| Paper | Title | Page |
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| WEPLT051 | Sub-Picosecond Electron Bunches in the BESSY Storage Ring | 1951 |
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BESSY is a low emittance, 1.7 Gev electron storage ring. A dedicated, low alpha optics is applied to produce short electron bunches for coherent synchrotron radiation (CSR) in the THz range[*]. By a further detuning of the optics, stable pulses as short as 0.7 ps rms length were produced. The sub-ps pulse shape is analysed by an auto-correlation method of the emitted CSR. The CSR-bursting instability is measured and compared with theory to estimate the current for stable, sub-ps pulses. Present limits of the low alpha optics are discussed.
* M. Abo-Bakr et al., Phys. Rev. Lett. 88, 254801 (2002). |
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| THPKF013 | Terahertz Diagnostics for the Femtosecond X-ray Source at BESSY | 2281 |
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A longitudinal electron density modulation caused by femtoslicing in a storage ring is accompanied by a strong broad band coherent THz-light emission between 0.3 and 10 THz at certain synchrotron radiation emitting devices downstream of the interaction region. A technique to use the THz signal for the control of the overlap of laser and electron bunch using fast infrared bolometers is described. A new dedicated THz extraction port at a bending magnet as well as a spectroscopic setup based on a Martin Puplett spectrometer will be commissioned in May 2004 together with the new femtoslicing source at BESSY.
* A. Zholentz, M. Zoloterev, PRL 76/1996, 912** H.-J. Baecker et al., these proceedings |
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| THPKF014 | Status of the BESSY II Femtosecond X-ray Source | 2284 |
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At the BESSY II storage ring, work is in progress to produce X-ray pulses with 50 fs (fwhm) duration and tunable energy and polarization by "femtoslicing" [*].This work includes extensive alterations to the storage ring (one new and one modified undulator, both in the same straight section, three additional dipole magnets, a new IR beamline, and nine meters of new vacuum vessels) and to two beamlines (relocation and new optical designs), as well as the installation of a femtosecond Ti:sapphire laser system. Commissioning is planned for May 2004. This paper reviews the principles and technical implementation of the new femtosecond X-ray source, and reports the status of the project.
* A. Zholentz, M. Zoloterev, Phys.Rev.Lett. 76 (1996), 912 |
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| THPKF015 | Compressed Electron Bunches for THz-Generation - Operating BESSY II in a Dedicated Low Alpha Mode | 2287 |
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For the first time an electron storage ring was operated during regular user shifts in a dedicated 'low alpha' mode, where electron bunches are compressed to 5 times shorter length for THz [*] and short X-ray pulses experiments. The 1 mm rms-long bunches emit powerfull, coherent THz waves, up to 107 times stronger than incoherent radiation. We report on machine set up and operating experience.
* M. Abo-Bakr et al., Phys. Rev. Lett. 88, 254801 (2002) |
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| THPLT027 | Optical Transition Radiation Based Beam Diagnostics at the BESSY Synchrotron Radiation Source and FEL Accelerators | 2529 |
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| Optical Transition Radiation (OTR) based diagnostics tools are widely used in linear accelerators to measure beam parameters like transverse beam size and emittance. Design ideas for OTR stations in the linac section of the BESSY FEL facility are presented. Several key components will be tested in the transfer lines of the BESSY storage ring. Furthermore a novel type of OTR monitor is introduced which enables the measurement of the transverse overlap of seed laser and electron beam in the undulator sections of the linac based FEL facility. Here a special radiator screen will be used allowing simultaneous imaging of both beams in the same optical readout channel. | ||
| THPLT140 | Commissioning of BL 7.2, the New Diagnostic Beamline at the ALS | 2780 |
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| BL 7.2 is a new beamline at the Advanced Light Source (ALS) dedicated to electron beam diagnostics. The system, which is basically a hard x-ray pinhole camera, was installed on the storage ring in August 2003 and the commissioning with the ALS electron beam followed immediately after. In this paper, the commissioning results are presented together with the description of the relevant measurements performed for the beamline characterization. |