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Study of the elastic scattering of 600-MeV protons from light nuclei. Differential cross sections have been obtained for the scattering of protons from hydrogen, deuterium, helium-3, and helium-4. Polarization was measured for deuterium and He-4 nuclei. The p-p cross-section data are in excellent agreement with the predictions from the Livermore phase shifts. Small-angle p-D, p-He-3 elastic scattering data are compared with calculations based on the multiple-scattering theories of Watson and Glauber.

The differential cross section for elastic scattering of 42 MeV α-particles from 3 He has been measured between 20° and 160° c.m. A phenomenological description of the elastic scattering data is given by an optical-model calculation. To reproduce the shape of the differential cross section it was found that the absorptive potential was required to extend radially beyond the real potential. Including a small spin-orbit potential in the calculation improves the agreement with the experiment and predicts a polarization which is consistent with one measurement at a nearby energy. The reaction cross section given by the optical-model calculation is close to a lower limit estimated from integration of inelastic events observed. The two-body reactions 3 He(α, p) 6 Li ground and first excited state, were measured between 20° and 160° c.m. Optical potentials determined from elastic scattering data were used in a distorted wave Born approximation prediction for these cross sections. Qualitative agreement was obtained assuming only the 3 He stripping mode.

Proton-deuteron elastic large angle scattering cross sections, noting backward peak consistent with baryon exchange mechanism with resonance transfer

The differential cross section for elastic scattering of 600-MeV protons from $^{4}\mathrm{He}$ has been measured for laboratory angles between 4\ifmmode^\circ\else\textdegree\fi{} and 44\ifmmode^\circ\else\textdegree\fi{}. The data are analyzed in terms of the diffraction approximation of Glauber.

Cross sections measured for symmetric /p, 2p/ reactions on deuterium and He, discussing nonsymmetric /p, 2p/ events in He

Thirteen angular distributions have been measured from 8\ifmmode^\circ\else\textdegree\fi{} to 70\ifmmode^\circ\else\textdegree\fi{} for the ${\mathrm{Sc}}^{45}(\ensuremath{\alpha},t){\mathrm{Ti}}^{46}$ reaction at 41 MeV. Very selective population of the states of ${\mathrm{Ti}}^{46}$ was observed, and the populated states correlate well with states of the ${\mathrm{Sc}}^{45}({\mathrm{He}}^{3},d){\mathrm{Ti}}^{46}$ reaction which have large ${l}_{p}=3$ spectroscopic strengths. The angular distributions have little structure and exhibit the same basic shape. The distorted-wave Born-approximation (DWBA) noncutoff calculations for the stripping of an ${l}_{p}=3$ proton provides an adequate description of the angular distributions. The relative spectroscopic strengths extracted from the DWBA analysis agree favorably with those deduced from a similar study of the ${\mathrm{Sc}}^{45}({\mathrm{He}}^{3},d){\mathrm{Ti}}^{46}$ reaction. Theoretical spectroscopic strengths calculated from the McCullen-Bayman-Zamick single-particle wave functions for the ground state of ${\mathrm{Sc}}^{45}$ and five low-lying states of ${\mathrm{Ti}}^{46}$ are in reasonable agreement with experiment.

Asymmetry of polarized protons scattered from He 4 at 540 Mev for laboratory angles between 4 and 42 degrees

High energy proton-He 3 elastic scattering cross section measurement, comparing result with Glauber model calculation

An external beam-bunch selector has been built to modulate the beam of the NASA 60-inch cyclotron for neutron time-of-flight studies. Electrostatic deflection at one-fourth the cyclotron frequency is used to lengthen the beam burst period, so that longer flight times can be used. The design and performance of this apparatus are described. With this equipment, flight times up to 400 nanoseconds are available, without distortion of the cyclotron beam burst width. Energy resolutions of the order of 2 percent are thus possible.

The differential cross sections for inelastic alpha particle scattering to large angles from 3+ states in 24Mg and 26Mg at 42 MeV show a clear diffraction type of pattern and pronounced enhancement compared with forward angles.

The cyclotron is routinely operated with three simultaneously extracted beams and more are planned. A double beam has been sent down one line with sufficient separation for magnetic splitting. The extracted beam intensity can now be continuously varied from 103 to 1015 protons/s (170 ?A). The highest intensities were obtained by the addition of a second harmonic buncher in the injection beam line. Direct measurements of the electromagnetic H- stripping losses agree with those expected. Beam-defining slits have been used to reduce the energy spread (?E/E) of the extracted beam to 10-3 at all energies between 200 and 500 MeV. Under certain circumstances the medium resolution spectrometer has measured a resolution a factor of two better. Depolarizing resonances have been located and one of them corrected. A number of new experimental facilities have been commissioned recently. These include a low intensity polarized proton line operating to a polarized target, a high luminosity, low energy ?-? channel, and a clean cloud or surface muon channel using a velocity separator. The influence of the beam size and target shape on the characteristics of secondary particles has been examined.

A measurement of the (p,2p) differential cross section dσ/dEdΩldΩ2 at 600 MeV on Deuterium and Helium-4 at the NASA Space Radiation Effects Laboratory is reported [1], [2]. Two coincident protons were detected with identical range telescopes. The energy sum of the outgoing protons was constrained to be equal to the incident energy minus the S-state proton separation energy, 2.2 and 20.4 MeV for D and He-4, respectively. By varying the detection angles symmetrically to the beam, events were selected with nuclear recoil momentum \(\vec q_r = \vec p_o - (\vec p_1 + \vec p_2 )\) along the beam line. Values of qr up to 370 MeV/c in D and 300 MeV/c in He-4 were observed.