共查询到20条相似文献,搜索用时 15 毫秒
1.
The intranuclear cascade model including the effect of changes in the properties of the target nucleus due to development of the shower of cascade particles is applied to calculations of the interactions of protons with fissioning nuclei in the energy region T ≈ 0.1–30 GeV. The fission cross sections, yields of different isotopes after the evaporation stage, and the characteristics of accompanying particles are calculated. The properties of the excited evaporating and fissioning nuclei are discussed. The calculated results are compared with experiment. 相似文献
2.
A. El-Naghy S. A. H. Abou-Steit S. S. Abdel-Aziz A. M. El-Shimy 《Acta Physica Hungarica A》2002,15(1-2):131-153
The characteristics of the nucleus-nucleus collisions at high energy for the interactions of 1H, 4He, 12C, 16O, 22Ne, 28Si and 32S with emulsion at momentum (4.1 – 4.5) AGeV/c have been investigated. It has been found that the multiplicity distributions of the different emitted particles and their average values can be described by the modified cascade evaporation model. The model reproduces satisfactorily the multiplicity distributions of the shower, grey and black particles and the correlations between their multiplicities. It has been seen that the number of the produced shower particles increases with the increase of the projectile mass number. From the correlation between the average multiplicity of the evaporation particles and the number of the produced particles, it was found that a phase transition in the target system may occur. The calculated pseudo-rapidity distributions of the produced shower particles are typically Gaussian shaped in the mid-rapidity region and agree well with the experimental data. Also, the angular distributions of the grey and black particles have been investigated. The angular distributions of the grey particles show a universal shape independent of the type of projectile. The angular distributions of the black particles are nearly isotropic with a small asymmetry in the forward direction. The modified cascade evaporation model, reproduces the general characteristics of the nucleus-nucleus interactions and gives an explanation for the multiparticle production process. 相似文献
3.
N. Suzuki 《Nuclear Physics A》1983,403(3):553-571
The probability distribution for the collision number of the primary particle ν and the number of gray particles is formulated in the framework of the leading particle cascade model. Rescattering effects of the recoil nucleons are taken into consideration in our formalism on the analogy of the birth and death problem in stochastic processes. Comparison of our model with the experimental data and some discussions about the production processes of shower particles and ν are made. 相似文献
4.
V. A. Khomyakov A. G. Bogdanov V. V. Kindin R. P. Kokoulin A. A. Petrukhin S. S. Khokhlov V. V. Shutenko I. I. Yashin 《Physics of Atomic Nuclei》2016,79(13):1546-1551
The spatial distribution of the Cherenkov light generated by cascade showers is analyzed using the NEVOD Cherenkov water detector. The dependence of the Cherenkov light intensity on the depth of shower development at various distances from the shower axis is investigated for the first time. The experimental data are compared with the Cherenkov light distributions predicted by various models for the scattering of cascade particles. 相似文献
5.
Ya. S. Elenskii 《Bulletin of the Russian Academy of Sciences: Physics》2009,73(5):606-608
In late stages of the extensive air shower (EAS) development (s ≥ 1.2–1.3) contributions to the electromagnetic component are made not only by hadrons but also partially by muons. In this case, the cascade curves are higher in comparison with the classical theory. If the number of particles is converted into the shower energy, this effect is not small in the energy range E 0 = 1013?1016 eV. In the numerical simulation of the experiment, it is important to make sure that the energy cutoff thresholds for muons and electrons are close to each other (this is usually ignored). 相似文献
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7.
V. A. Baskov V. V. Kim B. I. Luchkov V. Yu. Tugaenko V. A. Khablo 《Bulletin of the Lebedev Physics Institute》2013,40(5):109-112
The experimental results of the study of orientation dependences of the response of a composite Cherenkov shower spectrometer with a converter made of a 1-mm tungsten crystal oriented along the 〈111〉 axis at an electron energy of 28 GeV and two converter temperatures, 293 and 77 K, are presented. The parameters of the cascade curve of the shower development are varied depending on the orientation angle and crystal temperature. It is found that there is a point S in the cascade curve of the shower development in the spectrometer, at which all cascade curves intersect at any converter orientation. The position of this point in the spectrometer depth depends on the converter temperature. 相似文献
8.
《Comptes Rendus Physique》2004,5(4):495-503
The nature of the primary particle giving rise to an atmospheric shower may be, to some extent, inferred from the observable properties: longitudinal profile (especially position of the maximum of the number of charged particles) or shape at ground level (lateral distribution, curvature and thickness of the shower front, muonic component). Distinguishing different nuclei cannot be performed unambiguously on a single shower, because of the random fluctuations in the first steps of the cascade; however, it is possible to study the composition of the incident flux on a statistical basis: showers from heavier nuclei have a faster development, and contain more muons. The uncertainties on the hadronic interactions at the highest energies limit the reliability of the identification. Other primaries, if they exist, could be easier to distinguish. Photons would give a slower development than protons, especially at highest energies, and a very reduced muonic component; neutrinos would be characterized by deep interactions in the atmosphere, or even within the Earth, giving almost horizontal showers with a large electromagnetic component, clearly different from the muonic tail of showers induced in the upper atmosphere by nuclei. Such ‘exotic’ primaries have not yet been observed. To cite this article: P. Billoir, P. Sommers, C. R. Physique 5 (2004). 相似文献
9.
The muonic component of the extensive air showers (EAS) is of great importance for the astroparticle physics. It carries the information about the properties of primary cosmic ray (CR) particles, such as their mass, and electromagnetic and hadronic nature. It provides a sensitive test for the hadronic interaction models, which are inevitable for describing the cascade shower development of cosmic rays in EAS experiments. The YangBaJing Hybrid Array (YBJ-HA) experiment has been in operation since the end of 2016. Surface detectors are used for the measurements of primary energy, angular direction and core position of a shower event, while underground muon detectors are used for measuring the density of muons at various locations. Using the data obtained by the YBJ-HA experiment,this work reports the first measurement of the lateral muon distribution for the primary cosmic ray energy in the 100TeV region. The punch-through effect is evaluated via MC simulation. 相似文献
10.
L. G. Dedenko N. Inoue D. A. Podgrudkov T. M. Roganova G. F. Fedorova 《Bulletin of the Russian Academy of Sciences: Physics》2009,73(5):600-602
The space-time evolution of a signal in scintillation detectors used at the Yakutsk array is calculated within the quark-gluon string model. It follows from the calculations of the temporal distributions of the signal that the time to sample all particles at the distances 100, 600, 1000, and 1500 m is 0.1, 1, 2.5, and 4 μs respectively. At large distances from the shower axis in the region of superhigh energies, about 60–70% of the signal is sampled within the sampling time of 2 μs adopted in the experiment. At the distance 600 m from the shower axis, the estimated sampling time of all particles agrees with the one adopted in the Yakutsk experiment. 相似文献
11.
The standard deviationσ of the instantaneous distribution of electrons in extensive air showers at sea level has been measured by coincidence of two spark counters, a cloud chamber providing data on arrival directions and particle densities. The values published up to now were in the range 2<σ<8 ns and the standard time deviationσ 0 due to instrumental fluctuations was about 4 ns. In this experiment with aσ 0=1,8 ns mean delaysσ have been obtained between 1 and 2 ns, the values decreasing with increasing particle density. This tendency may be due to the fact that the mean separations of the electrons, taken perpendicular to the shower front, are increasing with distance from the shower axis. The fractional contribution of showers within a given range of sizes, the axes of which came down within a given interval of distances from the counters has been calculated. It was concluded that 80% of the showers triggering the two counters were in the range from 105 to 107 particles. By means of these calculations, using the measured values for the mean delaysσ at different particle densities, a simple curve has been constructed which gives the mean separations of electrons vs distance from the shower axis up to 1000 m and is in good agreement with the experimental data ofLinsley andScarsi for great distances from the shower axis. 相似文献
12.
A. V. Glushkov M. I. Pravdin I. E. Sleptsov V. R. Sleptsova N. N. Kalmykov 《Physics of Atomic Nuclei》2000,63(8):1477-1488
The results obtained from an analysis of the 1974–1998 Yakutsk array data on muons with threshold energy E μ ≈ 1.0 × secθ GeV and on all charged particles (electrons and muons) in extensive air showers (EAS) are reported and compared with the results of calculations based on the model of quark-gluon strings with jets. For energies of E 0≤3×1018 eV and zenith angles of θ≤45°, the results of the model calculations are consistent with the measured properties of the showers, while, for higher energy EASs, there are considerable discrepancies, which are probably due to the change in the development of the shower cascade in the region E 0≥3×1018 eV. 相似文献
13.
S. S. Khokhlov N. S. Barbashina A. G. Bogdanov A. N. Dmitrieva L. I. Dushkin E. A. Zadeba V. V. Kindin E. A. Kovylyaeva R. P. Kokoulin K. G. Kompaniets V. V. Ovchinnikov A. A. Petrukhin V. A. Khomyakov D. V. Chernov V. V. Shutenko I. I. Yashin 《Bulletin of the Russian Academy of Sciences: Physics》2013,77(5):638-640
We discuss measuring cascade shower energy using the NEVOD Cherenkov water detector with a spatial lattice of quasi-spherical modules (QSMs). Dense QSM spacing makes it possible to reconstruct a number of cascade particles along the shower axis from the PMT response amplitude. Our cascade curve reconstruction technique is applied to showers generated by near-horizontal high-energy muons selected using the DECOR coordinate detector deployed around NEVOD. The first results from cascade energy spectrum measurements are reported. 相似文献
14.
An experimental analysis of 855 events induced by 14.6 A GeV 28Si in nuclear emulsion is presented. Mean multiplicities of charged secondary particles produced in the nuclear interactions are studied and compared with the results from the other experiments for the same projectile at 3.7 A GeV as well as data for proton at similar energy (14 GeV). An analysis of pseudorapidity densities of target fragments (black and grey particles) is also performed. The behaviour of the KNO scaling law of the multiplicity distribution for shower particles has been examined. In order to accumulate knowledge about the intermittent behaviour of shower particles, the scaled factorial moments (SFMs) are computed in η-space and ?-space for a set of data in the 28Si–AgBr events. Furthermore, validity of limiting fragmentation of shower particles produced in central collision events induced by 28Si-emulsion interactions has been tested. A crude estimation for the energy density of the nuclear matter formed in the central collision events at our energy has been examined. 相似文献
15.
S. S. Khokhlov N. S. Barbashina A. G. Bogdanov A. N. Dmitrieva L. I. Dushkin E. A. Zadeba V. V. Kindin E. A. Kovylyaeva R. P. Kokoulin K. G. Kompaniets V. S. Kruglikova A. A. Petrukhin V. A. Khomyakov D. V. Chernov V. V. Shutenko I. I. Yashin 《Physics of Particles and Nuclei Letters》2014,11(1):27-30
A technique for measuring the cascade shower energy in the NEVOD Cherenkov water detector with a spatial lattice of quasi-spherical modules is discussed. The technique allows the number of cascade particles that move near the shower axis to be reconstructed on the basis of analysis of response amplitudes of triggered photomultiplier tubes. The technique of cascade-curve reconstruction was applied to cascade showers generated by near-horizontal high-energy muons extracted by means of the DECOR coordinate-tracking detector arranged around the Cherenkov water detector. The first results of measuring the energy spectrum of cascade showers of 10–1000 GeV are presented. 相似文献
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17.
V. V. Uchaikin A. V. Plyasheshnikov A. A. Lagutin V. V. Vetoshkin 《Russian Physics Journal》1978,21(4):433-436
A method is proposed for calculating the fluctuations in the total range of charged particles of an electromagnetic shower with energies above a certain threshold. The method involves a numerical integration of the adjoint cascade equations. It requires much less computer time than the Monte Carlo method does. Calculated results are reported and discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 27–30, April, 1978. 相似文献
18.
Intranuclear cascading mechanism one of the important non-linear effects in high energy nucleusnucleus collisions is investigated. The data on multiplicity (n s ) and pseudorapidity (η) distributions of shower particles produced by32S and16O at 200A GeV,16O at 60A GeV,28Si at 14.5A GeV and He at ≈140A GeV are presented and compared with the string model VENUS, which takes into account the cascade interactions of secondary particles. The effect of the intranuclear collisions on the distributions of <η> versus <n s > is discussed for all the beams. 相似文献
19.
V. M. Grigor’ev 《Physics of Particles and Nuclei Letters》2008,5(5):456-461
An empirical approach is presented for reconstruction of the extensive air shower (EAS) cascade curve according to data of the Cherenkov track detector. The proposed method, unlike conventional ones, is based on experimentally measured parameters and on calculated values which weakly depend on the model of shower development. 相似文献
20.
We apply our microscopic model for the topological cross section σn to produce n charged particles in hadron-proton interactions to hadron-nucleus scattering. The model is based on a stochastic branching process for hadronization. We calculate multiplicity distributions of hadron-nucleus collisions for 50 GeV ? EL ? 400 GeV based on a multiple collision model. The production of “grey” particles is considered together with the shower particles in order to test the model for higher number of collisions. The joint probability distribution of numbers of shower and grey particles F(ns, ng) is calculated. Finally, we critically compare the results to experimental data. 相似文献