A new pulse counting low-energy electron diffraction system based on a position sensitive detector

Journal Article · Wed Jan 01 04:00:00 EST 1992 · Review of Scientific Instruments; (United States)

DOI:https://doi.org/10.1063/1.1143196· OSTI ID:5643944

Ogletree, D F; Blackman, G S; Hwang, R Q; Starke, U; Somorjai, G A ^[1]; Katz, J E ^[2]

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1. Center for Advanced Materials, Materials Sciences Division, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)
2. Engineering Division, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)

A new low-energy electron diffraction (LEED) system has been constructed with a pulse counting position sensitive detector using channel plates and a wedge and strip anode. The detector accepts diffracted electrons over a 120{degree} angle and the LEED pattern is recorded as a 256{times}256 pixel image. Individual LEED spot intensities can be measured up to a maximum linear count rate of {similar to}5 kHz while the dark count rate is {similar to}0.02 Hz, yielding a dynamic range greater than 10{sup 5}. Incident beam currents for LEED measurements are {similar to}1 pA. Diffuse LEED intensities from disordered systems can be measured using the large dynamic range of this instrument. Examples of diffuse LEED measurements are presented. The low incident beam currents also allow for LEED intensity-voltage measurements on surfaces sensitive to electron beam damage and on nonconducting surfaces.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5643944
• Journal Information: Review of Scientific Instruments; (United States), Journal Name: Review of Scientific Instruments; (United States) Vol. 63:1; ISSN RSINA; ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

440800* -- Miscellaneous Instrumentation-- (1990-)
47 OTHER INSTRUMENTATION
COHERENT SCATTERING
DAMAGE
DESIGN
DIFFRACTION
DIFFRACTOMETERS
ELECTRON DIFFRACTION
LAWRENCE BERKELEY LABORATORY
MEASURING INSTRUMENTS
NATIONAL ORGANIZATIONS
PERFORMANCE
POSITION SENSITIVE DETECTORS
RADIATION DETECTORS
SCATTERING
US AEC
US DOE
US ERDA
US ORGANIZATIONS