Paper 
Title 
Other Keywords 
Page 
WEPPH008 
Measurements of Projected Emittances at FLASH

emittance, undulator, electron, linac 
338 

 F. Loehl, E. Prat
DESY, Hamburg
 K. Honkavaara
Uni HH, Hamburg


FLASH is a SASE FEL user facility at DESY (Hamburg) operating with photon wavelengths in the range from vacuum ultraviolet to soft xrays. Although the slice emittance is a more appropriate parameter to characterize the SASE process, the projected emittance provides a useful measure of the electron beam quality. At FLASH the projected emittance is measured at three location along the linac: in the injector (130 MeV), after the collimator (full electron beam energy), and in the undulator section. The transverse beam shape is measured with OTR monitors and wire scanners. The multimonitor method is used to determine the emittance. In this paper we describe the measurement setup and procedure and report recent results and planned upgrades.



WEPPH034 
Fourier and NonFourier Models for Photoemission

laser, electron, vacuum, cathode 
428 

 A. M. Mihalache, E. Mitru, M. Oane, C. PetitJeanGenaz
INFLPR, Bucharest  Magurele


This paper is a theoretical study on the photoemission properties of metallic photocathodes in the high intensity ultrashort laser pulse regime, using Fourier and nonFourier models. First of all the Fouriermodel was used. Next an analysis of the electron gas heating phenomenon and how this phenomenon leads to coupled heat equations (two temperature models). The authors also try to show that it is possible to use, in the second approximation, a nonFourier model instead of two temperature models, using a single temperature hypothesis (the electron gas temperature equals with the lattice temperature). The distributions for thermal fields and photocurrents function of space, time, laserintensity, incident angle and relaxation time are also represented.


