Touschek Lifetime for the NSLS Free Electron Laser Experiment

Technical Report · Mon Jan 01 00:00:00 EST 1979

DOI:https://doi.org/10.2172/5831968· OSTI ID:5831968

Krinsky, S.

The VUV-Ring of the National Synchrotron Light Source is designed to operate at an electron energy of 700 MeV with an average current of 1 Amp distributed in nine bunches. High brightness sources of synchrotron radiation are obtained by a lattice design yielding a small electron beam emittance, the uncoupled value at 700 MeV being 9 X 10^-8 m-rad. Recently there has been interest in using the VUV-Ring for an experiment to study the operation of a free electron laser. For this purpose it is necessary to operate at an energy lower than 700 MeV, say 400 or 500 MeV. A consequence of the lower energy is that the emittance will be reduced by a factor of 1/3 or 1/2, respectively, relative to the value at 700 MeV. Since it is the peak current which determines the laser gain, it is hoped to achieve an average current of 1 Amp distributed in three bunches, the length of a bunch being kept as short as possible. The combination of high peak current, small transverse dimensions, and low energy lead one to be concerned about the Touschek lifetime. In this note the Touschek lifetime for the free electron laser experiment is considered. The conclusion is reached that although minimizing the electron emittance is appropriate to optimize the performance of the ring as a synchrotron light source, for the free electron laser it is desirable to operate at a lower tune having a larger emittance. This increases the Touschek lifetime and does not result in any detrimental effects on the laser gain. In fact the match between the electron beam cross section and that of the radiation field in the laser cavity is improved.

• Research Organization: Brookhaven National Lab. (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: EY-76-C-02-0016
• OSTI ID: 5831968
• Report Number(s): BNL-26668
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
FREE ELECTRON LASERS
NSLS
FAR ULTRAVIOLET RADIATION
BEAM CURRENTS
BEAM EMITTANCE
ELECTRON BEAMS
MEV RANGE 100-1000
ACCELERATORS
BEAMS
CURRENTS
CYCLIC ACCELERATORS
ELECTROMAGNETIC RADIATION
ENERGY RANGE
LASERS
LEPTON BEAMS
MEV RANGE
PARTICLE BEAMS
RADIATION SOURCES
RADIATIONS
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SYNCHROTRONS
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420300* - Engineering- Lasers- (-1989)