The Optimized bunch compressor for the international linear collider

The International Linear Collider (ILC) utilizes a two stage bunch compressor (BC) that compresses the RMS bunch length from 9 mm to 200 to 300 micrometers before sending the electron beam to the Main Linac. This paper reports on the new design of the optimized BC wiggler. It was reduced in length by more than 30%. The introduction of nonzero dispersion slope in the BC wigglers enabled them to generate the required compression while having a small synchrotron radiation emittance growth, a tunability range of over a factor of 2 in each wiggler, and less than 3% RMS energy spread throughout the entire system.