A   B   C   D   E   F   G   H   I   K   L   M   N   O   P   Q   R   S   T   U   V   W  


Paper Title Other Keywords Page
TUP007 The Power and Polarisation Upgrade Project at the S-DALINAC Injector electron, cavity, cathode, vacuum 398
  • R. Eichhorn, R. Barday, U. Bonnes, M. Brunken, J. Conrad, C. Eckardt, J. Enders, H.-D. Gräf, C. Heßler, T. Kuerzeder, C. Liebig, M. Platz, Y. Poltoratska, M. Roth, S.T. Sievers, T. Weilbach
    TU Darmstadt, Darmstadt
  • W. Ackermann, W.F.O. Müller, B. Steiner, T. Weiland
    TEMF, TU Darmstadt, Darmstadt
  • K. Aulenbacher
    IKP, Mainz
  • J.D. Fuerst
    ANL, Argonne

Funding: Work supported by the DFG through SFB 634
At the superconducting Darmstadt linear accelerator S-DALINAC currently two upgrades of the injector are underway: The current upgrade for the injector mainly involves the superconducting rf part. In order to increase the maximum current from 60 uA to 150 or 250 uA the power coupler design had to be modified, resulting in major changes in the whole cryo-module. Second, an additional polarized electron source (SPIN) has been set-up at an offline test area. There, the polarized electrons are produced by photoemission at a strained GaAs cathode on a 100 kV platform. The test beam line includes a Wien filter for spin manipulation, a Mott polarimeter for polarization measurement and additional diagnostic elements. We will give an overview over the project, report on the status and present first measurement results including the proof of polarisation.

FR104 Review of Advanced Laser Technologies for Photocathode High-Brightness Guns laser, electron, cathode, gun 1105
  • H. Tomizawa, H. Dewa, H. Hanaki, A. Mizuno, T. Taniuchi
    JASRI/SPring-8, Hyogo-ken

I developed a 3-D pulse shaping system in UV as an ideal laser for yearlong stable photoinjector. At SPring-8, the laser's pulse-energy stability has been improved to 0.7~1.4% at the UV (263 nm) under the laser environmental control included humidity. In addition, the ideal spatial and temporal profiles of an UV-laser pulse are essential to suppress emittance growth in an rf gun. I apply a deformable mirror that automatically shapes the spatial profile with a feedback routine, based on a genetic algorithm, and a pulse stacking system consisting of three birefringence Alpha-BBO crystal rods for temporal shaping at the same time. The 3D shape of the laser pulse is spatially top-hat (flattop) and temporally a square stacked chirped pulse. Using a 3D-shaped laser pulse with diameter of 0.8 mm on the cathode and pulse duration of 10 ps (FWHM), we obtain a normalized emittance of 1.4 pi mm mrad with a beam energy of 26 MeV. To keep the mirror away from beam axis, I developed a new hollow laser incidence with an axicon final focusing. Furthermore, I am developing a laser-induced Schottky-effect-gated photocathode gun using Z-polarization of the laser source with the hollow incidence.


slides icon