The Brookhaven proton synchrotron (Cosmotron) is capable of accelerating protons to energies as high as 3.0 BeV. The biologic effects of particle bombardment at these energies have not been investigated but are of considerable radiobiologic interest. In addition, particle beams have long been discussed with regard to their potential usefulness in medical therapy, and actual clinical applications have been made, although at lower particle energies. Recent rapid advances in space technology have raised serious questions regarding the dosimetry of cosmic and solar radiations, the spectra of which contain energies in excess of those which have been investigated experimentally. For all of these reasons, we have recently begun a study of the effects of protons at 2.0-2.2 BeV, using the external beam of the Cosmotron.

It has been previously reported that within twenty days following bombardment of mice 10 MeV protons (as well as with 20 MeV deuterons and 40 MeV alpha particles) that atypical epithelial hyperplasia developed without underlying recognizable vascular or collagen alterations as predisposing factors. The source of these monoenergetic accelerator-produced heavy ionizing particles was the 60-inch cyclotron of the Brookhaven National Laboratory. The technique employed utilized a variable-thickness filter in the beam in order to deliver multiple Bragg peaks in depth in the path of the charged particles in the tissue being irradiated. In this way a cylinder of skin was bombarded with essentially uniform ionization limited to a depth of 1-2 mm. In some instances the epidermal lesions resulting from an exposure of 2000 to 5000 rad resembled the type of lesion considered in the skin of man to be carcinoma in situ. The eventual fate of such lesions then constituted a question of importance in the possible relationship atypical hyperplasia in the pathogenesis of carcinoma in situ and of invasive carcinoma in skin. It is with this problem that the currently reported study is concerned.

Many workers have recently attempted to evaluate the P-wave strength function from a measurement of average capture cross sections or average total cross sections in the kiloelectron volt region. The primary interest of these measurements has been to determine the strength of the spin-orbit potential in the optical model. In view of the interest in determining the size of the spin-orbit coupling and in view of the considerable disagreement group has undertaken to measure the average total neutron cross sections from 10 to 100 keV in the region of the P-wave giant resonance. The following elements were studied: Nb, Mo, Rh, Ag, Cd, and In. The wok was carried out at the BNL-AECL fast chopper facility at Chalk River, using an 88-meter flight path and a nominal resolution of 15 nsec/meter.

Technical report covering the functions of the Oak Ridge reactor, difficulties encountered with cartridge failures in the Oak Ridge reactor, and possible solutions including the incorporation of leak detection systems into the design of the reactor.