Neutron irradiation effects in superconducting A-15 compounds

The superconducting properties of A-15 (β-W) compounds are severely degraded when exposed to high energy neutron (E>1 MeV) irradiation at ambient reactor temperatures. Depressions in the superconducting transition temperature Tc, the upper critical field Hc2, critical current Ic, and degree of Long Range Order are observed above a fluence of ∼1018 n/cm2. These depressions are due to the disorder produced in the A-15 structure by the high energy neutrons.