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Proceedings Paper

Self-gridding and signal formation in the kinestatic charge detector for digital mammography
Author(s): Robert A. Terwilliger; Douglas Jay Wagenaar
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Paper Abstract

Various designs of the kinestatic charge detector (KCD) have used a Frisch Grid--a planar, meshed electrode sandwiched between the detector's anode and cathode. The grid shields the cathode from effects of drifting ions until they reach the region between the cathode and the grid. Including the grid, however, has made detector design difficult because of electric field non-uniformities and microphonics. Recent studies have shown that the KCD may not need a grid. `Self-gridding,' an effect which produces the same results, occurs when the ratio of cathode's collector width to the drift gap is sufficiently small. The greater this ratio, the more self-gridding takes place. The process of signal formation has been analyzed for the self- gridding geometry using ExcelTM (Microsoft Corporation, Redmond, WA). Detector response to microcalcifications has been simulated by small, drifting volumes with a steep dip in ion count; low-contrast lesions by larger volumes with a shallow dip in ion count. Both of these typical breast lesions can be detected with self-gridding geometry. This geometry will soon be tested in an experiment for validity as a detector design.

Paper Details

Date Published: 26 May 1994
PDF: 12 pages
Proc. SPIE 2132, Clinical Applications of Modern Imaging Technology II, (26 May 1994); doi: 10.1117/12.176565
Show Author Affiliations
Robert A. Terwilliger, UCLA School of Medicine (United States)
Douglas Jay Wagenaar, Brigham & Women's Hospital (United States)


Published in SPIE Proceedings Vol. 2132:
Clinical Applications of Modern Imaging Technology II
Leonard J. Cerullo; Kenneth S. Heiferman; Hong Liu; Halina Podbielska; Abund Ottokar Wist; Lucia J. Zamorano, Editor(s)

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