A complete understanding of neutrinos properties requires a study and a characterization of the interactions of the daughter particles created in a neutrino-nucleus interaction. The Liquid Argon In A ...Testbeam (LArIAT) experiment is a small-scale liquid argon detector situated in the Fermilab Test Beam Facility. The LArIAT experiment is exposed to a tertiary beam comprised of mostly pions along with a mix of muons, protons, kaons, and electrons. LArIAT's goal is to characterize the response of the Liquid Argon Time Projection Chamber (LArTPC) to known incoming charged particles and measure their interactions in Argon, in order to understand their cross-sections and to help developing and tuning simulations and reconstruction algorithms for LArTPC neutrino experiments. The world's first measurement of a pion cross-section on an Argon target, made with the LArIAT detector, is presented here.
State-of-the-art physics experiments require high-resolution, low-noise, and low-threshold detectors to achieve competitive scientific results. However, experimental environments invariably introduce ...sources of noise, such as electrical interference or microphonics. The sources of this environmental noise can often be monitored by adding specially designed “auxiliary devices” (e.g. microphones, accelerometers, seismometers, magnetometers, and antennae). A model can then be constructed to predict the detector noise based on the auxiliary device information, which can then be subtracted from the true detector signal. Here, we present a multivariate noise cancellation algorithm which can be used in a variety of settings to improve the performance of detectors using multiple auxiliary devices. To validate this approach, we apply it to simulated data to remove noise due to electromagnetic interference and microphonic vibrations. We then employ the algorithm to a cryogenic light detector in the laboratory and show an improvement in the detector performance. Finally, we motivate the use of nonlinear terms to better model vibrational contributions to the noise in thermal detectors. We show a further improvement in the performance of a particular channel of the CUORE detector when using the nonlinear algorithm in combination with optimal filtering techniques.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•A technique for active cancellation of Pulse Tube (PT) vibrational noise is proposed.•The technique controls the relative phase of the pressure waves of two or more PTs.•A scan of the phase ...parameter space allows to find the lowest noise configuration.•The PTs are driven locking their relative phases in the optimal working condition.
The Cryogenic Underground Observatory for Rare Events (CUORE) experiment at Gran Sasso National Laboratory of INFN searches for neutrinoless double beta decay using TeO2 crystals as cryogenic bolometers. The sensitivity of the measurement heavily depends on the energy resolution of the detector, therefore the success of the experiment stands on the capability to provide an extremely low noise environment. One of the most relevant sources of noise are the mechanical vibrations induced by the five Pulse Tube cryocoolers used on the cryogenic system which houses the detectors. To address this problem, we developed a system to control the relative phases of the pulse tube pressure oscillations, in order to achieve coherent superposition of the mechanical vibrations transmitted to the detectors. In the following, we describe this method and report on the results in applying it to the CUORE system.
•A large custom cryogen-free cryostat has been designed and built in order to operate the CUORE detector.•The CUORE cryostat has a 1 m3 experimental volume and is able to host a tonne-scale ...bolometric detector.•The CUORE cryostat guarantees a low noise and low radioactivity environment, needed to search for 0nbb.•The CUORE detector has been cooled down to 8.3 mK and steadily operated at 15 mK, proving the success of the cryostat.
The CUORE experiment is the world’s largest bolometric experiment. The detector consists of an array of 988 TeO2 crystals, for a total mass of 742 kg. CUORE is presently taking data at the Laboratori Nazionali del Gran Sasso, Italy, searching for the neutrinoless double beta decay of 130Te. A large custom cryogen-free cryostat allows reaching and maintaining a base temperature of ∼10 mK, required for the optimal operation of the detector. This apparatus has been designed in order to achieve a low noise environment, with minimal contribution to the radioactive background for the experiment. In this paper, we present an overview of the CUORE cryostat, together with a description of all its sub-systems, focusing on the solutions identified to satisfy the stringent requirements. We briefly illustrate the various phases of the cryostat commissioning and highlight the relevant steps and milestones achieved each time. Finally, we describe the successful cooldown of CUORE.
We present the application of a simplified thermal model for the description of the response function of low-temperature calorimeters consisting of
TeO
2
crystals read-out by NTD thermistors operated ...at temperatures
T
∼
10
mK. Relying on both the analysis of the NTD load curves (from which we measured the main thermal conductances of the system) (Biassoni et al. in J Low Temp Phys 206:80–96, 2022) and on the analysis of the shape of thermal pulses acquired at different temperatures, we identified and quantified the physical parameters that determine the characteristic time constants of the pulses. In particular, we identified three different contributions to the heat capacity of the detector: the crystal phonon system (scaling as
T
3
), the NTD electron system (scaling as
T
) and a term related to the metalization process of the NTD electrodes (scaling as
T
-
2
).
Next-generation experiments searching for rare events must satisfy increasingly stringent requirements on the bulk and surface radioactive contamination of their active and structural materials. The ...measurement of surface contamination is particularly challenging, as no existing technology is capable of separately measuring parts of the 232Th and 238U decay chains that are commonly found to be out of secular equilibrium. We will present the results obtained with a detector prototype consisting of 8 silicon wafers of 150 mm diameter instrumented as bolometers and operated in a low-background dilution refrigerator at the Gran Sasso Underground Laboratory of INFN, Italy. The prototype was characterized by a baseline energy resolution of few keV and a background <100 nBq/cm2 in the full range of α energies, obtained with simple procedures for cleaning of all employed materials and no specific measures to prevent recontamination. Such performance, together with the modularity of the detector design, demonstrate the possibility to realize an alpha detector capable of separately measuring all alpha emitters of the 232Th and 238U chains, possibly reaching a sensitivity of few nBq/cm2.
•Material screening.•Bolometric alpha detector.•Low-radioactivity measurements.
Thermal detectors are a powerful instrument for the search of rare particle physics events. Inorganic crystals are classically used as thermal detectors held in supporting frames made of copper. In ...this work, a novel approach to the operation of thermal detectors is presented, where TeO
2
crystals are cooled down to
∼
10 mK in a light structure built with plastic materials. The advantages of this approach are discussed.
The 1-ton-scale CUORE detector is made of 988
TeO
2
crystals operated as cryogenic bolometers at a working temperature of
∼
10
mK
. In order to provide the necessary cooling power at 4 K stage, a ...total of five pulse tube (PT) refrigerators are used. The PTs make the cryogenic system reliable and stable, but have the downside that mechanical vibrations at low frequencies (1.4 Hz and related harmonics) are injected into the experimental apparatus. An active noise cancellation technique has been developed in order to reduce such effect by taking advantage from the coherent interference of the pressure oscillations originated by the different PTs. The technique that will be presented consists in controlling the relative phases of the pressure waves running inside the CUORE PT lines, in order to achieve the lowest detector noise. By reducing the power of PT harmonics by a factor up to
10
4
, it drastically suppresses the overall noise RMS on the CUORE detector. In the following, we demonstrate the reliability and effectiveness of the technique, showing that the optimization of the detector noise level is possible in different experimental conditions.
The CUORE cryostat Nutini, I.
Journal of physics. Conference series,
03/2020, Letnik:
1468, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
Abstract
The CUORE experiment (Cryogenic Underground Observatory for Rare Events) is a ton-scale detector, operating at a cryogenic temperature around 10 mK, searching for neutrinoless double-beta ...decay in
130
Te and other rare events. The experiment cryogenic infrastructure, its subsystems and the cool-down procedure that allowed CUORE to obtained the first physics results will be presented.
The CUORE Cryostat D’Addabbo, A.; Alduino, C.; Bersani, A. ...
Journal of low temperature physics,
12/2018, Letnik:
193, Številka:
5-6
Journal Article
Recenzirano
Odprti dostop
The Cryogenic Underground Observatory for Rare Events (CUORE) is a bolometric experiment for neutrinoless double-beta decay in
130
Te
search, currently taking data at the underground facility of ...Laboratori Nazionali del Gran Sasso (LNGS). The CUORE cryostat successfully cooled down a mass of about 1 ton at
∼
7
mK
, delivering a uniform and constant base temperature. This result marks a fundamental milestone in low-temperature detector techniques, opening the path for future ton-scale bolometric experiments searching for rare events. In this paper, we present the CUORE cryogenic infrastructure, briefly describing its critical subsystems.
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