Design study of a transverse-to-longitudinal emittance exchange proof-of-principle experiment
Transverse-to-longitudinal emittance exchange can be achieved through certain arrangements of dipole magnets and a dipole mode rf cavity. Theory on such schemes has been developed in the past several years. In this paper we report our numerical simulations to optimize a low energy (E sime 15 MeV) proof-of-principle experiment planned at the Argonne Wakefield Accelerator (AWA). Parametric studies of the dipole magnets and cavity strengths, as well as initial beam parameters, are presented.
Transverse-Longitudinal Phase-Space Manipulations and Correlations
Manipulations on transverse and longitudinal phase‐space distribution of an electron beam are discussed within the constraints imposed by symplectic conditions. A few examples are presented: transverse‐longitudinal emittance exchange to improve performance of a high‐gain free‐electron laser (FEL) for hard x‐rays, and the flat beam technique and its application to compact Terahertz devices and ultrashort‐pulse generation. It is shown that emittance transfer to some degree would be advantageous for FELs and that introducing correlations would allow just such transfers. Also, it is shown that transverse‐longitudinal correlations would be distinctly advantageous for FELs. Conventional and exotic methods of producing such correlations are described. Practical difficulties associated with each of the conventional methods are described, although the nonconventional methods appear to hold promise.
Photoinjector generation of a flat electron beam with transverse emittance ratio of 100
The generation of a flat electron beam directly from a photoinjector is an attractive alternative to the electron damping ring as envisioned for linear colliders. It also has potential applications to light sources such as the generation of ultrashort x-ray pulses or Smith-Purcell free electron lasers. In this paper, we report on the experimental generation of a flat beam with a measured transverse emittance ratio of 100{+-}20 for a bunch charge of {approx}0.5 nC; the smaller measured normalized root-mean-square emittance is {approx}0.4 {micro}m and is limited by the resolution of our experimental setup. The experimental data, obtained at the Fermilab/NICADD Photoinjector Laboratory, are compared with numerical simulations and the expected scaling laws.