Dafinei_Otranto2012_Lesson-2 Ioan Dafinei INFN Sezione di Roma, ITALY OTRANTO 21-27 Settembre 2012 XXIV SEMINARIO NAZIONALE Di FISICA NUCLEARE E SUBNUCLEARE

Dafinei_Otranto2012_Lesson-2

Ioan DafineiINFN Sezione di Roma, ITALY

OTRANTO21-27 Settembre 2012

XXIV SEMINARIO NAZIONALEDi FISICA NUCLEARE E

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Double beta decay study at LNGS(the experiments CUORE and CUORE-0)

I. DafineiUniversità "La Sapienza" di Roma and Sezione INFN - Roma

made in the frame of LUCIFER experimentFP7/2007-2013ERC grant agreement n. 247115.

Lucifer

XXIV SEMINARIO NAZIONALE di FISICA NUCLEARE E SUBNUCLEAREOTRANTO, Serra degli Alimini, 21-27 Settembre 2012 Argomento: Studio del decadimento doppio beta ai LNGSLezione 2: Esperimento CUORE





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Outline

• double beta decay study at LNGS• cryogenic bolometers; insights• CUORE and CUORE-0 experiments





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LNGS in a glancepast experiments

neutrino physics

0νDBDDBD

0νDBD(claimed

evidence!)





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LNGS in a glancecurrent experiments:

neutrino physics

0νDBDDBD





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LNGS in a glancecurrent experiments:

GERDA – 76GeArray of enriched Ge diodes operated in liquid argonFirst phase: 18 Kg; second phase: 40 Kg - LNGSProved energy resolution: 0.2 % FWHMCUORE – 130TeArray of low temperature natural TeO2 calorimeters operated at 10 mKFirst step: 200 Kg (2014) – LNGS – it can take advantage from Cuoricino experienceProved energy resolution: 0.2 % FWHM

LUCIFER – 82Se – 116Cd – 100Mo Array of scintillating bolometers operated at 10 mK (ZnSe or ZnMoO4 or CdWO4 )First step: ~ 10 Kg (2014) – LNGS – essentially R&D project to fully test the principleProved energy resolution: 0.3 – 0.7 % FWHM





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(more about) LNGSmerits

LNGS (underground facility)•position: latitude 42°27'N, longitude 13°34'E•average depth: 3800 m of water equivalent (m.w.e.)•minimum depth: 3000 m.w.e.•altitude: 963 m above sea level•intensity of charged cosmic rays reduced 106 times with respect to the flux at the surface (~1muon·m-2·h-l; energy threshold 2 TeV).•reduced neutrons flux due to spontaneous fission in the rocks

~3×10-6cm-2s-1 (thermal neutrons)<0.3×10-6cm-2s-1 (fast neutrons)(three orders of magnitude less than at the surface)

•background due to gamma rays similar or higher than in a surface laboratory due to the radioactivity of the rocks and concrete which cover the halls (problem easily solved by proper shielding)





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(more about) LNGSmerits

C. Arpesella, Appl. Radiat. Isot. 47, 9/10 (1996), 991

background gamma spectra measured with Ge detector with proper shielding

Milano

LNGStypical HPGe spectrum in

hall C

radionuclides:• of natural radioactive series (226Ra, 214Bi, 214Pb 238Ac, 224Ra, 208Tl, 212Pb and the Actinium series)• long-lived natural (40K, 87Rb, 115In, 133La, 142Ce, etc.)• of cosmogenic origin (3H, 7Be, 14C, 22Na, 26Al, 60Co)• of artificial origin (long-lived fission products like 95Nb, 95Zr, l44Ce, l06Ru, 134Cs, 125Sb, 137Cs, etc.)





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energy resolution

: 100 eV 30 eV 3 eV < 0.01 eVscintillator gas detector solid state detectors LTD

energy thresholdmuch lower than in conventional devices

sensitivity to non-ionizing events

large choice for energy absorber materials

possible discrimination of interacting particle

advantages





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FWHM= 7.8 keV

largest (2.1kg)

bolometer ever

operated





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CUORE

19 towers containing 134=52 detectors each

988 TeO2 crystals (5x5x5 cm3)total detector mass: 741 kg

total 130Te mass: 206 kg (natural abundance)

CUORE in a glance

FWHM resolution~ 5 keV @0νDBD (2528 keV)

all the particle energy is converted into phonons,

producing a crystal temperature

variation of ~0.1 mK/MeV

crystal heating changes the thermistor resistance of

~3MΩ/MeVdetermining a voltage variation

of

~0.3 mV/MeV

2.528MeV





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11

pulse tube

remote motor

CUORE CUORE detectordetector

pulse tube head

detector suspension support

dilution unit

lateral Pb shield

top Pb shield

how?•dilution refrigerator (Leiden

Cryogenics)•detector suspensions independent

•minimum lead thickness ~ 36 cm•strict radiopurity controls

•materials•assembly





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CUORE

12

CUORE Hut

Cuoricino Hut

where?





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13

CUOREthe hut, now





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14

CUORECUORE-0

•52 CUORE crystals mounted in CUORE-style frames as a single tower (39 kg TeO2)•assembled from detector components manufactured, cleaned and stored following the same protocols defined for CUORE•to be operated in the Cuoricino cryostat•expected to surpass Cuoricino performance





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15

CUORECUORE-0

Cartesian Cartesian robot for robot for

glue dosingglue dosing

Cartesian Cartesian robot for robot for

glue dosingglue dosing

Anthropomorphous Anthropomorphous robot for sensors robot for sensors

and crystals and crystals handlinghandling

Anthropomorphous Anthropomorphous robot for sensors robot for sensors

and crystals and crystals handlinghandling

sensor-to-crystal connections





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16

CUORECUORE-0






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17

CUORECUORE-0

precise and uniform precise and uniform gluinggluing

precise and uniform precise and uniform gluinggluing






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18

CUORECUORE-0

CUORE Tower Assembling Line(CTAL)

single assembly station (4 interchangeable glove boxes)

•mechanics•wiring/shielding•bonding•storagezero contact system(controlled nitrogen atmosphere)

18

Universal Working

Plane

Clean Room Floor

Tower Garage

Tower can be conveniently lifted up and

down





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19

CUORECUORE-0




19

MechBoxMechBoxMechBoxMechBox





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20

CUORECUORE-0




20

CablingBoxCablingBoxCablingBoxCablingBox





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21

CUORECUORE-0




21

BondingBoxBondingBoxBondingBoxBondingBox





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22

CUORECUORE-0




22

StorageBoxStorageBoxStorageBoxStorageBox





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23

CUORECUORE-0

assembling

2323





SUBNUCLEARECUORECUORE-0 wiring

24





SUBNUCLEARECUORECUORE-0 wiring

2551/52 NTD successfully bonded51/52 NTD successfully bonded51/52 NTD successfully bonded51/52 NTD successfully bonded





SUBNUCLEARECUORECUORE-0 shielding

26






27






28





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acknowledgements

this work was made in the frame of LUCIFER experiment funded by the

European Research Council under the European Unions Seventh Framework

Programme

FP7/2007-2013 / ERCgrant agreement n. 247115.

Documents

Dafinei_Otranto2012_Lesson-2 Ioan Dafinei INFN Sezione di Roma, ITALY OTRANTO 21-27 Settembre 2012 XXIV SEMINARIO NAZIONALE Di FISICA NUCLEARE E SUBNUCLEARE