Growth of pure and doped TeO 2 crystals for scintillating bolometers Dafinei, I.; Diemoz, M.; Longo, E. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2005, Letnik:
554, Številka:
1
Journal Article
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Double-beta decay hybrid detectors (scintillating bolometers) are prospective sensitive tools for nuclear and particle physics investigations. For this goal, the bolometric capability of crystals ...should be combined with extrinsic scintillation. Tellurium dioxide (TeO
2) crystals have well established, suitable properties to be conveniently used as bolometers. A first attempt to grow doped TeO
2 crystals to increase their scintillation was performed. Preliminary room temperature transmission and luminescence measurements showed the incorporation of different dopants in TeO
2 host lattice.
The effect of several stable trivalentions (Lu, Y and Gd) and pentavalent Nb
5+
on the radiation resistance and thermoluminescence characteristics of PbWO
4
is investigated. While rather uniform ...behaviour is observed for all the trivalent ions, apparently different mechanisms apply in the case of the Nb doping. This fact could be explained by different effect of the dopants on the oxygen sublattice, namely on the concentration of oxygen vacancies. Electron centers based on oxygen vacancy(ies) participate in thermoluminescence processes round 200 K.
The barrel of the CMS electromagnetic calorimeter is currently under construction and will contain 61
200
PbWO
4
crystals. Half of them are being fully characterized for dimensions, optical ...properties and light yield in the INFN-ENEA Regional Centre near Rome. This paper describes the measurements and results from a sample of about 6000 crystals. Results are presented on long term stability and precision of light yield and transmission measurements. A strong correlation between crystal light yield and longitudinal transmission in the range 350–370
nm is observed. As it will not be possible to precalibrate with particles the whole calorimeter, the light yield and transmission measurements performed at the Regional Centre will be crucial to provide an initial intercalibration for most crystals. Thanks to the observed correlation, transmission measurements can be combined with those of direct light yield to improve the crystal intercalibration precision. Expectations on the achievable precision are derived.
A lead-scintillating fiber calorimeter has been built to fill the gap between endcap and barrel of the L3 BGO electromagnetic calorimeter. We report details of the construction, as well as results ...from test-beam and simulation.
We report on the test-beam results for three prototype modules of a lead-scintillating fiber (
spaghetti) calorimeter. We studied linearity, energy resolution and light collection. The results are in ...agreement with expectations from MC simulation. We also report on the studies for the optimal light guide to be used in the final design.
We present here a characterization of the low background NaI(Tl) crystal NaI-33 based on a period of almost one year of data taking (891 kgxdays exposure) in a detector configuration with no use of ...organic scintillator veto. This remarkably radio-pure crystal already showed a low background in the SABRE Proof-of-Principle (PoP) detector, in the low energy region of interest (1-6 keV) for the search of dark matter interaction via the annual modulation signature. As the vetoable background components, such as \(^{40}\)K, are here sub-dominant, we reassembled the PoP setup with a fully passive shielding. We upgraded the selection of events based on a Boosted Decision Tree algorithm that rejects most of the PMT-induced noise while retaining scintillation signals with > 90% efficiency in 1-6 keV. We find an average background of 1.39 \(\pm\) 0.02 counts/day/kg/keV in the region of interest and a spectrum consistent with data previously acquired in the PoP setup, where the external veto background suppression was in place. Our background model indicates that the dominant background component is due to decays of \(^{210}\)Pb, only partly residing in the crystal itself. The other location of \(^{210}\)Pb is the reflector foil that wraps the crystal. We now proceed to design the experimental setup for the physics phase of the SABRE North detector, based on an array of similar crystals, using a low radioactivity PTFE reflector and further improving the passive shielding strategy, in compliance with the new safety and environmental requirements of Laboratori Nazionali del Gran Sasso.
High energy cosmic muons and the calibration of the L3 electromagnetic calorimeter
Nuclear instruments and methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment/Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/1989
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