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cupid_pub:the_cupid_experiment [2021/05/22 13:12]
benato
cupid_pub:the_cupid_experiment [2021/06/01 08:23]
dilorenzo1 [The Experiment]
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 |{{ cupid_pub:​double_beta.png?​330 }} |{{ cupid_pub:​screenshot_20210522_144702.jpeg?​330 }}| |{{ cupid_pub:​double_beta.png?​330 }} |{{ cupid_pub:​screenshot_20210522_144702.jpeg?​330 }}|
-|Decay scheme of 2νββ (top) and 0νββ decay (bottom). The two processes share the same parent and daughter nucleus, but differ for the number of emitted ​partiles, and consequently their energy.|The measurable sum electron spectrum is a continuum for 2νββ decay, and an excess at Q<​sub>​ββ</​sub>​ for 0νββ decay.|+|Decay scheme of 2νββ (top) and 0νββ decay (bottom). The two processes share the same parent and daughter nucleus, but differ for the number of emitted ​particles, and consequently their energy.|The measurable sum electron spectrum is a continuum for 2νββ decay, and an excess at Q<​sub>​ββ</​sub>​ for 0νββ decay.|
  
  
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 It is located at the [[https://​www.lngs.infn.it|Laboratori Nazionali del Gran Sasso (LNGS)]] ​ of INFN, in the Abruzzo region in central Italy. It is located at the [[https://​www.lngs.infn.it|Laboratori Nazionali del Gran Sasso (LNGS)]] ​ of INFN, in the Abruzzo region in central Italy.
 CUORE is composed of 988 TeO<​sub>​2</​sub>​ crystals operated as cryogenic calorimeters at a temperature of 10-15 mK. The crystals act simultaneously as detectors and source of 0νββ decay: in fact, they contain the ββ decay isotope <​sup>​130</​sup>​Te,​ that contributes to ~27% of the crystal mass. CUORE is composed of 988 TeO<​sub>​2</​sub>​ crystals operated as cryogenic calorimeters at a temperature of 10-15 mK. The crystals act simultaneously as detectors and source of 0νββ decay: in fact, they contain the ββ decay isotope <​sup>​130</​sup>​Te,​ that contributes to ~27% of the crystal mass.
 +The CUORE detectors are operated in the largest dilution refrigerator ever build((J. Ouellet, [[https://​arxiv.org/​abs/​1410.1560|arXiv:​1410.1560]])),​ capable of cooling down ~1.5 tons of material to base temperature about a month, and operating it stably for years. ​
  
 |{{cupid_pub:​campo-imperatore.jpg?​450}}|{{cupid_pub:​cuore_clean_room.jpg?​350}}| |{{cupid_pub:​campo-imperatore.jpg?​450}}|{{cupid_pub:​cuore_clean_room.jpg?​350}}|
 |The Gran Sasso National Park, below which the underground lab of LNGS is located.|The CUORE detectors right after their installation in the cryostat.| |The Gran Sasso National Park, below which the underground lab of LNGS is located.|The CUORE detectors right after their installation in the cryostat.|
  
-The detectors are operated in the largest dilution refrigerator ever build((J. Ouellet, [[https://​arxiv.org/​abs/​1410.1560|arXiv:​1410.1560]])). +CUPID will profit ​of the established ​CUORE cryogenic infrastructureand deploy ~1500  Li<sub></sub>MoO<sub>4</subcrystals ​in place of the TeO<​sub>​2</​sub> ​ones. 
- +Thus, CUPID will not only change the crystal, but also the candidate isotope. The reason for this choice ​is twofold: 
- +on the one hand, Li<​sub>​2 </​sub>​MoO<​sub>​4</​sub> ​is a scintillating material with a particle-dependent light yield, 
-The future ​of the CUORE experiment is the  CUPID projectwhose  goal is  to measure the  0υ2β decay in the <sup>100</sup>Mo isotope instead of <sup>130</sup>Te used in CUORE using 1500   Li<​sub>​2 </​sub>​MoO<​sub>​4</​sub>​ crystals  ​. The main reason for the change in the target material ​is due to the scintillating properties of the  ​Li<​sub>​2 </​sub>​MoO<​sub>​4</​sub> ​which are necessary for the particle ​identification. +on the other hand the candidate isotope <​sup>​100</​sup>​Mo has a Q-value of 3034 keV 
- +(compared to 2527 keV of <​sup>​130</​sup>​Te),​ which lies above most of the γ background from environmental radioactivity. Special attention is paid to the minimization of the radioactive contamination levels of all employed materialsUsing the information from the predecessor experiments CUORE, [[https://cupid-0.lngs.infn.it/​|CUPID-0]], and [[https://​cupid-mo.mit.edu|CUPID-Mo]], the projected background at Q<​sub>​ββ</​sub> ​is expected ​to be at the level of 10<​sup>​-4</​sup>​ counts/​keV/​kg/​yr.
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-The CUPID crystal will be placed inside  ​the CUORE cryostat arranged as in the sketch shown below. +
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-{{ :cupid_pub:​image2.jpeg?200|}} +
-{{ :cupid_pub:​cryostat2.jpg?​200 ​|}} +
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-==== The Detector ==== +
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-The CUPID crystals are operated as cryogenic calorimeterseach equipped with a cryogenic light detector. A particle interaction in the crystal produces a phonon ​ and light signal (see figure below), the latter one is used to discriminate ​ α background from the electrons events +
-{{ :​cupid_pub:​cupid_detector.png?​450 |}} +
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 +|{{cupid_pub:​cuore_cryostat_3.jpg?​nolink&​545}}|{{cupid_pub:​cupidrendering.jpg?​nolink&​300}}|
 +|The CUORE/CUPID cryostat during its construction,​ with the distillation unit visible in the middle.|CUPID geometry in Geant4 Monte Carlo simulation.|
  
  
 +===== The Detector =====
  
 +In CUPID, the Li<​sub>​2</​sub>​MoO<​sub>​4</​sub>​ crystals are operated as cryogenic calorimeters,​ and coupled to a light detector. The light detectors are germanium wafers, and are also instrumented as calorimeters.
 +A particle interaction in the crystal produces phonons and scintillation light.
 +The heat from recombining phonons is read by a Neutron Transmutation Doped (NTD) germanium thermistor
 +glued to the crystal. The light escapes the crystal, inducing a phonon signal in the light detector, which is also read by an NTD.
  
 +|{{ cupid_pub:​cupid_detector.png?​350 }}|{{cupid_pub:​screenshot_20210522_221509.jpeg?​450}}|
 +|Schematic of a cryogenic calorimeter,​ with the heat channel (blue) and a light detector (gray).|Installation of crystals for a CUPID test run. A light detector is visible in the bottom right.|
Last modified: le 2021/06/04 08:31