P. Cermak Rez near Prague, December 2005
3. Zoom to 20keV region (after background reduction)
3736 hours, 106Cd
Energy windows: (16-19) keV(19-22) keV(28-31) keV
5533 hours, 106Cd
P. Cermak Rez near Prague, December 2005
Summary
• Full configuration operation (32 channels)
• Background, calibration, admixtures in sources
• Basic background measurements done (empty cryostat, natural Cd)
• From February 2005 long-term measurement with 106Cd
• Negotiation on 106Cd lease extension
First direct measurement of EC/EC process in 106Cd (~ 6 x 1019 years)