Measurements of high gain and noise fluctuations in a SASE free electron laser

Abstract

We report measurements of large gain for a single pass Free Electron Laser operating in Self Amplified Spontaneous Emission (SASE) at 16 µm starting from noise. We also report the first observation and analysis of intensity fluctuations of the SASE radiation intensity in the high gain regime. The results are compared with theoretical predictions and simulations.

Initial gain measurements of an 800nm SASE FEL, VISA

“…During the last few years, SASE FELs have demonstrated very high gain [2] and have agreed well with simulations in the far infrared. VISA, while R&D for the LCLS, will continue this study into the visible and harmonic UV wavelengths.…”

“…Recent SASE FEL research has aimed at developing shorter wavelength devices [1,2] and a current proposal [3] to generate high power, coherent x-rays at 1.5 Å has already received initial funding-LCLS (Linac Coherent Light Source). During the last few years, SASE FELs have demonstrated very high gain [2] and have agreed well with simulations in the far infrared.…”