STUDY OF ELECTRON FOCUSING BY NON-LINEAR SPIRALS
Abstract
The purpose of the research work was to develop an electrostatic image converter with the following capabilities: (1) Electrostatic image formation between two plane surfaces, (2) Control of electronic magnification by spiral-lens elements, (3) Development of reflective electronoptics for image formation from photoconductive targets. Early experiments used a thermionic analog. This consisted of a perforated 3 in. metal plate, which was illuminated by a collimated floodbeam at controlled voltage. The built-in field-lens problem was attacked first by a ray-tracing analysis. This suggested the use of a convex mesh, close to cathode. Although image quality was disappointing, the tests verified the need for a convex, rather than a concave, shape of the mesh. Next, the functions of first-anode and field-flattening were separated. This led to a two-mesh field-lens of the planoconvex type. This structure was retained for the remainder of the contract. As an alternative, the balancing of abberations in a lens doublet was investigated and was found to be operational.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1963
- Accession Number
- AD0414486
Entities
Organizations
- General Electric