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1.
No evidence for precursors to cosmic ray air showers was found (flux”?10?8cm?2sr?1s?1) in a sample 2.8 times that of Clay and Crouch and a system noise level several times lower. A simple model leads to a cross leation for production ?60 times the total proton-nucleus cross section.  相似文献   

2.
The main properties of the so-called neutron bursts produced by the passage of extensive air showers (EASs) through a detector array and the properties of these EASs are considered using the experiments that are being or have been carried out previously with the Carpet-2 array at Baksan Neutrino Observatory of the Institute for Nuclear Research, Russian Academy of Sciences, and at Cosmic-Ray Station of UNAM in Mexico as examples. We show that no exotic processes are required to explain the nature of neutron bursts. Based on a working prototype of the previously proposed MULTICOM array, we also show that this phenomenon can be successfully used in studying the EAS hadronic component and that adding special thermal neutron detectors can improve significantly the capabilities of the array for EAS study.  相似文献   

3.
The first results of measurements of the thermal-neutron flux in extensive air showers (EASs) using an unshielded scintillation thermal-neutron detector in the Multicom prototype array at the Baksan Neutrino Observatory of the Institute for Nuclear Research are reported. The operating capacity of the new method for studying the EAS hadron component via detection of thermal neutrons and good prospects of this method are demonstrated.  相似文献   

4.
Extensive air showers are produced when high energy cosmic rays or γγ-rays enter from the top of the atmosphere. Extensive air showers are multi-fractal in nature and in this paper we explore the topological properties of these showers. We show that the topology of extensive air showers has an exponential distribution which may arise due to the inherent tree structure character of its passage in the atmosphere.  相似文献   

5.
Double extensive air showers were studied at the Tien Shan high-mountain scientific station of the Lebedev Physical Institute using two different installations. One measured the electron-photon shower component, the other measured Cherenkov radiation. Double showers separated by a time interval of ~100 ns were detected by both setups. The frequency of the occurrence of such showers in each setup is analyzed. It is shown that these frequencies are identical when observing vertical showers (the zenith angle ? < 60°).  相似文献   

6.
A multilevel scheme for calculating estimates of the energy of extensive air showers on the basis of signals in different detectors is considered. The numerical energy estimates at specified values of signals in scintillation detectors are smaller than the experimental ones by a factor of about 1.6. The results of the calculation confirmed that the total flux of Cherenkov light is proportional to the shower energy. The flux of fluorescent light generated within 100 m from the shower core is due to only 60% of the total energy.  相似文献   

7.
At the present time, radio emission from extensive air showers (EASs) is being considered as a new promising method for detecting cosmic rays of energy in the region E 0 > 5 × 1016 eV. Radio emission from an EAS whose development is simulated by the Monte Carlo method is calculated here. The field of radio emission from an EAS is calculated on the basis of two representations of a shower: that as a set of individual particles and that as a continuous set of currents. The sensitivity of radio emission to EAS parameters in the frequency range 10–100 MHz is investigated. The results can be used to analyze experiments that being presently performed (CODALEMA and LOPES) and those that are being planned for the future.  相似文献   

8.
The results of a long-term experiment performed in the period between 1995 and 2006 with the aid of the MUON-T underground (20 mwe) scintillation facility arranged at the Tien Shan mountain research station at an altitude of 3340 m above sea level are presented. The time distribution of delayed muons with an energy in excess of 5 GeV in extensive air showers of energy not lower than 106 GeV with respect to the shower front was obtained with a high statistical significance in the delay interval between 30 and 150 ns. An effect of the geomagnetic field in detecting delayed muons in extensive air showers was discovered. This effect leads to the asymmetry of their appearance with respect to the north-south direction. The connection between delayed muons and extensive air showers featuring two fronts separated by a time interval of several tens of to two hundred nanoseconds is discussed. This connection gives sufficient grounds to assume that delayed muons originate from the decays of pions and kaons produced in the second, delayed, front of extensive air showers.  相似文献   

9.
Angular distributions of extensive air showers with different number of charged particles in the range 2.5 × 105–4 × 107 are derived using the experimental data obtained with the EAS MSU array. Possible approximations of the obtained distributions with different empiric functions available in literature, are analyzed. It is shown that the exponential function provides the best approximation of the angular distributions in the sense of the χ2 criterion.  相似文献   

10.
A detailed analysis of events with neutron multiplicity M = 3−30 on neutron monitors (NMs) in Barentsburg (Spitsbergen), Baksan (North Caucasus), and Apatity (Murmansk region) is performed on the data obtained using a unique new data collection system. It is now possible for the first time to register local showers in cosmic rays on NMs and to investigate their structure with a high precision. Multiplicity on NMs is simulated using the GEANT4 Monte Carlo toolkit. Local hadronic cascades in the atmosphere with transverse sizes of 1 to 6 m were observed for the first time using the NM data. NM multiplicity generated by EAS hadronic cascades is studied on the data set on coupling NMs with the CARPET EAS facility.  相似文献   

11.
12.
A large multiplate cloud chamber with fast timing scintillators inside is being operated with the extensive air shower array at Ootacamund to further elucidate the time structure of high energy hardons in air showers. The major interest in the present investigation is to understand the nature of the large delay (>20 ns) high energy (>40 GeV) events that appeared as strong cndidates for heavy mass particles in an earlier experiment carried out with a total absorption spectrometer. Two events observed during one year’s operation of the experiment are discussed. Now deceased.  相似文献   

13.
A macroscopic model of radio emission from extensive air showers is developed. This model is appropriate for calculating this radio emission at frequencies below 100 MHz. It is constructed on the basis of an analysis of the radiation integral and is verified by comparing field observables predicted by the model with the respective results obtained within the microscopic approach to calculating radio emission from extensive air showers.  相似文献   

14.
It is found that the power of the incoherent radiation of ionization electrons of an extensive air shower in the frequency range of 150 GHz is more than 10–24 W/m2Hz, with the shower energy ~1018 eV at a distance of 5 km from its axis. This means that, unlike fluorescent detectors, a radio telescope with an effective area of more than 300 m2 can monitor the trajectory of showers with an energy higher than 1018 eV at any time of the day regardless of the weather. The spectrum maximum near the frequency of 150 GHz is roughly three orders of magnitude higher than the value experimentally measured in the characteristic band (~5-10 GHz).  相似文献   

15.
The dependence of the number of extensive air showers with an energy above 1018 eV on the zenith angle θ is obtained in groups with a constant solid-angle step. The number of showers first decreases with an increase in the zenith angle and then, after reaching ~5°, increases strongly. With increasing energy, the kink on the dependence of the number of showers on θ is displaced towards larger angles, i.e., in the direction corresponding to the shift of the depth of the cascade-curve maximum.  相似文献   

16.
The small curvature option of the Randall-Sundrum model with two branes is considered which has almost continuous spectrum of low-mass Kaluza-Klein gravitons. It is shown that gravity effects related with these excitations can be detected in double diffractive events at the LHC and in inclined air showers induced by interactions of cosmic neutrinos with atmospheric nucleons at ultra-high energies.  相似文献   

17.
The radio emission from extensive air showers with energies up to 1017 eV has been calculated. The calculated lateral distribution of the radio emission is in good agreement with the LOPES-10 experimental data.  相似文献   

18.
The sonic files were written in the scheme of trigger start from a scintillation facility in order to study the acoustic phenomena caused by extensive air showers (EASs). With an aim to study the acoustic effects, the methods of peaks and anticoincidences (with an amplitude-independent algorithm) and the method of small peaks were suggested. Similar sonic effects (obtained in different geometries and at different noise levels) indicate that acoustic phenomena caused by EASs are detected.  相似文献   

19.
Summary A small air shower array of 21 detectors in conjunction with two shielded muon magnetic spectrographs has been operated for detection of muons of momentum in the range (2÷500) GeV/c at a geomagnetic latitude of 26o 45′ N at North Bengal University Campus. The array is sensitive to air showers initiated by cosmic-ray primaries of energy in the range (1014÷1016) eV. The initial results on muons with a comparison of other recent measurements have been given to infer information on the characteristics of high-energy interaction. An evaluation on the Monte Carlo simulation and observational data on muons in air showers have also been given to indicate the present status of the study of muons in air showers.
Riassunto Si utilizza un piccolo insieme di ventuno rivelatori di sciami cosmici congiunto a due spettrografi muonici magnetici schermati per rilevare muoni con momento nell'intervallo (2÷500) GeV/c ad una latitudine geomagnetica di 26o 45′ N al North Bengal University Campus. L'insieme è sensibile a sciami cosmici iniziati da primarie con energia nell'intervallo (1014÷1016) eV. Si effettua un confronto dei risultati iniziali sui muoni con altre misure recenti per riferire informazioni sulle caratteristiche dell'interazione ad alta energia. Si dà una valutazione della simulazione di Monte Carlo e dei dati osservativi sui muoni negli sciami cosmici per indicare lo stato attuale dello studio dei muoni nei raggi cosmici.

Реэюме НеболъшАя из 21 детектора атмосферных яяивней, соедненная с двумя мюонными магнитными спектрогафами, используется для детектектирования мюонов с импульсами в области (2÷500) ГзВ/с на геомагнитной широте 26° 45′ N в камрусе Северного ьенгалъского университета. Детектируюшая система чувстви-телъна к атмосферным ливням, образованным космическими частицами с знергиями в интервале (1014÷1016) зВ. Сравнение полученных резулътатов с данными других недавних измерений позволяет получитв информациу о характеристиках взаимо-действий при оченъ вюсоких знергиях. Проводится такзе сравнение моделирования по методу Монте Карло с данными наблюдений для мюонов в атмосферных ливнях.
  相似文献   

20.
Radio pulses from extensive air showers (EAS) at 30, 44, and 60 MHz frequencies have been studied, using wide band broad-side arrays of half-wave dipole antenna systems. The experimental results support the theoretical prediction that the field strength of radio emission depends on the shower size. An asymmetry has been noticed in the pulse height distributions of radio pulses detected by North-South and East-West directed arrays. These observations are in agreement with the theory that the charge separation mechanism is predominant in generating radio pulses from EAS and radio emission is polarised in the East-West direction. Experimental data are compared with those of earlier workers.  相似文献   

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