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Characterization of Large CaMoO4 crystals for 0n bb search. Presented by H.J.Kim (KyungPook National U.) 2007/11/24 2 nd Korea-China Joint workshop. Double beta work status. Sn-124 excited state, Zn-64 study was published in Nuclear Physics A 2007. - PowerPoint PPT Presentation
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Characterization of Large Characterization of Large CaMoO4 crystals for CaMoO4 crystals for
searchsearch
Presented by H.J.Kim Presented by H.J.Kim
(KyungPook National U.) (KyungPook National U.)
2007/11/242007/11/24
22ndnd Korea-China Joint workshop Korea-China Joint workshop
Korea-China Workshop 2007, H.J.Kim
Double beta work status• Sn-124 excited state, Zn-64 study was Sn-124 excited state, Zn-64 study was
published in Nuclear Physics A 2007. published in Nuclear Physics A 2007. for Sn-124 with LSC physics draft is for Sn-124 with LSC physics draft is
in progress (NIMA published in 2007)in progress (NIMA published in 2007)• CaMoO4 study is on going :• Mo-92: EC+ study in 4 CsI(tl) shielding
+CaMoO4 background test (J.I.Lee’s talk) • SrCl2 : EC+ study in 4 CsI(tl) (J.So)• CeBr3 crystal development for EC+,
+, study (Gulrooh’s talk)• Sn-112 resonant 0n ECEC study with
HPGe
Sino-Korean Workshop 2006, H.J.Kim
CaMoOCaMoO4 4 Scintillation crystalsScintillation crystals
12.5 cm
2.2 cm
2.2
cm
Korea(2004) Korea(2004) Ukraina(2006)Ukraina(2006) Russia(2006)Russia(2006)
Russia(2007), ISTC ProjectRussia(2007), ISTC Project
H.J.Kim
History• CaMoO4 crystal R&D in very fast progressCaMoO4 crystal R&D in very fast progress
1) 2002 : Idea and try to grow CMO in Korea1) 2002 : Idea and try to grow CMO in Korea
2) 2003 : Discussion with V.Kornokov2) 2003 : Discussion with V.Kornokov
=> Send test CMO (better quality)=> Send test CMO (better quality)
3) 2004 : CMO characterizations and Conference 3) 2004 : CMO characterizations and Conference presentation presentation
Extended idea of XMoO4, low temp. CaMoO4Extended idea of XMoO4, low temp. CaMoO4
4) 2005-2007 : Large CMO with ISTC4) 2005-2007 : Large CMO with ISTC
5) 2006 : Discussion with F. Fanevich5) 2006 : Discussion with F. Fanevich
=> CMO by Lviv and collaborative effort => CMO by Lviv and collaborative effort
6) 2007 : CMO R&D in low temp. started by SNU 6) 2007 : CMO R&D in low temp. started by SNU groupgroup
7) ……….7) ……….
Korea-China Workshop 2007, H.J.Kim
Crystal used for testCrystal used for test
12.5 cm
2.2 cm
2.2
cm
S1S122x22x30mm22x22x30mmS0S010x10x10mm10x10x10mm
Large (L1)Large (L1)22x22x12522x22x125
XL1, 2XL1, 230x30x21030x30x210
38x20 mm38x20 mmUkraineUkraineUK2UK2UK3UK3
Russia Russia
Korea-China Workshop 2007, H.J.Kim
Clustering method with 400 Mhz Clustering method with 400 Mhz FADCFADC
The same method with Darkmatter Search The same method with Darkmatter Search
Total 42 s window with 34 s pulse window
# of Photoelectron/keV
& Absolute light yield
Korea-China Workshop 2007, H.J.Kim
# of PE with 60keV gamma
CdWo4 :197+-19S1 :28+-8UK2 :37.5+-8UK2 :41.9+-10
Korea-China Workshop 2007, H.J.Kim
Number of photoelectron from 60keV Number of photoelectron from 60keV
# of photoelecton from Am-241# of photoelecton from Am-241
Crystals tested 0.6-0.7PE/keV : Ukraine0.4-6PE/keV : Russia0.5PE/keV : Korea* The size of crystals are different
0.6 PE/keV => 6% FWHM at 3MeV (theoretical limit)
CaMoO4 small absolute light CaMoO4 small absolute light yieldyield
CaMoO4 S0 test• Na-22 source• Gain:100• peak time:12us• HV:1800V• Peak:520±116• e-h of CsI(Tl): 8.6±1%• 4300±500ph/MeV• Assume 15% QE,90%
eff 0.6 ± 0.1 PE/keV Need more study
CsI(Tl) reference test• Cs-137 source• Gain:20• Shaping time:4us• HV:1800V• Peak:1597±34.4• Pedestal:33±10• Resolution(FWHM): 4.9%• e-h pair = 37000.• NP = 37000/0.8/0.9 =
51000
* Tested with LLAPD (Details by M.J.Kim)
Korea-China Workshop 2007, H.J.Kim
Attenuation Length& Relative light output with S1 & XL1, XL2
Large size CaMoO4 test
- using two 3" PMT’s and attached at both end faces of CaMoO4 crystal.
- made small holes of few millimeter diameter at every 2cm distance in the teflon along the length wise direction of the crystal.
PMT1 PMT2
12.5 cm
2.2 cm
2.2
cm
Comparison between S1 and Comparison between S1 and L1 L1 CaMoOCaMoO44
Light yield of Big CMO/ Small CMO is 90%
Energy spectrum of Am-241- Placed the Am-241 radioactive source at every 2cm mark
Red= 2cm
Green= 4cm
Blue= 6cm
Pink= 8cm
Black= 10cm
Attenuation LengthAttenuation Length
2.0x100 4.0x100 6.0x100 8.0x100 1.0x101
10000
12000
14000
16000
18000
20000
22000
24000
26000
Mea
n
Distance(cm)
PMT1PMT2PMT1+PMT2
Attenuation Length = ~ 30 cmAttenuation Length = ~ 30 cm
Larger (XL1, XL2) CaMoO4 test
- XL1,XL2 crystals were used for test.- using one 3" PMT (green extended) and one 2"
PMT (bi-alkali) of CaMoO4 crystal.
- made small holes of few millimeter diameter at every 3cm distance
test with S1 & XL1, XL2 test with S1 & XL1, XL2
XL1 : ~of S1, XL2 : ~80% of S2
H.J.Kim
3” PMT side with Cs-137 3” PMT side with Cs-137
H.J.Kim
L1-CMOL1-CMO
0 2 4 6 8 10 12 14 16 18 208000
10000
12000
14000
16000
18000
20000
22000
Lig
ht o
utp
ut
Distance
PMT1 PMT2 PMT1+PMT2
H.J.Kim
L2-CMOL2-CMO
0 2 4 6 8 10 12 14 16 18 209000
100001100012000130001400015000160001700018000190002000021000220002300024000250002600027000
M
ean
Distancs(cm)
2"PMT 3"PMTsum
Korea-China Workshop 2007, H.J.Kim
Resoultion & light output comparison with S1 and UK2,UK3
H.J.Kim
Checking energy resolution with CdWO4
Energy resolution of 9%
H.J.Kim
Cs137 source with CMOs and CdWo4
H.J.Kim
Cs-137 with S1 and UK2, UK3
Relative light yield ; 1.2 : 1.9 : 2.0
H.J.Kim
Different fitting, different results
• The best way is subtract background from data and fold MC data with data with Gausian fit only
H.J.Kim
S1 with Gaussian+Exp
FWHM
H.J.Kim
Mean time distribution of CMOs
H.J.Kim
Summary
• Different size of CMO crystals from Different size of CMO crystals from Russia (ISTC project) and Ukraine are Russia (ISTC project) and Ukraine are being testedbeing tested
• # of photoelectron/keV, absolute light # of photoelectron/keV, absolute light yield and attenuation length are yield and attenuation length are measured measured
• Relative light output and energy Relative light output and energy resolution were compared. resolution were compared.
H.J.Kim
Work list before experiment
• Resolution and light yield issueResolution and light yield issue
->Different crystal results need to be resolved->Different crystal results need to be resolved
Test with the same size of LU3 and XL1Test with the same size of LU3 and XL1
Improve light output…Improve light output…
->Further study of LAAPD : LAAPD or PMT?->Further study of LAAPD : LAAPD or PMT?
-> How low temperature is necessary?-> How low temperature is necessary?
-> Size of CMO optimization -> Size of CMO optimization • Internal Background issueInternal Background issue
-> measurement UK3 (results) XL (soon…)-> measurement UK3 (results) XL (soon…)
=> Shielding optimization for VETO=> Shielding optimization for VETO• Enriched 100Mo, purification, growing issues • Low temp Det., • XMoo4 (X->?)
H.J.Kim
Backgrounds and signal for 20kg of CaMoO4 with 5 years data taking (GEANT4)
Mo-100 2Mo-100 2
Ca-48 2Ca-48 2
Tl-208Tl-208
Bi-214Bi-214
Signal (m=0.4eV)Signal (m=0.4eV)
Sensitivity 10kg (100Mo) 5% FWHM resolution 0.05 mBq/kg for 208Tl, 214Bi5 years 7.1x1024 y (90% CL)( 0.18~0.71 meV)
•Current best limit on 100Mo : 4.6x1023 by NEMO3 with 6.9kg 100Mo•Claim by Klapdor-Kleingrothaus et al. ~ 400 meV Assuming optimistic theoretical value
1010 significance significance
H.J.Kim
•Thank you
H.J.Kim
New Crystal for Am-241
DistanceMean of det00 (2” PMT) Mean of det01(3” PMT)
1 15390 10960
3 14880 109506 14740 109909 14630 1093012 14390 1061015 13880 1139818 15120 9494
Old Crystal for Am-241
DistanceMean of det00(2” PMT) Mean of det01(3” PMT)
1 12810 93703 11280 97856 10910 97849 10890 969512 10530 975715 9663 1046018 11790 8416
H.J.Kim
H.J.Kim
H.J.Kim
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