304 research outputs found
Drift field generation with Cockcroft-Walton voltage multiplier in xenon gas for AXEL 0vββ search detector
16th International Conference on Topics in Astroparticle and Underground Physics (TAUP 2019) 9-13 September 2019, Toyama, JapanFor noble gas Time Projection Chambers (TPCs) in the field of rare event searches, operation of high voltage to generate an electric field is a key point. We designed a new structure of electrodes to shape a strong and uniform drift field without electric discharge, in which electrodes of two different radius are used. We also developed Cockcroft-Walton voltage multiplier as a high voltage generator inside a pressure vessel. We achieved −30.0 kV output and examined such kind of voltage generator is feasible as a high voltage supplier in a TPC
Design and performance of a high-pressure xenon gas TPC as a prototype for a large-scale neutrinoless double-beta decay search
A high-pressure xenon gas time projection chamber, with a unique cellular
readout structure based on electroluminescence, has been developed for a
large-scale neutrinoless double-beta decay search. In order to evaluate the
detector performance and validate its design, a 180~L size prototype is being
constructed and its commissioning with partial detector has been performed. The
obtained energy resolution at 4.0~bar is 1.73 0.07% (FWHM) at 511 keV.
The energy resolution at the Xe neutrinoless double-beta decay Q-value
is estimated to be between 0.79 and 1.52% (FWHM) by extrapolation.
Reconstructed event topologies show patterns peculiar to track end-point which
can be used to distinguish signals from gamma-ray backgrounds.Comment: 24 pages, 25 figures, 1 table. Preprint paper for PTE
Search for dinucleon decay into pions at Super-Kamiokande
A search for dinucleon decay into pions with the Super-Kamiokande detector
has been performed with an exposure of 282.1 kiloton-years. Dinucleon decay is
a process that violates baryon number by two units. We present the first search
for dinucleon decay to pions in a large water Cherenkov detector. The modes
O C, O
N, and O
O are investigated. No significant excess in the
Super-Kamiokande data has been found, so a lower limit on the lifetime of the
process per oxygen nucleus is determined. These limits are:
years,
years, and
years. The lower
limits on each mode are about two orders of magnitude better than previous
limits from searches for dinucleon decay in iron.Comment: 20 pages, 17 figures. Accepted for publication in Physical Review D
on March 30, 201
Search for astronomical neutrinos from blazar TXS 0506+056 in super-kamiokande
We report a search for astronomical neutrinos in the energy region from several GeV to TeV in the direction of the blazar TXS 0506+056 using the Super-Kamiokande detector following the detection of a 100 TeV neutrinos from the same location by the IceCube collaboration. Using Super-Kamiokande neutrino data across several data samples observed from 1996 April to 2018 February we have searched for both a total excess above known backgrounds across the entire period as well as localized excesses on smaller timescales in that interval. No significant excess nor significant variation in the observed event rate are found in the blazar direction. Upper limits are placed on the electron- and muon-neutrino fluxes at the 90% confidence level as 6.0 × 10−7 and 4.5 × 10−7–9.3 × 10−10 [erg cm−2 s−1], respectively
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