Abstract: A method has been developed to calibrate the relative radiation response of sensors in an array by substitutional analysis of the sensor outputs caused by a radiation field wider than the array. The array is positioned in the wide field in such a way that the sensor positions in the array are exchanged once by translation in order to calculate ratios of neighboring detector sensitivity and once by rotation in order to calculate ratios of mirror detector sensitivities. There is no dependence on dose reproducibility, field flatness or symmetry. The method requires that the profile shape produced by the machine during each measurement be reproducible and that the array movements do not affect the scattering conditions.

Abstract: A low-cost radon detector using a solid state diode having a depletion layer disposed close enough to a test medium that alpha particles deposit their energy in the depletion layer. The signal produced by the diode is amplified and pulses are discriminated for levels over a threshold typical of pulse levels produced by radioactive decay of radon daughters on the surface of the sensor. More than one amplifier and threshold detector are provided, and the sensor can have plural solid state diodes. Pulses occurring exclusively on one channel are counted and pulses occurring in coincidence on more than one channel are ignored as instances of transient disturbance. A conductive enclosure around the sensor element can be biased to force radon daughter ions to plate out the sensor, whereupon decay of the daughters produces pulses falling closely into pulse height ranges well above the noise threshold. Pulse counts and time lapse are monitored both long term and short term.

Abstract: A radiation analysis instrument is described for measuring the characteristics of radiation emanating from a source (XS). The instrument includes two absorbers (a, b) and corresponding detectors (10, 12) with the detectors being disposed in the path of the radiation and the absorbers being interposed between the corresponding detector and the source. A circuit (16) digitizes the analog signals derived by the two detectors and provides the digital values to a microcomputer (18) which stores these digitals values within a memory (50). A microprocessor (48) processes the digital signals stored within the memory (50) to analyze characteristics of the radiation emitted from and the potential applied across the source (XS). This instrument is particularly useful in measuring the kVp applied to X-ray tubes.