Emittance growth in the FEL RF-gun

Author

Krassilnikov, M. ; Setzer, S. ; Weiland, T. ; Novokhatski, A.

Author_Institution

Darmstadt Univ. of Technol., Germany

Volume

3

fYear

2001

fDate

2001

Firstpage

2257

Abstract

A high brightness and low emittance is of crucial importance for the SASE-FEL at the TESLA Test Facility. Therefore a photo-RF-gun has been installed as particle source. Numerical simulations with codes like ASTRA and MAFIA show that the space charge dominated processes inside the RF-gun contribute significantly to the emittance. In this paper we present the results of detailed studies with MAFIA TS2 which clarify the effects resulting in emittance growth for space charge dominated beams. It is shown that the resulting emittance can be minimized by changing the laser parameters like pulse length and spot size on the cathode. Additionally we present the concept of slice emittances which allows a more precise prediction of the real transverse emittance achievable with an emittance compensation scheme

Keywords

electron guns; free electron lasers; particle beam diagnostics; FEL RF-gun; MAFIA TS2; SASE-FEL; emittance growth; laser pulse length; laser spot size; photo-RF-gun; space charge dominated beams; Cathodes; Laser beams; Laser theory; Magnetic fields; Magnetic flux density; Optical pulses; Particle beams; Predictive models; Solenoids; Space charge;

fLanguage

English

Publisher

ieee

Conference_Titel

Particle Accelerator Conference, 2001. PAC 2001. Proceedings of the 2001

Conference_Location

Chicago, IL

Print_ISBN

0-7803-7191-7

Type

conf

DOI

10.1109/PAC.2001.987344

Filename

987344