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