Decrement Lines: A New Presentation of data in Cobalt 60 Beam Dosimetry

Abstract

A method of describing the dose distribution within a beam is outlined in which the dose distribution in a Co60 beam is related to the central axis depth dose by use of "decrement lines" which are defined and shown to be families of straight lines for the Hunslet apparatus and possibly for the Orbitron. The decrement system reduces necessary experimental work to very small amounts without loss of accuracy. The practical use of the system in the correction for surface obliquity and in the calculation of moving-field distributions is discussed.