A corrugated structure is built and tested on many FEL facilities,providing a'dechirper'mechanism for eliminating energy spread upstream of the undulator section of X-ray FELs.The wakefield effects are here st...A corrugated structure is built and tested on many FEL facilities,providing a'dechirper'mechanism for eliminating energy spread upstream of the undulator section of X-ray FELs.The wakefield effects are here studied for the beam dechirper at the Shanghai high repetition rate XFEL and extreme light facility(SHINE),and compared with analytical calculations.When properly optimized,the energy spread is well compensated.The transverse wakefield effects are also studied,including the dipole and quadrupole effects.By using two orthogonal dechirpers,we confirm the feasibility of restraining the emittance growth caused by the quadrupole wakefield.A more efficient method is thus proposed involving another pair of orthogonal dechirpers.展开更多
基金supported by the Youth Innovation Promotion Association CAS(Nos.2018300 and 2021282)the National Key Research and Development Program of China(No.2018YFE0103100)the National Natural Science Foundation of China(No.11935020)。
文摘A corrugated structure is built and tested on many FEL facilities,providing a'dechirper'mechanism for eliminating energy spread upstream of the undulator section of X-ray FELs.The wakefield effects are here studied for the beam dechirper at the Shanghai high repetition rate XFEL and extreme light facility(SHINE),and compared with analytical calculations.When properly optimized,the energy spread is well compensated.The transverse wakefield effects are also studied,including the dipole and quadrupole effects.By using two orthogonal dechirpers,we confirm the feasibility of restraining the emittance growth caused by the quadrupole wakefield.A more efficient method is thus proposed involving another pair of orthogonal dechirpers.