Measurement of free-free transitions in e^--Ar scattering

Two-photon bremsstrahlung processes in atoms: Polarization effects and analytic results for the Coulomb potential

“…In addition to spontaneous emission, considerable interest in multiquanta bremsstrahlung processes was stimulated by laser experiments, which made it possible to observe induced multiphoton bremsstrahlung emission and absorption in the optical frequency range. The first measurements of the cross sections of freefree electron transitions in the presence of a high-intensity laser wave were made in [21,22]. Such experiments were subsequently repeated more than once with different atomic targets for different electron beam energies and experimental geometries (see, for example, [23] and review [24]).…”

“…+ field (polarization effects and ED in this problem were analyzed in [53]). We can derive explicit expressions for dynamic parameters A i in relation (33) in terms of radial MEs (21) by integrating the squared modulus of amplitude (16) with respect to n'. By way of an example, we consider only the expression for the "dichroic parameter" A 4 :…”

“…Accordingly, the number of terms in the expression for the cross section, which are determined by linearly independent polarization-angular factors, increases considerably. Nevertheless, the general expression for the cross section in vector form, as (21) of transitions between the states of the continuum with fixed values of the orbital angular momentum in potential U(r). In accordance with the dipole selection rules, MEs of the following four types appear in expressions (20): (36) It can be seen from the definition that = ; consequently, it is sufficient to calculate , , and only.…”

Laser-assisted electron diffraction for femtosecond molecular imaging

“…20 Since the first observation of LAES, 25 the LAES experiments had been conducted using cw or long (≥ns) laser pulses 26 until our recent studies of femtosecond LAES experiments. 20,27 Probably because the major concerns in the previous LAES experiments were the scattering of slow electrons (≤76 eV) by rare gas atoms, 26 no experimental studies have been reported on the LAED of gas-phase molecules so far.…”

On the accuracy of soft-photon approximations for resonance free-free transitions

“…Due to the commercial availability of powerful lasers, it is now possible to study such scattering events in presence of laser fields, which induce bremsstrahlung processes or free-free transitions [1][2][3][5][6][7][8][9]. For resonant electron-atom scattering in the presence of moderately intense laser fields a N-state close coupling model has been developped [4].…”