| Paper | Title | Page |
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| MOPFI001 | Characterization of a Superconducting Pb Photocathode in a SRF Gun Cavity | 279 |
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Funding: Work supported by Bundesministerium für Bildung und Forschung and Land Berlin. The Pb deposition activity is supported by EuCARD. Photocathodes are a limiting factor for the next generation of ultra-high brightness photoinjector driven accelerators. We studied the behavior of a superconducting Pb cathode in the cryogenic environment of a superconducting rf gun cavity related to the quantum efficiency, its spatial distribution and the work function. Cathode surface contaminations can modify the performance of the photocathodes as well as the gun cavity. We discuss the possibilities to remove these contaminations. |
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| MOPFI002 | Results from Beam Commissioning of an SRF Plug-gun Cavity Photoinjector | 282 |
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| Superconducting rf photoelectron injectors (SRF guns) hold the promise to deliver high brightness, high average current electron beam for future lightsources or other applications demanding continuous wave operation of an electron injector. This paper discusses results from beam commissioning of a hybrid Pb coated plug-gun Nb cavity based SRF photoinjector for beam energies up to 3 MeV at Helmholtz-Zentrum Berlin. Emittance measurements and transverse phase space characterization with solenoid-scan and pepperpot methods will be presented. | ||
| TUPEA003 | Components for CW and LP Operation of the XFEL Linac | 1164 |
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| The European XFEL will use superconducting TESLA cavities operating with 650 μs long bunch trains. With 220 ns bunch spacing and 10 Hz RF-pulse repetition rate, up to 27000 high quality bunches/s will be delivered to insertion devices generating unprecedented high average brilliance photon beams at very short wavelength. While many experiments can take advantage of full bunch trains, others prefer an increased intra-pulse distance of several μ-seconds between bunches, or short bursts with a kHz repetition rate. In this contribution, we discuss progress in the R&D program for a future upgrade of the European XFEL linac, to operation in the continuous wave (cw) and long pulse (lp) mode, which will allow for much more flexibility in the electron and photon beam time structure. Modifications and cw tests of XFEL cryomodules, recent tests result of the SRF injector, test of the second prototype of 120 kW IOT are presented. In addition, computer modeling of the cw-operating TESLA-like cavity with modified HOM couplers is briefly discussed. | ||
| WEPWO002 | RF Measurements of the 1.6 Cell Lead/Niobium Photoinjector in HoBiCaT | 2313 |
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| The development of a simple and robust SRF photoinjector capable of delivering up to 1 mA average current in c.w. operation continues to progress with the horizontal RF testing of the 1.6 cell Pb/Nb hybrid photoinjector. This injector utilizes a sputtered lead coating on a removable Nb cathode plug as the photoelectron source and has recently been tested in the horizontal test cryostat facility, HoBiCaT, at HZB. In this paper we will report on the status of these RF measurements and compare the performance to previous vertical RF tests performed at JLab. We will also report on the experience operating this cavity with a TTF-III high power RF input coupler, as well as provide a summary of the microphonics susceptibility now that it has been installed into a helium vessel and equipped with a Saclay style tuner. | ||
| WEPWO007 | Shape Optimization of a SRF Injector Cavity | 2322 |
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| In this contribution we present studies on the shape optimization of 1.6-cell cavity with solenoid for a 1-mA class photo injector, meant as an electron source for FEL facilities. The main criterion for the optimization was the lowest slice emittance. Inclination angle of the cavity back wall, solenoid position and magnetic field, amplitude of the accelerating field, and emission phase were varied in these studies in order to find the minimum of slice emittance at the distance of 1 m from a photocathode, located in center of the cavity back wall | ||