共查询到20条相似文献,搜索用时 0 毫秒
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G. G. Savenkov V. A. Morozov A. A. Lukin V. A. Bragin G. V. Semashkin 《Technical Physics Letters》2014,40(3):256-259
Results of experiments on the initiation of ignition in high-energy materials with a broad range of physicochemical parameters by high-current electron beams of nanosecond duration are presented. It is shown that ignition of these materials can be initiated even at relatively low energy parameters of the electron beam, provided that the ignition temperature does not exceed 200°C. 相似文献
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With the aid of moments of the distribution function a system of differential equations is obtained to describe the dynamics
of a Gaussian high-current electron beam in magnetic fields with quadrupole and octupole symmetries. Results of its numerical
solution are reported.
Research Institute for Nuclear Problems at the Belarusian State University, Minsk, Belarus; Institute of Mathematics of the
Academy of Sciences of Belarus, Minsk, Belarus. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 70, No. 5, pp. 776–782,
September-October, 1997. 相似文献
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Ultra-short powerful electron beam is a suitable tool for producing of high rate deformation in substance. In paper we present a new model of high rate fracture and use this model for numerical investigation of fracture of copper target at irradiation by sub-nanosecond electron beam. In this model, fracture is considered as a time-dependent process of nucleation and growth of opening mode cracks. The nucleation and growth rates are controlled by specific free energy of crack surface which is sole fitted parameter. Plastic deformations, both in cracks vicinity and total in substance, are described in frames of dislocation theory. For verification of the model, we performed simulations of spall fracture at plate impact and at irradiation by high-current electron beam with pulse duration of tens of nanoseconds, and reasonable agreement with experimental data has been demonstrated. Simulations of the sub-nanosecond electron beam action on target indicate that spall fracture of the irradiated target surface is possible. This fracture takes place at the enclosed energy density slightly below the value, which is sufficient for melting of irradiated substance. Fracture threshold energy density does not depend on the origin dislocation density and it increases with the increase of pulse duration. As a result, at long pulse durations (more than ten nanoseconds) the substance melts before fracture. 相似文献
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A. E. Dubinov 《Technical Physics Letters》1999,25(7):571-572
Computer modeling using the particle-in-cell method confirmed that self-acceleration by induction of a high-current relativistic
electron beam predicted by G. A. Askar’yan [At. énerg. 6, 658 (1959)] may occur when this beam passes through a thick diaphragm containing an aperture.
Pis’ma Zh. Tekh. Fiz. 25, 52–56 (July 26, 1999) 相似文献
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We have studied the melting of porous silicon (por-Si) layers under the action of a nanosecond pulsed high-power proton-carbon ion beam. Dimensions of ellipsoidal silicon particles formed as a result of this processing have been determined. The threshold energy density necessary for the melting of por-Si with a porosity of ~50% is experimentally evaluated. 相似文献
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The temperature field generated by microsecond pulsed low-energy high-current electron beam (LEHCEB) in the surface layer
of a stainless-steel target containing second-phase (manganese sulfide, MnS) microinclusions has been numerically simulated.
The results of calculations show that the temperature is nonuniformly distributed over the target surface. By the end of the
LEHCEB pulse, the temperature in the regions of MnS inclusions significantly exceeds that of the steel matrix. This nonuniformity
is related to (i) markedly greater thermal conductivity of steel compared to that of MnS and (ii) the pulsed character of
the electron-beam-induced heating of the target surface. It is also established that LEHCEB-induced melting begins at the
inclusion-steel interface and then involves the inclusion and spreads over the entire irradiated surface. The dependence of
the characteristics of the irradiation-induced temperature field on the parameters of the pulsed electron beam has been studied. 相似文献
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Oleshko V. I. Zarko V. E. Lysyk V. V. Tsipilev V. P. Kalmykov P. I. 《Technical Physics Letters》2015,41(6):519-521
Results of investigations of physicochemical processes which develop in furazanotetrazine dioxide under irradiation by a high-current electron beam with an energy density varied in a range of 0.05–0.3 J/cm2 are represented. The spectral-kinetic characteristics of pulse cathodoluminescence are measured, and thresholds of the mechanical failure and explosive decomposition of samples are determined. A strong effect of the energy density of the electron beam on kinetics of the explosive transformation (induction period and duration of explosive glow) is revealed. The dimensional effect of the explosion initiation is found.
相似文献9.
The formation of periodic structures and micro- and nanoparticles on the surface of polycrystalline magnesium under the action
of a high-power proton-carbon ion beam of nanosecond duration have been studied. Spatial parameters of the observed structures
and dimensions of particles are determined and possible mechanisms of their formation are considered. 相似文献
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Structural phase transformations in tin dioxide under the action of a nanosecond high-power ion beam
V. S. Kovivchak O. V. Krivozubov N. N. Leont’eva E. V. Knyazev 《Technical Physics Letters》2013,39(11):982-985
Structural phase transformations in polycrystalline tin dioxide under the action of a nanosecond high-power ion beam with a current density of 50–150 A/cm2 are studied. It is found that the effect of a beam with a current density of 150 A/cm2 on SnO2 leads to the formation of submicron particles of tetragonal SnO with an average size of 210 nm on the exposed surface. The particles have a pronounced crystallographic facet pattern. Possible mechanisms of the observed transformations are discussed. 相似文献
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E. I. Lipatov V. F. Tarasenko V. M. Orlovskii S. B. Alekseev D. V. Rybka 《Technical Physics Letters》2005,31(3):231-232
Subnanosecond avalanche electron beams formed in air at atmospheric pressure ensure intense luminescence of synthetic ruby
and natural spodumene crystals. 相似文献
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A. I. Borodich V. I. Stolyarskii A. A. Khrushchinskii 《Journal of Engineering Physics and Thermophysics》1996,69(1):28-32
A method for calculation of the parameters of an intense beam of charged particles transported by the magnetic field of the
focusing elements is described, and the results of numerical modeling are presented.
Scientific Research Institute for Nuclear Problems, Belarusian State University, Minsk, Belarus. Translated from Inzhenerno-Fizicheskii
Zhurnal, Vol. 69, No. 1, pp. 33–38, January–February, 1996. 相似文献
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Kovivchak V. S. Panova T. V. Krivozubov O. V. Davletkil’deev N. A. 《Technical Physics Letters》2011,37(12):1183-1185
We have studied the formation of surface structures on single-crystalline silicon surface under the action of a nanosecond
pulsed high-power proton-carbon ion beam. Morphological features of the structures that appear as a result of this processing
are described and possible mechanisms of their formation are considered. 相似文献
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Emissive characteristics of electric discharge initiated by high-current electron beam in atmosphere
Spectral and kinetic characteristics of electric discharge induced by a high-current electron beam in air at atmospheric pressure
have been experimentally studied. The luminescence spectrum of a volume (diffuse) discharge generated under the conditions
studied displayed emission bands due to the second positive system of nitrogen molecules. The cathode region of discharge
exhibited bright cathode spots, which emitted short-term (nanosecond) pulses with continuous spectrum and long-term line radiation
from atoms entering into the cathode material composition. 相似文献
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Results are presented of an experimental investigation of the decomposition of small quantities of acrolein vapor in air irradiated
by a pulsed electron beam. It is shown that the reduction in the impurity concentration as a function of the energy deposited
in the gas is satisfactorily approximated by an exponential law. An empirical expression is derived to predict the energy
consumption for a given initial acrolein concentration and required degree of purification.
Pis’ma Zh. Tekh. Fiz. 24, 35–39 (August 26, 1998) 相似文献
17.
Specific features of surface relief formation on a polycrystalline bismuth target under the action of a high-power proton-carbon
ion beam of nanosecond duration have been studied. Local melt extrusion from subsurface layers and its crystallization on
the surface is observed, which is explained by a significant (3.35%) thermal expansion of bismuth during the transition from
liquid to solid state. 相似文献
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We have studied the transport of a relativistic electron beam with supercritical current in a cylindrical drift chamber in
the presence of an ion flux. A theoretical analysis of the electron-ion flux dynamics was based on the coarse particle PIC
method (code SOM). Simultaneous injection of a supercritical electron beam and a weak-current low-energy ion beam may result
in the formation of a virtual anode in addition to the electron virtual cathode in a drift chamber. The virtual anode exhibits
periodic pulsations. Numerical results obtained for hydrogen and nitrogen ions show that the ratio of the frequencies of these
pulsations is inversely proportional to the square root of the ion mass ratio. These oscillations of the virtual anode lead
to temporal modulation, at the same frequency, of both electron and ion currents at the drift chamber output. 相似文献
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An analysis is made of a possible method of collective ion acceleration by combining spatial modulation of the electron beam
potential with temporal modulation of the current. A conceptual design is proposed.
Pis’ma Zh. Tekh. Fiz. 24, 74–78 (September 26, 1998) 相似文献