During the past year notable progress was made in several laboratories on design for linear accelerators in the energy range up to and above 1 Bev. Interest in linacs for this energy centers on two possible applications: first, as injectors for 300 to 1000 Bev synchrotrons, and second, as sources of intense meson beams. To review this progress, a conference jointly sponsored by the Brookhaven National Laboratory and Yale University was held at Brookhaven during the week of August 20, 1962.

When the nucleus of an atom in a crystalline solid undergoes radiative neutron capture there is disruption of the crystal in the vicinity of the event due to energetic processes accompanying the nuclear transformation. This local disruption has been termed a "hot-zone" or "displacement spike". The chemical state of a transformed recoil atom immediately following transformation is unknown. Within a microsecond the "hot zone" has cooled sufficiently to "freeze" the recoil atom into a stable (or metastable) chemical state. A fraction of the metastable recoil atoms can undergo thermal annealing reactions, and the chemical nature of the metastable state can sometimes be inferred from annealing data. It is characteristic of these reactions that the recoil atoms tend to be reincorporated into the parent chemical form.

A study of the effects of gamma radiation with respect to the formation of nitro-hydrocarbons on the Purex and Redox systems shows that no appreciable formation of nitro-paraffins occurs.

During a visit to Professor H.G. Harb at the University of Wisconsin, it was apparent that he had succeeded in obtaining fresh, clean chemisorptive layers of titanium by sublimation and chat that this could be adapted into an effective high vacuum pump. Two previous techniques of obtaining a chemisorptive layer of titanium, namely catholic sputtering and evaporation from the liquid droplet, have been extensively investigated and reported. Each of these seem to have inherent difficulties in stability and continuity of operation that appear to be eliminated or effectively reduced by the sublimation procedure. A development program was started at Brookhaven National Laboratory to investigate the possibilities of each sublimation of titanium as opposed to evaporation from the liquid.

A series of measurements of ε in slightly enriched uranium, light water lattices is presently under way at Brookhaven. Figure 1 shows ε as a function of water-to-metal ratio for .600" diameter rods, of 1.3% enrichment. Because of interaction between neighboring groups of rods, ε increases rapidly as the water-to-metal ratio decreases.

Using requirements of analyticity and the unitarity of the S-matrix we obtain the dependence of a transition amplitude on the invariant mass of two particles strongly coupled to other two particle channels. As an example, we consider the production of a Σπ state near the Y*₀ resonance assuming it is coupled to a KN state in an s 1/2 state.