Inhibition of radiation blistering in tin bombarded by protons and alpha particles

Tin monocrystals have been bombarded with large doses ${\text{([inverted lazy s]5×10}}^{17}\hspace{0.17em}{\mathrm{particles/cm}}^2)$ of 1.5–4‐MeV ions of H and He. Proton irradiations above 225 °C produce neither visible surface damage nor degradation of the ability of a crystal to channel the incident particles. Room‐temperature irradiations by H or He ions produce little observable damage near the crystal surfaces unless followed by post‐irradiation anneals to 220 °C or above. After such anneals, however, channeling measurements show permanent deterioration and the surfaces may show deformations such as swelling, blistering, and effervescence.