Cavendish Laboratory : Walton observing alpha-particles with the Cockcroft-Walton machine (1932)
Cavendish Laboratory
<p style='text-align: justify;'>Black and white photograph of the Cockcroft-Walton machine with Walton sitting in the observation 'tent' and Cockcroft in the background taken in 1932. Protons were directed onto a lithium target and the products of the interactions were observed on a zinc flouride fluorescent screen. Walton succeeded in observing the first artificial nuclear disintegrations, at the same time validating Einstein's mass energy relation <i>E = mc<sup>2</sup></i>. Nothing remains of this instrument. Cockcroft and Walton were awarded the 1951 Nobel Prize in Physics for this work.</p>