THOA03
Kyoto University, Institute for Advanced Energy, Kyoto, Japan
| Paper | Title | Page |
|---|---|---|
THOA03 |
Use of Fringe-Resolved Autocorrelation for the diagnosis of the wavelength stability of a FEL | |
|
||
| For the spectroscopic applications of a FEL it is very important to monitor its wavelength stability. The most straightforward way is to take a laser spectrum at once with an array-type photodetector. This, however, is not an easy task at the wavelength regions (<190 nm or >1100 nm) where a Si-based array-type photodetector does not work. An alternative method has to be developed. In this paper we propose to use the autocorrelation setup, which is usually used to measure the pulse duration, to monitor the wavelength stability of a FEL. During the numerical simulation to demonstrate the above idea, we have included various kinds of instabilities such as the central wavelength, intensity, and pulse duration as well as the chirps. Our results show that we can estimate the stability of the wavelength from the width of the upper envelope of fringe-resolved autocorrelation (FRAC) signals: Given the same pulse duration the FEL pulse with larger wavelength instability results narrower envelope width of FRAC signals. Based on this fact, the FRAC can be used as a tool to diagnose the wavelength stability in the wavelength region where a direct spectrum measurement is not possible. | ||
|
|
Slides THOA03 [1.580 MB] | |