Cancer and the neutron

I think of cancer, and radiation therapy for it, as modern phenomena. It was surprising, then, to learn that radon ‘seeds’ were being used for radiation therapy of cancer in 1929 – before the neutron had even been discovered. Indeed, polonium extracted from depleted seeds from Baltimore’s Kelly Hospital provided James Chadwick with the neutron source for the experiment that confirmed their existence. Neutrons are critical for inducing the fission of atoms, whether in bombs or power plants, because they are not repelled by the electric fields around atoms.

A detailed account of the experiment is in chapter 6 of Richard Rhodes’ The Making of the Atomic Bomb.

Author: Milan

In the spring of 2005, I graduated from the University of British Columbia with a degree in International Relations and a general focus in the area of environmental politics. Between 2005 and 2007 I completed an M.Phil in IR at Wadham College, Oxford. I worked for five years for the Canadian federal government, including completing the Accelerated Economist Training Program, and then completed a PhD in Political Science at the University of Toronto in 2023. View all posts by Milan