Search results with tag "Thermionic"
5: Thermionic Emission
www.physics.csbsju.eduThermionic Emission 103 where V(x) is the potential difference (“voltage”) at xand mis the mass of an electron. Because the accelerating electrons constitute a steady current (i.e., J
Class Notes of BET102 Basic Electronics Engineering Common ...
sctevtservices.nic.in2. Field Emission - (Due to application of strong electric field) 3. Secondary Emission – (due to bombardment of high-speed electrons) 4. Photo Electric Emission – (by the application of light) 1. Thermionic Emission The process of electron emission from a metal surface by supplying thermal energy to it is known as Thermionic emission.
X-ray tube design The Production and Properties
www.utoledo.eduthermionic emission (V f ~ 10V, I f ~ 4A, resulting in T>2000oC) • X rays are produced by high-speed electrons bombarding the target • Typically < 1% of energy is converted to x rays; the rest is heat Figure 2-1 (a). Schematic diagram of x-ray tube and circuit V f X-ray tube current • Electron cloud near the filament creates space charge ...
Metal/Semiconductor Ohmic Contacts - Stanford University
web.stanford.edu(1) Thermionic emission (TE), occurring in the case of a depletion region so wide that the only way for electrons to jump the potential barrier is by emission over its maximum (Fig. 3a). The barrier height is reduced from its original value as a result of image force barrier lowering.
Chapter 9 Metal-Semiconductor Contacts
inst.eecs.berkeley.edu9.2 Thermionic Emission Theory / / 2 0 2 / / 3 2 ( )/ 3/2 2 ( )/,where 100 A/cm 4 2 1 3 / 2 / 2 2 q kT o qV kT n q kT qV kT S M thx th n thx n q V kT n q V kT c B B B B J e J e T e e h qm k J qnv v kT m v kT m e h m kT n N e
주사전자현미경의 기본원리와 응용(Part Ⅱ
www.cheric.orgSEM의 전자총에는 열방사형(thermionic electron gun)과 전계방사형(field emission electron gun)으 Figure 2. Hair Pin 형태의 열방사형 전자총의 모식도[9]. 로 나뉘어진다. 열방사형(thermal emission)의 경우 음극은 주로 텅스텐으로 약 100 µm 직경의 선 필라멘트로서
Electron Diffraction - Boston University
physics.bu.eduthe cathode. Electrons are ejected by thermionic emission from this heated piece of metal (see Figure 4). Once emitted, the electrons are accelerated by two pairs of anode rings. You apply an adjustable acceleration potential Va (2000-4000 V dc) with the kilovolt power supply between the cathode (-) and anode (+). This accelerates electrons to ...
Physical Chemistry of Surfaces - sciencenet.cn
image.sciencenet.cnThermionic Work Function 208 C. Electrode Potentials 209 D. Irreversible Electrode Phenomena 212 10. Problems 215 General References 217 Textual References 218 VI. Long-Range Forces 225 1. Introduction 225 2. Forces between Atoms and Molecules 226 3. Long-Range Forces 232 A. The Microscopic Approach 232 B. The Retarded Dispersion Interaction 234