Measurement of the heat defect in water and A-150 plastic for high energy protons, deuterons, and α particles

An experimental set-up is described which allows the calorimetric determination of the heat defect of solids and fluids relative to that of gilded copper which is used as the reference material. The calorimeter operates in a quasi-adiabatic mode and is suitable for protons, α particles and other heavy ions with energies above 5 MeV. Corrections have been made for secondary electron emission and also for heat losses due to the temperature gradient on the surface of the calorimeter core. Measurements over 26 months indicate a repeatability of the measured heat defect within 4 x 10-3 (68% confidence level). Measurements show an LET dependence of the heat defect for two different samples of A-150 plastic, and for distilled water. (author)