Cryogenic Coulomb's Law experiment

John J. Ryan

For my Senior Thesis at Princeton University, I performed a Coulomb's Law experiment at liquid helium temperatures. This was to investigate the possibility of a phase transition by which the photon could acquire a mass. My advisor, Prof. Bob Austin, and I found no such mass, and we published the result in reference[1].

For this experiment, my machining experience was a great asset; I had apprenticed in the Machine Shop at the University after my junior year. I designed and constructed a system for coating the inside surface of pyrex tubing with copper. I machined a set of clamps with Teflon bushings which allowed the tube to spin; it was driven by a small eletric motor, and an O-ring was used as a drive belt. The whole apparatus operated inside an evacuated bell jar.

Last modified: Mon Sep 20, 1999