https://doi.org/10.1140/epjc/s10052-025-14809-3
Regular Article - Experimental Physics
The CRAB facility at the TU Wien TRIGA reactor: status and related physics program
1
TU Wien, Atominstitut, 1020, Vienna, Austria
2
Physik-Department, Technische Universität München, 85748, Garching, Germany
3
Univ. Lyon, Université Lyon 1, CNRS-IN2P3, IP2I-Lyon, 69622, Villeurbanne, France
4
Institut für Hochenergiephysik der Österreichischen Akademie der Wissenschaften, 1050, Vienna, Austria
5
INFN, Sezione di Roma, 00185, Rome, Italy
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INFN, Sezione di Roma “Tor Vergata”, 00133, Rome, Italy
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Dipartimento di Fisica, Università di Roma “Tor Vergata”, 00133, Rome, Italy
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Université Paris-Saclay, CEA, DES, SRMP, 91191, Gif-sur-Yvette, France
9
Dipartimento di Fisica, Sapienza Università di Roma, 00185, Rome, Italy
10
Istituto Nazionale di Fisica Nucleare, Sezione di Roma, 00185, Rome, Italy
11
IRFU, CEA, Université Paris-Saclay, 91191, Gif-sur-Yvette, France
12
TRIGA Center Atominstitut, TU Wien, 1020, Vienna, Austria
13
Max-Planck-Insitut für Physik, 80805, Munich, Germany
14
CEA, DES, IRESNE, DER, Cadarache, 13108, Saint-Paul-Lez-Durance, France
15
Université Paris-Saclay, CNRS/IN2P3, IJCLab, 91405, Orsay, France
16
Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117, Heidelberg, Germany
a
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b
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Received:
22
May
2025
Accepted:
18
September
2025
Published online:
22
October
2025
Abstract
The Crab (Calibrated nuclear Recoils for Accurate Bolometry) project aims to precisely characterize the response of cryogenic detectors to sub-keV nuclear recoils of direct interest for coherent neutrino-nucleus scattering and dark matter search experiments. The Crab method relies on the radiative capture of thermal neutrons in the target detector, resulting in a nuclear recoil with a well-defined energy. We present a new experimental setup installed at the TRIGA Mark-II reactor at Atominstitut (Vienna), providing a low intensity beam of thermal neutrons sent to the target cryogenic detector mounted inside a wet dilution refrigerator Kelvinox 100. After the presentation of all components of the setup we report the analysis of first commissioning data with CaWO
detectors of the Nucleus experiment. They show stable operation of the cryostat and detectors on a week-scale. Due to an energy resolution currently limited to 20 eV we use neutron beam induced events at high energy, in the 10 to 100 keV range, to demonstrate the excellent agreement between the data and simulation and the accurate understanding of external background. Thanks to these data we also propose an updated decay scheme of the low-lying excited states of 
W. Finally, we present the first evidence of neutron-capture induced coincidences between BaF
-detectors installed around the dewar and the inner cryogenic detector. These promising results pave the way for an extensive physics program with various detector materials, like CaWO, Al
O
, Ge and Si.
© The Author(s) 2025
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Funded by SCOAP3.
