X-ray radiation emitted by an atom and a diatomic molecule interacting with ultrarelativistic charged particles.

A theoretical analysis is presented for the bremsstrahlung produced during the interaction of recoiling atomic or diatomic molecular electrons with an ultrarelativistic charged particle, depending on their orientation relative to the trajectory of the charged particle. It is shown that for wavelengths much greater than the molecule size, the radiation cross-section on the diatomic molecule is nearly four times as large as the cross-section corresponding to a single atom. The correction for the molecule cross section due to the interference of radiation from each atom is calculated. An astrophysical application of the results is provided as an illustrative example.