FEASIBILITY OF ISOTOPIC X-RAY SOURCES FOR PORTABLE STRESS ANALYSIS EQUIPMENT

摘要

The feasibility of using a 10 millicurie Fe-55 x-ray source for x-ray diffraction was examined. Diffraction lines from iron were easily measured in a few minutes time to within 0.2° using a proportional counter and rudimentary apparatus, but experiments with film were unsuccessful because of the low Mn Ka photon output (108 /sec)„ Further improvement in speed and resolution is possible for general diffraction work but the diffraction angles are poorly situated for stress work. Other source and film characteristics measured in the study include the angular dependence of the radiation, x-ray transmission of the Polaroid XR-7 cassette, Polaroid film sensitivity, and a comparison of intensifier screens. Suggested collimator arrangements to permit using a larger area source with less self-absorption are given. In conjunction with a smaller diffraction camera than used here, it is concluded that the present source would be adequate for a portable diffraction instrument of modest resolution for field work with either pulse counters or film. A film system would be particularly simple and highly portable. Film exposure times producing a weak but definite line would be of the order 10 hours.