Abstract
The present study is directed towards quantifying some of the parameters which define the quality of the image obtained on x-ray sensitive films and its usual accompanying intensifying screens. Both industrial (Agfa-Geveart D2,D4,D7) and medical (Kodak XAR-5) films with a variety of screens such as metallic (lead) and fluorescent (calcium tungstate, rare earth) were compared. A variety of sources were employed (radioactive, linear accelerators, flash) in order to cover the average x-ray energy spectrum from 100KeV to 3000KeV. This energy spectrum is of interest for non destructive testing, terminal ballistics and for medical purposes. The results indicate that the sensitivity of industrial x-ray films decreases with energy in the range of 100KeV to 1MeV, 21/4 levels off and increases again with increasing energy. A 2.75MeV Na radioactive source was used to achieve accurate calibration at the high end of the spectrum. Also, the noise level of x-ray industrial films versus film density was found to peak at a density of D=1.4. The line spread function (LSF) - or resolution - of both industrial and medical film/screen combinations were derived from the optical density of a step wedge response on the film. The noise level of medical films is twice as high compared to industrial films and their LSF is 4 to 8 times larger at x-ray energies of 3MeV. Using Pb screens in contact with common industrial x-ray films yields amplification of 2 (compared to a bare film).
Original language | English |
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Pages (from-to) | 134-141 |
Number of pages | 8 |
Journal | Proceedings of SPIE - The International Society for Optical Engineering |
Volume | 674 |
DOIs | |
State | Published - 1 Sep 1987 |
Externally published | Yes |
Event | 17th International Congress on High Speed Photography and Photonics 1986 - Pretoria, South Africa Duration: 1 Sep 1986 → 5 Sep 1986 |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Computer Science Applications
- Applied Mathematics
- Electrical and Electronic Engineering