A thin film dispenser or micro-dispenser cathode can be generated using standard RF sputtering deposition technology. These films are compositionally modulated structures based on W and a multi-component Ba oxide. Annealing to temperatures from 900 to 1300 K results in Ba reduction, transport and diffusion across the emitter surface. A finite temperature range exists (<1200 K) where a uniform Re coating can be retained at the emitter surface. The metallic coating results in a nearly homogeneous work function based on emission characteristics. These films produce stable emission at higher temperatures (⩾1200 K) where the uniform Re coating is lost. Analysis of emission properties yield a work function of 2.2 eV and an apparent emission coefficient of 6 A⋅cm−2⋅K−2 after annealing to 1200 K. This high apparent emission coefficient yields a film suitable for milliwatt power generation applications. Microminiature Thermionic Converters (MTCs) are one potential application for these films.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    A novel thin film dispenser cathode for thermionic emission


    Contributors:

    Conference:

    Space Technology and Applications International Forum - 2001 ; 2001 ; Albuquerque, New Mexico


    Published in:

    AIP Conference Proceedings ; 552 , 1 ; 1165-1170


    Publication date :

    2001-02-02


    Size :

    6 pages





    Type of media :

    Conference paper


    Type of material :

    Electronic Resource


    Language :

    English



    A Novel Thin Film Dispenser Cathode for Thermionic Emission

    Zavadil, K. R. / King, D. B. / Ruffner, J. A. et al. | British Library Conference Proceedings | 2001


    Barium-Dispenser Thermionic Cathode

    Wintucky, Edwin G. / Green, M. / Feinleib, M. | NTRS | 1989


    Results from thermionic cathode gyro-TWA experiments

    Phelps, A.D.R. / Ronald, K. / He, W. et al. | IEEE | 2004


    Diamond Thin Film Exposure to Simulated Thermionic Reactor Environments

    Tagavi, Kaveh / John Hahn, O. / Clausing, Robert E. et al. | SAE Technical Papers | 1992