Stopping powers of a tissue-equivalent gas for 40--200 keV protons

The stopping powers of a tissue-equivalent gas were measured for protons using the proton beam from a Cockcroft and Walton type accelerator and a differentially pumped gas cell. The stopping powers of each component of the tissue-equivalent gas were also measured and used to calculate expected values of the stopping powers of the tissue-equivalent gas. Results from direct measurement and from calculation showed good agreement. The results of the measurements on the component gases were also used to calculate the stopping power of Rossi's gas.