Mason Bates ’25


Electrical and Computer Engineering

Project Title

Small Clean Fusion Reactor Shields

I worked with the Princeton Plasma Physics Laboratory to investigate a more energy efficient neutron shield design for the Princeton Field Reversed Configuration (PFRC) fusion reactor. To keep operators safe and equipment functional, such a shield must be able to block high energy neutrons, a byproduct of the PFRC’s fusion reaction, but it must not block the magnetic fields required for radio frequency heating to avoid siphoning off wasted energy. I designed and conducted experiments to investigate the electrical properties and radio frequency penetration through shields of packed stainless-steel spheres, a proxy for electrically conductive high temperature shielding materials. I also performed calculations to model the Hertzian contact mechanics of conductive spheres. I mapped the magnetic fields produced by our antennas through various shield models to evaluate their energy efficiency. The experience taught me hands-on skills in radio frequency design, electrical engineering experimentation and plasma physics. I’ve learned a lot about nuclear fusion and the avenues it may open for clean energy in the future.

Internship Year


Project Category

Innovation and a New Energy Future


Princeton Plasma Physics Laboratory - Princeton, New Jersey


Samuel Cohen, Director, Program in Plasma Science and Technology, Princeton Plasma Physics Laboratory