Record Details
Field | Value |
---|---|
Title | Dosimetry considerations in the irradiation of biological populations |
Names |
Denovan, James Thomas
(creator) Elder, Robert L. (advisor) |
Date Issued | 1967-07-14 (iso8601) |
Note | Graduation date: 1968 |
Abstract | The effects of changes in dosimetry conditions on the radiation sensitivity of a constant biological population were determined. The organism used for this study was the strain B of Escherichia coli. The percentage survivals of these cells in an aqueous solution were determined at the same total exposure with different quality x-rays. The total absorbed dose was measured as a function of x-ray quality. During all irradiations the focal-target distance, tube current, field size, and biological population were held constant. The distribution of radiation to which the organisms were exposed was kept constant by the use of a rotating exposure platform. This platform was constructed of materials such that the contributions from backscatter would be minimized. The results indicated that the test organism was more sensitive to low energy x-rays than to high energy x-rays in the range from 15 keV to 145 keV effective energy. However, at low effective x-ray energies the absorbed dose was found to be lower than at higher effective energies. This was explained by differences in the specific ionization of different energy x-rays in aqueous solutions. It was concluded that dosimetry conditions are a significant factor in the determination of the radiation sensitivity of E. coli B. The results indicate the necessity of reporting accurate exposure conditions when studying the radiation response of biological populations. |
Genre | Thesis/Dissertation |
Topic | Radiation -- Dosage |
Identifier | http://hdl.handle.net/1957/47230 |