Post on 29-Jan-2016
TTelescope elescope GGermanium ermanium V Verticalertical
JINR Dubna, RussiaCSNSM Orsay, France
CTU Prague, Czech RepublicRRC - Kurchatov Institute Moscow,
RussiaCU Bratislava, Slovakia
status report
V. Egorov
Double Beta Double Beta SpectrometersSpectrometers
Ge76
Calorimetric
M o100
Tracking
Source = detector
High efficiency
Energy resolution
Source = detectorMulti-sourceAngular info
Precise signature
Semiconductormulti-detector
Nuclei - candidatesNuclei - candidates
Ca Sc
T i
4848
48
0 +6 +
0+
CdA g
P d106
106106
0 +1+
0+Q(2 )=4.27 MeV Q(2EC)=2.78 MeV
0.187%1.25%
)(2~24822
4820 eTiCa e
)X(22 10646
10648 ePdCde
2 X-rays$ 0.25 ×106/g
TGV-1 (1994 – 2000) resultsTGV-1 (1994 – 2000) results
2000 2500 3000 3500 40000
2
4
6
8
10
12
14
16
18
20
2000 2500 3000 3500 40000
2
4
6
8
10
12
14
16
18
20
R eg io n -O f-In terest R eg io n -O f-In terestCa Canat 48
T1/2 (22) = =(2.97.5)•1019 y
T1/2 (20) 1.5•1021 y
(90%CL)Zero
Telescope Germanium Vertical Telescope Germanium Vertical (TGV-2)(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 @ 60Co
LE-threshold : 5 6 keV
Double EC (2005-2006):
- 12 samples of 106Cd: 10 g 106Cd (~ 50 µm )
U+Th<0.1 ppb
TGV-2TGV-2 (2000 – …)(2000 – …)
SM
Signal w ires
PA
Cold finger
Pb
Cu
LN Dewar
LN2
N2
Borated Polyethylene
1 m
TG V -2
EnergyADCAmp. Gedetector
ADC-1
ADC-2
E1
E2
1
2
High freq. noise: E1 > E2
Real signal: E1 = E2
Low freq. noise: E1 < E2
Suppression of low energy noise Suppression of low energy noise with primitive Fourier analysiswith primitive Fourier analysis
Low frequency
(microphonic)
ννGEMMAGEMMA
search for the
Neutrino Magnetic Moment
BTW:
0
5
10
15
20
0 5 10 15 20
ADC-3 [keV]
ADC-1 [keV]
Low Energy Threshold [keV] ~ measurement quality
µ
[ 10
–10
µB
]
1 10 100 1000 10000
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
TEXONO2006
MuNu2003
Rovno1993
Krasno- yarsk1992
SavannahRiver1976-1989
GEM MA (2007)
15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
KX(Cd)
E [keV]
15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
KX(Pd)
E [keV]
Results of one-year (2005) measurement Results of one-year (2005) measurement
2νEC/EC (0+→0+,g.s.) decay of Cd-106 Experiment T1/2 ≥ 1.8 x 1020 y (95%CL) (TGV-2) T1/2 ≥ 5.8 x 1017 y (90%CL) (F.Danevich et.al.) T1/2 ≥ 1.5 x 1017 y (68%CL) (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)
4
8
12
16
20
24
28
32
048121620
-line 238 keV
Counts / day /detector4
8
12
16
20
24
28
32
0.00.51.01.52.02.53.03.54.0
-line 352 keV
Counts / day /detector
Gas-tight cup of the cryostat (ultra-pure Al,
made by CANBERRA)
has a weld seam here
Drastic Drastic solutionsolution
0 100 200 300 400 500 600 700
0.1
1.0
10.0
100.0 Counts / keV / day (central det. 12..18)
After
Before }1:10
2νEC/EC (0+→0+,g.s.) decay of Cd-106 Experiment T1/2 ≥ 1.8 x 1020 y (95%CL) (TGV-2) T1/2 ≥ 5.8 x 1017 y (90%CL) (F.Danevich et.al.) T1/2 ≥ 1.5 x 1017 y (68%CL) (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)
Comparision of resultsComparision of results
Muon Capture Rates Muon Capture Rates for Double Beta for Double Beta DecayDecay
( PSI experiment R02-02 )
CR42CR42
A, Z
A, Z+2
A, Z+1
Virtual transition( Left leg )
Virtual transition( Right leg )
A,Z (p,n)
CR42CR42
((d,d,22HeHe))[[ PR PR C70C70(2004)(2004) ]]
OOrdinary rdinary MMuon uon CCapture (apture (OMCOMC))
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
CR42CR42
A, Z
A, Z+2
A, Z+1
n
A-1, Z+1
Target:
A+1, Z+2
A+1, Z+1
n
OMC OMC
CR42CR42
Set-upSet-up
PMTLightgu ide
PMT
PMT
Lightgu ide
Lightgu ide
HPGe
Cryostat
C1
C2
C3
Target
10 cm
HPGe
-beam-
CR42CR42
Observables measured:Observables measured:
-radiation energy (30 .. 8000 keV)Time between the µ-Stop and
the -emission (0 .. 1000 ns)
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850
0
50
100
150
200
250
300
350
400
450
500
550
600
650
Energy of gamma-rays [keV]
Time after the Muon Stop [ns]
Data Analysis:Data Analysis:
Time evolution of the -lines intensity
Muon Life Time in the given isotopeµ-Capture Rate in the given isotope
0 500 1000 1500 2000 2500 3000
Time [ns]
Num ber of events
4848CaCa599599±2 ns±2 ns
4848TiTi360360±1 ns±1 ns
4040CaCa362362±2 ns±2 ns
Total Total -Capture Rates-Capture RatesCR42CR42
Data Analysis:Data Analysis:
Intensity of the -lines in the
intermediate nucleusDetailed balance of the -intensitiesPartial µ-capture rates to the (1+), (2–)
and other (low) excited states of the intermediate nucleus
A, Z
A, Z+2
A, Z+1
Target:
OMC OMC
CR42CR42
Data Analysis:Data Analysis:
Intensity of the -lines of the other daughter nuclei
Yield of the different daughter nucleiBranching of the reactions:
(µ,) (µ, n) (µ, 2n) (µ, p) …Population of high-excited states in
the intermediate nucleus
-lines observed with -lines observed with 7676Se targetSe target
Se76
As76
E > 7.328
As75
nE > 7.727
Ge75
pE > 12.003
Ge74
n+nE > 17.573
EC
As74
n+p
BTW:BTW: µµ–– stopped in Argon stopped in Argon
Long-lived
nuclei produced
by µ–-capture in Ar
T , Q
[keV]
Yield [%] per stopped
muon
40Ar(µ–,µ)40Cl 1.35m 7480 7.17 ± 0.16
40Ar(µ–,µn)39Cl39Cl → 39Ar
55.6m 3442
269d 565
47.55 ± 1.31
40Ar(µ–,µ2n)38Clm 0.72s (IT) 1.64 ± 0.0840Ar(µ–,µ2n)38Cl 37.2m 4917 15.14 ± 0.57
Λcapture=(1.165±0.013) 1/µs
(Could be important for GERDA)
Status of the Status of the µCR42µCR42ββ experimentexperiment
2β 48Ca 76Ge 82Se 100Mo 106Cd 116Cd 150Nd
µC-
target
48Ti 76Se 82Kr 100Ru 106Cd 116Sn 150Sm
Expe-riment
2002 2004 2006 — 2004 2002 2006
Ana-
lysis
done done In pro-
gress
— In pro-
gress
— Star-ted