Starting from 2018, the LHCb detector will be upgraded to operate at higher luminosity and extend its potential for new discoveries. The Ring Imaging Cherenkov (RICH) detectors are one of the key ...components for particle identification of the LHCb detector and the upgraded specifications will require a redesign of the optoelectronic readout chain. In the present work, we describe the experimental setup and the results of the tests carried out with a particle beam to assess and validate the performance of the optoelectronic readout system.
The R&D project COSINUS (Cryogenic Observatory for SIgnatures seen in Next-generation Underground Searches) aims to develop a cryogenic scintillating calorimeter using an undoped NaI-crystal as ...target for direct dark matter search. Dark matter particles interacting with the detector material generate both a phonon signal and scintillation light. While the phonon signal provides a precise determination of the deposited energy, the simultaneously measured scintillation light allows for particle identification on an event-by-event basis, a powerful tool to study material-dependent interactions, and to suppress backgrounds. Using the same target material as the DAMA/LIBRA collaboration, the COSINUS technique may offer a unique possibility to investigate and contribute information to the presently controversial situation in the dark matter sector. We report on the dedicated design planned for the NaI proof-of-principle detector and the objectives of using this detection technique in the light of direct dark matter detection.
Background model of the CUPID-0 experiment Azzolini, O.; Beeman, J. W.; Bellini, F. ...
The European physical journal. C, Particles and fields,
07/2019, Volume:
79, Issue:
7
Journal Article
Peer reviewed
Open access
CUPID-0 is the first large mass array of enriched Zn
82
Se scintillating low temperature calorimeters, operated at LNGS since 2017. During its first scientific runs, CUPID-0 collected an exposure of ...9.95 kg year. Thanks to the excellent rejection of
α
particles, we attained the lowest background ever measured with thermal detectors in the energy region where we search for the signature of
82
Se
neutrinoless double beta decay. In this work we develop a model to reconstruct the CUPID-0 background over the whole energy range of experimental data. We identify the background sources exploiting their distinctive signatures and we assess their extremely low contribution down to
∼
10
-
4
counts/(keV kg year) in the region of interest for
82
Se
neutrinoless double beta decay search. This result represents a crucial step towards the comprehension of the background in experiments based on scintillating calorimeters and in next generation projects such as CUPID.
A
bstract
Neutrinoless double-beta decay is a key process in particle physics. Its experimental investigation is the only viable method that can establish the Majorana nature of neutrinos, providing ...at the same time a sensitive inclusive test of lepton number violation. CROSS (Cryogenic Rare-event Observatory with Surface Sensitivity) aims at developing and testing a new bolometric technology to be applied to future large-scale experiments searching for neutrinoless double-beta decay of the promising nuclei
100
Mo and
130
Te. The limiting factor in large-scale bolometric searches for this rare process is the background induced by surface radioactive contamination, as shown by the results of the CUORE experiment. The basic concept of CROSS consists of rejecting this challenging background component by pulse-shape discrimination, assisted by a proper coating of the faces of the crystal containing the isotope of interest and serving as energy absorber of the bolometric detector. In this paper, we demonstrate that ultra-pure superconductive Al films deposited on the crystal surfaces act successfully as pulse-shape modifiers, both with fast and slow phonon sensors. Rejection factors higher than 99.9% of
α
surface radioactivity have been demonstrated in a series of prototypes based on crystals of Li
2
MoO
4
and TeO
2
. We have also shown that point-like energy depositions can be identified up to a distance of
∼
1 mm from the coated surface. The present program envisions an intermediate experiment to be installed underground in the Canfranc laboratory (Spain) in a CROSS-dedicated facility. This experiment, comprising
∼
3
×
10
25
nuclei of
100
Mo, will be a general test of the CROSS technology as well as a worldwide competitive search for neutrinoless double-beta decay, with sensitivity to the effective Majorana mass down to 70 meV in the most favorable conditions.
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•Hydroxyapatite can be easily functionalized to give interesting catalytic material.•Copper-hydroxyapatite has good catalytic performances in the NH3-SCR reaction.•Dispersed or ...aggregated copper centers can be deposited on hydroxyapatite surface.•Nature of copper salt precursor and deposition method affect catalyst performances.
Hydroxyapatite loaded with different amounts of copper (from 2 to 11 wt.%, by using different Cu-precursors) was investigated as catalytic material for the NH3-SCR reaction. The method of copper addition affected the location and distribution of the copper phase in the hydroxyapatite samples as well as the aggregation state (isolated Cu2+ or CuxOy or CuO nano-aggregates). Ionic exchange procedure gave rise to Cu2+ stabilization in the exchange sites of HAP lattice, irrespective of the amount of Cu addition. Incipient wetness impregnation procedure provided samples with copper aggregation up to formation of CuO species at the highest Cu-loading. Sample characterization was performed by N2-adsorption/desorption, acidity measurement, EDX, TGA-DTGA, XRPD, UV–vis-DRS, and EPR to study the morphological and structural aspects of the copper phase.
Catalytic tests of NH3-SCR revealed significant differences between the samples prepared by ionic exchange and impregnation, with activity that was dependent on the copper concentration on hydroxyapatite. Presence of 6 wt.% Cu was associated to the most active catalysts, in any case. Use of Cu-chloride and Cu-nitrate as precursors of Cu-phase, with the ionic exchange procedure, gave copper-hydroxyapatite catalysts with high activity/selectivity. Use of Cu-acetate as Cu-precursor caused some modification of the hydroxyapatite surface with enrichment of carbonate groups that were detrimental for the SCR activity.
The catalytic properties of niobic acid (Nb
2O
5·
nH
2O) and niobium phosphate (NbOPO
4) surfaces were studied in the reaction of fructose dehydration carried out in water. The reaction was performed ...in a continuous reactor at different temperatures 90–110
°C and pressures (from 2 to 6
bar). Superior activity and selectivity to 5-hydroxymethyl-2-furaldehyde (HMF) of niobium phosphate compared to niobic acid was observed. The initial higher catalytic performance of niobium phosphate than niobic acid could be related to the higher effective acidity of its surface, as was evidenced by acid–base titrations realized in different polar liquids. Deactivation studies showed a deeper decay for niobium phosphate than niobic acid at short time on stream, while, for higher time, light losses of activity were observed for both the catalysts.
The signal digitization for CROSS, a bolometric experiment for the search of neutrinoless double beta decay at LSC—Canfranc Underground Laboratory, will be based on a custom solution comprised of an ...analog-to-digital board interfaced to an Altera Cyclone V FPGA module. Each analog-to-digital board hosts 12 channels that allow data digitization up to 25 ksps per channel and an effective resolution of 21 bits at the typical sample rate required by the experiment (5 ksps). The board also allows to digitally select the cutoff frequency of the anti-aliasing filter with 10 bit resolution from 24 Hz up to 2.5 kHz, as required by fast scintillating bolometers. The FPGA is responsible for the synchronization of the analog-to-digital boards and for the data transfer to the storage, using UDP protocol on a standard Ethernet interface. Each FPGA can manage the data coming from eight boards (96 channels), allowing an excellent scalability. In this contribution, we will present a complete overview of the system and a detailed characterization of the system performance.
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