Spallation cross sections and the LAMPF medical radioisotope program

The intense beam of medium-energy protons (600 to 800 MeV) from the LAMPF accelerator will be used to prepare multi-curie quantities of radioisotopes of value in diagnostic and therapeutic nuclear medicine. Thin-target cross section measurements of spallation-induced reactions represent a significant segment of the LASL Medical Radioisotope Research Program, as these data provide a basis for calculating specific radioisotope yields in thick targets, evaluating potential isotopic interferences, and monitoring hot-cell operations. Recent measurements include the cross sections (cumulative yields) of 123I, 127Xe, 82Sr, and 43K formed in the interaction of 800-MeV protons with La, Mo, and V targets; they are reported to be 51 +- 3 mb, 51 +- 7 mb, 24.5 +- 0.8 mb, and 5.4 +- 0.3 mb, respectively. Comparison with previous results at 590 MeV are made, and quantity and product quality estimates are presented for biomedical isotopes under the irradiation conditions expected to prevail at LAMPF