Library

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 70 (1999), S. 1530-1534 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Generation of a uniform density plasma has been a key consideration in the design of microwave/plasma processing systems. A circularly polarized wave can generate a plasma with good azimuthal uniformity as well as provide strong resonant interaction with the plasma electrons. In this article, we report the development of a three-port polarization converter which efficiently converts the TE10 wave of a standard rectangular waveguide into a circularly polarized TE11 wave of a cylindrical waveguide. Employing the same principle for mode conversion, the converter is also made to function as a protective device of the high power microwave source by providing a separate port for the return and damping of the reflected wave. Such a converter has been analyzed, constructed, and tested. At the operating frequency of 2.45 GHz, test results indicate a 25 dB return loss, 97% end-to-end polarization conversion efficiency, and better than 20 dB rejection of the reflected wave. The structural simplicity of the device allows high power operation as well as easy construction for system research and applications. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 3 (1991), S. 2403-2408 
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Mode interactions in the gyrotron traveling wave tube amplifier (gyro-TWT) are examined with particle simulations and compared with experimental observations. Studies focus on the competition between the absolute and convective instabilities. Detailed diagnostics on mode structures, field growth profiles, and evolution of electron distribution in momentum and energy spaces allow an in depth look at the basic physical processes, such as the mechanism of mode competition and suppression. Mutual verifications between the theory and experiment have strengthened understanding of the multimode behavior and added to the predictability of high-power gyro-TWT's.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 65 (1994), S. 2404-2406 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A novel scheme producing multiple, coherently phased, high charge (nC), short duration (ps) electron bunches in a radio-frequency (rf) photoinjector is presented. In this configuration, the mirror photocathode is an integral part of an optical resonator. The ultrashort laser pulse is reflected off the photocathode and recirculated through the optical cavity at a subharmonic of the rf drive frequency after extracting a photoelectron bunch. This new technique can dramatically increase the effective quantum efficiency of metals and produce high current, high brightness, prebunched electron beams ideally suited for high power coherent microwave generation. A proof-of-principle experiment operating at 0.250 GHz and using a frequency-quadrupled, mode-locked Nd:YAG laser has shown the production of a train of coherently phased photoelectron bunches, with a measured effective quantum efficiency enhancement of 4.2. © 1994 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 60 (1992), S. 292-294 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Computer simulation results reveal that the superradiant modes in free-electron laser amplifiers with high gain and long interaction length tend to degrade the amplifier performance. If these modes are kept at low levels, the amplifier efficiency can be significantly improved. This observation can be employed to interpret the recent MIT reversed guide field free-electron laser experiment.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    International journal of infrared and millimeter waves 5 (1984), S. 103-121 
    ISSN: 1572-9559
    Keywords: gyrotron ; microwaves ; millimeter waves ; space charge
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Analytical expression for the space charge limited current is derived on the basis of a simplified model. Numerical data for wide ranging beam and geometrical parameters are presented.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    International journal of infrared and millimeter waves 12 (1991), S. 297-322 
    ISSN: 1572-9559
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The cyclotron autoresonance maser (CARM) is shown to be capable of extremely high power efficient operation with relatively weak magnetic field requirements. A general description of the CARM traveling wave amplifier is presented. The linear theory is applied to study the stability of the device and a self-consistent numerical simulation code is used to predict the performance. It is found that grazing intersection often gives superior performance, especially for high current electron beams. The designs of two CARM amplifiers for the applications of a high gradient rf linac and electron cyclotron resonance plasma heating as well as a proof of principle experiment are presented.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    International journal of infrared and millimeter waves 13 (1992), S. 1571-1598 
    ISSN: 1572-9559
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    International journal of infrared and millimeter waves 2 (1981), S. 159-174 
    ISSN: 1572-9559
    Keywords: Gyrotrons ; high power mm wave sources ; power limits
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Upper and lower limits to the output power of highly efficient gyrotron oscillators operating with TEon1 modes, due to lower and upper limits on the cavity Q, are given.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    International journal of infrared and millimeter waves 2 (1981), S. 415-425 
    ISSN: 1572-9559
    Keywords: wide-band fast wave gyro-TWA ; tapered magnetic field ; bandwidth ; contoured waveguide ; streaming electrons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A simple scheme is proposed for the construction of a wide-band fast wave gyrotron travelling wave amplifier. The key features of this scheme include a contoured waveguide, a tapered magnetic field, and injection of input signals in opposite direction of the streaming electrons. Bandwidths at tens of percents, and gain at tens of decibals, are projected.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    International journal of infrared and millimeter waves 2 (1981), S. 373-393 
    ISSN: 1572-9559
    Keywords: gyrotron travelling wave amplifier ; oscillations ; threshold currents ; oscillation suppression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The operation of the gyrotron travelling wave amplifier is based on the convective cyclotron maser instability. It is found that this convective instability may become absolute (nonconvective) at a sufficiently high current level, resulting in oscillation instead of amplification. This threshold current for the transition depends sensitively on the applied magnetic field. The axial wavelength and the characteristic frequency of oscillation at the onset of absolute instability are given. It is found that momentum spread has virtually no effect on the threshold current. A small amount of resistive wall loss, however, raises the threshold current significantly. Oscillations due to partial reflection at the ends of the system are also examined. Preliminary experimental results on both types of oscillations are reported and are found to be in good agreement with the theory.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...