Abrikosov vortex structure change in superconducting films of Josephson tunnel diode under γ-irradiation

A study was made on the effect of γ-irradiation on captured magnetic vortices in superconducting films, using Josephson tunnel transition (JTT). Pb(Au - 4%, In - 12%) film of 1800 A thickness with superconducting transition temperature about 6.8 K was examined. The tunnel barrier formed in result of thermal oxidation of the lower electrode in oxygen atmosphere. 57Co with γ-quantum energies, equal to 6.4 keV, 14.4 keV and 122 keV was used as γ-source. It is shown that change of magnetic vortex configuration in JTT region leads to change of the value of effective magnetic field. It was established that γ-irradiation, changing the structure of magnetic vortices, affected the value of JTT critical current. This can be used for nuclear particle detection