Nonlinear amplification of x-ray channeling radiation

Channeling radiation of moderate energy electrons in the presence of laser beams

“…For instance, though the results of some nonlinear theoretical approaches as [15][16][17] are available, nevertheless, it is necessary to have numerical estimates and the study of various dependences which are absent in these works. This is of interest, in particular, because in [17] it is mentioned that ChR enhancement in nonlinear process can be achieved at laser beam intensities lower than it is required in linear processes.…”

“…In [6][7][8][9] and many other works it has been considered the enhancement of ChR intensity periodically distorting the structure of the crystallographic planes with the help of external fields, say, with ultrasonic oscillations. In [10][11][12][13][14][15][16][17][18][19][20][21] it has been considered the possibility of obtaining SChR using laser beam photons which gives additional resonance transitions between E i and E k . To the best of our knowledge, no one of these predictions [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] on the SChR has not been confirmed experimentally.…”

“…Since the cross section of such absorption near the resonance is much higher than the Thomson cross section then it is expected that when the resonance condition is satisfied SChR will take place. The works [15][16][17] have been carried out in non-linear approximation when a few photons of the laser beam are absorbed.…”

Strong field electrodynamics of a thin foil

“…[6,9]. These features provide novel regimes for ion acceleration [10][11][12][13][14], relativistic high order harmonics generation [15][16][17], light frequency upshifting [20][21][22][23][24][25][26], and laser pulse shaping [9,[27][28][29][30][31]. They become important when the foil thickness is shorter than, or of the order of, both the laser wavelength and the plasma collisionless skin depth.…”

Quantum self-amplified spontaneous emission regime of the x-ray Compton laser

“…To achieve the x-ray domain with moderate relativistic electron beams (energy of electrons 50 MeV), the frequency of electron selfoscillation should be high enough 10 14 -10 15 s ÿ1 (in undulator 10 10 s ÿ1 ). The latter can be realized, e.g., in the Compton backscattering scheme [5] or in the channeling radiation scheme [6]. On the other hand, for moderate relativistic electron beams as the photon wavelength moves into the deep UV and x-ray regions, the interaction becomes quantum mechanical, i.e., quantum recoil becomes comparable to or larger than the gain bandwidth and the resonance widths due to energetic and angular spreads.…”