Pinning Force of a Nonideal Superconductor Containing Pins with Large Interaction Forces. II. Low Pin Density

Abstract

The global pinning force density was calculated for a superconductor containing strong and dilute pins using the statistical method. The resultant pinning force density was found to be proportional to both the elementary pinning strength and the density of pins. This means that the pinning force density is describable by the linear summation model. The present theoretical approach is compared with the one by Campbell which predicts direct summation for very strong pins. Satisfactory agreement was obtained between the present result and the results of previous experiments qualitatively and quantitatively.