csr
| Paper | Title | Other Keywords | Page |
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| MOPP035 | Bunch Length Measurements Using a Martin-Puplett Interferometer at the VUV-FEL | radiation, interferometer, electron, bunch-compressor | 114 |
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The longitudinal charge distribution of short electron bunches can be characterized by a measurement of their coherent far-infrared radiation spectrum. This paper will present the results obtained at the DESY VUV-FEL linear accelerator by observation of synchrotron radiation with a Martin-Puplett interferometer. The reconstructed bunch shapes are strongly asymmetric with a full width at half maximum of about 1 ps. |
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| TUPP035 | Generation of Coherent Synchrotron Radiation from JAERI-ERL | fel, electron, beam-transport, undulator | 301 |
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An electron beam with high-average current and short bunch length can be accelerated by energy-recovery linac. Coherent synchrotron radiation (CSR) from such an electron beam will be a useful light source around millimeter wavelength. We report results from a preliminary measurement of CSR emitted from a bending magnet of JAERI-ERL. Possible enhancement of CSR power by FEL micro-bunching is also discussed. |
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| THPP056 | Initial Measurements of CSR from a Bunch-Compressed Beam at APS | auto-correlation, gun, linac, radiation | 608 |
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Funding: Work supported by U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38. The interest in bunch compression to generate higher peak current electron beams with low emittance continues in the free-electron laser (FEL) community. At the Advanced Photon source (APS) we have both an rf thermionic gun and an rf photocathode (PC) gun on the S-band linac. At the 150-MeV point in the linac, we have a flexible chicane bunch compressor whose four dipoles bend the beam in the horizontal plane. There is also a vertical bend dipole after the chicane that allows measurement of energy and horizontal beam size at the imaging screen station to study possible effects on emittance due to coherent synchrotron radiation (CSR) in the chicane. A far-infrared (FIR) coherent radiation monitor is located downstream of the chicane as well. We have begun recommissioning of this device with coherent transition radiation (CTR), but we also have directly observed CSR from the bunch-compressed beam as it transits the vertical dipole and goes into the down leg. The unique geometry allows simultaneous tracking of bunch length, horizontal emittance, and energy distribution effects. Initial measurements of the CSR and CTR as a function of linac phase are described. |
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| THPP061 | Self-Consistent Simulation of a Bunched Electron Beam Including Radiation, Space-Charge and Boundary Conditions | electron, radiation, simulation, space-charge | 624 |
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Funding: Work supported by the Office of Naval Research and the Joint Technology Office. High power Free Electron Laser (FEL) designs require high-brightness beams. These beams may suffer beam quality degradation during transport through bending sections from effects that were previously insignificant at low bunch charges. Potential mechanisms include microbunching from longitudinal space-charge and transverse emittance dilution from coherent synchrotron radiation. The effects are not well-understood in the transient state, in the presence of conducting boundaries or when these effects operate together and in conjunction with the beam dynamics. A simulation method applicable under the conditions of a MW-class average power FEL driver has been developed that accounts for radiation, space-charge and boundary conditions in a self-consistent manner. This simulation may be useful in evaluating design concepts under consideration including chicane bunch compressors and energy recovery bending arcs. |
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