Title :
Measurement of the beam energy spread in the TTF photo-injector
Author :
Hüning, M. ; Schlarb, H.
Author_Institution :
Fermi Nat. Accel. Lab., USA
Abstract :
At the TESLA Test Facility (TTF) linac the required high peak current for FEL operation is achieved by compressing the beam longitudinally in a magnetic chicane. The peak current after the chicane is determined by the residual energy spread of the electron bunch which is produced by an rf photo-injector. By residual energy spread we refer to the energy spread of a temporal slice of the bunch which can not be compensated by any time dependent energy modulation. To determine the energy distribution, an improved optical system has been implemented to image the beam at an OTR-station after a spectrometer dipole. In this paper the results of the beam profile measurements are presented and compared to particle tracking simulations. It is shown that the residual energy spread in the injector on in order of a few keV only, even at bunch charges of 4 nC.
Keywords :
accelerator RF systems; accelerator magnets; electron accelerators; linear accelerators; particle beam bunching; particle beam diagnostics; particle beam dynamics; particle beam injection; particle track visualisation; particle tracks; transition radiation; FEL operation; OTR-station; TESLA Test Facility linac; TTF photo-injector; beam energy spread; beam profile measurements; bunch charges; electron bunch; energy distribution; high peak current; magnetic chicane; optical system; optical transition radiation; particle tracking simulations; residual energy spread; rf photoinjector; spectrometer dipole; temporal bunch slice; time dependent energy modulation; Electron optics; Energy measurement; Linear particle accelerator; Optical modulation; Particle beam measurements; Particle beams; Particle measurements; Particle tracking; Spectroscopy; Test facilities;
Conference_Titel :
Particle Accelerator Conference, 2003. PAC 2003. Proceedings of the
Print_ISBN :
0-7803-7738-9
DOI :
10.1109/PAC.2003.1288783
