ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • American Institute of Physics (AIP)  (3)
  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 66 (1989), S. 4425-4430 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Experiments were conducted in which a high-power CO2 TEA laser interacted with metallic cathode in a high-vacuum (10−8 Torr) diode. For power densities lower than 5×107 W/cm2, no current was detected. For power densities in the range of 5×107–5×108 W/cm2, the Cu cathode emitted a maximum current of 40 mA. At a higher power density level, a circuit-limited current of 8 A was detected. The jump of a few orders of magnitude in the current is attributed to breakdown of the diode gap. The experimental results are similar to those of a triggered vacuum gap, and a thorough comparison is presented in this paper. The influence of the pressure in the vacuum chamber on the current magnitude shows the active role that adsorbed gas molecules have in the initial breakdown. When the cathode material was changed from metal to metal oxide, much lower laser power densities were required to reach the breakdown current region.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 76 (2000), S. 16-18 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We present a method for enhancing the efficiency of a Free Electron Laser Maser oscillator by locking it to a preferred resonator mode. This is done by prebunching of the e beam before injection into the wiggler. In a free running oscillator, the longitudinal mode that dominates the mode competition process during the oscillation buildup period is usually the highest gain mode. However, this mode does not extract the highest energy from the e beam. Lower eigenfrequency modes would provide a higher efficiency if they could dominate the mode competition process. By prebunching the e beam at a frequency near any one of the longitudinal eigenfrequencies of the resonator (having a gain〉1), we can make that mode dominant at saturation. The eigenfrequency for which the maximum efficiency is obtained is the lowest eigenfrequency of the resonator for which the net small signal gain is greater than 1. Employing an experimental setup of a prebunched beam Free Electron Maser, we demonstrated efficiency enhancement of 30% for this lowest eigenfrequency mode (as compared to the highest gain mode). Simulation results predict an efficiency enhancement of up to 50%. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The lasing of a Van de Graaff electrostatic accelerator–free-electron laser (EA–FEL) with an internal cavity is reported. An EA–FEL employing an internal cavity is a FEL configuration that has a potential to operate at high average power, high frequency, and possibly in a continuous wave (cw) mode. The initial lasing provided a pulsed radiation power of 1 kW at 100.5 GHz frequency. The FEL operated with a 1.4 A, 1.4 MeV electron beam in a recirculation (depressed collector) configuration. It utilizes a high quality (Q(approximate)30 000) Talbot effect resonator and a Halbach-type wiggler placed internally in the center of the accelerator tank. Nonlinear features of the oscillation power buildup and decay near saturation and mode hopping were observed and are interpreted. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...