Normal conducting RF cavity of high current photoinjector for high power CW FEL.

Conference · Thu Jan 01 04:00:00 EST 2004

OSTI ID:977827

Kurennoy, S ^[1]; Schrage, D L ^[2]; L, Wood R ^[3]; Schultheiss, T ^[4]; Rathke, J ^[5]; Christina, V; Young, L M ^[6]

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1. Sergey
2. Dale L.
3. Richard L.
4. Thomas
5. John
6. Lloyd M.

An RF photoinjector capable of producing high continuous average current with low emittance and energy spread is a key enabling technology for high power CW FEL. The design of a 2.5-cell {pi}-mode 700-MHz normal-conducting RF photoinjector cavity with magnetic emittance compensation is completed. With the electric field gradients of 7, 7, and 5 MV/m in the three cells, the photoinjector will produce a 2.5-MeV electron beam with 3-nC charge per bunch and 7 mm-mrad transverse rms emittance. Electromagnetic modeling was used extensively to optimize ridge-loaded tapered waveguides and RF couplers, which led to a new improved coupler-iris design. The results, combined with a thermal/stress analysis, show that the challenging problem of cavity cooling can be successfully solved. A demo 100-mA (at 35-MHz bunch-repetition rate) photoinjector is being manufactured. The design is scalable to higher power levels by increasing the bunch repetition rate, and provides a path to a MW-class amplifier FEL. The cavity design and details of RF coupler modeling are presented.

• Research Organization: Los Alamos National Laboratory
• Sponsoring Organization: DOE
• OSTI ID: 977827
• Report Number(s): LA-UR-04-5873
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
AMPLIFIERS
BEAM EMITTANCE
BEAM INJECTION
CAVITIES
DESIGN
ELECTRON BEAMS
FREE ELECTRON LASERS
RF SYSTEMS
THERMAL ANALYSIS