| Paper | Title | Page |
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| TUPEA038 | A Digital Baseband Low Level RF Control for the P-linac Test Stand at GSI | 1413 |
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During the redesign of the low level RF system for the S-DALINAC, a baseband approach was chosen. The RF signals from/ to the cavity are converted into the baseband via I/Q Modulators/ Demodulators. The advantage of this design was realized lateron, as adaption of other frequencies becomes rather easy. The system, originally designed for 3 GHz superconducting cavity in cw operation is currently modified to control a 324 MHz room temperature CH cavity in pulsed operation. We will report on the rf control system principle, the required modifications and first results. |
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| THPEC019 | Implementation of a Polarized Electron Source at the S-DALINAC | 4083 |
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At the superconducting 130 MeV Darmstadt electron linac S-DALINAC* a source of polarized electrons** is being installed, extending the experimental capabilities with polarized electron and polarized photon probes for nuclear structure studies. This involves disassembling the existing low energy test stand and rebuilding the beam line in the accelerator hall. The beam itself is produced from a GaAs cathode by irradiation with a pulsed laser. The low-energy electron beam line includes diagnostic elements, a Wien filter for spin manipulation, a 100 keV Mott polarimeter for polarization measurement and a chopper-prebuncher section to modulate the time structure of the beam. At higher energies a 5-10 MeV Mott polarimeter and a 50-130 MeV Moeller polarimeter as well as a Compton transmission polarimeter will be installed to measure the beam polarization after acceleration. The Mott polarimeter is working with backscattered electrons under 165° scattering angle while for the Moeller polarimeter a wide-angle (3°-15°) spectrometer magnet was designed. We report on the performance of the test stand, the ongoing implementation, and the polarimeter research and development. * A. Richter, Proc. EPAC 96, Sitges, p.110. |