  The actual theoretical research investigates the resonant spontaneous
bremsstrahlung (RSB) of ultrarelativistic electrons under the condition of
scattering on a nucleus in the field of a weak electromagnetic wave. The
progression of the functional mechanism indicates the transformation of the
intermediate virtual electron into the real particle state. As a result, the
initial second order process with accordance to the fine structure constant in
the light field productively splits into two consequent first order formations:
the laser-stimulated Compton effect and the laser-assisted scattering of an
electron on a nucleus. It is important to emphasize that the resonance
escalation possesses a possibility to develop within two reaction channels.
Therefore, the first channel - delineates the occurrence that correlates to the
spontaneous photon emission by an electron with subsequent scattering on a
nucleus. The second channel - illustrates the configuration corresponding to
the electron scattering on a nucleus with consecutive spontaneous photon
emission in the wave field. Moreover, the spontaneous photon radiation angle
allocates a single-valued dependency with the resonant frequency for the first
channel in contrast to the second displacement that categorizes a composite
area with three various resonant frequency magnitudes for the particular
emission angle diapason. The project data analysis proposes that the reaction
channels do not interfere within the whole range of observation. To summarize,
the investigation calculates that the particular cross-section within the
resonant ambience significantly exceeds the according cross-section in the
approximation of an external field absence. In conclusion, numerous scientific
facilities with specialization in pulsed laser radiation (SLAC, FAIR, XFEL,
ELI, XCELS) may experimentally validate the computational estimations.
