Measurement of the Neutron (³He) Spin Structure Function at Low Q²: A Connection between the Bjorken and Drell-Hearn-Gerasimov Sum Rules

Citation

Jensen, John Steffen (2001) Measurement of the Neutron (³He) Spin Structure Function at Low Q²: A Connection between the Bjorken and Drell-Hearn-Gerasimov Sum Rules. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/wmxe-ge51. https://resolver.caltech.edu/CaltechTHESIS:07142014-135205986

Abstract

The spin dependent cross sections, σT_1/2 and σT_3/2 , and asymmetries, A_∥ and A_⊥ for ³He have been measured at the Jefferson Lab's Hall A facility. The inclusive scattering process ³He(e,e)X was performed for initial beam energies ranging from 0.86 to 5.1 GeV, at a scattering angle of 15.5°. Data includes measurements from the quasielastic peak, resonance region, and the deep inelastic regime. An approximation for the extended Gerasimov-Drell-Hearn integral is presented at a 4-momentum transfer Q² of 0.2-1.0 GeV².

Also presented are results on the performance of the polarized ³He target. Polarization of ³He was achieved by the process of spin-exchange collisions with optically pumped rubidium vapor. The ³He polarization was monitored using the NMR technique of adiabatic fast passage (AFP). The average target polarization was approximately 35% and was determined to have a systematic uncertainty of roughly ±4% relative.

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