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Strategies for Next Generation Neutrinoless Double-Beta Decay Experiments
Frank AvignoneUniversity of South Carolina
Neutrino-2004College de France, ParisJune 2004
General Theme
I will not discuss the details of individual experiments.
I will discuss the important parameters and how they impact the experimental techniques.
The Parameters of interest are: , ,G0ν M0ν
b ≡
δE ≡
! ≡ detection efficiency, Mass, Isotopic abundance, background rate, and energy resolution.
Parameters of Sensitivity
€
T1/20ν
T 0ν1/2 !
ln2Nt!
γ√
bMt δE
T 0ν1/2 !
ln2(A0/W ) × 103(Mat!)γ√
bMt δE
T0ν1/2 ∝
a!
W
√Mt
b δE
a ≡ isotopic abundance
b ≡ background rate in c/(keV · kg · y)
M ≡ source mass
δE ∝ energy resolution
! ≡ detection efficiency
W ≡ molecular weight
Detection with a 4 CL
€
σ
C
€
C −B = 4 C
B
€
δE
a ≡ isotopic abundance
b ≡ background rate in c/(keV · kg · y)
M ≡ source mass
δE ∝ energy resolution
! ≡ detection efficiency
W ≡ molecular weight
T 0ν1/2 ! 4.74 × 10
25a!
W
√Mt
b δEy
Neutrinoless Double-Beta Decay Experimental Figure of Merit
f ≡ηa"
W
√M
bδE
η ≡ G0ν |M0ν |2 × 1013 = FN × 1013
η ≡ 〈η〉nuclear models
Available Experimental Techniques
Cryogenic Bolometry
Ionization Detectors
Scintillation Detectors
Time Projection Chambers
Tracking Chambers
Available Enriched Isotopes 48Ca - AVLIS† (USA)
76Ge - Centrifuge (Russia)
82Se - Centrifuge (Russia)
100Mo - Centrifuge (Russia) & AVLIS† (USA)
116Cd - Centrifuge (Russia) & AVLIS† (USA)
130Te - Centrifuge (Russia)
136Xe - Centrifuge (Russia)
150Nd - AVLIS† (USA) † Technology available at LLNL. No known production program.
Average TheoreticalNuclear Structure Factors
Parent Isotope
!
FN " G0#M
0#2
y$1
48Ca
!
(5.4"1.4+3.0) #10
"14
76Ge
!
(7.3± 0.6) "10#14
82Se
!
(1.7"0.3+0.4) #10
"13
100Mo
!
(1.0 ± 0.3) "10#12
116Cd
!
(1.3"0.3+0.7) #10
"13
130Te
!
(4.2 ± 0.5) "10#13
136Xe
!
(2.8 ± 0.4) "10#14
150Nd
!
(5.7"0.7+1.0) #10
"12
Table of Values of
η ≡ 〈G0ν |M0ν |2〉 × 1013
Isotope
!
" 48Ca 0.5476Ge 0.7382Se 1.70
100Mo 10.0116Cd 1.30130Te 4.20136Xe 0.28150Nd 57.0
€
η
Cryogenic Detector
CUORE/CUORICINO (Gran Sasso)
760 kg of (nat. abundance = 33.8%)
1000 bolometers at ~ 8 mK
25 Towers of 40 bolometers per tower
CUORICINO ~ 1 tower, operated 03/04
€
TeO2
€
T1/20ν ≥ 7.5x1023 y
!"#"$#%&'()#*" "+","-#.&/ ,%01+"
! "#$%&'(!)*+)!,- .'*!*/-$0!,.$!))&*.,1-+-,1-,(*/213)-*/!1-*24*"*5-67 $%&'(!)'*
89:;*?>?>*$/@A=* B!%.23'*"#$%&'(!)*+)!,-'*0!B-*C--,* (-'(-1*D.(0*(."#$&
!"#$%!%'()*+,!"#$%!%'()*+,
!"#$%&'(&)*+,-.+%/&01&2#&-$3,!$-4,53,!%$-&)*+,-.)6! 17&2#&'(&8&17&2#&-"9&$23&'(! %,:3!"%&)*+,-.6&;-./.01'234-5+,!'6'7'-8
!9),.2.0)
!9),.2.0)&!"#$%6&@A&B,CA&2!>)3$-)
!!!!
!DEF'2-
!"#$%!%'()*+,'+--./0,1!"#$%!%'()*+,'+--./0,1
$2/+*',.+3'-4).,3+*3'-5-6.*-)2*
728.9'62-):)2*)*;'-1-:./
!"#$%!%'()*+,'+--./0,1!"#$%!%'()*+,'+--./0,1
$2/+*',.+3'-4).,3+*3'-5-6.*-)2*
728.9'62-):)2*)*;'-1-:./
CUORICINO
Ionization Detectors
COBRA - CdTe
GEM - (Ge Crystals in LN)
GENIUS - (Ge Crystals in LN)
Majorana - (Ge Crystals in Cryostat)
MPI - (Ge Crystals in LN)
€
76Ge
€
76Ge
€
76Ge
€
76Ge
COBRA
10 kg of CdTe (CdZnTe) Detectors
Measure 7(9) double-beta isotopes at once
Systematic studies of Cd and Te isotopes
Rare beta decays of 113Cd and 123Te
Dark matter search
Slide adapted from presentation of K. Zuberat DESY Zeuthen, 19-21 June 2001
NaI
Veto system
Pb
Cu
Fig. 1. Schematic layout of the proposed COBRA experiment. An array of CdTedetectors is installed within two NaI detectors, serving as active veto and part ofcoincidence measurements. This will be installed inside an OFHC copper shield,surrounded by low level lead. As a veto the complete setup will be surrounded by amuon veto consisting of high efficiency plastic scintillators.
11
CdTe - Array
Slide adapted from presentation of K. Zuberat DESY Zeuthen, 19-21 June 2001
COBRA
1 ccm crystals
Option:
Pixel Detectors
Tracking
Majorana Proposal
500 kg of Ge (86% 76Ge)
Conventional Cryostat Technology
Could use GENIUS direct immersion in LN if feasible; cooperation with MPI
Digital Electronics
Pulse-Shape Discrimination
Majorana
Majorana
MPI 76Ge Proposal for Gran Sasso
Bare Ge detectors in pure LN/LAr
Phase 1: ~ 20 kg, HM/IGEX; 86% 76Ge
Phase 2: Add 20 kg new enriched detectors
Physics Reach
Phase 1: refute claim at 99.6% or confirm at
Phase 2: 10% measurement if KKDK correct. Push limit to 2×1026 years if not.
Start construction early 2005
Begin data acquisition 2006
€
5σ
Ge
water
insulation
LN/LAr
cleanroom
lock
lead
MPI 76Ge Proposal
Scintillation Detectors
CAMEO - 116Cd (CdWO4 crystals in liq. scint.)
CANDLES - 48Cd (CaF2 crystals in liq. scint.)
CARVEL - 48Cd (CaWO4 scintillators)
GSO - 160Gd (Gd2SiO4 crystals in liq. scint.)
Xe - 136Xe (Xe dissolved in liq. scint.)
1
10
102
103
104
1000 2000 3000 4000 5000
210Bi, Q
! = 1.16 MeV
214Pb, Q
! = 1.02 MeV
211Pb, Q
! = 1.37 MeV
234mPa, Q
! = 2.27 MeV
214Bi, Q
! = 3.27 MeV
2! of 48
Ca
Energy (keV)
Co
un
ts/1
0 k
eV
210Pb,
! = 64 keVQ
Energy, keV
Counts
/10 k
eV
0
2000
4000
6000
8000
50 100 150
0
100
200
300
400
1000 2000 3000 4000 5000
E219
Rn, ! = 6.82 MeV
!/" = 0.27
E214
Po, ! = 7.69 MeV
!/" = 0.27
Q", 214
Bi, " = 3.27 MeV
Energy in # scale (keV)
Co
un
ts/1
0 k
eV
T1/2
= 120+30
-50 µs
Time interval (µs)
Co
un
ts/1
0 µ
s
0
50
100
150
200
250
100 200 300 400 500
Carvel
tr 50
o
.= 45o
r-
a40
35
30
.,<
20
154000 5000
Energy (keV)
Carvel
Time Projection, Tracking , & Drift Chambers
DCBA - 150Nd (Nd foils in a drift chamber)
MOON - 100Mo (Mo foils in plastic scint. - tracking chamber)
NEMO/Super NEMO - 82Se (Se foils in a magnetic tracking chamber)
EXO - 136Xe (Gas or liquid Xe TPC with +Ba identification)
DCBA
DCBA-T (Test apparatus for technical development)
DCBA-I (4xDCBA-T - Standard Module (SM) with natural Nd source)
DCBA-II(1) (100-SM with natural Nd - 7.7 mol 150Nd)
DCBA-II(2) (100-SM with 124 mol 150Nd enriched source)
Sensitivity to effective neutrino mass ~0.05eV
Drift Chamber Beta-ray Analyzer
Slide adapted from presentation of N. Ishihara at NDM03 Nara, 9-14 June 2003
Slide from presentation of N. Ishihara at APPI 2004 Iwate, 16-20 February 2004
DCBA
!""#$$$%&'($)*+$,--. /($#0121343 5
678β)
β,
8
9 678
β,
β)
:
9
β)
678
β,
8
:
B
9
8:
ee mmpT
rBp
!"#
#
,;),, (-?@0$
p =A&6;?
Molybdenum Observatory Of Neutrinos (MOON)
Molybdenum foils between plastic scintillators for energy readout optical fibers for position readout
MOON-I: 1 kg, 3 y, T1/2~6x1025 y (mee~0.1 eV)
MOON-II: 250 kg, 3 y, T1/2~8x1026 y (mee~0.03 eV)
MOON III: 750 kg, 7 y, T1/2~3x1027 y (mee~0.02 eV)
Tracking with angular resolution
Size ; Plastic Scintillator ~ 50cm X 50cm
100Mo foil ~ 30cm X 30cm
100Mo
Plastic Scintillator
SciFi (X axis)
SciFi (Y axis)
Plastic Scintillator
6mm
0.4mm
0.8mm
Light Guide
NaI active shield
4 ~ 10 layers
MOON
PlasticScintillator
PlasticScintillator
50cm
100Mo
2”PMT
MA-PMT
SciFi flax (X axis)
SciFi flax(Y axis)
SciFi(X axis)
SciFi(Y axis)
50cm
50cm Light guide
MOON
Beginning of data taking: February 2003 NEMO
The Super-NEMO Double-Beta Decay Expression of Interest
At least 10 times the capacity of NEMO-3
~ 100 kg of enriched isotopes
Sensitivity
€
mν ~ 30 meV
€
82Se, 100 Mo, 116Cd, 130Te, 136Xe
Super-NEMO Proposed Schedule
Phase 1. (2004 - 2006) Feasibility Studies
Phase 2. (mid 2006 - 2007) Engineering, Design, and Acceptance
Phase 3. (2008 - end 2010) Construction
Phase 4. (2011- ) Operation
Enriched Xenon Observatory
136Xe - 40 m3 at 10 Atm. (2000 kg)
80% 136Xe (Xe is a good scintillator.)
Energy resolution ~2% at 2.5 MeV
Possible Liquid Version
R&D on tagging +Ba daughter ion
200 kg Prototype (no tagging) was approved and is funded. It will be located in the DOE WIPP site in Carlsbad, New Mexico.
March 14-16, 2002 Sendai Neutrino Conference 21
!"#$%&'()*+,$-%.%+"/+)+-01-+&2%,,(2%+3%+1),+45!+60'-+*),%2+')110!"#$%&'()*+,$-%.%+"/+)+-01-+&2%,,(2%+3%+1),+45!+60'-+*),%2+')110#1#1
!"#$%&'()**)+,")-* .&/)01,2)(&34)#)$31"'5$&)/3562)7 89
!"!" #$$"%&'(')*(+,-(-,."+/'0"1'-##+'(2(,0&-'3(452%#*067#$$"%&'(')*(+,-(-,."+/'0"1'-##+'(2(,0&-'3(452%#*06789:89:!"'''''''!"'''''''89:89:;(;(/ ??@A@#"@A@#" BCDEE'?8FF8G'F98GBCDEE'?8FF8G'F98G
!"!"## $%$&'()*'$&)$&+,-',$%$&'()*'$&)$&+,-',../'+0"+$'1/'+0"+$'12)2)340'5$&"&&340'5$&"&&2264$0'764$0'72)2)8'0('9&8'0('9& :;:;?'1%)$@'A-B-A)$-C5"&+1'?'1%)$@'A-B-A)$-C5"&+1'
D$0'9E-5CFD$0'9E-5CFG-5C9')-45$)A"5)*'),'&'A&',G-5C9')-45$)A"5)*'),'&'A&',B14()")@04&45)1"&')4B):=B14()")@04&45)1"&')4B):=HHI$I$
HHIJ>#%-(0-'(66,-,#0(+IJ>#%-(0-'(66,-,#0(+4#0&-%(,0-4#0&-%(,0-
HHK*2"'3(452%#*06K*2"'3(452%#*06%"6*4-,#0%"6*4-,#0
!!""#$!#$!
%%&&'$!'$!
!!((#$!#$!
%)'*+%)'*+
,-.*+,-.*+
('&"$&"*9'('&"$&"*9' JH$JH$
!"#$%&'()**)+,")-* .&/)01,2)(&34)#)$31"'5$&)/3562)7 89
!!"#$%&'(#)*#&+#$)+#$+#,-(#,.&/!!"#$%&'(#)*#&+#$)+#$+#,-(#,.&/
,.&/,.&/(0'((0'(
EXO
Sample Figures of Merit
500 kg of Ge enriched to 86% 76Ge
760 kg of TeO2 nat. ab. 33.8% 130Te
122 kg of TeO2 enriched to 85% 130Te
f =(0.73)(0.86)(0.8)
76
√500
(0.005)(4)! 1.05
! = 0.8 b = 0.005
! = 0.84 b ! 0.01 f = 0.89
f = 0.90! = 0.84 b ! 0.01
Large Tracking Detector(Super NEMO?)
M = 100 kg a = 0.9 ! = 0.3 b = 0.003 δE = 125 keV
f =ηa"
W
√M
b δE=
η
W(4.4)
η
W=
1.7
82= 0.002 f ! 0.09
€
82Se:
η
W=
57
150= 0.38 f ! 1.7
€
150Nd:
Target Half-Lives for
€
mν = 0.04 eV
Isotope
!
T1/ 20"
48Ca 3.0!1027
76Ge 2.3!1027
82Se 9.4!1026
100Mo 1.6!1026
116Cd 1.3!1027
130Te 3.9!1026
136Xe 5.8!1027
150Nd 2.9!1025
ConclusionsLarge value of
High Efficiency
High Isotopic Abundance
Large Source Mass
Good Energy Resolution
Low Background
Cost Feasibility
G0ν |M0ν |2
€
η (linear)
(linear) !
√M
(linear) a
√δE
√b
$
f ≡ηa"
W
√M
b δE