Ernest Walton 1903-1995

Early Years

Ernest Thomas Sinton Walton was born in Epworth Cottage, Strandside South, Dungarvan, Co. Waterford on the 6th of October, 1903.  He was the son of John Arthur Walton [1874-1936], a Methodist Minister and native of County Tipperary and Anne Elizabeth Sinton [1874-1906]. Anna was from County Armagh where her family had lived for over 200 years.  His father, as a Minister, was regularly transferred to new Ministries and hence Ernest’s childhood was characterised by frequent re-location including periods in Rathkeale Limerick, and Monaghan as well as the North of Ireland. His schooling included periods at a day school in Banbridge Co. Down, Cookstown Co. Tyrone, and he was a border at the Methodist College Belfast in 1915.  From the start his aptitude for Mathematics and Science was unmistakable.
Walton won a scholarship to Trinity College Dublin in 1922 where he studied mathematics and science.  He took a first class honours degree in Maths and Physics in 1926 and a Master of Science Degree in 1927.

Cambridge

Following his graduation, Walton won an 1851 Scholarship and departed for Trinity College, Cambridge where he commenced work under the guidance of the Nobel Prize laureate, Lord Ernest Rutherford [1871-1937] in the Cavendish Laboratory.  The Cavendish Laboratory has a direct link to Robert Boyle (1)  as it was endowed in the name of Henry Cavendish the famous physicist by William Cavendish 7th Duke of Devonshire when Chancellor of the University.  He gave £6000 towards the building of a Laboratory subject to the establishment of a Professorship of Experimental Physics.  It opened in 1874.  In addition to Rutherford the Cavendish Laboratory staff,

“included J.J. Thomson [1856-1940] who discovered the electron.  Lord Rutherford who transmuted nitrogen to oxygen, C.T.R. Wilson [1869-1959] who invented the Wilson Cloud Chamber and Francis William Aston [1877-1945]  who developed the mass spectrograph.” (2)
 
Initially Walton’s research at the Cavendish Laboratory focused on indirect ways of accelerating particles.  However in 1929, he began a working collaboration with John D. Cockcroft [1897-1967].  At the core of their work was the investigation of the nature of the atom and sub-atomic particles probing the nucleus to ascertain its composition.  This necessitated the separation of the various particles.  This entailed probing the nucleus with accelerated particles to ascertain its composition.
To achieve this separation a methodology needed to be chosen and a device needed to be created.  The method chosen involved the bombardment of atoms with protons using a particle beam accelerator, a device which did not exist at that time.  The pair persuaded Ernest Rutherford to back the project and following a first unsuccessful attempt advice from visiting Russian Physicist George Gamow [1904-1968] was critical in achieving a positive outcome.
The accelerator cost some £1000 to build and “represented almost the entire budget for the laboratory” and can be seen today in London Science Museum.  Quoting Walton, Julian Walton local broadcaster states:

“The equipment was somewhat primitive, to put it mildly.  It included bicycle crossbars, plasticine, biscuit tins, sugar crates, and other junk.  ‘You had to be a bit of a scrounger,’ Walton later recalled ‘and Cockcroft was a very good scrounger.''(3) 

The scientists “using a voltage multiplier, they accelerated protons to energies as high as 710 keV and showed that these react with the lithium nucleus to produce two energetic alpha particles…”  With their new tool on the 14th of April, 1932 Walton and Cockcroft became the first scientists to carry out the artificial disintegration of an atomic nucleus. [Rutherford had previously accomplished disintegration using the particles emitted from naturally occurring radioactive materials.]  Walton later described the visual results of the experiment as “a wonderful sight, lots of scintillation, looking just like stars” what Walton was witnessing was the energy released from the atom as it split.   The experiment had split the nucleus of the lithium atom with the result being the creation of two alpha particles and the liberation of energy.
Following the successful completion of their experiments the results were announced to the Royal Society on June the 15th and published subsequently in the scientific journal Nature on the 30th of April 1932.
The implications of these successful experiments were enormous and groundbreaking because “it represented the first time that anyone had produced a change in the atomic nucleus by means totally under human control.”   Ernest Walton and John D. Cockcroft’s innovative experiment signified a major contribution to modern scientific thought which gave rise to a whole new generation of research in physics.  It was of paramount importance because it validated many scientific theories within the realm of relativity theory and quantum mechanics, provided proof for Einstein’s mass-energy equation (i.e. e=mc2) and ushered in the new era of nuclear power production.  In summary, it would appear that the potential of the research and its results was not fully anticipated by the participants whose greatest preoccupation was in validation of conjectures in “pure science.”
Walton remained at Cambridge for a further two years.  He was awarded his Ph.D. from the College in 1931.

(1) Charlotte Boyle the great-great-grandniece of Robert Boyle married William Cavendish 4th Duke of Devonshire.  It was through this marriage that the Irish Estates passed to the Devonshire family.
(2) Keith, Tom.  In living memory: people and events from Dungarvan of the 1900s.  Waterford: Tom Keith, 2002.  IV, 179p. pg. 171
(3) Walton, Julian.  Walton’s Waterford – Tuesday 15th April 2008 WLRFM