Title: Charged particle beam apparatus

Abstract: A charged particle beam (e.g., ions or electrons) apparatus including two electrostatic focusing lenses and an electrode having a diameter limiting aperture positioned between the lenses is further provided with two electrode assemblies which interact with an extractor electrode and with a source of charged particles such that the trajectories of the particles in the beam passing through the second of the two assemblies are substantially parallel. This feature and other disclosed improvements facilitate the production of a substantially monoenergetic beam which under a first set of conditions can be focused to provide a small-diameter, spherical-aberration limited beam and which under another set of conditions, can be focused to provide a high current beam.

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Inventors: Rusch, Thomas W. (Falcon Heights, MN, US)
Sievers, Jerry A. (Stillwater, MN, US)

Application Number: 563330
Filing Date: 1975-03-31
Publication_date: 1976-02-10
Assignee: Minnesota Mining and Manufacturing Company (St. Paul, MN)
Primary Class(es): 250/307 250/396R, 976/DIG433
Other Classes:
US Patent Ref:

2422807	Jun, 1947	Smith	250/396.
3840743	Oct, 1974	Tamura et al.	250/307.

Other Refs:
Primary Examiner: Borchelt, Archie R.
Assistant Examiner: Grigsby, T. N.
Attorney: Alexander, Sell, Steldt & DeLaHunt