A Hands-On Approach to Nuclear Physics

Dr. David Ticehurst ’99 applies science mindset and engineering skill to build radiation detectors.
Dr. David Ticehurst ’99 is not your average nuclear physicist. He likes to work with his hands, and as a doctoral student, he couldn’t see himself spending the rest of his life at a blackboard or behind a computer screen.

It’s rare for scientists with a Ph.D. in physics to pursue work outside of academics or research, but Dr. Ticehurst is an anomaly, finding challenge and reward building germanium gamma-ray imaging detectors with Knoxville, Tennessee-based PHDS Co.

On an average day at PHDS Co., Dr. Ticehurst balances tasks revolving around science, engineering, and research.

“The work that I do is one part sitting at a computer, it’s another part dressing up in a white bunny suit working with hydrofluoric acid,” he said. “It’s another part being in a clean room with gloves and a facemask on, loading one of our $100,000 cryostats; it’s working with high-vacuum vapor-deposition machines that fabricate these detectors; and sometimes I find myself working on a mill or lathe doing actual metalwork.”

The result of this work is a hand-held radiation detector that personnel ranging from lab researchers to Navy SEALS can use to evaluate whether an object registers high levels of gamma-rays and radioactive isotopes. 

“At a low level, gamma-rays are not harmful. They’re a natural part of our universe, and we live with them. But like anything, too much can be dangerous or fatal,” he said. “That’s the whole purpose behind the detectors that I build, to be aware of what is in the vicinity of you, be it natural or unnatural, and unnatural is what you want to be careful of.” 

Dr. Ticehurst was exposed to the sciences from infancy thanks to his father, a biological scientist at the National Institutes of Health; he flipped through books on DNA and cells and saw the centrifuges and water baths at his father’s lab. Over the years his interest focused on physical sciences, and at St. Andrew’s he found the perfect mentor to shape his curiosity into a course of study. 

“The first person who really sparked my interest in physics, per se, was Kurt Sinclair,” he said. “I knew a lot of physical science when I came into his class but had never had formal physics. I really liked math to begin with, I liked science, and the combination of the two in physics was extremely appealing to me. The rigorous way Kurt goes about it worked just right.”

At Williams College, Dr. Ticehurst studied astrophysics and planned to continue with it in graduate school at UNC-Chapel Hill, but an encounter with a particle accelerator pulled him toward nuclear physics. For his Ph.D., Dr. Ticehurst conducted experimental work with the particle accelerator and radiation detectors.

“Nuclear physics is very much like a game of pool, where you have a cue ball – that’s the accelerated particle – and you’re shooting it at an atom – that’s all the numbered balls on the table. You can imagine, if you could not actually view the collision, but you could measure how you shot the cue ball and where all the numbered balls ended up, you can figure out how they were arranged to begin with,” he said. “A miniature game of pool is nuclear physics.”

Connections and timing landed him his role at PHDS Co., which would turn out to be a perfect match for his academic expertise as a scientist and his practical experience as a “pseudo-engineer,” which was supplemented by years learning in machine shops, designing with CAD programs, and building projects in his spare time. 

“My advice to people who are looking to follow a similar path in the sciences is not to limit yourself to just one interest,” he said. “Those skills you develop that may seem insignificant to the path you think you want to go on may in fact be critical for getting you the position that is right for you later in your life.”
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St. Andrew’s Episcopal School is a private, coeducational college preparatory day school for students in preschool (Age 2) through grade 12, located in Potomac, Maryland.