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Title: Electrostatic lens to focus an ion beam to uniform density

Abstract

A focusing lens for an ion beam having a gaussian or similar density profile is provided. The lens is constructed to provide an inner zero electrostatic field, and an outer electrostatic field such that ions entering this outer field are deflected by an amount that is a function of their distance from the edge of the inner field. The result is a beam that focuses to a uniform density in a manner analogous to that of an optical ring lens. In one embodiment, a conically-shaped network of fine wires is enclosed within a cylindrical anode. The wire net together with the anode produces a voltage field that re-directs the outer particles of the beam while the axial particles pass undeflected through a zero field inside the wire net. The result is a focused beam having a uniform intensity over a given target area and at a given distance from the lens.

Inventors:
 [1]
  1. Oak Ridge, TN
Issue Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
OSTI Identifier:
862744
Patent Number(s):
4002912
Assignee:
United States of America as represented by United States Energy (Washington, DC)
Patent Classifications (CPCs):
G - PHYSICS G21 - NUCLEAR PHYSICS G21K - TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR
H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01J - ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
electrostatic; lens; focus; beam; uniform; density; focusing; gaussian; similar; profile; provided; constructed; provide; inner; zero; field; outer; entering; deflected; amount; function; distance; edge; result; focuses; manner; analogous; optical; embodiment; conically-shaped; network; fine; wires; enclosed; cylindrical; anode; wire; net; produces; voltage; re-directs; particles; axial; pass; undeflected; inside; focused; intensity; target; density profile; cylindrical anode; zero field; uniform density; uniform intensity; focusing lens; electrostatic field; focused beam; particles pass; fine wire; electrostatic lens; /250/313/315/976/

Citation Formats

Johnson, Cleland H. Electrostatic lens to focus an ion beam to uniform density. United States: N. p., 1977. Web.
Johnson, Cleland H. Electrostatic lens to focus an ion beam to uniform density. United States.
Johnson, Cleland H. Tue . "Electrostatic lens to focus an ion beam to uniform density". United States. https://www.osti.gov/servlets/purl/862744.
@article{osti_862744,
title = {Electrostatic lens to focus an ion beam to uniform density},
author = {Johnson, Cleland H},
abstractNote = {A focusing lens for an ion beam having a gaussian or similar density profile is provided. The lens is constructed to provide an inner zero electrostatic field, and an outer electrostatic field such that ions entering this outer field are deflected by an amount that is a function of their distance from the edge of the inner field. The result is a beam that focuses to a uniform density in a manner analogous to that of an optical ring lens. In one embodiment, a conically-shaped network of fine wires is enclosed within a cylindrical anode. The wire net together with the anode produces a voltage field that re-directs the outer particles of the beam while the axial particles pass undeflected through a zero field inside the wire net. The result is a focused beam having a uniform intensity over a given target area and at a given distance from the lens.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1977},
month = {1}
}

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