We discuss a small-scale experiment, called
ν
-cleus, for the first detection of coherent neutrino–nucleus scattering by probing nuclear-recoil energies down to the 10 eV regime. The detector ...consists of low-threshold CaWO
4
and Al
2
O
3
calorimeter arrays with a total mass of about 10 g and several cryogenic veto detectors operated at millikelvin temperatures. Realizing a fiducial volume and a multi-element target, the detector enables active discrimination of
γ
, neutron and surface backgrounds. A first prototype Al
2
O
3
device, operated above ground in a setup without shielding, has achieved an energy threshold of
∼
20
eV and further improvements are in reach. A sensitivity study for the detection of coherent neutrino scattering at nuclear power plants shows a unique discovery potential (5
σ
) within a measuring time of
≲
2
weeks. Furthermore, a site at a thermal research reactor and the use of a radioactive neutrino source are investigated. With this technology, real-time monitoring of nuclear power plants is feasible.
The CRESST-II experiment uses cryogenic detectors to search for nuclear recoil events induced by the elastic scattering of dark matter particles in CaWO
4
crystals. Given the low energy threshold of ...our detectors in combination with light target nuclei, low mass dark matter particles can be probed with high sensitivity. In this letter we present the results from data of a single detector module corresponding to 52 kg live days. A blind analysis is carried out. With an energy threshold for nuclear recoils of 307 eV we substantially enhance the sensitivity for light dark matter. Thereby, we extend the reach of direct dark matter experiments to the sub- GeV/
c
2
region and demonstrate that the energy threshold is the key parameter in the search for low mass dark matter particles.
The energy threshold of a cryogenic calorimeter can be lowered by reducing its size. This is of importance since the resulting increase in signal rate enables new approaches in rare-event searches, ...including the detection of MeV mass dark matter and coherent scattering of reactor or solar neutrinos. A scaling law for energy threshold vs detector size is given. We analyze the possibility of lowering the threshold of a gram-scale cryogenic calorimeter to the few eV regime. A prototype 0.5 g Al2O3 device achieved an energy threshold of Eth=(19.7±0.9) eV, the lowest value reported for a macroscopic calorimeter.
Models for light dark matter particles with masses below 1 GeV/c Formula omitted are a natural and well-motivated alternative to so-far unobserved weakly interacting massive particles. Gram-scale ...cryogenic calorimeters provide the required detector performance to detect these particles and extend the direct dark matter search program of CRESST. A prototype 0.5 g sapphire detector developed for the Formula omitted-cleus experiment has achieved an energy threshold of Formula omitted eV. This is one order of magnitude lower than for previous devices and independent of the type of particle interaction. The result presented here is obtained in a setup above ground without significant shielding against ambient and cosmogenic radiation. Although operated in a high-background environment, the detector probes a new range of light-mass dark matter particles previously not accessible by direct searches. We report the first limit on the spin-independent dark matter particle-nucleon cross section for masses between 140 and 500 MeV/c Formula omitted.
The existence of dark matter is undisputed, while the nature of it is still unknown. Explaining dark matter with the existence of a new unobserved particle is among the most promising possible ...solutions. Recently dark matter candidates in the MeV mass region received more and more interest. In comparison to the mass region between a few GeV to several TeV, this region is experimentally largely unexplored. We discuss the application of a RNDR DEPFET semiconductor detector for direct searches for dark matter in the MeV mass region. We present the working principle of the RNDR DEPFET devices and review the performance obtained by previously performed prototype measurements. The future potential of the technology as dark matter detector is discussed and the sensitivity for MeV dark matter detection with RNDR DEPFET sensors is presented. Under the assumption of six background events in the region of interest and an exposure of 1 kg year a sensitivity of about
σ
¯
e
=
10
-
41
cm
2
for dark matter particles with a mass of 10 MeV can be reached.
The CRESST-II cryogenic dark matter search aims for the detection of WIMPs via elastic scattering off nuclei in CaWO
4
crystals. We present results from a low-threshold analysis of a single upgraded ...detector module. This module efficiently vetoes low energy backgrounds induced by
α
-decays on inner surfaces of the detector. With an exposure of 29.35 kg live days collected in 2013 we set a limit on spin-independent WIMP-nucleon scattering which probes a new region of parameter space for WIMP masses below 3 GeV/c
2
, previously not covered in direct detection searches. A possible excess over background discussed for the previous CRESST-II phase 1 (from 2009 to 2011) is not confirmed.
Coherent elastic neutrino–nucleus scattering (CEνNS) offers a unique way to study neutrino properties and to search for new physics beyond the Standard Model. Nuclear reactors are promising sources ...to explore this process at low energies since they deliver large fluxes of anti-neutrinos with typical energies of a few MeV. In this paper, a new-generation experiment to study CEνNS is described. The NUCLEUS experiment will use cryogenic detectors which feature an unprecedentedly low-energy threshold and a time response fast enough to be operated under above-ground conditions. Both sensitivity to low-energy nuclear recoils and a high event rate tolerance are stringent requirements to measuring CEνNS of reactor anti-neutrinos. A new experimental site, the Very-Near-Site (VNS), at the Chooz nuclear power plant in France is described. The VNS is located between the two 4.25 GWth reactor cores and matches the requirements of NUCLEUS. First results of on-site measurements of neutron and muon backgrounds, the expected dominant background contributions, are given. In this paper a preliminary experimental set-up with dedicated active and passive background reduction techniques and first background estimations are presented. Furthermore, the feasibility to operate the detectors in coincidence with an active muon veto at shallow overburden is studied. The paper concludes with a sensitivity study pointing out the physics potential of NUCLEUS at the Chooz nuclear power plant.
Display omitted
•Docetaxel can be measured in dried blood spots by LC–MS/MS.•Docetaxel plasma concentrations can be estimated through DBS measurements.•Area under the curve (AUC) are accurately ...obtained from DBS concentrations.•Docetaxel measurement in DBS can potentially be used to optimize cancer therapy.
In this study, a LC–MS/MS method for the measurement of docetaxel in Dried Blood Spots (DBS) samples was developed and validated. Docetaxel was extracted from 8 mm DBS punch with a mixture of methanol and acetonitrile (9:1, v/v). The chromatographic separation occurred in an Acquity® C18 column (150 × 2.1 mm, 1.7 μm) eluted with a mixture of water and acetonitrile plus 0.1% formic acid (45:55, v/v). Total analytical run time was 7 min. The method was linear from 50 to 3000 ng ml−1. Precision assays showed CV% < 9.8% and accuracy between 99 and 103%, mean recovery was 81%. The method was applied in the determination of the docetaxel in 31 patients, after collection of two paired venous blood and DBS samples, following a limited sampling strategy protocol. The analyte was stable in DBS for 18 days at 25 °C and 9 days at 45 °C. The interval of docetaxel concentrations measured in DBS collected before the end of the infusion was 756–3047 ng ml−1 and 60 ± 10 min after the end of the infusion was 57–331 ng ml−1. AUC values calculated from DBS-derived estimated plasma concentrations (EPC) represented on average 100% of those obtained in plasma samples of 3.1 mgh/l (2.4–4.9 mg h/l). There was a 93% agreement between the classification of patients as within or without the therapeutic range by plasma and EPC AUC. These findings support the clinical use of DBS sampling for routine therapeutic drug monitoring of docetaxel.
The CRESST experiment (Cryogenic Rare Even Search with Superconducting Thermometers), located at Laboratori Nazionali del Gran Sasso in Italy, searches for dark matter particles via their elastic ...scattering off nuclei in a target material. The CRESST target consists of scintillating CaWO4 crystals, which are operated as cryogenic calorimeters at millikelvin temperatures. Each interaction in the CaWO4 target crystal produces a phonon signal and a light signal that is measured by a second cryogenic calorimeter. Since the CRESST-II result in 2015, the experiment is leading the field of direct dark matter search for dark matter masses below 1.7 GeV/c2, extending the reach of direct searches to the sub-GeV/c2 mass region. For CRESST-III, whose Phase 1 started in July 2016, detectors have been optimized to reach the performance required to further probe the low-mass region with unprecedented sensitivity. In this contribution the achievements of the CRESST-III detectors will be discussed together with preliminary results and perspectives of Phase 1.
CRESST is a direct dark matter search experiment, aiming for an observation of nuclear recoils induced by the interaction of dark matter particles with cryogenic scintillating calcium tungstate ...crystals. Instead of confining ourselves to standard spin-independent and spin-dependent searches, we re-analyze data from CRESST-II using a more general effective field theory (EFT) framework. On many of the EFT coupling constants, improved exclusion limits in the low-mass region (< 3–4 GeV/
c
2
) are presented.
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