NDTnet 1998 Aug, Vol.3 No.8

Abstract

To convert pulse X-radiation a gas-discharge converter (GDC) was used in our systems for testing and diagnostics. High sensitivity was attained at the expense of gas amplification in a pulse discharge with a dense discrete structure. The typical design GDC is brought on a drawing (1 - contact tracks, 2,7 - glass substrates; 3 - transparent electrode; 4 gas-discharge volume; 5 - frame; 6 - luminophor layer; 8 -opaque electrode; 9 - protective film of organic polymer; 10 - terminal of opaque electrode; I I -resistive layer; 12 - levelling electrode). A gas medium was on Xe basis, pressure-atmospheric. To form a visible image UV radiation of discharges was used.

Currently a new theory of image formation GDC has been developed, a design of a converter was optimized together with power supply and radiation modes. Some converters have been fabricated with maximum dimension of an input window 500*600 mm and service life above 5000 hours. A number of modular testing and diagnostics systems has been developed having different types of synchronization between radiation source and GDC and different methods ofimage recording from an output window.

Fig.: Design of GDC

Principal technical characteristics:
- dose sensitivity	1 -2 mcR
- ultimate resolution	1,5 line/mm
- ultimate line sensitivity	5-6%
- GDC screen luminance at operating frequency 25 Hz	not less than 10 - 20 C
- weight (without TV-channel)	less than 20 Kg

The systems are safe in operation and can be usedby special safety services of airports, banks andother organizations and also for registration offast-proceeding processes and in medicalexpress-diagnostics.

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

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