Title :
A traveling wave accelerator with HOM outcouplers for FELs
Author :
Miller, R. ; Lampel, M.
Author_Institution :
SLAC, Stanford, CA, USA
Abstract :
The application to FELs (free-electron lasers) of RF electron guns with laser-driven photocathodes has opened the door to developing efficient optical FELs. The next task is to develop accelerator structures which can transport such beams with a minimum of beam degradation. A low-cost approach to this using four 1.26-m constant gradient (CG) TW sections driven in parallel by a SLAC 5045 klystron is suggested. Using CG sections makes the higher order modes incoherent due to the linearly decreasing group velocity along the structure. Together with incorporating higher-order-mode outcouplers, this system is predicted to accelerate 1 nC per micropulse, 0.4 A per macropulse to 75 MeV from an injection energy of 5 MeV. Emittance growth is predicted to be 5 mm-mr.<>
Keywords :
electron accelerators; electron guns; free electron lasers; klystrons; linear accelerators; photocathodes; FEL; HOM outcouplers; RF electron guns; SLAC 5045 klystron; TW sections; accelerator structures; beam degradation; constant gradient; emittance growth; free-electron lasers; higher order modes; higher-order-mode outcouplers; injection energy; laser-driven photocathodes; linearly decreasing group velocity; low-cost approach; macropulse; micropulse; traveling wave accelerator; Cathodes; Character generation; Degradation; Electron guns; Electron optics; Free electron lasers; Klystrons; Laser beams; Particle beams; Radio frequency;
Conference_Titel :
Particle Accelerator Conference, 1991. Accelerator Science and Technology., Conference Record of the 1991 IEEE
Conference_Location :
San Francisco, CA, USA
Print_ISBN :
0-7803-0135-8
DOI :
10.1109/PAC.1991.165259
