Sub-picosecond, high flux, Thomson X-ray sources at Jefferson Lab´s high power FEL

With the advent of high average power FELs, the idea of using such a device to produce X-rays via the Thomson scattering process is appealing, if sufficient flux and/or brightness can be generated. Such X-rays are produced simultaneously with FEL light, offering unprecedented opportunities for pump-probe studies. We discuss non-invasive modifications to the Jefferson Lab\´s FEL that would meet the criteria of high flux, sub-picosecond, X-ray source. One allows proof-of-principle experiments, is relatively inexpensive, but is not conducive as a "User-facility". Another is a User facility configuration but requires FEL facility modifications. For all sources, we present Thomson scattering flux calculations and potential applications.