Modification of Richardson-Dushman Equation, variation of thermionic emission constants, temperature variation of workfunction in metals

ORAL

Abstract

For proper modeling of the thermionic converters and evaluation of efficiency and power output (from given input energy flux) it is necessary to estimate accurately the thermionic currents from the hot emitter surface. In this paper we derive the expression for the work function of a metal as a function of temperature considering thermal expansion and constant number of free electrons. We then modify the Richardson-Dushman equation for thermionic emission and explain the variation of the Thermionic emission constant from metal to metal. This theory of modification of Richarson-Dushman thermionic equation is quite different from that of Seely (1941) and explains better the observed temperature rate of change of work function of tungsten and the variation of thermionic emission constants from metal to metal.

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Authors

  • Dilip De

    Kaduna State University, Kaduna, Kaduna State, Nigeria, Kaduna State University, Kaduna State, Kaduna, Nigeria

  • Iman Rezanejad

    TAMU, TTU, TCU, Texas State University, Department of Physics, Texas Tech University, Lubbock, TX, Department of Chemistry \& Biochemistry, Texas Tech University, Lubbock, TX, Department of Mechanical Engineering, Texas Tech University, Lubbock, TX, Universidade de Sao Paulo, Ohio University, Stanford University, University of Waterloo, Canada, Institute for Quantum Science and Engineering (IQSE) and Department of Physics and Astronomy, Texas A\&M University, Beijing Computational Science Research Center, Beijing, China, Institute for Quantum Studies and Department of Physics, Texas A\&M University, College Station, Texas 77843, USA, Texas A\&M University at Qatar, Education City, P.O. Box 23874, Doha, Qatar, TTU Center for Pulsed Power and Power Electronics, Texas A\&M University - Commerce, Meyer Observatory, Clifton TX, CASPER, Baylor University, Waco TX, CASPER NSF-REU, Baylor University, Waco TX, Texas Tech University, University of Texas at Dallas, Oklahoma University, Princeton University, University of Chicago, Cornell University, Los Alamos National Laboratory, Department of Physics, Lamar University, Department of Physics \& Geosciences, Angelo State University, Brookhaven National Laboratory, Fermi National Accelerator Laboratory, Texas A\&M University, Physics Dept, Texas State University, San Marcos, Istanbul University, Department of Electrical Engineering, University of Texas at Arlington, Department of Physics \& Astronomy, University of Texas at Brownsville, V. N. Bakul Institute for Superhard Materials, University of North Texas, Department of Physics, TCU, Department of Physics and Astronomy, Department of Computer Science, Texas State University at San Marcos, Department of Physics, Texas State University at San Marcos, Institute for Quantum Science and Engineering and Department of Physics and Astronomy, Texas A\&M University, College Station, Texas 77843, USA, The National Center for Mathematics and Physics, KACST, P.O. Box 6086, Riyadh 11442, Saudi Arabia, Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, Anhui, 230026, People's Republic of China, Department of Physics, the University of Texas at Dallas, Richardson, TX, 75080 USA, State Key Laboratory of Quantum Optics and Quantum Optics Devices, College of Physics and Electronic Engineering, Shanxi University, Taiyuan 030006, Department of Physics and Astronomy, Washington State University, Pullman, Washington, 99164 USA, University of Guelph, Guelph Canada, Department of Physics, National Chung Cheng University, Chia-Yi 621, Taiwan, University of Houston Clear Lake, The University of Texas at Dallas, The University of Texas at San Antonio, Angelo State University, Department of Physics and Astronomy and Center for Gravitational Wave Astronomy, University of Texas at Brownsville, Brownsville, Texas 78520 USA, Laboratoire des Mat\'eriaux Avanc\'es, Universit\'e Claude Bernard Lyon 1, Campus de la DOUA, Villeurbanne Cedex 69622 France, Department of Engineering, University of Texas at Brownsville, Brownsville, Texas 78520 USA, BAE Systems, Advanced Systems and Technology, Nashua, NH, Istanbul University, Beyazit 3449 Istanbul, Turkey, Texas Tech University, Physics, Texas Tech University, Lubbock, TX, Istanbul University, Istanbul, Turkey, Arkansas State University, Jonesboro, AK, Abilene Christian University, Department of Physics and Astronomy, Clemson University, Clemson, SC, 29634 USA, Department of Physics, University of Texas at El Paso, Qatar Biomedical Research Institute, Texas A\&M University at Qatar, FUTY, Yola, Adamawa State, Nigeria, FUTY, Yola, Adamawa State, Department of Physics, University of Abuja, Abuja, Nigeria, Department of Electrical and Computer Engineering, Texas A\&M University