254 research outputs found
Indirect Signatures of Type I See-Saw Scenarios
We consider the low energy constraints that can be applied to type I see-saw
extensions of the Standard Model in which the right-handed neutrinos are taken
at the electroweak scale. In the reported scenarios, the flavour structure of
the charged current and neutral current weak interactions of the Standard Model
leptons with the heavy right-handed neutrinos is essentially determined by the
neutrino oscillation parameters. In this case, correlations among different
measurable phenomena in the lepton sector may provide compelling indirect
evidence of low energy see-saw mechanism of neutrino mass generation.Comment: 4 pages, 2 figures. Contributions to the Proceedings of the 12th
International Conference on Topics in Astroparticle and Underground Physics
(TAUP 2011), Munich, Germany, 5-9 September 201
Experiments on Sonoluminescence: Possible Nuclear and QED Aspects and Optical Applications
Experiments aimed at testing some hypothesis about the nature of Single
Bubble Sonoluminescence are discussed. A possibility to search for micro-traces
of thermonuclear neutrons is analyzed, with the aid of original low-background
neutron counter operating under conditions of the deep shielding from Cosmic
and other sources of background. Besides, some signatures of QED-contribution
to the light emission in SBSL are under the consideration, as well as new
approaches to probe a temperature inside the bubble. An applied-physics portion
of the program is presented also, in which an attention is being paid to
single- and a few-pulse light sources on the basis of SBSL.Comment: 4 pages; to be published by AIP in the Proc. ISNA-1
Mitigation of Ar/K background for the GERDA Phase II experiment
Background coming from the Ar decay chain is considered to be one of
the most relevant for the GERDA experiment, which aims to search of the
neutrinoless double beta decay of Ge. The sensitivity strongly relies on
the absence of background around the Q-value of the decay. Background coming
from K, a progeny of Ar, can contribute to that background via
electrons from the continuous spectrum with an endpoint of 3.5 MeV. Research
and development on the suppression methods targeting this source of background
were performed at the low-background test facility LArGe. It was demonstrated
that by reducing K ion collection on the surfaces of the broad energy
germanium detectors in combination with pulse shape discrimination techniques
and an argon scintillation veto, it is possible to suppress the K
background by three orders of magnitude. This is sufficient for Phase II of the
GERDA experiment
Highly sensitive gamma-spectrometers of GERDA for material screening: Part I
The GERDA experiment aims to search for the neutrinoless double beta-decay of
76Ge and possibly for other rare processes. The sensitivity of the first phase
is envisioned to be more than one order of magnitude better than in previous
neutrinoless double beta-decay experiments. This implies that materials with
ultra-low radioactive contamination need to be used for the construction of the
detector and its shielding. Therefore the requirements on material screening
include high-sensitivity low-background detection techniques and long
measurement times. In this article, an overview of material-screening
laboratories available to the GERDA collaboration is given, with emphasis on
the gamma-spectrometry. Additionally, results of an intercomparison of the
evaluation accuracy in these laboratories are presented.Comment: Featured in: Proceedings of the XIV International Baksan School
"Particles and Cosmology" Baksan Valley, Kabardino-Balkaria, Russia, April
16-21,2007. INR RAS, Moscow 2008. ISBN 978-5-94274-055-9, pp. 228-232; (5
pages, 0 figures
Working characteristics of the New Low-Background Laboratory (DULB-4900, Baksan Neutrino Observatory)
A concise technical characteristic of a new low-background laboratory
DULB-4900 of the BNO INR RAS is presented. The technique and the results of
background measurements in the Hall, ordinary box and low-background box are
presented. Rn-222 contamination in the laboratory air has been measured by
direct detection of gamma-radiation of its daughter Bi-214 distributed over the
volume of the low-background box. The results of the data analysis are
presented.Comment: 5 pages, 6 figure
Conceptual Design of Experimental Facility for Large-Diameter NTD-Si at the IRT-T Reactor
The IRT-T reactor has been conducting research in the field of irradiation of ingots of single-crystal semiconductor materials since 1987. The article describes the existing silicon doping facility. The results of studies on the possibility of creating an additional irradiation channel for neutron-transmutation doping of silicon are presented. It is shown that the use of a graphite reflector and a thermal neutron filter based on boron makes it possible to achieve non-uniformity of irradiation up to 5 %. The principal possibility of irradiating single-crystal silicon ingots with a diameter of up to 203 mm and a length of up to 500 mm is shown. The questions of optimizing the configuration of the core and the regime of reactors operation for increasing the neutron flux in the irradiation channels are discussed. In addition, applying the facility to produce base materials for neutron dosimeter in neutron capture therapy studies is proposed
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