PARTICLE-ACCELERATION BY RESONANT ABSORPTION OF RADIATION

This paper reconsiders, in a quantum approach, the efficient gyroresonance absorption of laser light by gyrating charges, assumed to be at quasi-atomic states; the configuration (in the comoving frame) is analogous to traps in atomic physics. Applying also angular momentum conservation, kinematical relations are obtained, which describe the dynamical behaviour of this interaction; previous results appear modified. A synchronous resonance absorption can be maintained during acceleration mainly due to the Doppler-upshifted divergent laser beam. With a 10(12) W laser, an efficiency of only 1% and 10(8) e+/- per bunch (sigma(z) = 30 cm), an acceleration from 250 MeV to 1 TeV within -1 m is expected. Testing of this plasma-density independent concept seems feasible with the existing apparatus in accelerators. Furthermore, stimulated resonance interaction and spontaneous collective emission of cyclotron radiation are discussed; a possible beam energy compression and a noninvasive continuous beam energy measurement with approximately 10(-5) accuracy (even per beam crossing) are also expected.