High-resolution digital dosimetric system for spatial characterization of radiation fields using a thermoluminescent CaF2:Dy crystal

Journal Article · Thu May 01 00:00:00 EDT 1986 · Med. Phys.; (United States)

DOI:https://doi.org/10.1118/1.595875· OSTI ID:5028836

Atari, N A; Svensson, G K

A high-resolution digital dosimetric system has been developed for the spatial characterization of radiation fields. The system comprises the following: 0.5-mm-thick, 25-mm-diam CaF2:Dy thermoluminescent crystal; intensified charge coupled device video camera; video cassette recorder; and a computerized image processing subsystem. The optically flat single crystal is used as a radiation imaging device and the subsequent thermally stimulated phosphorescence is viewed by the intensified camera for further processing and analysis. Parameters governing the performance characteristics of the system were measured. A spatial resolution limit of 31 +/- 2 microns (1 sigma) corresponding to 16 +/- 1 line pairs/mm measured at the 4% level of the modulation transfer function has been achieved. The full width at half maximum of the line spread function measured independently by the slit method or derived from the edge response function was found to be 69 +/- 4 microns (1 sigma). The high resolving power, speed of readout, good precision, wide dynamic range, and the large image storage capacity make the system suitable for the digital mapping of the relative distribution of absorbed doses for various small radiation fields and the edges of larger fields.

• OSTI ID: 5028836
• Journal Information: Med. Phys.; (United States), Vol. 3
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
DOSEMETERS
DESIGN
CALCIUM FLUORIDES
CRYSTALS
DIGITAL SYSTEMS
IMAGE PROCESSING
IMAGES
RADIOACTIVITY
REMOTE VIEWING EQUIPMENT
SPATIAL RESOLUTION
THERMOLUMINESCENCE
ALKALINE EARTH METAL COMPOUNDS
CALCIUM COMPOUNDS
CALCIUM HALIDES
EQUIPMENT
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
LUMINESCENCE
MEASURING INSTRUMENTS
PROCESSING
RESOLUTION
440102* - Radiation Instrumentation- Radiation Dosemeters