Filters

2017 - 201912020 - 20211

More filters

2022 - 20232
Reset filters

Settings

Type: Text × Subject: Electron sources ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Successful user operation of a superconducting radio-frequency photoelectron gun with Mg cathodes
    (College Park, MD : American Physical Society, 2021) Teichert, J.; Arnold, A.; Ciovati, G.; Deinert, J.-C.; Evtushenko, P.; Justus, M.; Klopf, J.M.; Kneisel, P.; Kovalev, S.; Kuntzsch, M.; Lehnert, U.; Lu, P.; Ma, S.; Murcek, P.; Michel, P.; Ryzhov, A.; Schaber, J.; Schneider, C.; Schurig, R.; Steinbrück, R.; Vennekate, H.; Will, I.; Xiang, R.
    At the electron linac for beams with high brilliance and low emittance (ELBE) center for high-power radiation sources, the second version of a superconducting radio-frequency (SRF) photoinjector has been put into operation and has been routinely applied for user operation at the ELBE electron accelerator. SRF guns are suitable for generating a continuous wave electron beam with high average currents and high beam brightness. The SRF gun at ELBE has the goal to generate short electron pulses with bunch charges of 200–300 pC at typical repetition rates of 100 kHz for the production of superradiant, coherent terahertz radiation. The SRF gun includes a 3.5-cell, 1.3-GHz niobium cavity and a superconducting solenoid. A support system with liquid nitrogen (LN2) cooling allows the operation of normal-conducting, high quantum efficiency photocathodes. We present the design and performance of the SRF gun as well as beam measurement results of the operation with Mg photocathodes at an acceleration gradient of 8  MV/m (4 MeV kinetic energy). In the last section, we discuss the SRF gun application for production of coherent terahertz radiation at the ELBE facility.
  • Thumbnail Image
    Item
    Towards shot-noise limited diffraction experiments with table-top femtosecond hard x-ray sources
    (Melville, NY : AIP Publishing LLC, 2017) Holtz, Marcel; Hauf, Christoph; Weisshaupt, Jannick; Salvador, Antonio-Andres Hernandez; Woerner, Michael; Elsaesser, Thomas
    Table-top laser-driven hard x-ray sources with kilohertz repetition rates are an attractive alternative to large-scale accelerator-based systems and have found widespread applications in x-ray studies of ultrafast structural dynamics. Hard x-ray pulses of 100 fs duration have been generated at the Cu Kα wavelength with a photon flux of up to 109 photons per pulse into the full solid angle, perfectly synchronized to the sub- 100-fs optical pulses from the driving laser system. Based on spontaneous x-ray emission, such sources display a particular noise behavior which impacts the sensitivity of x-ray diffraction experiments. We present a detailed analysis of the photon statistics and temporal fluctuations of the x-ray flux, together with experimental strategies to optimize the sensitivity of optical pump/x-ray probe experiments. We demonstrate measurements close to the shot-noise limit of the x-ray source.