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Keith, Christopher

Publications and source records attributed to Keith, Christopher.

Transversely Polarized Solid Target for Hall B at Jefferson Lab

The physics program for Hall B at Jefferson Lab includes multiple, high-impact experiments scattering electrons from transversely polarized protons. These experiments will measure, for example, the Transverse Momentum Distributions and the Generalized Parton Distribution for protons, using, respectively, semi-inclusive deep inelastic scattering and deeply virtual Compton scattering. In this talk I will discuss the technical challenges to implementing a polarized solid-state target in the Hall B experimental environment, examine potential solutions, and describe the current status of the target design.

Keith, Christopher↗

Digital Q-Meter for continuous-wave NMR

A method to perform continuous-wave NMR measurements of nuclear magnetization at high magnetic fields, above 2.5 T, without analog down-mixing is described. An FPGA controls a digital clock pulse which is used to stimulate a resonant circuit and provide a reference signal. An algorithm determines the real portion of a resonant circuit signal near the Larmor frequency of the species of interest using only two measurements of the waveform per cycle. The FPGA automatically alters a variable capacitance to tune the resonant circuit to the Larmor frequency.

Maxwell, James↗

First Use of a Longitudinally Polarized Target with CLAS12

Run Group C comprises eight experiments utilizing the CLAS12 detector system in Hall B at Jefferson Lab to study the multidimensional partonic structure of nucleons. The experiments scatter electrons from polarized protons and neutrons in samples of solid NH$_3$ and ND$_3$, dynamically polarized at a temperature of 1 K in a 5 T magnetic field. After a brief description of the target system, the current status of the target and preliminary results of its performance in the experiment are presented.

Keith, Christopher↗

The EIC on a Table Top (Final Report)

A research collaboration between JLab and the Atomic and Molecular Optics group of Olivier Pfister at UVA was established to adapt and enhance their optics-based Quantum Computing (QC) system for the calculation of Doubly-Deeply Virtual Compton Scattering amplitudes relevant for JLab12 and the EIC program. The formalism and simulation infrastructure for computing matrix elements of such Compton amplitudes was established. In partnership with UVA, JLab has provided the technical expertise to enhance the current system, and explored significantly scaling it to become a unique and powerful resource.

97 MATHEMATICS AND COMPUTING↗