In this work, carbon \(^{14}\)C and Tritium were considered as possible background source in the XENON1T experiment. The simulation results show that if \(^{14}\)C is located in dust particles with a ...characteristic size of tens of micrometers, then its beta spectrum is softened and can contribute to the low-background part of the spectrum (up to 20 keV) of the XENON1T experiment. In addition, it has been shown that the tritium spectrum is also significantly distorted due to the threshold effect and the form in which tritium is living in xenon. Comparison of the simulation results with experimental data allowed us to estimate the activity level of \(^{14}\)C at about 1500 decays / t / year, which gives the level of organic impurities containing \(^{14}\)C at the level of 2x10\(^{-13}\) g/g. In the case of tritium background, spectrum distortions are already caused by nanoparticles. Wherein the shape of the spectrum from tritium sitting on the surface of the dust fits better into the experimental data than the spectrum from pure tritium. In addition, since the dust absorbs part of the decays, the total amount of tritium in xenon can be several times greater than assuming a background from pure tritium in xenon (the factor strongly depends on the size of the dust particles).
Measurements of reactor antineutrino play an important role in the efforts at the frontier of the modern physics. The DANSS collaboration presents preliminary results of a one year run with a cubic ...meter solid state detector placed below 3.1 GW industrial light water reactor. The experiment is sensitive to sterile neutrino in the most interesting region of mixing parameter space. 2500 scintillation strips of the sensitive volume of the detector have multilayer passive shielding of copper, lead and borated polyethylene and active muon veto. Detector position below the reactor gives an advantage of overburden about 50 m of water equivalent providing factor of six in cosmic muon suppression and eliminating fast neutrons.The detector is placed on a vertically movable platform which allows to change the distance to the reactor core center in the range 10.7-12.7 m within a few minutes. The strips are read out individually by SiPMs and in groups of 50 by PMTs. 5000 inverse beta-decay events per day are collected in the fiducial volume, which is 78% of the whole detector, at the position closest to the reactor. Overburden, active veto and good segmentation of the detector result in an excellent signal to background ratio.
The talk is dedicated to the data analysis and preliminary results. The experiment status is also presented.
A new low-background spectrometer based on a HPGe detector with a sensitive volume of 600 cm
3
is developed to investigate rare nuclear processes such as resonance neutrinoless double electron ...capture and two-neutrino double beta decay to excited states of daughter nuclei. The spectrometer is installed at the Modane underground laboratory (France) at a depth of 4800 m w.e. The spectrometer background is measured and the spectrometer sensitivity is determined for measuring sources of double beta decay.
A new multi-detector spectrometer based on Timepix silicon pixel detectors is developed to investigate the 2ν
EC
/
EC
decay of
106
Cd. The detectors have high efficiency for recording two low-energy ...KX radiation quanta emitted during 2ν
EC
/
EC
decay. The ability of pixel detector to identify α, β, and γ particles and precisely localize them allows us to suppress background radiation efficiently. Test measurements for an assembly of two pixel detectors in an underground laboratory were performed. They showed the possibility of using them in the search for the 2ν
EC
/
EC
decay of
106
Cd.
Measurements of average pulse profiles made with a single linear polarization over the range 41–112 MHz are presented for PSR B0950+08. We show that the observed variable structure of the pulse ...profiles is a result of Faraday sinusoidal modulation of the pulse intensity with frequency. The rotation measure corresponding to this effect, $RM \approx 4\ {{\rm rad\, m^{-2}}}$, is about 3 times greater than the published value of $RM = 1.35\ {{\rm rad\, m^{-2}}}$ (Taylor et al. CITE).
The results of long-term monitoring of irregularies in the rotation rate of the pulsar B1822-09 (J1825-0935) are presented. Observations of the pulsar carried out since 1991 on the Large Phased Array ...of the Pushchino Radio Astronomy Observatory have revealed a new type of irregularity in the rotation, which has the form of "slow glitches" and is manifest as a gradual exponential growth in the rotation frequency of the star over several hundred days. In 1995-2004, five slow glitches in the rotation frequency were observed, with relative amplitudes of Δν/ν (2.5-32) × 10^sup -9^. Together with these unusual "slow glitches" in the rotation frequency, two modest ordinary glitches, associated with sudden, jump-like increases in the rotation frequency, were also observed. The observed irregularities in the rotation frequency of the pulsar are analyzed in detail, and possible interpretations of the results are discussed.PUBLICATION ABSTRACT
We report observations of the microstructure of 7 pulsars at 102 MHz with a time resolution of up to 1 μs. We have detected fine pulse structure with a μs time-scale for all seven pulsars. We observe ...that interstellar scattering does not broaden the μs time-scale pulsar microstructure, and find structure of a time-scale much shorter than the interstellar scatter broadening. In addition to the previously known structure with time-scale τμ of tens of μs, we have detected structures with characteristic time-scale of a few μs, nearly equal to the reciprocal of the analysis bandwidth. This suggests that even shorter micropulses may exist. Micropulses usually cluster in groups, each of duration tens to hundreds of μs, which may be identified as microstructure observed previously with smaller time resolution. In addition to the previously known quasi-periodicity of hundreds of milliseconds, we reveal a structures with characteristic period of tens of μs. We observe structures with short quasi-periodicity to have a limited bandwidth. The characteristic period Pμ of these structures in PSR B0950+08 does not have a common value for different frequency regions in the same single pulse. Scattering was revealed as a train of quasi-periodic micropulses with an exponentially damped envelope. The scatter-broadening and decorrelation bandwidth were measured. We report two time-scales of decorrelation bandwidth of pulsar PSR B0950+08 and propose two branches of Δνd(ν) dependence. The dispersion measure of PSR B0950+08 as DM= 2.9686 ± 0.0001 pc cm−3 has been determined.
The possibility to probe new physics scenarios of light Majorana neutrino exchange and right-handed currents at the planned next generation neutrinoless double
β
decay experiment SuperNEMO is ...discussed. Its ability to study different isotopes and track the outgoing electrons provides the means to discriminate different underlying mechanisms for the neutrinoless double
β
decay by measuring the decay half-life and the electron angular and energy distributions.
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