Mark Oliphant - The man who discovered the Helium-3 isotope

Born in Kent Town, Adelaide, Australia, Mark Oliphant was a Physicist, who received the prestigious Hughes Medal (other recipients include Alexander Graham Bell, Enrico Fermi, Stephen Hawking, and Andre Geim). He was also a life-long vegetarian after seeing a pig slaughtered at a farm as a child. Oliphant initially wanted to be a chemist or to practice medicine but, he says, his physics teacher, Dr Roy Burdon, “who weaned me away... from my ideas of being a chemist or a doctor and taught me the extraordinary exhilaration there was in even minor discoveries in the field of physics.” (1) 

It was, however, the New Zealand physicist, Ernest Rutherford who, he says, “has influenced me to the greatest extent in [my] life” (2) and that he was “was the most inspiring man I have ever met” (3). After Rutherford’s speech about the work taking place at the Cavendish Library, Cambridge, England, Oliphant “just immediately decided that this was the man I was going to work with, if possible.” (4) In 1927, after winning the ‘1851 Exhibitioner’ scholarship, he was able to do just that, as he went to study under Rutherford at Cambridge.

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In 1929, Oliphant gained his PhD in nuclear physics, specifically looking at the artificial disintegration of the atomic nucleus, and investigating positive ions. As the Cavendish Laboratory received significantly less funding than its findings deserved, laboratory equipment tended to be constructed from unconventional resources. One example of this was the “famed "string and ceiling wax" approach ... which included the use of biscuit and coffee tins as essential pieces of apparatus”. (5)

Some of the amazing research taking place in the 1930’s included the splitting of the atom with the first ever high-powered particle accelerator, by Sir John Cockcroft and Ernest Walton, and the discoveries of both the Neutron (Sir James Chadwick) and confirmation of the existence of the Positron and the opposing spiral traces present at the production of a positron/electron pair (Patrick Blackett).

It was Rutherford’s request that Oliphant investigate further the discoveries of Cockroft and Walton that lead to the discovery of the Helium-3 isotope.  Oliphant says of this work that he and Rutherford “were able to discover two new kinds of atomic species, one was hydrogen of mass 3 [Tritium], unknown until that time, and the other helium of mass 3, also unknown. These new atoms were produced as a result of atomic transformations induced by our ion beam hitting targets of lithium, beryllium and other materials.” (6)

The second discovery made from this work was that they “were able to show that heavy hydrogen nuclei, that is to say the cores of heavy hydrogen atoms, could be made to react with one another to produce a good deal of energy and new kinds of atoms. This particular reaction, which we discovered at this time, is the basic reaction in the so-called hydrogen bomb,” (7) athough at the time they had “no idea whatever that this would one day be applied to make hydrogen bombs. Our curiosity was just curiosity about the structure of the nucleus of the atom, and the discovery of these reactions was purely, as the Americans would put it, coincidental.” (8)

It was this discovery, and his subsequent work at the University of Birmingham, which steered Oliphant towards the Manhattan Project and his work on Uranium with Ernest Lawrence (he did not work directly with Oppenheimer). He was a vociferous advocate for the peaceful proliferation of atomic energy, but early on he realised that “anybody who has a nuclear reactor can extract the plutonium from the reactor and make nuclear weapons, so that a country which has a nuclear reactor can, at any moment that it wants to, become a nuclear weapons power. And I, right from the beginning, have been terribly worried by the existence of nuclear weapons and very much against their use.” (9)

After the war, Oliphant returned to Birmingham. Later, he was invited to the Australian National University, from which he established the Australian Academy of Sciences. In 1954, on her first royal visit, Queen Elizabeth II was presented with a charter from the Academy, marking its official establishment. His last major public role came as State governor of South Australia in 1971.

Bibliography:

(1) (Conversation with Sir Mark Oliphant,  July 1967, National Library Collection, Tape 276, p. 1 of 12 page transcript (Interviewed by Hazel de Berg)).
(2) (Moyal, Ann, Portraits in Science, National Library of Australia, 1994, p. 37).
(3) (Conversation with Sir Mark Oliphant, 24 July 1967, National Library Collection, Tape 276, pp. 1 & 4 of 12 page transcript (Interviewed by Hazel de Berg)).
(4) (Moyal, Ann, Portraits in Science, National Library of Australia, 1994, p. 37).
(5) (Cockburn, Stewart & Ellyard, David, Oliphant: the life and times of Sir Mark Oliphant, Axiom Books, Adelaide, 1981, p. 37)
(6) (Conversation with Sir Mark Oliphant, 24 July 1967, National Library Collection, Tape 276, p. 5 of 12 page transcript (Interviewed by Hazel de Berg)).
(7) (Conversation with Sir Mark Oliphant, 24 July 1967, National Library Collection, Tape 276, p. 5 of 12 page transcript (Interviewed by Hazel de Berg)).
(8) Conversation with Sir Mark Oliphant, 24 July 1967, National Library Collection, Tape 276, p. 5 of 12 page transcript (Interviewed by Hazel de Berg).
(9) Moyal, Ann, Portraits in Science, National Library of Australia, 1994, p. 31.