Author/Authors :
Rimjaem، نويسنده , , S. and Stephan، نويسنده , , F. and Krasilnikov، نويسنده , , Jack M. and Ackermann، نويسنده , , W. and Asova، نويسنده , , G. and Bنhr، نويسنده , , J. and Gjonaj، نويسنده , , E. and Grabosch، نويسنده , , H.J. and Hakobyan، نويسنده , , L. and Hنnel، نويسنده , , M. and Ivanisenko، نويسنده , , Y. and Khojoyan، نويسنده , , M. and Klemz، نويسنده , , G. and Lederer، نويسنده , , S. and Mahgoub، نويسنده , , M. and Michelato، نويسنده , , P. and Monaco، نويسنده , , L. and Nozdrin، نويسنده , , M. and OʹShea، نويسنده , , B. and Otevrel، نويسنده , , M. and Petrosyan، نويسنده , , B. E. Richter، نويسنده , , D. and Rِnsch-Schulenburg، نويسنده , , J. and Sertore، نويسنده , , D. Servan-Schreiber، نويسنده , , S. and Schnepp، نويسنده , , S. and Shapovalov، نويسنده , , A. and Spesyvtsev، نويسنده , , R. and Staykov، نويسنده , , L. and Vashchenko، نويسنده , , G. and Weiland، نويسنده , , T. and Will، نويسنده , , I.، نويسنده ,
Abstract :
High brightness electron sources for linac based short-wavelength free-electron lasers are developed and optimized for small transverse projected emittance at the photo-injector test facility at DESY, location Zeuthen (PITZ). A major part of the measurement program at PITZ is dedicated to transverse phase space optimization in order to fulfill the requirements of the European X-ray free-electron laser (European XFEL). A laser-driven RF-gun, treated with a dry-ice sublimation-impulse cleaning technique, a new photocathode laser system allowing short rise and fall times of the flat-top temporal distribution as well as several new diagnostic components have been installed at PITZ in 2008. The electrons generated via the photo-effect at a cesium telluride (Cs2Te) cathode are accelerated by a 1.6 cell L-band RF-gun cavity with a maximum accelerating gradient at the cathode of about 60 MV/m. The transverse projected emittance is measured using a single slit scan technique. In the 2008–2009 run period, a detailed characterization of the projected transverse emittance was performed at different operating conditions. Optimizations and measurement results as well as simulation predictions of the transverse projected emittance for bunch charges of 1, 0.5, 0.25 and 0.1 nC are presented and discussed in this paper. The geometric mean of the normalized projected rms emittance in both transverse directions for an electron bunch charge of 1 nC was measured to be 0.89±0.01 mm mrad for a 100% rms phase-space distribution.
