Deuteron elastic scattering at 110 and 120 MeV.

We have measured deuteron elastic scattering cross sections at 110 MeV on C and Pb, and at 120 MeV on C and Ni, with the Texas ARM K500 cyclotron. The motivation for this experiment is that, except for some limited data above 200 MeV [1], there exists no elastic scattering data above 90 MeV. In order to calculate deuteron optical potentials in the energy range accessible by the K500 cyclotron, 110—160 MeV, these elastic scattering cross sections must be measured. The immediate interest in these data is to obtain optical potentials with which the (d, He) data taken with the proton spectrometer facility [2] can be analyzed. More generally, these data can be used to extend the deuteron global optical potentials [3,4] to this energy region. To do this the addition of analyzing power data would be useful, but a polarized beam is not available to us at this time. The experimental setup differed for the two energies only in that the energy detector was changed. A detector telescope was mounted on a turntable that was rotated from —10 to +60'. The first element in the telescope was a collimator that, along with the mounting position, defined the solid angle. The solid angles for the two data runs at 110 MeV were 0.159 and 0.128 msr, and for the 120 MeV data it was 0.150 msr. After the collimator was a 1 mm thick transmission mount silicon surface barrier detector for a AE signal. For the 110 MeV data this was followed by a 5.08 cm thick, 2.54 cm diameter BaF2 scintillator coupled to a Hammamatsu R1397 photomultiplier tube and base that provided a total energy signal. The energy resolution for this system was about 2 MeV full width at half maximum (FWHM). In order to improve the resolution, this scintillator was replaced by a NaI scintillator 5.08 cm thick by 1.91 cm diameter, backed by an EMI 9902KB phototube. The energy resolution for the 120 MeV data was 0.96 MeV FWHM. This can be seen in the Ni spectrum at 10, shown in Fig. 1, where both the ground state and 1.45 MeV first excited state are clearly resolved. The beam that did not interact with the target went on to a shielded Faraday cup at 0 which was connected to an integrator. A monitor detector, another BaFq scintillator, was mounted at —20 for detector angles less than +25, and at —45 for the larger detector angles. The purpose of this detector was to provide a consistency check on the beam current integration and to provide the correct normalization at the smallest angles where the beam intensity was so low that the integrator was unreliable. An overall systematic normalization uncertainty in our measured cross sections of V (r ) = VR f (r, ro —a o) —i Ws f (r, r I, aI ) d+i4alWa f (r, rI, as) dr( y ' (1'td +VI,s