Numerical analysis of pencils of rays in a point cathode thermionic emission gun

Ryo Iiyoshi

doi:10.1117/12.255509

25 October 1996 Numerical analysis of pencils of rays in a point cathode thermionic emission gun

Ryo Iiyoshi

Proceedings Volume 2858, Charged-Particle Optics II; (1996) https://doi.org/10.1117/12.255509
Event: SPIE's 1996 International Symposium on Optical Science, Engineering, and Instrumentation, 1996, Denver, CO, United States

Abstract

The trajectory and width of the pencils of rays in a point cathode thermionic emission gun have been analyzed with numerical methods. The numerical model of the gun consists of the point cathode with the tip radius of 0.4 micrometers , the wehnelt with the aperture diameter of 1 mm, and the anode. The electric field was computed with a surface charge method, which is one of the integral methods of the charge distribution on the electrode surface. A direct ray-tracing was done in 3D from the axial and off-axial positions on the spherical tip part of the cathode for different emitting conditions. The shape of each pencil of rays was estimated from these rays. Some 3D views of the pencils are given, together with the electrode geometry. The pencils have large widths when they pass through the wehnelt aperture, and then focus onto different positions with different cross- sections. The methods and results are presented.

Citation Download Citation

Ryo Iiyoshi "Numerical analysis of pencils of rays in a point cathode thermionic emission gun", Proc. SPIE 2858, Charged-Particle Optics II, (25 October 1996); https://doi.org/10.1117/12.255509

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available