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Coherence time characterization method for hard X-ray free-electron lasers
- Source :
- Optics express. 28(8)
- Publication Year :
- 2020
-
Abstract
- Coherence time is one of the fundamental characteristics of light sources. Methods based on autocorrelation have been widely applied from optical domain to soft X-rays to characterize the radiation coherence time. However, for the hard X-ray regime, due to the lack of proper mirrors, it is extremely difficult to implement such autocorrelation scheme. In this paper, a novel approach for characterizing the coherence time of a hard X-ray free-electron laser (FEL) is proposed and validated numerically. A phase shifter is adopted to control the correlation between X-ray and microbunched electrons. The coherence time of the FEL pulse can be extracted from the cross-correlation. Semi-analytical analysis and three-dimensional time-dependent numerical simulations are presented to elaborate the details. A coherence time of 218.2 attoseconds for 6.92 keV X-ray FEL pulses is obtained in our simulation based on the configuration of Linac Coherent Light Source. This approach provides critical temporal coherence diagnostics for X-ray FELs, and is decoupled from machine parameters, applicable for any photon energy, radiation brightness, repetition rate and FEL pulse duration.
- Subjects :
- Physics
Brightness
Coherence time
business.industry
Astrophysics::High Energy Astrophysical Phenomena
Attosecond
Autocorrelation
Pulse duration
02 engineering and technology
Photon energy
021001 nanoscience & nanotechnology
Laser
01 natural sciences
Atomic and Molecular Physics, and Optics
law.invention
010309 optics
Optics
law
0103 physical sciences
Physics::Accelerator Physics
0210 nano-technology
business
Coherence (physics)
Subjects
Details
- ISSN :
- 10944087
- Volume :
- 28
- Issue :
- 8
- Database :
- OpenAIRE
- Journal :
- Optics express
- Accession number :
- edsair.doi.dedup.....b2777f5e6f17ab56aae7859c14cc896f