Hard x-ray emission by atomic clusters in an intense femtosecond laser field at the collective recombination

X-ray generation by electron photo-recombination in charged atomic clusters formed in intense femtosecond laser pulses

“…According to our results [14,15], for a uniformly charged cluster the maximum photo-recombination cross section is…”

“…(1) the remaining electrons concentrate in the central region of the cluster: this leads to a neutral cluster core; a positive charged surface region consists only of positive atomic ions; this assumption corresponds to a statistical equilibrium of the electron cloud; (2) the remaining electrons are distributed uniformly within the whole charged cluster ball because of their high velocities (non-equilibrium distribution). In [14,15], we considered photo-recombination of ejected electrons into the charged cluster, considering using as a quantum-mechanical potential well, the second assumption about uniform electron distribution inside the cluster.…”

“…The x-ray spectra contain line emission that reflects the recombination of electrons in weakly bound atomic levels with core-level vacancies.In conclusion, let us estimate the number N of x-ray photons emitted according to our model. Using equation(15), one obtains in the maximum of the photo-recombination cross section:…”