Liquid Argon Instrumentation and Monitoring in LEGEND-200

LEGEND is the next-generation experiment searching for the neutrinoless double beta decay in 76Ge. The first stage, LEGEND-200, takes over the cryogenic infrastructure of GERDA at LNGS: an instrumented water tank surrounding a 64 m3 liquid argon cryostat. Around 200 kg of Ge detectors will be deployed in the cryostat, with the liquid argon acting as cooling medium, high-purity passive shielding and secondary detection medium. For the latter purpose, a liquid argon instrumentation is developed, based on the system used in GERDA Phase II. Wavelength shifting fibers coated with TPB are arranged in two concentric barrels. Both ends are read out by SiPM arrays. A wavelength shifting reflector surrounds the array in order to enhance the light collection far from the array. The LLAMA is installed in the cryostat to permanently monitor the optical parameters and to provide in-situ inputs for modeling purposes. The design of all parts of the LEGEND-200 LAr instrumentation is presented. An overview of the geometry, operation principle, and off-line data analysis of the LLAMA is shown.

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GERDA results and the future perspectives for the neutrinoless double beta decay search using 76Ge

International Journal of Modern Physics A ◽

10.1142/s0217751x18430042 ◽

2018 ◽

Vol 33 (09) ◽

pp. 1843004 ◽

Cited By ~ 5

Author(s):

◽

M. Agostini ◽

A. M. Bakalyarov ◽

M. Balata ◽

I. Barabanov ◽

...

Keyword(s):

Phase I ◽

Beta Decay ◽

Phase Ii ◽

Half Life ◽

Liquid Argon ◽

Neutrinoless Double Beta Decay ◽

Double Beta Decay ◽

Second Phase ◽

Inverted Hierarchy ◽

Phase Phase

The GERmanium Detector Array (GERDA) is a low background experiment at the Laboratori Nazionali del Gran Sasso (LNGS) of INFN designed to search for the rare neutrinoless double beta decay ([Formula: see text]) of [Formula: see text]Ge. In the first phase (Phase I) of the experiment, high purity germanium diodes were operated in a “bare” mode and immersed in liquid argon. The overall background level of [Formula: see text] was a factor of ten better than those of its predecessors. No signal was found and a lower limit was set on the half-life for the [Formula: see text] decay of [Formula: see text]Ge [Formula: see text] yr (90% CL), while the corresponding median sensitivity was [Formula: see text] yr (90% CL). A second phase (Phase II) started at the end of 2015 after a major upgrade. Thanks to the increased detector mass and performance of the enriched germanium diodes and due to the introduction of liquid argon instrumentation techniques, it was possible to reduce the background down to [Formula: see text]. After analyzing 23.2 kg[Formula: see text]⋅[Formula: see text]yr of these new data no signal was seen. Combining these with the data from Phase I a stronger half-life limit of the [Formula: see text]Ge [Formula: see text] decay was obtained: [Formula: see text] yr (90% CL), reaching a sensitivity of [Formula: see text] yr (90% CL). Phase II will continue for the collection of an exposure of 100 kg[Formula: see text]yr. If no signal is found by then the GERDA sensitivity will have reached [Formula: see text] yr for setting a 90% CL. limit. After the end of GERDA Phase II, the flagship experiment for the search of [Formula: see text] decay of [Formula: see text]Ge will be LEGEND. LEGEND experiment is foreseen to deploy up to 1-ton of [Formula: see text]Ge. After ten years of data taking, it will reach a sensitivity beyond 10[Formula: see text] yr, and hence fully cover the inverted hierarchy region.

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The MGDO software library for data analysis in Ge neutrinoless double-beta decay experiments

Journal of Physics Conference Series ◽

10.1088/1742-6596/375/1/042027 ◽

2012 ◽

Vol 375 (4) ◽

pp. 042027 ◽

Cited By ~ 3

Author(s):

M Agostini ◽

J A Detwiler ◽

P Finnerty ◽

K Kröninger ◽

D Lenz ◽

...

Keyword(s):

Data Analysis ◽

Beta Decay ◽

Neutrinoless Double Beta Decay ◽

Double Beta Decay ◽

Software Library

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Scintillation and optical properties of xenon-doped liquid argon

Journal of Instrumentation ◽

10.1088/1748-0221/17/01/c01031 ◽

2022 ◽

Vol 17 (01) ◽

pp. C01031

Author(s):

C. Vogl ◽

M. Schwarz ◽

X. Stribl ◽

J. Grießing ◽

P. Krause ◽

...

Keyword(s):

Optical Properties ◽

Particle Physics ◽

Rare Event ◽

Liquid Argon ◽

Optical Parameters ◽

Attenuation Length ◽

Scintillation Light ◽

Tenfold Increase ◽

Detection Medium ◽

Triplet Lifetime

Abstract Liquid argon (LAr) is a common choice as detection medium in particle physics and rare-event searches. Challenges of LAr scintillation light detection include its short emission wavelength, long scintillation time and short attenuation length. The addition of small amounts of xenon to LAr is known to improve the scintillation and optical properties. We present a characterization campaign on xenon-doped liquid argon (XeDLAr) with target xenon concentrations ranging from 0 to 300 ppm by mass encompassing the measurement of the photoelectron yield Y, effective triplet lifetime τ 3 and effective attenuation length λ att. The measurements were conducted in the Subterranean Cryogenic ARgon Facility, Scarf, a 1 t (XeD)LAr test stand in the shallow underground laboratory (UGL) of TU-Munich. These three scintillation and optical parameters were observed simultaneously with a single setup, the Legend Liquid Argon Monitoring Apparatus, Llama. The actual xenon concentrations in the liquid and gaseous phases were determined with the Impurity DEtector For Investigation of Xenon, Idefix, a mass spectrometer setup, and successful doping was confirmed. At the highest dopant concentration we find a doubling of Y, a tenfold reduction of τ 3 to ∼90 ns and a tenfold increase of λ att to over 6 m.

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Status and results from the CUORE experiment

International Journal of Modern Physics A ◽

10.1142/s0217751x20440169 ◽

2020 ◽

Vol 35 (36) ◽

pp. 2044016

Author(s):

A. Campani ◽

D. Q. Adams ◽

C. Alduino ◽

K. Alfonso ◽

F. T. Avignone ◽

...

Keyword(s):

Data Analysis ◽

Data Processing ◽

Beta Decay ◽

Half Life ◽

Precise Measurement ◽

Rare Events ◽

Neutrinoless Double Beta Decay ◽

Double Beta Decay ◽

Compact Structure ◽

Cubic Crystals

The Cryogenic Underground Observatory for Rare Events (CUORE) is a tonne-scale cryogenic experiment located at the Laboratori Nazionali del Gran Sasso that exploits bolometric technique to search for neutrinoless double beta decay [Formula: see text] of [Formula: see text]Te. The detector consists of a segmented array of 988 natural [Formula: see text] cubic crystals arranged in a cylindrical compact structure of 19 towers. The detector construction was completed in August 2016 and data taking started in Spring 2017. In this work, we present a brief description of the bolometric technique for rare events search and the CUORE detector, then we concentrate on the data analysis results. In this respect, we focus on the procedure for data processing and on the first [Formula: see text] results we obtained from a total [Formula: see text] exposure of [Formula: see text]. Next, we illustrate the main background sources and the CUORE background model, from which we obtain the most precise measurement of [Formula: see text]Te [Formula: see text] half-life to date. Finally, we discuss the improvements achieved with 2018 and 2019 detector optimization campaigns and the current perspectives of our experiment.

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Status of the GERDA Experiment at the Laboratori Nazionali del Gran Sasso

Advances in High Energy Physics ◽

10.1155/2013/506186 ◽

2013 ◽

Vol 2013 ◽

pp. 1-15 ◽

Cited By ~ 6

Author(s):

R. Brugnera ◽

A. Garfagnini

Keyword(s):

Beta Decay ◽

High Purity ◽

Pulse Shape ◽

Germanium Detector ◽

Liquid Argon ◽

Neutrinoless Double Beta Decay ◽

Double Beta Decay ◽

Second Phase ◽

High Purity Germanium ◽

Better Than

The Germanium Detector Array (Gerda) is a low background experiment at the Laboratori Nazionali del Gran Sasso (LNGS) of the INFN designed to search for the rare neutrinoless double beta decay (0νββ) of76Ge. In its first phase, high purity germanium diodes inherited from the former Heidelberg-Moscow and Igexexperiments are operated “bare” and immersed in liquid argon, with an overall background environment of 10−2 cts/(keV·kg·yr), a factor of ten better than its predecessors. Measurements on two-neutrino double beta decay (2νββ) givingT1/22ν=(1.88±0.10)×1021 yrand recently published background model and pulse shape performances of the detectors are discussed in the paper. A new result on0νββhas been recently published with a half-life limit on0νββdecayT1/20ν>2.1×1025 yr(90% C.L.). A second phase of the experiment is scheduled to start during the year 2014, after a major upgrade shutdown. Thanks to the increased detector mass with new designed diodes and to the introduction of liquid argon instrumentation techniques, the experiment aims to reduce further the expected background to about 10−3 cts/(keV·kg·yr) and to improve the0νββsensitivity to aboutT1/20ν>1.5×1026 yr(90% C.L.).

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