Long-Range Migration of Self-Interstitial Atoms in Tungsten

Resistivity annealing following irradiation with 3-MeV electrons at 4.5 K has been investigated on tungsten single crystals. High-purity samples showed a recovery stage between 24 and 30 K, which apparently shifts with increasing dose to lower temperatures. We conclude that it is associated with long-range migration of self-interstitial atoms with a migration energy of 54 \ifmmode\pm\else\textpm\fi{} 5 meV. The relationship to recent conclusions of other authors is discussed.