Walton, the only Irish Nobel Laureate in Science

Nov 04 2013

E.T.S. Walton created an instant world-wide scientific and media sensation when in 1932 he split the atomic nucleus by artificial means.  For this landmark achievement he and J.D. Cockcroft shared the 1951 Nobel prize for physics.  To this day Walton remains the only Irish Nobel Laureate in any of the sciences.

Using his great experimental skills Walton, together with Cockcroft, was able to produce fast protons and use them to split lithium nuclei into pairs of alpha particles.  By measuring the large amount of energy released they provided the first major experimental proof of Einstein’s mass-energy relation E = mc2.  They were also the first to work out the detailed theoretical physics of the splitting process.  As a result they beat no fewer than three competing American research teams.

The simple particle accelerator that Cockcroft and Walton designed and built paved the way to today’s huge accelerators such as the CERN LHC that discovered the Higgs boson.  It also led to the thousands of smaller accelerators now used worldwide in industry and medicine.

Walton was an all-Ireland physicist.  He was born in 1903 in Dungarvan, Co Waterford, the son of a Methodist minister.  As a child Walton moved from place to place throughout Ireland, both north and south, before attending first Wesley College Dublin and then Methodist College Belfast.

Between 1922 and 1927 Walton was a student at Trinity College Dublin.  He excelled in his physics and mathematics primary degrees and then studied for an M.Sc. with the mathematician J.L. Synge, nephew of the playwright J.M. Synge.  In 1927 he was accepted into the famous Cavendish laboratory at Cambridge.  There he gained a Ph.D. with Ernest Rutherford, the so-called ‘father of nuclear physics’, before staying on and splitting the atomic nucleus.

In 1934 Walton returned to Trinity College Dublin, where he remained for over 50 years as College Fellow and head of the department of Physics.  Here he built another accelerator despite the minimal research funding available.  He contributed to the government’s emergency efforts during the 1939-1945 war.  Afterwards he urged the then Taoiseach, Éamon de Valera, to construct a strong and much-needed scientific foundation to support Ireland’s agricultural and scientific needs.

Walton had to carry a very heavy teaching load.  Many generations of students still remember the clarity and excellence of his lectures, which were often illustrated with experimental demonstrations.

Walton was twice asked to join in scientific war work for the Allies, but judged Ireland’s needs to be his greater priority.  Afterwards he became strongly committed to minimising the threat of nuclear war.  To this end he joined the Irish Pugwash group, in due course becoming its president.

Walton was a quiet, unassuming and devout man, preferring to shun the limelight brought by his great scientific fame.  He died in 1995 and is buried with his wife Freda in a modest grave in south Dublin’s Deans Grange cemetery.

In November 2013 Eilis O’Connell’s sculpture honouring Walton will be unveiled beside Trinity’s Physics laboratory where he worked for so many years.

This guest post was written by Professor Eric Finch, who is an emeritus fellow of the School of Physics in Trinity College Dublin. Professor Finch was the last person to be appointed to the School of Physics by E.T.S. Walton before he retired.


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