RADIOLOGICAL PHYSICS DIVISION SEMIANNUAL REPORT FOR JANUARY THROUGH JUNE 1959

A list of publications and papers submitted for publication during the period is included. Progress is reported in the following studies: a decay-time study of an irradiated scintillating solution; the development of methods and equipment for use in measurements of the cosmic-ray neutron background; the effects of the addition of various gases singly and in pairs to the inert gas argon on results obtained with the halogen-sensitive positive ion tube used to measure the concentration of tracers in atmospheric air; the calibration of a quantitative alpha-track autoradiographic technique; studies on radiation carcinogenesis of radium and thorium oxides in the human skeleton; development of a method for counting individual alpha activities in mixtures in which the component activities do not show considerable variation; a survey of natural radium-226 and radium-228 content in municipal water supplies; radioac- . tivity measurements and dose calculations of soil collected at Argonne; the effect of various meteorological parameters on thermal conditions in the soil; design of an automatic data processing system which records data from nearly 200,000 meteorological measurements made annually; and studies on meteorological parameters affecting atmospheric diffusion of particles. (For preceding period see AN1.-5967.) (C.H.