Operation and cross calibration of the activation foil system on TFTR

Abstract

Time-integrated neutron yields are measured with an activation foil system which pneumatically sends the foils to and from TFTR by remote control. The foils are then counted by high-purity germanium coaxial detectors which have an absolute efficiency calibration. Using different nuclear reactions in different foils with different energy thresholds allows measurements of both DD and DT neutron yields. Details of the system hardware, operation, and efficiency calibration are provided. The cross calibration of the system to other measurements of neutron source strength to provide an absolute measure of yield is described. Comparison of this cross calibration is made to previous absolute calibrations and to neutronics calculations of the response coefficients.