3 September 1993 Computer simulation of energetic Boersch effect in the diode region of the field emission gun
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Abstract
A computer simulation program for calculating the energetic Boersch effect in the diode region of the field emission (FE) gun has been developed. The diode system consists of a hyperboloid of revolution as the cathode (FE tip) and a plane electrode as the first anode (extraction anode). The radius of curvature of the FE tip is Ro and the FE tip-to-1st anode distance is d. The simulation has been done for the various combinations of Ro (0.05 approximately 0.4 micrometers ) and d (0.5 approximately 10 mm). The work function of the cathode tip is assumed to be 4.5 eV. The electrons leave the cathode surface at time intervals selected to approximate a Poisson process and also realize a specific emission current using a random number. The positions and velocities of the electrons are successively calculated as a result of the force produced by both the Coulomb interaction and the electric field inside the gun. The resultant energy spread (Delta) E is found to be (Delta) E equals (root)(Delta) E2o + (Delta) E2B, where (Delta) Eo is the initial energy width of the emitted electrons and (Delta) EB is the energy broadening of monochromatically emitted electrons. The simulation also shows that the dependence of (Delta) EB on Ro, d, and the emission current IE is given by (Delta) EB (alpha) I-0.75E X R-0.5o X d0.
© (1993) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Hiroshi Shimoyama, Yasuhisa Shimazaki, Akiro Tanaka, "Computer simulation of energetic Boersch effect in the diode region of the field emission gun", Proc. SPIE 2014, Charged-Particle Optics, (3 September 1993); doi: 10.1117/12.155689; https://doi.org/10.1117/12.155689
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