Electrical and Computer Engineering ETDs

Publication Date

1967

Abstract

With the rapidly expanding use of X-radiation devices for medical, industrial and military purposes, the need arises for diverse methods of producing and measuring the X-ray portion of the electromagnetic spectrum.

X rays may be purposefully produced by a source in a continuous manner, in short pulses or flashes or in a random manner. X rays are also produced undesirably by devices having extremely high voltages or as a byproduct of some energy-producing device such as a nuclear weapon. In most cases X radiation is produced over a wide spectral range of varying intensities rather than at discrete energy levels such as is usually the case with radio waves. A knowledge of the spectral distribution is required for many applications. Historically this information was obtained by three methods. These methods were developed because of the fact that X rays produce fluorescence in certain chemicals, they affect photographic plates, and they ionize gases. More recently these classic methods have been improved and other methods of determination of spectra have been developed.

The intent of this thesis is to study one novel way of producing X radiation in pulses in the submicrosecond region. A triode X-ray tube* driven by a submicrosecond pulse was used as a source. The concomitant purpose of this thesis is to demonstrate one method of determining the spectral output of this test source.

Introductory material presented here is a review of methods and devices used in the production and measurement of X radiation. Suf­ficient theoretical background information is presented to afford an understanding of the nature of X radiation. Next is a presentation of the design of the triode X-ray source and the detector. This is followed by a study of a theoretical method of calculating spectra. Finally, the absorption method of spectral determination is delineated.

The contribution of this presentation lies in the use of a triode rather than the usual diode type of X-ray tube and in solving the instru­mentation problems of handling extremely narrow pulses in the region of several nanoseconds to several hundred nanoseconds duration. When a diode is used the extremely high voltage for the target supply must be modulated to produce flash X rays; the use of a triode affords the capability of modulating a control grid with voltages of only several hundred volts and a constant target voltage.

Document Type

Thesis

Language

English

Degree Name

Electrical Engineering

Level of Degree

Masters

Department Name

Electrical and Computer Engineering

First Committee Member (Chair)

Harold D. Southward

Second Committee Member

Martin D. Bradshaw

Third Committee Member

Ahmed Erteza

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