Date of Award
Spring 5-2023
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Physics
Program/Concentration
Nuclear and Particle Physics
Committee Director
Sebastian Kuhn
Committee Member
Stephen Bültmann
Committee Member
Balša Terzić
Committee Member
Ted Rogers
Committee Member
Linda Vahala
Abstract
A new polarized nuclear target has been developed, constructed, and deployed at Jefferson Laboratory in Newport News, VA for use with the upgraded 12 GeV CEBAF (Continuous Electron Beam Accelerator Facility) accelerator and the Hall B CLAS12 (12 GeV CEBAF Large Acceptance Spectrometer) detector array. This ‘APOLLO’ (Ammonia POLarized LOngitudinally) target is a longitudinally polarized, solid ammonia, nuclear target which employs DNP (Dynamic Nuclear Polarization) to induce a net polarization in samples of protons (NH3) and deuterons (ND3) cooled to 1K via helium evaporation, held in a 5T polarizing field supplied by the CLAS12 spectrometer, and irradiated with 140 GHz microwave radiation. It was utilized in the RGC (Run Group C) experiment suite through a collaboration of the JLab Target Group, Old Dominion University, Christopher Newport University, the University of Virginia, and the CLAS Collaboration. RGC comprised six experiments which measured multiple spin-dependent observables across a wide kinematic phase space for use in nucleon spin studies. The dimensional constraints necessary for the incorporation of APOLLO into CLAS12, as well as the considerations necessary to utilize the CLAS12 solenoid, introduced unique challenges to the target design. This document presents the innovative solutions developed for these challenges including a novel material transport system, superconducting magnetic correction coils, and an all new bespoke NMR (Nuclear Magnetic Resonance) system. In addition to a detailed description of the complete target system and an initial report of the RGC experimental run, it will also present a study of Quark-Hadron Duality in the g1 spin structure function based on Hall B EG1b data and pQCD fits from the JAM (Jefferson Lab Angular Momentum) Collaboration.
Rights
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DOI
10.25777/36yz-ft35
ISBN
9798379734374
Recommended Citation
Lagerquist, Victoria.
"Design and Construction of a Longitudinally Polarized Solid Nuclear Target for CLAS12"
(2023). Doctor of Philosophy (PhD), Dissertation, Physics, Old Dominion University, DOI: 10.25777/36yz-ft35
https://digitalcommons.odu.edu/physics_etds/180
ORCID
0000-0001-6967-0385