Investigation of Two-Bunch Train Compression by Velocity Bunching

Dan Wang, Yingchao Du, Wenhui Huang, Xing Liu, Xiaolu Su, Chuanxiang Tang, Qi Tian, Lixin Yan, Hongze Zhang, Schaa, Volker RW (Ed.), Satogata, Todd (Ed.)
Two electron beamlets, also referred as two-bunch train with adjustable time and energy spacing are popular in many applications such as two color FEL and pump-probe experiments. We investigate compression of two-bunch train via velocity bunching scheme in a traveling wave accelerator (TWA) tube by varying the phase of TWA tube in a very large range. Beam dynamics simulations show that when the phase injected into the accelerator tube for the beam is set to ≪-100 degree, velocity bunching
more » ... city bunching occurs in a deep over-compression mode, where two-bunch train is continuously tunable in time and in energy space, and the emittance of each sub-bunch is also preserved. In the experiment, we use energy spectrum and defecting cavity to diagnose the train's energy space and time space respectively, the measurements demonstrated that two-bunch train through deep over-compression scheme is separated both in time and in energy space, which also agree well with the predictions.
doi:10.18429/jacow-ipac2018-thpak131 fatcat:mo25wiikknbo5psde4qws5lrjm