Stable operation of a self-amplified spontaneous-emission free-electron laser in the extremely ultraviolet region
Abstract
We achieved stable operation of a free-electron laser (FEL) based on the self-amplified spontaneous-emission (SASE) scheme at the SPring-8 Compact SASE Source (SCSS) test accelerator in the extremely ultraviolet region. Saturation of the SASE FEL power has been achieved at wavelengths ranging from 50 to 60 nm. The pulse energy has reached ∼30μJ at 60 nm. The observed fluctuation of the pulse energy is about 10% (standard deviation) for several hours, which agrees with the expectation from the SASE theory showing the stable operation of the accelerator. The SASE FEL has been routinely operated to provide photon beams for user experiments over a period of a few weeks. Analysis on the experimental data gave the normalized-slice emittance at the lasing part is around 0.7πmmmrad. This result indicates that the normalized-slice emittance of the initial electron beam, 0.6πmmmrad in a 90% core part, is kept almost unchanged after the bunch compression process with a compression factor of approximately 300. The success of the SCSS test accelerator strongly encourages the realization of a compact XFEL source.
- Publication:
-
Physical Review Accelerators and Beams
- Pub Date:
- July 2009
- DOI:
- 10.1103/PhysRevSTAB.12.070701
- Bibcode:
- 2009PhRvS..12g0701S
- Keywords:
-
- 29.20.Ej;
- 29.27.Eg;
- 41.60.Cr;
- 52.59.Sa;
- Linear accelerators;
- Beam handling;
- beam transport;
- Free-electron lasers;
- Space-charge-dominated beams