Abstract
A theoretical and experimental analysis of scatter from inhomogeneous slabs in a 60Co beam has been developed. This analysis has been used to examine the differential scatter-air ratio method (DSAR). It has been found that a simplification of this method gives more accurate results than the original one. Thus, a method which takes advantage of this simplification has been developed, called the 'differential tissue-air ratio method (DTAR)'. It is compared with experimental results. The accuracy is satisfied for a wide range of applications (usually approaching the limits of the precision of the measurements, about 2%) and leads to calculation times not significantly longer than any conventional method (e.g. Batho).