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Title: A Low-Charge, Hard X-Ray FEL Driven with an X-band Injector and Accelerator

Abstract

After the successful operation of FLASH (Free-Electron Laser in Hamburg) and LCLS (Linac Coherent Light Source), soft and hard X-ray Free Electron Lasers (FELs) are being built, designed or proposed at many accelerator laboratories. Acceleration employing lower frequency RF cavities, ranging from L-band to C-band, is usually adopted in these designs. In the first stage bunch compression, higher-frequency harmonic RF system is employed to linearize the beam's longitudinal phase space, which is nonlinearly chirped during the lower frequency RF acceleration process. In this paper, a hard X-ray FEL design using an all X-band accelerator at 11.424 GHz (from photo-cathode RF gun to linac end) is presented, without the assistance of any harmonic RF linearization. It achieves LCLS-like performance at low charge using X-band linac drivers, which is more versatile, efficient and compact than ones using S-band or C-band rf technology. It employs initially 42 microns long (RMS), low charge (10 pC) electron bunches from an X-band photoinjector. An overall bunch compression ratio of roughly 100 times is proposed in a two stage bunch compressor system. The start-to-end macro-particle 3-D simulation employing several computer codes is presented in this paper, where space charge, wakefields, incoherent and coherent synchrotron radiation (ISR andmore » CSR) effects are included. Employing an undulator with a short period of 1.5 cm, a Genesis FEL simulation shows successful lasing at a wavelength of 0.15 nm with a pulse length of 2 fs and a power saturation length as short as 20 meters, which is equivalent to LCLS low charge mode. Its overall length of both accelerators and undulators is 180 meters (much shorter than the effective LCLS overall length of 1230 meters, including an accelerator length of 1100 meters and an undulator length of 130 meters), which makes it possible to be built in places where only limited space is available.« less

Authors:
; ; ; ;
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1035070
Report Number(s):
SLAC-PUB-14367
Journal ID: ISSN 1098--4402; TRN: US1201080
DOE Contract Number:  
AC02-76SF00515
Resource Type:
Journal Article
Journal Name:
Submitted to Physical Review Special Topics - Accelerators and Beams
Additional Journal Information:
Journal Volume: 15; Journal Issue: 3; Journal ID: ISSN 1098--4402
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; ACCELERATION; ACCELERATORS; CAVITIES; COMPRESSION; COMPRESSION RATIO; COMPRESSORS; COMPUTER CODES; ELECTRONS; FREE ELECTRON LASERS; HARMONICS; LINEAR ACCELERATORS; PHASE SPACE; RF SYSTEMS; SATURATION; SPACE CHARGE; SYNCHROTRON RADIATION; WAVELENGTHS; WIGGLER MAGNETS; Accelerators,ACCPHY, XFEL

Citation Formats

Sun, Yipeng, Adolphsen, Chris, Limborg-Deprey, Cecile, Raubenheimer, Tor, Wu, Juhao, and /SLAC. A Low-Charge, Hard X-Ray FEL Driven with an X-band Injector and Accelerator. United States: N. p., 2012. Web. doi:10.1103/PhysRevSTAB.15.030703.
Sun, Yipeng, Adolphsen, Chris, Limborg-Deprey, Cecile, Raubenheimer, Tor, Wu, Juhao, & /SLAC. A Low-Charge, Hard X-Ray FEL Driven with an X-band Injector and Accelerator. United States. https://doi.org/10.1103/PhysRevSTAB.15.030703
Sun, Yipeng, Adolphsen, Chris, Limborg-Deprey, Cecile, Raubenheimer, Tor, Wu, Juhao, and /SLAC. Fri . "A Low-Charge, Hard X-Ray FEL Driven with an X-band Injector and Accelerator". United States. https://doi.org/10.1103/PhysRevSTAB.15.030703. https://www.osti.gov/servlets/purl/1035070.
@article{osti_1035070,
title = {A Low-Charge, Hard X-Ray FEL Driven with an X-band Injector and Accelerator},
author = {Sun, Yipeng and Adolphsen, Chris and Limborg-Deprey, Cecile and Raubenheimer, Tor and Wu, Juhao and /SLAC},
abstractNote = {After the successful operation of FLASH (Free-Electron Laser in Hamburg) and LCLS (Linac Coherent Light Source), soft and hard X-ray Free Electron Lasers (FELs) are being built, designed or proposed at many accelerator laboratories. Acceleration employing lower frequency RF cavities, ranging from L-band to C-band, is usually adopted in these designs. In the first stage bunch compression, higher-frequency harmonic RF system is employed to linearize the beam's longitudinal phase space, which is nonlinearly chirped during the lower frequency RF acceleration process. In this paper, a hard X-ray FEL design using an all X-band accelerator at 11.424 GHz (from photo-cathode RF gun to linac end) is presented, without the assistance of any harmonic RF linearization. It achieves LCLS-like performance at low charge using X-band linac drivers, which is more versatile, efficient and compact than ones using S-band or C-band rf technology. It employs initially 42 microns long (RMS), low charge (10 pC) electron bunches from an X-band photoinjector. An overall bunch compression ratio of roughly 100 times is proposed in a two stage bunch compressor system. The start-to-end macro-particle 3-D simulation employing several computer codes is presented in this paper, where space charge, wakefields, incoherent and coherent synchrotron radiation (ISR and CSR) effects are included. Employing an undulator with a short period of 1.5 cm, a Genesis FEL simulation shows successful lasing at a wavelength of 0.15 nm with a pulse length of 2 fs and a power saturation length as short as 20 meters, which is equivalent to LCLS low charge mode. Its overall length of both accelerators and undulators is 180 meters (much shorter than the effective LCLS overall length of 1230 meters, including an accelerator length of 1100 meters and an undulator length of 130 meters), which makes it possible to be built in places where only limited space is available.},
doi = {10.1103/PhysRevSTAB.15.030703},
url = {https://www.osti.gov/biblio/1035070}, journal = {Submitted to Physical Review Special Topics - Accelerators and Beams},
issn = {1098--4402},
number = 3,
volume = 15,
place = {United States},
year = {2012},
month = {2}
}