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Title: Investigation of a charge-coupled device detection system for ion microscopy

Abstract

Ion microscopy is a unique form of secondary ion mass spectrometry in which the distribution of elements on the surface of a sample are simultaneously imaged. On the CAMECA IMS-3f ion microscope, parallel detection of secondary ions is accomplished by a microchannel plate that converts ions to electrons which subsequently strike a fluorescent screen and produce a luminous image. Ideally, a quantitative relationship should exist between the digitized intensities in the resultant image and the concentration gradient of a particular element (isotope) on the surface of the sample. In practice, however, quantification of image data is complicated by significant deviations in both sampling and detection of ions, resulting in artifactual contrast within an image. Contrast artifacts arising from differential secondary ion production due to sample surface relief were identified by correlation of ion with electron microscopic images. An algorithm was designed to map a sample image onto a reference image while preserving the information content of the image. Detector discrimination was found to be a serious impediment to quantification of ion images because the fidelity of information was compromised by the circuitous detection system. Although methods were developed to correct some of the artifacts caused by detector discrimination, the bestmore » solution to the problem of indirect digitization of ion images was determined to be the replacement of the existing detection system with a charge-coupled device (CCD) detector. While CCDs have never before been used to detect ions in the keV regime, a CCD detection system was successfully implemented. The microchannel plate, fluorescent screen, and optical recording medium were replaced entirely with a single CCD.« less

Authors:
Publication Date:
Research Org.:
Cornell Univ., Ithaca, NY (United States)
OSTI Identifier:
7039088
Resource Type:
Miscellaneous
Resource Relation:
Other Information: Thesis (Ph.D.)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 47 OTHER INSTRUMENTATION; ION DETECTION; CHARGE-COUPLED DEVICES; EXPERIMENTAL DATA; ION MICROSCOPY; MASS SPECTROSCOPY; MICROCHANNEL ELECTRON MULTIPLIERS; CHARGED PARTICLE DETECTION; DATA; DETECTION; ELECTRON MULTIPLIERS; ELECTRON TUBES; INFORMATION; MICROSCOPY; NUMERICAL DATA; RADIATION DETECTION; SEMICONDUCTOR DEVICES; SPECTROSCOPY; 400102* - Chemical & Spectral Procedures; 440000 - Instrumentation

Citation Formats

Kapustay Turner, L V. Investigation of a charge-coupled device detection system for ion microscopy. United States: N. p., 1989. Web.
Kapustay Turner, L V. Investigation of a charge-coupled device detection system for ion microscopy. United States.
Kapustay Turner, L V. 1989. "Investigation of a charge-coupled device detection system for ion microscopy". United States.
@article{osti_7039088,
title = {Investigation of a charge-coupled device detection system for ion microscopy},
author = {Kapustay Turner, L V},
abstractNote = {Ion microscopy is a unique form of secondary ion mass spectrometry in which the distribution of elements on the surface of a sample are simultaneously imaged. On the CAMECA IMS-3f ion microscope, parallel detection of secondary ions is accomplished by a microchannel plate that converts ions to electrons which subsequently strike a fluorescent screen and produce a luminous image. Ideally, a quantitative relationship should exist between the digitized intensities in the resultant image and the concentration gradient of a particular element (isotope) on the surface of the sample. In practice, however, quantification of image data is complicated by significant deviations in both sampling and detection of ions, resulting in artifactual contrast within an image. Contrast artifacts arising from differential secondary ion production due to sample surface relief were identified by correlation of ion with electron microscopic images. An algorithm was designed to map a sample image onto a reference image while preserving the information content of the image. Detector discrimination was found to be a serious impediment to quantification of ion images because the fidelity of information was compromised by the circuitous detection system. Although methods were developed to correct some of the artifacts caused by detector discrimination, the best solution to the problem of indirect digitization of ion images was determined to be the replacement of the existing detection system with a charge-coupled device (CCD) detector. While CCDs have never before been used to detect ions in the keV regime, a CCD detection system was successfully implemented. The microchannel plate, fluorescent screen, and optical recording medium were replaced entirely with a single CCD.},
doi = {},
url = {https://www.osti.gov/biblio/7039088}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 1989},
month = {Sun Jan 01 00:00:00 EST 1989}
}

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