UBC Theses and Dissertations
The scattering of polarized neutrons and the gamma rays from the reactions B(d,p8) B and B(d,n8) C Sample, John Thomas
Detailed calculations have been carried out which indicate that the small-angle scattering of fast neutrons by lead depends on the polarization, or spin orientation, of the neutrons. When the scattering of neutrons whose spin vectors point upward is observed in the horizontal plane, more neutrons should be found scattered to the right than to the left. For completely polarized 3.1 Mev neutrons, the theory predicts a maximum "right to left" intensity ratio of 14.5:1 at a scattering angle of 0.5°, the ratio decreasing to 1.6:1 at 5°, and approaching unity rapidly as the scattering angle increases. An attempt to detect this effect with neutrons from the reaction D(d,n)He³ failed because the degree of neutron collimation attainable, while satisfactory for most scattering experiments, was insufficient to permit investigation of neutron scattering at very small angles. A three crystal pair spectrometer has been used to investigate the complex gamma ray spectrum arising from bombardment of B¹⁰with deuterons of several energies between 0.8 and 2.2 Mev. Gamma rays of energy 4.46 ≠.04, 4.75 ≠ .03, 5.03 ≠ .09, 5.35 ≠ .05, 6.52 ≠ .05, 6.78 ≠ .07, 7.29 ≠ .04, 8.27 ≠ .09, and 8.87 ≠ .02 Mev have been assigned to transitions in B¹¹ and C¹¹, with excellent agreement in almost all cases with the energy level schemes proposed from other experiments. The excitation curves of three of the gamma rays have been found to rise smoothly between bombarding energies of 0.8 and 2.2 Mev, indicating that the reactions B¹⁰(d,p [symbol omitted])B¹¹l and B¹⁰(d, n [symbol omitted])C¹¹ are primarily of non-resonant character, at least in this energy region.
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