The description of the recording system of a new installation for registration of atmospheric neutrons (URAN array) which is created as a part of the experimental complex NEVOD is presented. The ...recording system is based on 12-bit ADC with a sampling frequency of 200 MHz and possibility to reduce a clock frequency to 1 MHz for detection of neutrons after their thermalization. The setup has an independent cluster structure. The URAN first stage includes 6 clusters of 12 detectors each located on the roofs of two buildings: complex NEVOD and its neighbor.
Long-term variations in the natural thermal neutron flux in Tibet at an altitude of 4300 m above sea level are studied using scintillation en-detectors developed at the Institute for Nuclear ...Research, Russian Academy of Sciences. Substantial growth (on the level of several per cent each year over the last three years) in both the thermal neutron flux and the background recorded by the detectors is observed. This growth is associated with the intensity of cosmic rays. The effect is explained by an increase in the low-energy cosmic ray flux, due to reduced solar activity in the current solar cycle.
Baksan Neutrino Observatory's results on variations of thermal neutron flux below and above the ground surface measured with an unshielded scintillator detector are presented. Experimental evidences ...were obtained of the existence of seasonal wave in the long-term thermal neutron flux variations as well as correlation between this variations and lunar periods.
Thermal neutrons are detected using a scintillator compound based on ZnS(Ag) with B
2
O
3
added to it. The pulse height generated by single charged particles in a scintillator of small thickness (50 ...mg/cm
2
) is not larger than that of a noise signal due to a low sensitivity to single charged particles. As a result, the detector satisfies the requirements of a low-background one in the context of cosmic-ray experiments. The detector is to be used for neutron detection in extensive air showers.
Some results on the EAS neutron component measurements by means of the PRISMA-32 array are presented. The array consists of 32 electron-neutron detectors (en-detectors) capable to detect two main EAS ...components: electromagnetic one consisting of charged particles, and hadronic one by measuring delayed thermal neutrons accompanying the showers. For thermal neutrons detection, a compound of a well-known inorganic scintillator ZnS(Ag) and LiF, enriched to 90 % with 6Li isotope is used. The setup allows us to record neutron component over the whole array area.
The project of a new setup is directed at the registration of atmospheric neutrons (URAN) generated by hadronic component of extensive air showers (EAS). The setup includes 72 en-detector which ...simultaneously register two major EAS components: electromagnetic by the group passage of charged particles and hadron component by the thermal neutrons. The neutrons and charged particles are detected using a specialized scintillation composition made of granulated alloy of crystals based on the ZnS(Ag) powder with an admixture of B2O3.
EAS array of novel type have been constructed on the base of ARGO-YBJ experiment (Tibet, China). It consists of the four specially designed scintillator en-detectors capable to measure two main EAS ...components: hadrons through thermal neutrons (n) and electrons (e). The results of simulation for these arrays using CORSIKA and GEANT4 codes are presented. Simulated thermal neutron and electron lateral distributions are compared with experimental data. Obtained distributions are compared with those obtained by other arrays.
We report on a measurement of thermal neutrons, generated by the hadronic component of extensive air showers (EAS), by means of a small array of EN-detectors developed for the PRISMA project (PRImary ...Spectrum Measurement Array), novel devices based on a compound alloy of ZnS(Ag) and 6LiF. This array has been operated within the ARGO-YBJ experiment at the high altitude Cosmic Ray Observatory in Yangbajing (Tibet, 4300 m a.s.l.). Due to the tight correlation between the air shower hadrons and thermal neutrons, this technique can be envisaged as a simple way to estimate the number of high energy hadrons in EAS. Coincident events generated by primary cosmic rays of energies greater than 100 TeV have been selected and analyzed. The EN-detectors have been used to record simultaneously thermal neutrons and the air shower electromagnetic component. The density distributions of both components and the total number of thermal neutrons have been measured. The correlation of these data with the measurements carried out by ARGO-YBJ confirms the excellent performance of the EN-detector.
Variations in the neutron flux during thunderstorms Alekseenko, V. V.; Gromushkin, D. M.; Dzhappuev, D. D. ...
Bulletin of the Russian Academy of Sciences. Physics,
05/2015, Letnik:
79, Številka:
5
Journal Article
Recenzirano
The results from the registration and analysis of sporadic variations of atmospheric thermal neutron flux during thunderstorms are reported. Measurements were performed in Moscow and at the Baksan ...Neutrino Observatory of the Institute for Nuclear Research of the Russian Academy of Sciences. The neutron flux was detected by unscreened scintillation en-detectors based on
6
LiF + ZnS (Ag) compound targets with signals selected according to pulse shape. Reductions of 5–10% in the neutron flux due to shower precipitates during thunderstorms are detected. No incidents of increased neutron flux during thunderstorms were detected over four summer seasons. The upper limits for the integrated and pulsed flux of neutrons from thunderbolts are estimated.
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