This study will undertake a small experimental effort to test some of the physical basis for the principles of an inverse free-electron laser accelerator (IFELA). The principle of the IFELA is to use an intense laser beam to accelerate a group of electrons. The Columbia free-electron laser will be configured as an IFELA, in which its intense laser wave is used to trap and bunch electrons that in the presence of a suitable undulator may be accelerated to higher energy. This study will be a proof of principle experiment using a two-section undulator: the first section causes laser oscillation at high power level while the second is for the acceleration. The FEL is configured as an autoaccelerator which increases the energy of one group of electrons at the expense of the remaining group. The laser oscillates at a wavelength of 2mm and the electron beam energy is 800kV; the accelerated particles will have an energy of approximately lMV, well resolved from the unaccelerated group. Diagnostics include an array of power and spectral instruments, which are used to understand the stimulated absorption of the laser, together with a new electron momentum analyser which will be constructed at Columbia. Theoretical studies include one and two dimensional numerical simulations, as well as a continuing examination of how the use of a background plasma may be used to improve the acceleration.
