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

Miscellaneous · Sun Jan 01 00:00:00 EST 1989

OSTI ID:7039088

Kapustay Turner, L V

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.

• Research Organization: Cornell Univ., Ithaca, NY (United States)
• OSTI ID: 7039088
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

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