Production and mutual annihilation of frenkel pairs in low temperature irradiated zirconium

12.5 μ thick zirconium foils were irradiated by monoenergetic electrons in the range 0.5–1.7 MeV at liquid helium temperature. To the measured defect production rate, a theoretical curve was fitted, assuming an atomic displacement probability function P d, (T) and estimating the multiple displacement contribution. The best fit was obtained with: Isochronal and isothermal annealing studies were performed in the recovery stage I (up to 150 °K) and compared with results obtained earlier by Neely. An effect of radiation doping on the behaviour of the different substages has been observed. and a Frenkel pair resistivity of 4 × 10−3 ω cm. The implications of such a multiple displacement function are considered.