Buckling measurements were taken with hollow natural uranium slugs in graphite-moderated lattices, in which the lattice spacing was varied from 6 3/16 to 15 inches in five steps. A 1.66" O.D. slug was used with two different core sizes, 1.11" I.D. and 0.81" I.D. The results of wet (water in the core) and dry measurements are reported. Buckling curves are given showing the effect on the buckling of coring the slug and placing water in the core. Simple three-region diffusion theory is applied to the measured lattices in an effort to correlate measurement with theory, but with only limited success.

Abstract: "The definitions of the fundamental measures of calutron operation including enhancement, current ratio, and process efficiency are set forth with derivations of the relationships between them. An analysis of the plant process is carried out for both the tanks limited and the charge limited case. Equations are derived for plant X output and plant X utilization efficiency. Effective production is defined and the value of increment to a mass of product material in terms of effective production is determined. An equation giving the X concentration below which product material should be reprocessed is derived."

The following report was written to replace previous directions submitted in the February 6, 1943 report on the preparation of the solution X(OC₂H₅)₅.