The effect of electron irradiation on YBa sub 2 Cu sub 3 O sub x with gold bead contacts

We have investigated the effect of 1-MeV electron irradiation up to a total dose of 5.7{times}10{sup 17} electrons/cm{sup 2} at room temperature on YBa{sub 2}Cu{sub 3}O{sub {ital x}} with gold bead contacts made by the melting technique. We measured the superconducting transition temperature {ital T}{sub {ital c}}, the critical current density {ital J}{sub {ital c}} at 77 K, the normal-state resistivity, and the contact resistance for gold bead contacts as a function of fluence on the same samples without disturbing the contacts. {ital T}{sub {ital c}} remained constant at 91 K, and {ital J}{sub {ital c}} at 77 K remained constant around 90 A/cm{sup 2}. The normal-state resistivity increased systematically by about 15% for the total dose. Finally, the surface contact resistance at 77 K remained less than 4.2 {mu}{Omega} cm{sup 2} throughout the radiations. These studies took place over an 8-month period, and subsequent measurements indicate that the results are definitely due to radiation effects and not aging effects. Since the total dose represents 120 years of electron exposure in geosynchronous orbit, we conclude that the superconductor YBa{sub 2}Cu{sub 3}O{sub {ital x}} with gold bead contacts would perform well in a space environment of electron irradiation.