Absolute Measurement of Low Energy Electron Deposition Profiles in Semi-Infinite Geometries

Two different techniques have been used to measure absolute electron energy deposition profiles in semi-infinite geometries. The first, employing an ionization chamber, was used to measure energy deposition by normally incident electrons at incident energies of 1.0, 0.5, and 0.3 MeV in aluminum, and 1.0 MeV in tantalum. The second method is unique in that it represents the first calorimetric measurement of energy deposition from a monoenergetic D. C. source. Results are given for normally incident electrons at an incident energy of 1.0 MeV in aluminum, and at incident energies of 1.0 and 0.5 MeV in tantalum. The latter method circumvents some of the difficulties inherent in the ion chamber technique and provides more precise results.