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We study magnetic-wiggler bremsstrahlung (MWB) and amplifcation of the laser power in a Raman free-electron laser (FEL). We fnd that as the electron becomes highly relativistic, the power of MWB, calculated under the quantum-electrodynamic concept that MWB is a two-quantum process and the wave-function phase (WFP) of the fnal state is independent of the routes of the two-quantum process, approaches that calculated under the concept that MWB is a two-quantum process but the WFP of the fnal state is random. We also fnd that the power of MWB calculated with quantum electrodynamics is the same as that calculated with classical electrodynamics, except for a numeral factor of 5/12, but is generally different from that calculated with quantum-wiggler electrodynamics (QWD) in the functional form of the electron energy and the wavelength and the amplitude of the magnetic wiggler. We fnd that unlike the frst FEL, in a Raman FEL, there is no ultra-strong absorption mechanism. We conffrm that the ampliffcation in the Raman FEL is only due to amplifed free-electron two-quantum Stark emission, which can be accounted for only with QWD. We show that if the beam electrons ll the cavity, the laser wavelength depends on the transverse density profle, and the theoretical gain agrees, in order of magnitude, with the measured value.