Threshold Detector Cross-Section Intercalibration in a Pure Fission Spectrum

Intercalibrated values of fission-spectrum-averaged cross sections have been obtained for the ²⁴Mg (n,p),⁴⁶ Ti (n,p), ⁵⁴Fe (n,p), ^5eFe (n,p), ⁵⁸Ni (n,p), ⁵⁹Co (n,α), ⁹²Mo (n,p), and ¹¹⁵In (n,n') threshold reactions. All values are given relative to an assumed value of 0.61 mb for ²⁷Al (n,α) ²⁴Na. Irradiations were performed in a specially designed Converter Facility, located in a beam port near the thermal column of the Ispra-I Reactor. The converter is a disk of enriched uranium-aluminum alloy suspended in an essentially material-free cavity. Spectral purity correction factors were calculated using the Monte Carlo code TIMOC. The measured values are compared to the results of other workers.