Electron and proton radiation effects in the high temperature superconductor YBa2Cu3O7-δ

The particle-induced depression of the superconducting critical temperature, T_c, of YBa₂Cu₃O _7-δ is shown to be directly proportional to the nonionizing energy loss (NIEL) of primary knock-on atoms (PKAs) displaced by incident electrons, protons, and heavy ions, which cover a NIEL range of over seven orders of magnitude. Calculations of the NIEL for electrons and protons are given for YBa₂Cu₃O ₇ over the range 1-1000 MeV. The partition of NIEL among the elements as a function of incident electron energy is discussed. For a given particle fluence Φ, it is concluded that dT_c /dΦ is proportional to the average number of defects produced, is not affected by the formation of defects in cascades, and is independent of the PKA spectrum. This means that the particle-induced depression of T_c can be predicted for any particle type, for any energy, and for any fluence