Performances of ENDA-INR prototype array Shchegolev, O; Alekseenko, V; Kuleshov, D ...
Journal of physics. Conference series,
12/2020, Letnik:
1690, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Electron Neutron Detector Array (ENDA) is an ambitious project inside the Large High Altitude Air Shower Observatory (LHAASO) in China, Tibet. ENDA is intended to measure simultaneously electronic ...and hadronic components of the extensive air showers (EAS) over large area of 104 m2. The array will consist of 400 specially developed electron-neutron detectors based on inorganic ZnS(Ag) + B2O3 scintillator compound. The prototype ENDA cluster of 16 electron-neutron detectors has been build in Moscow in the Institute for Nuclear Research of Russian Academy of Sciences and named ENDA-INR. The main goal of the array is to test techniques of simultaneous measurement of extensive air showers and background variations using pulse shape selection. Details of the array and its techniques are presented.
Some unexpected sporadic increases of an environmental radioactive background have been recorded at mountain level at Baksan Neutrino Observatory (BNO, 1700 m above sea level) using electron-neutron ...detectors (en-detectors), which could be explained by radioactive aerosol enhancements. The large area inorganic scintillator en-detectors developed for cosmic ray study are continuously monitoring environmental thermal neutron fluxes at various geophysical conditions. Application of the pulse shape discrimination method allows us to select and separately measure both thermal neutrons and radioactive beta-decay nuclides being products of radon decays in air (mostly Rn-222 and Rn-220). There are two en-detector setups running now at BNO, one deep underground while another one at surface. Both installations had recorded some strange sporadic increases of radioactive nuclides in air. In this paper, we present results and the most probable explanation of the significant increases joint by radioactive aerosols production but caused by different reasons: Baksan river floods or nearby underground experiment with powerful Cr-51 radioactive source.
•High mountain river flow level, flood and waterfall can increase nearby charged aerosol concentration.•Radon and its progenies above mountain rivers attracting by charged aerosols make them radioactive.•Intensive radioactive source can be a reason of radioactive aerosol concentration enhancement in underground laboratories.
The gamma-ray background problem is known to be acute in any low-background underground experiment. The variations of this background depend on many parameters and should be taken into account when ...interpreting the results of experiments combined under the term “underground physics”. This paper is devoted to studying the long-term variations of the gamma-ray background in an underground laboratory with a scintillation detector based on a CsI crystal. Our studies have revealed a new effect in underground physics—a delayed nonlinear pumping effect for the gamma-ray background in an underground room that can lead to a significant rise of this background at an anomalously low atmospheric pressure.
By accurate measurement of components and energy spectrum in the knee region, problem of origin of cosmic ray can be solved. In one extensive air shower (EAS), high energy hadrons, which constitute ...the EAS skeleton as G.T. Zatsepin called it, carry important information for multi-parameter correlation studies. The nuclear reaction between hadrons and matter in the surrounding environment produces a large number of evaporation neutrons, moderating to thermal neutrons. At the beginning of the 21th century, a new technology, electron–neutron detector (EN-detector) was designed at Institute for Nuclear Research of Russian Academy of Science (INR RAS), and the PRImary Spectrum Measurement Array (PRISMA) project was proposed to reinforce array capability of cosmic ray composition separation and then improve measurement accuracy of cosmic ray components and energy spectrum. Besides, EN-detectors can be used for continuous environmental thermal neutron flux monitoring and its variation study is needed not only for EAS experiment background estimation but also for geophysical applications (e.g., earthquakes, thunderstorms, radioactive aerosol control, etc.) and solar activity study (e.g., solar flares, Forbush effects, etc.). Under the Chinese–Russian cooperation, we put forward to build so called EN-Detector Array (ENDA) at high altitude in China. At YangBaJing Hybrid Array (YBJHA, 4300 m a.s.l.) and at Large High Altitude Air Shower Observatory (LHAASO, 4410 m a.s.l.), two clusters of ENDA were built individually and all have obtained coincident events with the local arrays. In the near future, we plan to extend ENDA to ENDA-64 with array area of 1000 m
inside LHAASO to study the knee region of the light components (H and He). After it, ENDA will be extended up to 400 detectors with array area of 10 000 m
to extend the energy range up to 300 PeV.
The ENDA Electron–Neutron Detector Array is under development in Tibet mountains as an integral part of a Large High-Altitude Air-Shower Observatory (LHAASO). A prototype of a single ENDA cluster ...consisting of 16 electron–neutron detectors has been constructed at the Moscow Institute for Nuclear Research (INR) and is used to study extensive air showers with energies above 1 PeV. A new procedure for data acquisition (DAQ) that relies on a 32-bit analog–digital converter (ADC) is used in these measurements. Calibration with radioactive sources shows that the DAQ procedure correctly selects neutron hits. Extensive air showers are detected in parallel with measuring variations of the thermal-neutron background.
Variations in the natural thermal neutron flux are measured at the
n
-Kamchatka installation in Petropavlovsk-Kamchatsky during May 2019, using electron-neutron detectors designed at the Russian ...Academy of Sciences’ Institute for Nuclear Research. Because of its high level of seismic activity, the South Kamchatka subduction zone was chosen as the location of yet another installation belonging to the global network of this type of arrays under different geological and geophysical conditions. The aim of the
n
-Kamchatka installation is to study correlations between the dynamics of the natural thermal neutron flux and seismic activity. Results are presented from of the first 1.5 years of the installation’s operation.
Status of the High-Altitude ENDA-LHAASO Array Stenkin, Yu. V.; Alekseenko, V. V.; Danzengluobu ...
Bulletin of the Russian Academy of Sciences. Physics,
04/2021, Letnik:
85, Številka:
4
Journal Article
Recenzirano
A description is given of the ENDA (electron–neutron detector array) setup launched as part of the international LHAASO project in December 2019 in Tibet at an altitude of 4410 m above sea level. A ...unique feature of the ENDA is its simultaneous recording of two main components of extensive air showers (hadronic and electronic) over whole array using the same detectors. The main parameters of the array obtained from calculations and measurements are presented.
We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J 0622 + 3749 with the Large High-Altitude Air Shower ...Observatory (LHAASO). The source is detected with a significance of 8.2 σ for E > 25 TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) = ( 95.47 ° ± 0.11 ° , 37.92 ° ± 0.09 ° ) , and the extension is 0.40 ° ± 0.07 ° . The energy spectrum can be described by a power-law spectrum with an index of − 2.92 ± 0.17stat± 0.02sys. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼ 160 TeV , is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.
This paper is devoted to an experimental check of a method for performing individual calibration of a spectrometer for human body radiation, using the Monte Carlo method, on 35-40 kg pigs. The ^sup ...241^Am content was measured on a low-energy γ spectrometer with a detector based on highly pure germanium. Tomographic images of pigs were used to calculate, using the MCNP4c2 program, the spectra of absorbed energy in a detector. The experimental results are reproduced with an error of less than 30% for injection of ^sup 241^Am and less than 10% for ^sup 241^Am introduced in a capsule.PUBLICATION ABSTRACT
PDF
