The activity of radon daughters in high-rise buildings.
Abstract Forty measurements are reported in similar rooms in two high-rise buildings. The geometrical means for the concentration of radon daughters including and excluding the basement results, respectively, were 0.90 and 1.00 mWL, which is less than the quoted mean 2.0 mWL for 65 measurements in typical houses in the same city. The frequency distribution of these measurements shows a log-normal distribution. The concentrations did not depend on the distance from ground level but may depend on the ventilation rate of the room examined. The correlation between the concentration of radon daughters in WL in rooms above the first floor in the two high-rise buildings with the inverse of their ventilation rate were 0.73 and 0.67, respectively.
Radon emanation from uranium corridor in Orkney islands and in kinver caves
ABSTRACT Some farm houses on the uranium corridor in Orkney where the uranium concentration varied between 500–1200 ppm were studied. An inverted open-mouthed can with a piece of CR-39 stuck to the inside of the closed end was used as an arrangement for radon detection. The cans were buried at a depth of about 30 cm below the soil surface in the garden of each farm house studied. The radon concentrations inside the cans were found to vary from 7–600 pCi l −1 . This corresponds to an exhalation rate of 5–500 p Ci m −2 h −1 . These figures were 100 times more than the average figures under those cans attached to the walls of the same houses. The can technique was also used in the sand-stone Kinver caves near Birmingham which were occupied until 1950. The activity of radon inside and outside the can was found to be on average 14 and 10 pCi l −1 respectively. This is much more than activity in the houses in Birmingham (3.4 and 1.4 pCi l −1 respectively).
A new measurement of the intensity of cosmic-ray ionization at sea level
Using a new type of ion chamber, featuring a technique that discriminates against residual wall currents, and a thin plexiglas wall, cosmic-ray ionization measurements have been made at ambient pressures ranging approximately from 71 to 77 cm Hg. A least-squares interpolation at sea level yields an ionization density of (2.18±.05) I. (I corresponds to one ion pair per second per cm3 of NTP air.) The variation with pressure is found to be −3.96%/cm Hg, which compares favorably with the published values of the cosmic-ray barometer coefficient.