|
abstract:
|
The Brookhaven Accelerator Test Facility (ATF) consists of a 50-MeV/c electron linac and a high-brightness RF gun, both operating at 2856 MHz. An extremely short (a few picoseconds) electron pulse with a low transverse emittance is generated by the RF gun. In order to preserve both longitudinal and transverse emittances, great care must be taken in transporting the electron beam from the RF gun to the linac. The injection line is described, first- and second-order lattice studies of the injection line are presented, and nonlinear effects on the emittance are studied. It is shown that it is possible to preserve transverse emittance in a low-energy beam-transfer line by use of slits and contoured edges of the dipole magnets. Bunch lengthening is induced by the large beam divergence out of the RF gun, thus requiring strong focusing. (11 References).
|