Stephan, F.
Paper | Title | Page |
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MOPP034 | Upgrades of the Laser Beam-line at PITZ | 110 |
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Funding: This work has partly been supported by the European Community, contract numbers RII3-CT-2004-506008 and 011935, an by the "Impunls-und Vernetzungsfonds" of the Helmholtz Association, contract number VH-FZ-05 In spring of 2005 an essential upgrade of the photocathode laser and of the 27 m long laser beam-line took place at PITZ. A detectable improvement of the laser beam profile at the photocathode is expected. This improvement should lead to an additional reduction of the transverse emittance of the electron beam. The upgraded laser consists of a fully laser diode pumped scheme of pulse train oscillator, pre-amplifiers and booster amplifiers. The main advantages of this upgrade are improved stability, easier maintenance and long-term operations at 10 Hz repetition rate. In addition, the scheme of the optical beam-line was changed: The distance between the beam shaping aperture and the cathode was strongly reduced. Therefore a further improvement of the laser beam profile at the photocathode is expected. The laser beam-line is upgraded by an enlarged number of remotely controlled optical elements that allows the fine tuning of the laser beam characteristics during the running. New diagnostics tools are included in the laser beam-line. The paper focuses on the design of the new optical beam-line. It describes the results of electron beam measurements using the upgraded laser and the new PITZ2 electron beam-line in detail. |
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THPP042 | Measurements of Thermal Emittance for Cesium Telluride Photocathodes at PITZ | 560 |
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Funding: This work has partly been supported by the European Community, contract numbers RII3-CT-2004-506008 and 011935, and by the 'Impuls- und Vernetzungsfonds' of the Helmholtz Assciation, contract number VH-FZ-005 The thermal emittance determines the lower emittance limit and its measurement is of high importance to understand the ultimate injector performance. In this contribution we present results of thermal emittance measurements under rf operation conditions for various Cs2Te cathodes and different accelerating gradients. Measurements of thermal emittance scaling with the cathode laser spot size are presented and analysed. The significance of the Schottky effect in the emittance formation process is discussed. |
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THPP073 | Commissioning of the SPARC Movable Emittance Meter and Its First Operation at PITZ | 652 |
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For the SPARC Project a novel diagnostic device, called "Emittance-meter", has been conceived and constructed to perform a detailed study of the emittance compensation process in the SPARC photo-injector and to optimize the RF-gun and the accelerator working point. It consists of a movable emittance measurement system, based on the 1D pepper-pot method, installed between two long bellows with the possibility to scan a region 1.5 m long downstream the RF-gun. The construction of the device was completed in the first part of this year and a series of laboratory tests, to evaluate its performances, were carried out in Spring 2005. At the beginning of the summer the complete system was moved to DESY at Zeuthen to be installed on the Photo Injector Test Facility PITZ. After the commissioning it will used for measurements of the PITZ electron beam in the framework of a collaboration between the SPARC and PITZ Projects aiming on studies and operations with photo injectors. |
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THPP040 | Longitudinal Phase Space Studies at PITZ | 552 |
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Funding: This work has partly been supported by the European Community, contract numbers RII3-CT-2004-506008 and 011935, and by the 'Impuls- und Vernetzungsfonds' of the Helmholtz Association, contract number VH-FZ-005. The main goal of the Photo Injector Test facility at DESY Zeuthen (PITZ) is to test and to optimize photo injectors for Free-Electron Lasers (FELs). The demands on such a photo injector are small transverse emittances, short bunches and a high bunch charge. A FEL is driven by an accelerator which consists of a rf gun followed by an acceleration section and a magnetic bunch compressor. For the effective bunch compression detailed studies of the longitudinal phase space have to be performed. The correlation between the positions of the particles in the bunch and their longitudinal momenta has to be understood and the non-linearities of the longitudinal phase space have to be analysed. A special apparatus for longitudinal phase space tomography at 5 MeV using a dipole, a Cherenkov radiator, an optical transmission line and a streak camera was developed. Results of longitudinal phase space measurements are presented and compared with simulations. |
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THPP043 | Status and First Results from the Upgraded PITZ Facility | 564 |
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Funding: This work has been partly supported by the European Community, contract numbers RII3-CT-2004-506008 and 011935, and by the 'Impuls- und Vernetzungsfonds" of the Helmholtz Association, contract number VH-FZ-05. Since December 2004, the photo injector test facility at DESY in Zeuthen (PITZ) has been upgraded. A normal conducting copper booster cavity has been installed and the diagnostics beamline has been strongly modified. An extended water cooling system has been installed and was successfully taken into operation. Actually, the new diagnostics elements are being commissioned. After the installation of the new 10 MW klystron in June/July, the gun can be conditioned towards higher average power, and the whole beamline including the booster will be taken into operation. First results from the commissioning phase including gun and booster conditioning are reported. |
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