Undergraduate Research at Jefferson Lab

Optimization of Bipolar Electropolishing

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(Electron Beam Dynamics)

Electron Beam Dynamics

The Sidereal Time Variations of the Lorentz Force and
Maximum Attainable Speed of Electrons

Student: Gabriel Nowak

School: Oregon State University

Mentored By: Bogdan Wojtsekhowski

The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab produces electrons that orbit through a stable magnetic system. The electron beam's momentum can be determined through the radius of the beam's orbit. This project compares the beam orbit's radius while travelling in a transverse magnetic field with theoretical predictions from special relativity; which predicts constancy of beam orbit radius as a function of earth's rotation. Time variations in the beam orbit's radius are found at the beginning and the end of a magnetic arc. These variations in the orbit correspond to variations in the beam's momentum. Beam position monitors (BPMs) provide the information needed to calculate the beam momentum. Multiple BPM's are included in the analysis and fitted using the method of least squares to decrease statistical uncertainty. Preliminary results from data collected in ARC #1 over a 24 hour period show that the relative momentum change was less than 10-4; which corresponds to an upper limit in the relative one way speed of light of 10-10. The results from this analysis will be used in an experiment to better determine the upper bound on the anisotropy of the one way speed of light. The current upper bound is on the level of 10-14 and we hope to achieve 10-16 using ARC #9 data.
The Sidereal Time Variations of the Lorentz Force and<br>Maximum Attainable Speed of Electrons