first cuoricino results and the cuore · pdf filefirst cuoricino results and the cuore project...
TRANSCRIPT
![Page 1: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/1.jpg)
First Cuoricino results and the CUORE project
Outline1. From Mi-DBD to CUORICINO and CUORE2. The CUORE project3. CUORICINO4. CUORICINO construction5. CUORICINO detector performances6. CUORICINO background7. CUORICINO results8. perspectives for CUORE
Oliviero Cremonesi
on behalf of the CUORE collaboration
Prague, 7-10 July 2003, MEDEX '03 Workshop
![Page 2: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/2.jpg)
The CUORE Collaboration
C. Arnaboldi, C. Brofferio, S. Capelli, L. Carbone, O. Cremonesi, E. Fiorini, A. Nucciotti, M. Pavan,G. Pessina, S. Pirro, E. Previtali, M. Sisti, and L.TorresDipartimento di Fisica dell’ Università and Sez. INFN di Milano- Milano – Italy
J. Beeman, R.J. McDonald, E.E. Haller, E.B. Norman and A.R. SmithLawrence Berkeley Laboratory, Berkeley - California- USA
A. Giuliani, M. Pedretti, and A. FascillaDipartimento di Scienze CC, FF e MM dell'Universita` dell' Insubria e Sez. INFN di Milano, Como - Italy
M. Barucci, E. Pasca, E. Olivieri, L. Risegari, and G. VenturaDipartimento di Fisica dell’Università and Sez. INFN di Firenze- Firenze- Italy
G. Frossati and A. de WaardKamerling Onnes Laboratory, Leiden University- Leiden -The Netherlands
M. Balata, C. Bucci, and M. PyleLaboratori Nazionali del Gran Sasso, INFN - L'Aquila – Italy
D.R. Artusa, F.T. Avignone III, I. Bandac, R.J. Creswick, H.A. Farach and C. RosenfeldDepartment of Physics and Astronomy, University South Carolina - Columbia S. C. - USA
V. PalmieriLaboratori Nazionali di Legnaro, INFN - Padova - Italy
S. Cebrian, P. Gorla, I.G. Irastorza, A. Morales, C. PobesLab. of Nucl. and High En. Physics, University of Zaragoza - Zaragoza – Spain
![Page 3: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/3.jpg)
From Mi-DBD to CUORICINO and CUORE
Omogeneous (source = detector) approach with bolometers
e_
e_ wide choice of materials
detectors with an energy resolution comparable with that of Ge diodes
130Te nice features
high natural isotopic abundance (i.a. = 33.87 %)
high transition energy (Q = (2528.8 ±1.3) keV )
encouraging theoretical calculations for 0ν−DBD lifetime
already observed with geo-chemical techniques ( τ 1/2 incl = ( 0.7 - 2.7 ) × 1021 y)
excellent feature for future reasonable-cost expansion of Double Beta Decay experiments
large phase space, lower background(clean window between full energy and
Compton edge of 208Tl photons)
mee ≈ 0.1 eV ⇔ τ ≈ 1026 y
study new DBD candidates
![Page 4: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/4.jpg)
Low Temperature Detectors (LTD's)
♦ Temperature signal: ΔT = E/C ≅ 0.1 mK for E = 1 MeV♦ Bias: I ≅ 0.1 nA ⇒ Joule power ≅ 1 pW ⇒Temperature rise ≅ 0.25 mK♦ Voltage signal: ΔV = I × dR/dT × ΔT ⇒ ΔV = 1 mV for E = 1 MeV
♦ Noise over signal bandwidth (a few Hz): Vrms = 0.2 µV♦ Signal recovery time: τ = C/G ≅ 0.5 s
Heat sinkT ≅ 10 mK
Energy absorberTeO2 crystal
C ≅ 2 nJ/K ≅ 1 MeV / 0.1 mK
Thermal couplingG ≅ 4 nW / K = 4 pW / mK
ThermometerNTD Ge-thermistor
R ≅ 100 MΩdR/dT ≅ 100 kΩ/µΚ
In real life signal about a factor 2 - 3 smaller
Energy resolution (FWHM): ≅ 1 keV
Te dominates in mass the compoundExcellent mechanical and thermal properties Calorimetric approach
Good energy resolutionNo limit to material choice
![Page 5: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/5.jpg)
From Mi-DBD to CUORICINO and CUORE
1990: the first TeO2 bolometer1993: the first experiment with a 334 g TeO2detector
1997: the 20 (340 g) crystal array (Mi-DBD I)
1998-2002: tests on 750 g TeO2 crystals
2001: the 20 crystal array is rebuild witha new structure and with cleanermaterials (Mi-DBD II)
FWHM 15 keV (0.33 +/- 0.11) c/keV/kg/yτ1/2 > 2.1 1023 y at 90% C.L
![Page 6: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/6.jpg)
The Mi DBD - II: experimental set-up
5 modules, 4 detector each (3x3x6 cm3 TeO2 crystals, 340 g)
are arranged in a tower-like compact structure (6.8 kg)
the tower is surrounded byan inner Roman lead shield,
and all the refrigerator
by a 20 cm thick outer lead shield + borated PET shield
the tower is mounted insidea dilution refrigerator
... a general test for the CUORICINO set-up
![Page 7: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/7.jpg)
Mi DBD: limits on 0νDBD
Total statistics:4.3 kg y
DBD Q-value
τ > 2.08 × 1023 y @ 90% c.l.
<mν> < 1.09 – 2.64 eV
Bkg ~ 0.3 c/keV/kg/y
Physics Letters B 557/3-4, 2003, pp. 167-175
![Page 8: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/8.jpg)
The CUORE project
CUORE is an array of ~ 1000 bolometers
0.75 kg x 1000 = 750 kg TeO2= 600 kg Te = 203 kg 130Te
x 1000
crystals are grouped in 250 modules of 4 crystals each, the modules arearranged in 25 towers assembled in a 5x5 matrix
bolometers placed (in a single dilution refrigerator at ~ 10 mK) as close aspossible with a minimum amount of material among them
A SINGLE HIGH GRANULARITY DETECTOR
750 kgTeO2
![Page 9: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/9.jpg)
CUORE elementary module
a 4-crystal unit (“plane”) is a mechanically independent modulemade of 4 crystals
Various 4-crystal planes have been tested with good results onboth reproducibility and reliability (... before CUORICINO)
Energy resolution ~ 1 keV at threshold 5 - 10 keV at 3 MeV
nuclear recoil quenching factor ~ 1
Teflon tips
ThermistorTeO2 crystal
copper frame
contact pins
![Page 10: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/10.jpg)
TheCUORE detector
a tower contains 10 modules, as in thecase of the 4-crystal modules also towersare indipendent structures
a single tower of CUORE has been alreadybuilt and is installed in Hall A
The tower ...
the 25 towers are organized in a square structure (a 5x5matrix), the towers will be suspended from a large squarecopper plate suspended with a vertical spring
The array
![Page 11: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/11.jpg)
The CUORE experimental set-up
The CUORE array:
closed inside a cubic copper box
surrounded by 3 cm of roman lead
an additional 20 cm layer of low activitylead will be used to shield the array fromthe refrigerator dilution unita lead shield and a borated PETneutron shield will surround completelythe cryostat
![Page 12: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/12.jpg)
CUORICINO
44 TeO2 crystals 5x5x5 cm3 + 18 TeO2 crystals 3x3x6 cm3
array with a tower-like structure similar to the single tower of CUORE(the only difference is that it contains 2 planes of 3x3x6 crystals)
mounted inside the Hall A refrigeratorwhere the Mi-DBD 20 array worked
CUORICINO is a self-consistent experimentand will give significant results concerning
Double Beta Decay and Dark Matter
![Page 13: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/13.jpg)
CUORICINO and CUORE location
Two dilution refrigerators:Hall A (CUORICINO)
Hall C (R&D final tests for CUORE)
CUORE experiment will be installed in the
Underground National Laboratoryof Gran Sasso
L'Aquila – ITALY
the mountain providing a 3500 m.w.e.shield against cosmic rays
![Page 14: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/14.jpg)
CUORICINO setup
Cold finger
CUORICINO Tower
Roman lead shield
Coldest point
CUORICINO (and all previousexperiments) is carried out in thecryostat located in hall A of GranSasso National Laboratory
Pumps and
control system
Faraday
Cage
Outer Lead
shield
Inner Lead
shield
Cryostat
Experimental
volume
Plexiglass box
B-Polyethy lene He Liquefier
![Page 15: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/15.jpg)
CUORICINO (2)
This detector is completelysurrounded by active materials.
substantial improvement in BKG reduction
11 modules, 4 detector each,crystal dimension 5x5x5 cm3
crystal mass 790 g
4 x 11 x 0.79 = 34.76 kg of TeO2
2 modules, 9 detector each,crystal dimension 3x3x6 cm3
crystal mass 330 g
9 x 2 x 0.33 = 5.94 kg of TeO2
CUORICINO TOTAL ACTIVE MASS = 40.7 kg of TeO2
![Page 16: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/16.jpg)
Assembling the detectors
All operations done in nitrogen atmosphere
![Page 17: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/17.jpg)
Assembling the tower
Almost completely done in nitrogen atmosphere
![Page 18: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/18.jpg)
The CUORICINO Tower
![Page 19: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/19.jpg)
CUORICINO: inner shield and suspension
![Page 20: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/20.jpg)
CUORICINO: Final Assembly
![Page 21: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/21.jpg)
CUORICINO results/statisticsCool down: february 2003Detectors: some electrical connection were lost during the cooling of the tower, as a result some
detectors cannot be read-out (to recover the electrical connections it is necessary to warm upthe cryostat)
4x11 = 44 large size crystals (~5x5x5 cm3 av. mass = 790 g) 32 working9x2 = 18 small size crystals (~3x3x6 cm3 av. mass = 330 g) 16 working
Active mass during this run: 10.4 kg 130Te32 x 0.790 = 25.28 kg12 x 0.330 = 3.96 kg
2 (130Te-enriched) x 0.330 = 0.660 kg = 0.495 kg 130Te2 (128Te-enriched) x 0.330 = 0.660 kg = 0.543 kg 128Te
29.24 kg = 9.9 kg 130Te - 72% }
Start date: 19 April 2003Stop date: 23 June 2003
Live time: 72% Background measurement: 57% (891.27 h
/ch) Calibration: 20% (227.73 h/ch)
![Page 22: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/22.jpg)
Detector performances: pulse height
0
1
2
3
4
5
6
7
8
9
1 0
11
1 2
13
1 4
Pulse height (normalized to 1 kg of TeO2)
C o l u m n D
Column E
5 0 1 0 0 2 0 0 3 0 0 4 0 0 5 0 0 u V / M e V
num
ber
of
dete
cto
rs
Pulse height distribution µV/MeV (normalized to 1 kg of TeO2)
5x5x5 crystals
3x3x6 crystals
average pulse height for 5x5x5 crystals = 340 µV/MeVaverage pulse height for 3x3x6 crystals = 440 µV/MeV
![Page 23: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/23.jpg)
Detector performances: energy resolution
0
2
4
6
8
10
12
14
16
Energy resolution FWHM
C o l u m n S
C o l u m n T
5 1 0 1 5 2 0 3 0 F W H M [ k e V ]
n u m b e r o f d e t e c t o r s
3x3x6 crystals
5x5x5 crystals
FWHM [keV] of the 2615 keV gamma line of208Tl (calibration with a 232Th source ~ 3 days)
average 5x5x5 cm3 crystals ~ 7 keVaverage 3x3x6 cm3 crystals ~ 9 keV
0
1
2
3
4
5
6
7
8
9
10
11
12
13
Energy resolution FWHM
C o lu m n F
C o lu m n G
5 1 0 1 5 2 0 3 0 F W H M [ k e V ]
n u m b e r o f d e t e c t o r s
20 cryst. array II run20 cryst. array I run
![Page 24: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/24.jpg)
232Th calibration: 5x5x5 cm3 crystals
2615 keV 208Tl
single escape 208Tl
double escape 208Tl
![Page 25: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/25.jpg)
CUORICINO background
- CUORICINO- Mi-DBD II
![Page 26: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/26.jpg)
Observed γ lines
Array OLD: 1 cm (600 mK) + 10 cm above the towerArray NEW: 3 cm (2cm in 50mK + 1cm in 600mK) + 15 cm above the towerCuoricino: 1.3 cm (IVC) + 10 cm above the tower
Amount of internal roman lead shield:
2 0 c r y s t a l s " O L D " 2 0 c r y s t a l s " N E W " C u o r i c i n o
E ( k e V ) I s o t o p e c o u n t s / h e r r . c o u n t s / h e r r . c o u n t s / h e r r .
88 1 2 3 m T e + 1 2 7 m T e 1 . 9 1 E - 0 0 1 8 . 0 4 E - 0 0 3 1 . 0 9 E - 0 0 2 1 . 4 2 E - 0 0 3
122 5 7 C o 1 . 8 5 E - 0 0 3 1 . 1 8 E - 0 0 3 9 . 1 7 E - 0 0 3 2 . 4 3 E - 0 0 3 2 . 9 5 E - 0 0 2 1 . 8 0 E - 0 0 3
145 1 2 5 m T e 4 . 2 7 E - 0 0 3 1 . 0 7 E - 0 0 3 1 . 9 3 E - 0 0 1 7 . 8 6 E - 0 0 3 1 . 6 4 E - 0 0 2 1 . 4 2 E - 0 0 3
238 2 1 2 P b 6 . 8 8 E - 0 0 3 9 . 9 5 E - 0 0 4 4 . 7 2 E - 0 0 3 1 . 7 1 E - 0 0 3
247 1 2 3 m T e 8 . 2 5 E - 0 0 2 6 . 1 7 E - 0 0 3 6 . 3 9 E - 0 0 3 1 . 0 7 E - 0 0 3
351 2 1 4 P b 4 . 9 3 E - 0 0 3 8 . 9 4 E - 0 0 4 5 . 3 6 E - 0 0 3 9 . 1 3 E - 0 0 4
568 2 0 7 B i 5 . 9 8 E - 0 0 3 5 . 9 1 E - 0 0 4 < 4 E - 3 3 . 7 9 E - 0 0 3 9 . 9 9 E - 0 0 4
835 5 4 M n 9 . 9 5 E - 0 0 4 3 . 0 3 E - 0 0 4 5 . 8 0 E - 0 0 3 1 . 6 8 E - 0 0 3 1 . 1 7 E - 0 0 2 9 . 1 8 E - 0 0 4
911 2 2 8 A c 4 . 7 1 E - 0 0 3 4 . 3 2 E - 0 0 4 < 2 . 3 E - 3 5 . 1 4 E - 0 0 3 7 . 9 6 E - 0 0 4
1060 2 0 7 B i 6 . 4 7 E - 0 0 3 4 . 9 0 E - 0 0 4 < 3 . 5 E - 3 3 . 2 7 E - 0 0 3 5 . 6 1 E - 0 0 4
1120 2 1 4 B i 1 . 5 0 E - 0 0 3 2 . 5 9 E - 0 0 4 < 1 . 5 E - 3 6 . 8 5 E - 0 0 3 6 . 9 2 E - 0 0 4
1173 6 0 C o 8 . 3 5 E - 0 0 3 5 . 3 3 E - 0 0 4 5 . 0 5 E - 0 0 3 1 . 6 8 E - 0 0 3 1 . 5 2 E - 0 0 2 9 . 1 8 E - 0 0 4
1333 6 0 C o 7 . 5 1 E - 0 0 3 6 . 4 9 E - 0 0 4 3 . 9 3 E - 0 0 3 1 . 3 1 E - 0 0 3 1 . 5 1 E - 0 0 2 8 . 5 0 E - 0 0 4
1461 4 0 K 3 . 3 1 E - 0 0 2 1 . 1 7 E - 0 0 3 5 . 9 0 E - 0 0 3 1 . 6 3 E - 0 0 3 3 . 1 7 E - 0 0 2 1 . 1 8 E - 0 0 3
2615 2 0 8 T l 5 . 0 6 E - 0 0 3 4 . 6 1 E - 0 0 4 1 . 6 8 E - 0 0 3 7 . 4 8 E - 0 0 4 6 . 9 7 E - 0 0 3 5 . 4 3 E - 0 0 4
---
+
++++++
Gamma peaks of 60Co, 40K, 208Tl have a higher intensity in CUORICINO but the internalroman lead shield has a lateral thickness much reduced (2 cm less).
Copper activation gamma lines have a higher intensity in CUORICINO (more copperbetween the roman lead shield and the tower)
Tellurium activation gamma lines have a smaller intensity in CUORICINO
![Page 27: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/27.jpg)
2505 keV line: 60Co
2505 keV counting rate: (0.28 +/-0.13) x 10-3 c/h
Hard to see it in the 20 crystal array: the bkg was higher, the resolution slightly worse
![Page 28: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/28.jpg)
2505 keV line: 60Co MC simulations
Spectra normalized at the 1173 keV line
Measured spectrumContamination of Co60 in the crystal's bulkContamination of Co60 in the copper box's bulk
Main contribution from crystals bulk excludedGood agreement with a bulk contamination of the copper (c.r. activation)
![Page 29: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/29.jpg)
CUORICINO: Alpha region
3250keV
Heater linesArray newCuoricino
![Page 30: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/30.jpg)
3250 keV line: 190Pt
Alpha decay from 190Pt to 186Os(6.5x1011 y): Ealpha + Enuclear recoil = Q = 3250keVThe crystals were grown in a Pt crucible!!!
With more statistics we'd be able to understand the origin of thispeak (surface/bulk)
![Page 31: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/31.jpg)
We have identified 4 possible sources for the residual BKG in the DBD region:
♦ Neutrons♦ Degraded alphas from TeO2 surface♦ Degraded alphas from Cu frame and plate surface♦ Energy degraded 2615 keV environmentalphotons
Excluded @ MiDBD & CUORICINO level since adding B-polyethilene shield had no effect
Coincidences between adjacent detectors show that crystal surfaces emit alphas belonging to 238U and 232Th series.Crystal contamination determines peaks more than continuum.
The alpha continuum extends down to the DBD region
A Montecarlo simulation shows that the alpha BKG is determined mainly
by a superficial contamination of U-Th in Cu plates and frames.This contamination explains
the alpha region BKG, the DBD region BKG and the 208Tl peak.
Experimental spectrum Montecarlo
Straight lines correspond to full energy shared by two detectors
Alpha region(continuum)
208Tl -2615 keV peak
Alpha region(peaks)
Discussion on the BKG (1)
![Page 32: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/32.jpg)
Evidence for contributions to the BKG in the DBD region from degraded alpha particles (surface effect):
Clear correlation between:
BKG in the DBD region ⇔ BKG in the region 3-4 MeV
Mi DBD - I Mi DBD - II
BKG 2500-2556 keV (c/keV/kg/y)
BKG 3000-4000 keV (c/keV/kg/y)
0.33±0.11
0.27±0.03
0.59±0.06
0.66 ±0.01
free from alpha and gamma peaks
Discussion on the BKG (2)
![Page 33: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/33.jpg)
Mi-DBD/CUORICINO Background Model
Experiment/Montecarlo comparison:Experiment/Montecarlo comparison:•• reliabilityreliability•• quantitative contributions from different sourcesquantitative contributions from different sources
ExperimentalExperimental
MC: SurfaceMC: Surface(crystals+mounting box)(crystals+mounting box)
Energy (keV)Energy (keV)
Cou
nts
Cou
nts
MC: bulkMC: bulkMounting boxMounting box
CrystalsCrystals
ExternalExternal
GEANT4GEANT4
Mi DBD IMi DBD IMi DBD IIMi DBD IICuoricinoCuoricinoCuoreCuore
Reliable estimate of Reliable estimate of experimental sensitivityexperimental sensitivity
![Page 34: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/34.jpg)
Background: MC estimates
Geant4Gendec
Mibeta I
Mibeta II
CUORE
5x5x5 TeO2 crystals
3x3x6 TeO2 crystals
![Page 35: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/35.jpg)
Background: MC estimates (2)
Cryostat, shields and detector details
![Page 36: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/36.jpg)
Background: MiDBD II vs CUORICINO
continuous background in the 3-4 MeV region (cutting off the 3.3MeV peak) is reduced
→ cleaning operation of the copper surfaces
alpha peaks due to surface contamination of the crystals are reduced
→ cleaning operation of the TeO2 crystal surfaces
E n e r g y r a n g e [ k e V ] 2 4 7 0 - 2 5 8 5 2 7 5 0 - 3 2 5 0 3 4 5 0 - 3 9 0 0 3 0 0 0 - 4 0 0 0 4 0 0 0 - 5 0 0 0
[ c o u n t s / k e V / k g / y ]
M i - D B D 4 . 0 3 e - 0 1 + / - 8 . 8 0 e - 0 2 2 . 2 1 e - 0 1 + / - 3 . 1 2 e - 0 2 2 . 3 1 e - 0 1 + / - 3 . 3 6 e - 0 2 2 . 8 0 e - 0 1 + / - 2 . 4 9 e - 0 2 1 . 8 3 e + 0 0 + / - 6 . 3 5 e - 0 2
C u o r i c i n o 5 x 5 x 5 2 . 4 6 e - 0 1 + / - 3 . 0 7 e - 0 2 1 . 0 8 e - 0 1 + / - 9 . 7 5 e - 0 3 1 . 3 9 e - 0 1 + / - 1 . 1 7 e - 0 2 2 . 1 6 e - 0 1 + / - 9 . 7 7 e - 0 3 5 . 5 2 e - 0 1 + / - 1 . 5 6 e - 0 2
C u o r i c i n o 3 x 3 x 6 2 . 5 8 e - 0 1 + / - 9 . 7 5 e - 0 2 1 . 6 1 e - 0 1 + / - 3 . 6 9 e - 0 2 1 . 7 9 e - 0 1 + / - 4 . 1 0 e - 0 2 2 . 3 7 e - 0 1 + / - 3 . 1 7 e - 0 2 8 . 0 5 e - 0 1 + / - 5 . 8 4 e - 0 2
Is the flat continuum actually due to the Copper surface contamination?
Comparison between the central and the lateral 3x3x6 crystals, but we need more statistics
![Page 37: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/37.jpg)
CUORICINO: new limits on 130Te bb(0n)
anticoincidence spectrum,only 5x5x5 crystals,
19846 h x kgτ1/2 > 5 x 1023 years at 90% C.L.
![Page 38: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/38.jpg)
CUORICINO: mee lower limits
![Page 39: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/39.jpg)
Background: ββ region
3 year sensitivity CUORICINO (full mass): b=0.23 G=8 keV
F0ν3 years = 1 x 1025
<mν> ~ 0.15 - 0.38 eV
F0ν = 4.17 × 1026 × × εaA
1/2M Tb Γ
Atomic mass
Isotopic abundance
Detector mass (kg)
BKG (counts/keV/kg/y)Energy resolution (keV)
Running time (y)
Detector efficiency
Sensitivity:
2480-2600 keV (ββ 130Te transition energy = 2528.8 keV)anticoincidence spectrum, only 5x5x5 crystals
b = 0.23 +/- 0.04 c/keV/kg/y
![Page 40: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/40.jpg)
Perspectives for CUORE
CUORICINO:
apparatus: proves thefeasibility of a large bolometricarray with the tower-likestructure
detectors: shows that detectorperformances are not affectedby the increase in crystal size(from 340 g to 790 g)
CUORE:
apparatus: it will contain 25towers similar to theCUORICINO one, R&D will bededicated to cryostat andmechanical apparatus design
detectors: R&D to guaranteedetector reproducibility anduniformity (pulse shape andresolution)
![Page 41: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/41.jpg)
Perspectives for CUORE (2)
CUORICINO:
background achievements: MiDBD-II was used as a testbench to verify surface cleaning techniques, the improvement inbkg obtained in Cuoricino (despite the reduced shield) provesthe reproducibility of cleaning and handling procedures
background study: Cuoricino data will be used to further studybkg sources in view of Cuore
![Page 42: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/42.jpg)
Perspectives for CUORE (3)
a completely new set-up will allow the optimization of shielding
CUORE is specifically designed to reduce as far as possible theamount of materials interposed between the crystals.
the high granularity of the CUORE detector will allow to use withhigh efficiency the coincidence/anticoincidence technique toidentify and reject background events
the real challenge of CUORE will be the control and reduction ofbackground
only low radioactivity materials will be employed to build the refrigerator and theentire mechanical set up for CUORE
special techniques for surface cleaning will be applied.
![Page 43: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/43.jpg)
CUORE sensitivity
MC simulation for BKG contributions:
♦ Bulk contamination is not a problem < 0.004 counts/keV/kg/y MC simulation with MEASURED 90% upper limits on material contaminations
♦ Surface contamination from passive materials is potentially dangerous, but there will be the possibility to reduce by a factor 10 -100 the amount of Cu facing the detector and/or improve the materials surface treatment
~ 0.01 – 0.001 counts/keV/kg/y
♦ Environmental radioactivity contribution is reduced to a minimum thanks to the lead and neutron shields
♦ Cosmogenic activation of Cu and Te will be reduced to a minimum by the underground storage of materials
♦Two neutrino double beta decay contribution < 0.0001 counts/keV/kg/y
![Page 44: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/44.jpg)
CUORE ββ sensitivity
0ν sensitivity = ln 2 NA = 2.1 1025
Α b Γ √a.i. M t ε
b Γ √ t
Pessimistic estimation: b = 0.01 - Γ = 5 keV
mee < 27 - 70 meV × ( T[y ] )1/4
(18-47 meV in 5 years)
F0ν = 9.4 × 1025 × ( T[y ] )1/2 mee < 49 – 124 meV × ( T[y ] )1/4
(33-83 meV in 5 years)
F0ν = 2.96 × 1026 × ( T[y ] )1/2
Optimistic estimation: b = 0.001 - Γ = 5 keV
![Page 45: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/45.jpg)
CUORE: R&DCUORE: R&D
Long term stability:• Cryogenics• Detector optimization
Large number of detectors:• reproducibility• read-out & calibration
Background suppression:• materials selection
• setup materials• cleaning/preparation materials
• surface treatment improvement• radiation shields improvement
![Page 46: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/46.jpg)
CUORE temptative time schedule
![Page 47: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/47.jpg)
CUORE temptative cost statement
![Page 48: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/48.jpg)
Conclusions
CUORICINO is running (February 2003) Some channels lost during cool down of the detector Energy resolution is good and even better than in MiDBD
Background shows a reduction in α energy region Background at low energy is comparable with MiDBD Background in DBD energy region in good agreement with expectations
Efforts to lower energy threshold are in progress
New (improved) limit on neutrinoless DBD of 130Te and mee Future: New setup to solve wiring problem Reduction of energy threshold at level of MiDBD (DM) Complete definition of the CUORE project Formal CUORE proposal Start of the required CUORE R&D
![Page 49: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/49.jpg)
CUORICINO: criostat & wiringCUORICINO: criostat & wiring
![Page 50: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/50.jpg)
CUORICINO: cold electronicsCUORICINO: cold electronics
![Page 51: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/51.jpg)
CUORICINO: thermistors andCUORICINO: thermistors andheatersheaters
![Page 52: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/52.jpg)
CUORICINO: anti-RnCUORICINO: anti-Rn
Lapping machine
Gluing box
![Page 53: First Cuoricino results and the CUORE · PDF fileFirst Cuoricino results and the CUORE project ... 340 g) are arranged in a tower-like compact ... Colum n G 51 02 3 F W H M [k e V](https://reader035.vdocuments.us/reader035/viewer/2022062907/5aabeb8b7f8b9aa06a8c7ec0/html5/thumbnails/53.jpg)
CUORICINO: 4 crystal CUORICINO: 4 crystal planeplaneCopper surface treatment TeO2 crystal surface treatment
New improved mounting design