It is often assumed that thermodynamic and non-equilibrium properties of superconductors scale with the upper critical field or irreversibility fields, such as in the form, f(H)= f(h)=f(H/_H_c2(theta)) or f(h)=f(H/_H_irr(theta)) [1]. There are however relatively few measurements of the irreversibility fields for pinning enhanced REBCO coated conductors. We have measured _B_irr(theta) for temperatures near _T_c and _T_irr(theta) up to 8 T, for REBCO coated conductor samples with and without additional columnar pinning. The columnar pinning was added through Ag ion irradiation with 150 MeV ions up to a fluence of 6 x 1011ions/cm2. The results do not follow the expected cos(theta) angular dependence but rather have narrower peaks and double peaks for samples with additional c-axis pinning. We fit the peaks with maximum entropy probability distributions and conclude pinning effects are dominating the form of these results. The conclusions for scaling of non-equilibrium properties such as critical currents and resistivity are briefly discussed.
[1] Z. Hao and J.R. Clem, Phys Rev. B 46, 5853 (1992)
Acknowledgements: Martin W Rupich, American Superconductor Corporation, Ayer, MA 01432
Ruth Knibbe, Ming Li, School of Mechanical and Mining Engineering, University of Queensland, Brisbane, QLD
Christian Notthoff and Patrick KluthResearch School of Physics, Australian National University, Canberra, Australia