Professor Peter Thonemann - A Reflection of his Life

Professor Peter Thonemann, one of the century’s foremost physicists, and a long-serving member of Swansea University has passed away at the age of 100.

In his lifetime, Professor Thonemann had been a leading global figure in the race for nuclear fusion. He became Head of Physics at Swansea University in 1968 and retired in 1984.

Thonemann 1Peter Thonemann was born on 3 June 1917 in Melbourne, Australia.  He graduated with a BSc from Melbourne University in 1940.  From 1940 to 1942 he worked at a munitions supply laboratory at Maribyrnong before moving to the research department of Amalgamated Wireless at Ashfield near Sydney.  In 1944 he started work on his MSc Thesis entitled “Measurement of Electron Density in Microwave Methods” at the University of Sydney.

In 1946 he moved to Oxford where he joined Trinity College and worked on his DPhil thesis entitled “Study of Gas Discharge Phenomena and their Application to Nuclear Science”, funded by an ICI Fellowship at the Clarendon Laboratory. There he met Dr James Tuck and the two sought funding for their scheme for magnetic confinement. 

Thonemann 2In 1950, under interrogation, Klaus Fuchs, then director of theoretical physics at Harwell, was forced to admit leaking UK and US atom secrets to the USSR and as a result was stripped of his British Nationality and sentenced to prison. Probably as a consequence of this, Thonemann’s research was classified and he was moved to AERE Harwell, the UK Atomic Energy Research Establishment. He later claimed that in 1948, and in collaboration with Dr James Tuck, he had started to confine a hot, electrically conducting gas by magnetic fields. 

In 1949, Professor Thonemann was appointed a Principal Scientific Officer in the General Physics Division at AERE Harwell and between 1949 and 1960 he designed and built the fusion reactor ZETA (Zero-Energy Toroidal Assembly). Because of the Fuchs affair this research was classified.

Thonemann 4The design of ZETA evolved through discussions between Professor Thonemann and his colleagues, Bob Carruthers and Roy Bickerton and its construction was authorised in 1954. ZETA was the ultimate device in a series of UK designs to be built using the Z-pinch confinement technique.

The construction of ZETA was completed by August 1957 and enormous energy was devoted to commissioning it.  ZETA went into operation in 1957, under the leadership of Professor Thonemann and William P Thompson, and on each experimental run a burst of neutrons was observed.

With news of success being leaked, there was a pressure to make an announcement.  In January 1958, the journal Nature was the first to cite that following experiments, thermonuclear fusion had occurred.  Following this, The Financial Times dedicated an entire two column article and the British Press published two articles a week to ZETA.  The publication and press releases were premature and the detection of neutrons was not found to be consistent with fusion reactions.  Despite this ZETA would go on to have a long experimental lifetime and produced numerous important advances in the field, being highly significant in the subsequent toroidal designs known as Tokamaks and the contributions to plasma physics and laser physics. Work continues with fusion experiments in Culham known as JET (Joint European Torus) and an international project based in France called ITER (originally an acronym for International Thermonuclear Experimental Reactor).  The holy grail of ‘our very own sun’ energy source is still some years away.  

Thonemann 3In September 1958, Professor Thonemann was a delegate at the “Second International Conference on the Peaceful Uses of Atomic Energy”, organised by the IAEA at the Palais de Nations at the United Nations in Geneva. The event attracted 5,000 participants and Switzerland issued special stamps to celebrate the occasion. The reason for the popularity was that all embargos of secrecy had been lifted for the first time, even for the Russians. Under the caption “Three Stars of Fusion” Thonemann, Edward Teller and a Russian, Dotkvokhov were photographed, having given presentations in the same conference session where Thonemann spoke on “Controlled Nuclear Fusion Research in the UK”.

In 1968 ZETA achieved its maximum current of 1MA and established the “reversed field pinch” before finally being switched off.   Meanwhile Thonemann had become Deputy Director of the Culham Laboratory from 1965-66 after which he decided to accept an offer from Swansea.

On 22 April 1968 at the age of 50 Thonemann was made Professor of Physics and Head of Department in Swansea.

In 1969 he took two month’s leave of absence to accept the award of Senior Visiting Fellowship in Plasma Physics to visit universities in Australia.

Thonemann 6In 1980-81 he took sabbatical leave for a year to study the application of linear algebra to physics and to complete writing a book on Nuclear Energy and Safety.  He was, however, unable to raise research council funds for fusion research in Swansea, so, instead, he turned his interest to the bacterium E Coli and specifically in its behaviour in response to gradients of nutrient concentration which could be measured and modelled using the same mathematics as for dynamics of particles. This resulted in collaboration with the Biology Department, now known as the Department of Biosciences, in the University’s College of Science. 

Professor Thonemann retired in 1984 and still resides in the Swansea area.

Thonemann 5Professor Peter Dunstan, of the Physics Department at Swansea University said: “Physics at Swansea has a rich history as one of the founding departments of the University in 1920.  It has been blessed with distinguished alumni, such as E.J. Williams FRS (1903-45), who co-discovered the muon and was the first to observe its decay; E.G. Bowen (1911-91) with his major contribution to the development of radar; and Lyn R. Evans CBE FRS who has made major contributions to accelerator physics at CERN, where he was director of the Large Hadron Collider project from its inception to successful operation. Throughout its existence and into the present day the department has within its ranks outstanding and world-renowned academics that have conducted research and inspired the next generation.  Professor Peter Thonemann was certainly one of those, where his pioneering work on fusion in the 1950-60s made considerable contributions to the research underpinning the current large-scale fusion research programmes of today.  More than once Professor Thonemann has been referred to as one of ‘the fathers of fusion’ due to the significance of his work.  He has lived an exceptional life and through exceptional times.  He has reached a remarkable milestone and we wish him every happiness on the celebration of his 100th birthday with his family and friends.”


Pictures from top:

  • Professor Peter Thonemann CREDIT: NDA (Nuclear Decommissioning Authority)
  • British magazine publisher Sir Edward Hulton (right) presenting atomic scientists Dr Peter Thonemann (left) and Sir John Cockcroft with awards for the production of ZETA, Zero Energy Thermonuclear Assembly, at the Savoy Hotel in London, 16th April 1958 CREDIT: NDA (Nuclear Decommissioning Authority)
  • The ZETA machine CREDIT: NDA (Nuclear Decommissioning Authority)
  • Professor Peter Thonemann (left) with Aneurin Bevan and Hugh Gaitskell on a visit to ZETA CREDIT: NDA (Nuclear Decommissioning Authority)
  • Professor Thonemann  (left), Mr Claude Jenkins (centre) and Professor Frank Llewellyn Jones (Principal of the then University College of Swansea) CREDIT: Swansea University
  • University College of Swansea Department of Physics Final Year Honours Class 1970-71. CREDIT: Swansea University