Improved calorimetric method for energy deposition measurement

An improved technique has been developed for the measurement of electron energy deposition versus depth profiles using thin foil calorimeters. A square-wave modulated beam is employed, and the time derivative of the thermocouple signal is measured at a specified time after beam switch. The method and apparatus are described, and results are presented for Al and Ta for 0.3, 0.5, and 1.0 MeV normally incident electrons. Data are also presented for the same energies and 60° (relative to normal) incidence in Al. Deposition data in a layered Ta and Al system at 1.0 and 0.5 MeV energy (normal incidence) are also presented.