t−tElastic Scattering from 1.6 to 2.0 Mev

A magnetically analyzed triton beam from an electrostatic accelerator has been scattered from tritium in a 14-inch scattering chamber and the differential cross section for elastic scattering measured in 10° steps from 20° to 140° in the center-of-mass system for incident energies of 1.8 and 2.0 Mev. Two proportional counters with a fixed angular separation of 90° were used in coincidence to detect both the scattered and recoil tritons for the laboratory range from 45° to 70°, with an absolute probable error of ±3%. A single counter was used for laboratory angles between 10° and 20°, with resultant probable errors of +5%, -15%. Excitation functions in 100-kev steps from 1.6 to 2.0 Mev show no evidence for an excited state of ${\mathrm{He}}^6$ in this region.