47 research outputs found
Proteomic analysis of Cucumis Melo L. Phloem as an approach to study resistance to Bemisia Tabaci gen
Comunicaciones a congreso
Optimal operation of cryogenic calorimeters through deep reinforcement learning
Cryogenic phonon detectors with transition-edge sensors achieve the best
sensitivity to light dark matter-nucleus scattering in current direct detection
dark matter searches. In such devices, the temperature of the thermometer and
the bias current in its readout circuit need careful optimization to achieve
optimal detector performance. This task is not trivial and is typically done
manually by an expert. In our work, we automated the procedure with
reinforcement learning in two settings. First, we trained on a simulation of
the response of three CRESST detectors used as a virtual reinforcement learning
environment. Second, we trained live on the same detectors operated in the
CRESST underground setup. In both cases, we were able to optimize a standard
detector as fast and with comparable results as human experts. Our method
enables the tuning of large-scale cryogenic detector setups with minimal manual
interventions.Comment: 23 pages, 14 figures, 2 table
Latest observations on the low energy excess in CRESST-III
The CRESST experiment observes an unexplained excess of events at low
energies. In the current CRESST-III data-taking campaign we are operating
detector modules with different designs to narrow down the possible
explanations. In this work, we show first observations of the ongoing
measurement, focusing on the comparison of time, energy and temperature
dependence of the excess in several detectors. These exclude dark matter,
radioactive backgrounds and intrinsic sources related to the crystal bulk as a
major contribution.Comment: 10 pages, 5 figures; to be published in IDM2022 proceeding
Detector development for the CRESST experiment
Recently low-mass dark matter direct searches have been hindered by a low
energy background, drastically reducing the physics reach of the experiments.
In the CRESST-III experiment, this signal is characterised by a significant
increase of events below 200 eV. As the origin of this background is still
unknown, it became necessary to develop new detector designs to reach a better
understanding of the observations. Within the CRESST collaboration, three new
different detector layouts have been developed and they are presented in this
contribution.Comment: 8 pages, 4 figure
Observation of a low energy nuclear recoil peak in the neutron calibration data of the CRESST-III Experiment
New-generation direct searches for low mass dark matter feature detection
thresholds at energies well below 100 eV, much lower than the energies of
commonly used X-ray calibration sources. This requires new calibration sources
with sub-keV energies. When searching for nuclear recoil signals, the
calibration source should ideally cause mono-energetic nuclear recoils in the
relevant energy range. Recently, a new calibration method based on the
radiative neutron capture on W with subsequent de-excitation via single
-emission leading to a nuclear recoil peak at 112 eV was proposed. The
CRESST-III dark matter search operated several CaWO-based detector
modules with detection thresholds below 100 eV in the past years. We report the
observation of a peak around the expected energy of 112 eV in the data of three
different detector modules recorded while irradiated with neutrons from
different AmBe calibration sources. We compare the properties of the observed
peaks with Geant-4 simulations and assess the prospects of using this for the
energy calibration of CRESST-III detectors.Comment: 8 pages, 4 figures; submitted to Phys. Rev.
Testing spin-dependent dark matter interactions with lithium aluminate targets in CRESST-III
In the past decades, numerous experiments have emerged to unveil the nature
of dark matter, one of the most discussed open questions in modern particle
physics. Among them, the CRESST experiment, located at the Laboratori Nazionali
del Gran Sasso, operates scintillating crystals as cryogenic phonon detectors.
In this work, we present first results from the operation of two detector
modules which both have 10.46 g LiAlO targets in CRESST-III. The lithium
contents in the crystal are Li, with an odd number of protons and neutrons,
and Li, with an odd number of protons. By considering both isotopes of
lithium and Al, we set the currently strongest cross section upper
limits on spin-dependent interaction of dark matter with protons and neutrons
for the mass region between 0.25 and 1.5 GeV/c.Comment: 9 pages, 8 figure
High-Dimensional Bayesian Likelihood Normalisation for CRESST's Background Model
Using CaWO crystals as cryogenic calorimeters, the CRESST experiment
searches for nuclear recoils caused by the scattering of potential Dark Matter
particles. A reliable identification of a potential signal crucially depends on
an accurate background model. In this work we introduce an improved
normalisation method for CRESST's model of the electromagnetic backgrounds.
Spectral templates, based on Geant4 simulations, are normalised via a Bayesian
likelihood fit to experimental background data. Contrary to our previous work,
no assumption of partial secular equilibrium is required, which results in a
more robust and versatile applicability. Furthermore, considering the
correlation between all background components allows us to explain 82.7% of the
experimental background within [1 keV, 40 keV], an improvement of 18.6%
compared to our previous method.Comment: 24 pages, 14 figures, submitted to EPJ