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Title |
Other Keywords |
Page |
| TUPPH067 |
Commissioning of a New Emittance Measurement System at PITZ
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emittance, electron, diagnostics, gun |
474 |
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| THPPH008 |
High Peak Current Design of a Superconducting Cavity for a SRF Photoinjector
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emittance, gun, laser, cathode |
571 |
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- D. Janssen
FZR, Dresden
- F. Marhauser
BESSY GmbH, Berlin
- V. Volkov
BINP SB RAS, Novosibirsk
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In collaboration between BESSY, DESY, FZR, MBI and BINP a SRF electron gun is under development. The progress obtained in the last year is reported on this conference. The motivation for the design of a new gun cavity is the FEL project at BESSY. The electron injector of the linac should produce bunches with a charge of 2.5 nC and a transverse emittance of 1.5 mm mrad. In order to compensate the emittance expansion by space charge effects a large electric field on the cavity axis and a strong magnetic field near the cathode are necessary. The strengths of these fields are limited by the maximum magnetic surface field in superconducting cavities. We have designed a 1.5 cell gun cavity, where the magnetic field is realized by an additional RF mode (TE mode). In order to reduce third order effects of the RF fields, for the accelerating field a frequency below the linac frequency is used. The laser pulse, which creates the electron bunch, has a length of 20ps and a rise time of 2ps. In the tracking calculation the electrons start with an average energy of 1eV. For a bunch charge of 2.5 nC a transverse emittance of 1.8 mm mrad has been obtained. The maximal surface field is 160 mT.
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| THPPH019 |
Investigations of Longitudinal Beam Properties at the Photoinjector Test Facility in Zeuthen
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electron, gun, photon, dipole |
597 |
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- J. R. Roensch, J. Rossbach
Uni HH, Hamburg
- G. Asova, J. W. Baehr, H.-J. Grabosch, S. Khodyachykh, S. A. Korepanov, M. Krasilnikov, A. Oppelt, B. Petrosyan, S. Riemann, L. Staykov, F. Stephan
DESY Zeuthen, Zeuthen
- D. Lipka, F. Marhauser, R. Richter
BESSY GmbH, Berlin
- A. P. Onuchin
BINP SB RAS, Novosibirsk
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The goal of the Photoinjector Test Facility at DESY in Zeuthen (PITZ) is to test and optimise electron guns for FELs like FLASH at DESY in Hamburg. In 2005 the setup was extended by a booster cavity. In order to measure longitudinal and transverse beam properties in the range between 5 to 40 MeV/c, a viewport after the booster cavity was developed. It contains several radiators. One of them is Silica aerogel used as Cherenkov radiator for the measurement of the longitudinal electron distribution with a streak camera. Design considerations are presented and maybe first measurement results are available. The longitudinal distributions after the booster for different beam parameters are compared to the distributions before the booster.
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| THPPH020 |
Design of the Multipurpose Dispersive Section at PITZ
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quadrupole, emittance, electron, dipole |
601 |
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- S. Khodyachykh, J. W. Baehr, M. Krasilnikov, A. Oppelt, L. Staykov, F. Stephan
DESY Zeuthen, Zeuthen
- T. Garvey
LAL, Orsay
- D. Lipka
BESSY GmbH, Berlin
- J. R. Roensch
Uni HH, Hamburg
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A detailed knowledge of the parameters of a high-brightness electron beam is of major importance for evaluating the performance of a free electron laser using the beam. Therefore, a full characterization of the beam parameters is required during the commissioning of RF photoinjectors. Contributing to this task, at the Photo Injector Test Facility at DESY in Zeuthen (PITZ) a multi-purpose high energy dispersive arm (HEDA1) for electron energies up to 40 MeV is presently under construction. The dispersive section is designed such that it will combine the functionality of 1) an electron spectrometer, 2) a device for characterization of the longitudinal phase space, and 3) a transverse slice emittance measuring system. The HEDA1 consists of a 180° dipole magnet (C-Bend), followed by a slit, a quadrupole magnet, and a screen station with a read-out for the streak camera. Design considerations and the detailed lay out of the high-energy dispersive section will be presented.
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| THPPH058 |
Beam Spreading and Emittance Oscillation of an Intense Magnetized Beam in Free Space
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emittance, space-charge, focusing, electron |
721 |
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- C.-X. Wang, K.-J. Kim
ANL, Argonne, Illinois
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Intense beams with large angular momentum have important applications in electron cooling and in producing flat beams suitable for ultrafast x-ray generation, Smith-Purcell radiators, and possibly for a future linear collider. To gain basic understanding of the influence of beam angular momentum in an otherwise space-charge-dominated beam, the behavior of such a beam in free space will be examined here, in particular, beam spreading due to space-charge force, as well as emittance oscillation. Drift space is an important part of a split photoinjector and plays a significant role in emitance compensation of a high-brightness photoinjector.
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