Design of an x-ray free electron laser undulator

Conference · Mon Sep 01 00:00:00 EDT 1997

DOI:https://doi.org/10.1063/1.54589· OSTI ID:663315

Carr, R

An undulator designed to be used for an x-ray free electron laser has to meet a set of stringent requirements. With no optical cavity, an x-ray FeL operates in the single pass Self Amplified Spontaneous Emission (SASE) mode; an electron macropulse is microbunched by an undulator and the radiation it creates. The microbunched pulse emits spontaneous radiation and coherent FEL radiation, whose power may reach saturation in a sufficiently long and perfect undulator. The pulse must have low emittance and high current, and its trajectory in the undulator must keep the radiation and the pulse together with a very high degree of overlap. The authors shall consider the case of the Linear Coherent Light Source (LCLS) FEL project at SLAC, which is intended to create 1.5 {angstrom} x-rays using an electron beam with 15 GeV energy, 1.5{pi} mm-mrad normalized emittance, 3,400 A peak current, and 280 fsec FWHM bunch duration. They find that this 65 {micro}m rms diameter beam must overlap its radiation with a walk/off of no more than 5 {micro}m for efficient gain. This places severe limitations on the magnetic field errors and other mechanical tolerances. The following is a discussion of the undulator design, specifications, alignment, engineering, and beam position monitoring they plan to implement for the LCLS X-ray FEL.

• Research Organization: Stanford Univ., Stanford Linear Accelerator Center, CA (US)
• Sponsoring Organization: USDOE Office of Energy Research, Washington, DC (US)
• DOE Contract Number: AC03-76SF00515
• OSTI ID: 663315
• Report Number(s): SLAC-PUB--7651; CONF-9706157--; ON: DE98059141
• Resource Type: Conference paper/presentation
• Conference Information: SRI '97: 10. U.S. national conference on synchrotron radiation instrumentation, Ithaca, NY (US), 06/17/1997--06/20/1997
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
43 PARTICLE ACCELERATORS
ALIGNMENT
BEAM POSITION
ELECTRON BEAMS
ELECTRONS
FREE ELECTRON LASERS
LIGHT SOURCES
MAGNETIC FIELDS
MONITORING
RADIATIONS
SATURATION
SPECIFICATIONS
STANFORD LINEAR ACCELERATOR CENTER
SYNCHROTRON RADIATION
WIGGLER MAGNETS