ISSN 1063-7850, Technical Physics Letters, 2007, Vol. 33, No. 1, pp. 69–72. © Pleiades Publishing, Ltd., 2007. Original Russian Text © N.B. Volkov, N.D. Kundikova, A.Ya. Leivi, A.E. Maier, A.P. Yalovets, 2007, published in Pis’ma v Zhurnal Tekhnicheskoœ Fiziki, 2007, Vol. 33, No. 2, pp. 43–52. 69 The action of highly intense energy fluxes on con- densed matter is widely used both in basic sciences and in numerous technologies. Recent achievements in the development of electron accelerators generating sub- nano- and picosecond pulsed electron beams [1] and high-power laser radiation pulses of femto- and subpi- cosecond duration [2] led to the discovery of new phys- ical phenomena, in particular, the generation of high- energy particles and soft x-ray radiation [3]. The absorption of high-power laser radiation or high-energy electrons induces primarily the rapid heating of an elec- tron subsystem of the target material, after which the ion subsystem is heated due to the electron–phonon interaction [4]. The characteristic time of electron–ion energy relaxation in a condensed medium is on the order of τ ε ~ 10 –12 s, while the time of establishment of a local thermodynamics equilibrium in each subsystem is ~10 –14 s. Therefore, a correct description of the inter- action of ultrashort (10 –14 s < τ b < 10 –9 s) electron bunches or laser pulses with solids must take into account the local temperature difference between elec- trons and the lattice. In the range of 10 –14 s < τ b < 10 -9 s, these processes can be studied in terms of a two-tem- perature continuum model [4–6]. This Letter presents the results of investigation of the action of electron beam pulses with 10 –14 s < τ b < 10 –9 s on metals and the mechanisms of electron beam energy transformation in the target material within the framework of the two-temperature continuum model. Let us write a system of equations describing in terms of a two-temperature continuum model the elas- toplastic flow of the target material irradiated by an intense flux of electrons. In the one-dimensional geom- etry, this system can be written in the Lagrange vari- ables as (1) (2) (3) (4) where the upper dot denoted the operator d/dt = ∂/∂t + (v · ∇). In this system, Eq. (1) is the equation of conti- nuity, Eq. (2) is the equation of motion, and Eqs. (3) and (4) are the equations of energy balance for the ions and electrons, respectively; ρ is the mass density; V = ρ –1 is the specific volume; κ e is the coefficient of elec- tron heat conductivity; U i , T i and U e , T e are the energy and temperature of ions and electrons, respectively; γ = 3mρ Z i (m i T i τ ei ) –1 is the coefficient characterizing the rate of leveling of the electron and lattice tempera- tures [4, 7]; m and m i are the effective electron and ion mass, respectively; C s is the ion sound velocity, Z i is the mean ion charge; τ ei is the electron–ion momentum relaxation time; σ ik is the stress tensor; S ik is the stress V ˙ V --- ∂ν ∂ z ----- ; = ν ˙ 1 ρ -- ∂σ zz ∂ z ---------, σ zz p i ρ T i , ( ) p e ρ T e , ( ) + ( ) – S zz ; + = = ρ U ˙ i p i V ˙ V --- – S zz ∂ν ∂ z ----- γ T e T i – ( ) ; + + = ρ U ˙ e p e V ˙ V --- ∂ ∂ z ----- κ e ∂ T e ∂ z -------- ⎝ ⎠ ⎛ ⎞ γ T e T i – ( ) – + – Dzt , ( ) , + = C s 2 The Action of Ultrashort High-Power Electron Beam Pulses on Metal Targets N. B. Volkov*, N. D. Kundikova, A. Ya. Leivi, A. E. Maier, and A. P. Yalovets Institute of Electrophysics, Ural Division, Russian Academy of Sciences, Yekaterinburg, Russia * e-mail: nbv@ami.uran.ru Received August 3, 2006 Abstract—The action of high-power subnano- and picosecond electron beam pulses on metal targets has been numerically studied within the framework of a one-dimensional two-temperature model of a metal. The dynam- ics of strain and stress fields generated in the target by pulses of various durations have been simulated. The rates of tensile straining are significantly higher than the rates of compressive straining. The straining rate is determined by the rate of energy supply and can reach 10 7 –10 8 s –1 for tensile strains. A decrease in the time of energy deposition from tens of nanoseconds to ~1 ns and below gives rise to the level of mechanical stresses. It is established that subnanosecond pulses provide a more effective conversion of the electron beam energy into the kinetic energy of a target material and the potential energy of a mechanical stress field. PACS numbers: 61.80.-x DOI: 10.1134/S1063785007010191