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  • North-Holland, Research Sectiona, K Batchelor, I Ben-Zvi, R C Fernow, J Fischer +20 others
  • 2002
The Brookhaven Accelerator Test Facility (ATF) uses a photocathode rf gun to provide a high-brightness electron beam intended for FEL and laser acceleration experiments. The rf gun consists of 1-,' cells driven at 2856 MHz in 7r-mode with a maximum cathode field of 100 MV/m. To achieve long lifetimes, our photocathode development concentrates on robust(More)
VISA (Visible to Infrared SASE Amplifier) is an FEL (Free Electron Laser) designed to saturate at a radiation wavelength of 800 nm within a 4-m long, strong focusing undulator. Large gain is achieved by driving the FEL with the 72 MeV, high brightness beam of BNL's Accelerator Test Facility (ATF). We present measurements that demonstrate saturation in(More)
CA Initial design parameters and early operational results of a 50 MeV high brightness electron linear accelerator are described. The system utilizes a radio frequency electron gun operating at a frequency of 2.856 GHz and a nominal output energy of 4.5 MeV followed by two, 2x/3 mode, disc loaded, traveling wave accelerating sections. The gun cathode is(More)
—This paper presents a new type of control scheme and device for controlling gas flow into semiconductor process chambers. The key component of the Gas Flow Controller (GFC) is a high-precision valve with an integrated position sensor, which is used to maintain a constant flow rate. A map lookup scheme is employed to adjust the valve position to accommodate(More)
Nonlinear harmonic radiation was observed using the VISA self-amplified, spontaneous emission (SASE) free-electron laser (FEL) at saturation. The gain lengths, spectra, and energies of the three lowest SASE FEL modes were experimentally characterized. The measured nonlinear harmonic gain lengths and center spectral wavelengths decrease with harmonic number,(More)
The self-amplified, spontaneous emission free-electron laser (SASE FEL) gain process is a collective instability which induces microbunching in the electron beam. Micro-bunching approaching unity at the fundamental FEL wavelength (845 nm), and its second harmonic, have been measured at the VISA FEL, at or near saturation. These measurements, which use the(More)
VISA (Visible to Infrared SASE Amplifier) is an FEL designed to obtain high gain at a radiation wavelength of 800 nm. Large gain is achieved by driving the FEL with the 71 MeV, high brightness beam of the Accelerator Test Facility (ATF) and using a novel, strong focusing, 4 m long undulator with a gap of 6 mm and a period of 1.8 cm. We report measurements(More)
The longitudinal phase space distribution of electron beam plays critical role in ultra-short electron bunch production, coherent radiation, free electron laser (FEL) and many other applications. Photocathode RF gun is capable of controlling not only the transverse emittance of electron beam, but also longitudinal emittance. The longitudinal phase space(More)
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