An experimental study of the beam-steering effect on the FEL gain at LEUTL's segmented undulators.
The electron trajectories at the low-energy undulator test line (LEUTL), a self-amplified spontaneous emission (SASE) free-electron laser (FEL) facility at Argonne, were routinely corrected during the user run in order to deliver maximum radiation power to the user. Even though we knew from experience that SASE gain at the segmented undulators was dependent on the trajectory, the quantitative understanding of steering effects associated with the specific trajectory was lacking. Recently Tanaka et al. [1] proposed an analytical model for the single-kick error (SKE) effect. Since the LEUTL has eight segmented undulators, we performed the first measurement of SKE on the FEL gain. In the experiments we varied the corrector strength up to the critical angle, and the gain over the undulator was measured for each corrector setting. The results were compared with the analytical model and GENESIS simulations. We also measured the e-beam positions and SASE intensities over the undulators. The experimental data were analyzed and their results were reproduced by GENESIS simulation. The simulation condition, including the measured not-so-ideal trajectory, was used to predict performance enhancements that could be achieved by upgrading ebeam current, e-beam emittance, or trajectory control.
- Research Organization:
- Argonne National Laboratory (ANL)
- Sponsoring Organization:
- SC
- DOE Contract Number:
- AC02-06CH11357
- OSTI ID:
- 975430
- Report Number(s):
- ANL/ASD/CP-113296
- Country of Publication:
- United States
- Language:
- ENGLISH
Similar Records
Benchmark and comparisons of FEL simulation programs TDA3D and GENESIS.
Tapered undulator for SASE FELs