Gudmar Grosshög 1932 - 2015

Associate Professor Gudmar Grosshög died on 22 June 2015. Together with Professor Nils Göran Sjöstrand, he was the founder of the Department of Reactor Physics (now Nuclear Engineering). Gudmar has witnessed the birth and shaped the development and maturing of nuclear power in Sweden in several ways, as well as he was an essential part of the varied and adventurous history of the Department. With his passing away Nuclear Engineering has lost both of its founding members.

Gudmar Grosshög was born 1932 in Forestad, Skåne in south Sweden. He often joked about the coincidence that he was born the same year as the neutron was discovered – the elementary particle which was central to his research throughout life. Gudmar had his primary school in Osby, secondary school in Helsingborg and studied economy during one year in Malmö before moving to Göteborg to do military service in 1953. He started studying in Chalmers in 1954, originally at Marine Technology, but soon switched to Mechanical Engineering. He never left Chalmers ever since his enrolment in 1954, until his retirement in 1997.
The mid-50’s were the times when Sweden entered the “atomic age” with much ambitions. Sweden had far-reaching plans of building up nuclear power by own design and based on domestic uranium resources. Originally the development and education was handled by the governmental research institute Studsvik, but soon there was a need of building up university courses. In Chalmers the reactor physics oriented courses were given by the Department of Mathematical Physics at the newly founded School of Applied Physics, started up by Nils Svartholm, and Gudmar took all those courses. After getting his diploma in 1958, he became an assistant in Mathematical Physics, having responsibility for all the reactor oriented courses.

In 1960 the Department of Reactor Physics was created in Chalmers and Gudmar became the first employee as an assistant. When Nils Göran Sjöstrand was installed as state-endowed professor in 1961, Gudmar became the first PhD student. Although he was not the first to get his PhD exam in reactor physics (there were many “external” students from Studsvik who made a PhD before him), he was the first to get his PhD based on work at the Department in 1970. His employment continued at the Department, and he became associate professor and Deputy Head of the Department the same year.

Neutron generator at Storgatan
Gudmar’s research concerned experimental reactor- and neutron physics. Experimental activity needs a lab and heavy equipment, which was quite a challenge to build up in view of the fact that in the first 15 years the Department only had temporary offices. The department started out at the premises of the “old Chalmers”, what is now the Valand Art School, from where they were moved to Storgatan in central Göteborg, where the department occupied a storey consisting of ordinary apartment rooms. Yet, by building extra radiation protection, the first neutron generator of the department was installed there, which lead to some complications later (see below). It was not before 1975 the department could move to a “permanent” place, an own building at Gibraltargatan, which contained a large experiment hall. A high-yield, high performance permanent neutron generator, designed by Gudmar and built by Sames was installed, which was among the best four in the world in its category at the time.

The absolute highlight of neutron physics research led by Gudmar was the design and construction of a neutron spectrometer called “Tansy”, which was built for the largest international fusion reactor experiment, JET, in England, and delivered in the early 1990’s. Several PhdD students earned their thesis on research and development work performed in the Tansy project. It was a large collaboration project, including, among others, people from the Subatomic Physics group of Chalmers. Tansy had the best energy resolution for 14 MeV fusion neutrons internationally, and is still the world record holder in this category by the measurements performed in the tritium phase of the JET project.

The Tansy project was financed fully by an external contract with JET. Such projects were unusual at that time to the extent that Chalmers’ administration could not handle the requirements from JET for the legal aspects. The contract became only possible by Gudmar taking a personal financial responsibility for the successful delivery of the equipment (for a sum of 11 Mkr, at 1985 year’s value!)

Gudmar with the installation of Tansy at JET, and data from the “record” shot during the tritium phase (see Phys. Rev. Letters 80, 4681 (1997))

Gudmar was a superb educator, lecturer and speaker, and not the least had an interest in “public outreach” and popular science talks and writings. This came to good use for the department in several different ways. One of this was his zeal for writing press releases for PhD theses at the department. He had an outstanding feel to formulate a metaphorical description of complicated technical matters. One of these became national news, many local and national newspapers picked up the idea and published it in various forms.

Handling false news
Another utilisation of Gudmar’s public outreach activities was during the campaigns before the national vote (folkomröstning) in 1980 about the future of nuclear energy in Sweden. In the debate Gudmar represented the “yes” line for Chalmers. This meant many public meetings and talks, but also handling journalist’s misconceptions. A famous one was when the false news started circulating that a nuclear reactor had been in operation earlier in central Göteborg. The newspapers were alluding to the previous offices of the department at Storgatan, where a low-yield neutron generator was installed (which is lightyears away of being a nuclear reactor). It took a long time before Gudmar managed to get a denying article published in a local newspaper.

(Sideline: Gudmar wrote in some of his memoires that such fake news never die. Many years later, during the reconstruction of those apartments at Storgatan, several of the construction workers felt suddenly ill when they heard that there was some nuclear activity performed in those offices earlier. Gudmar’s statement was actually ever more valid than he probably had thought. In 2005, Chalmers converted our “permanent” offices to a gym (Friskis och Svettis) in its pursuit of getting better profit from letting the premises than for using it for research. Very recently, when some of the people using the gym heard that the building had been used for nuclear experiments, felt suddenly ill again).

Gudmar enjoyed very much travelling, to meet new people and to explore alien cultures. In addition to the usual conference trips in Europe, US and Japan, he had also a number of far more exotic trips.  For instance he gave several lectures in Thailand, Chiang Mai university (from where he also had a PhD student, supported by the International Science Programme, ISP, of Uppsala). Inspired by his visits and contacts with Chiang Mai University, the Department of Physics in Chiang Mai built a Fast Neutron Facility, by copying, in a smaller and more modest scale, the neutron physics laboratory of Gudmar in Chalmers. He also undertook missions for the IAEA Nigeria on two occasions, lecturing at the Ahmadu Bello University in Zaria. Also from that university he had a PhD student, supported by ISP. Together with Nils Göran, he acted also as a lecturer at “The Nile Winter School” in Khartoum, Sudan. Quite long after his retirement, at the age of 77, he made a single-handed trip to Vietnam, visiting the university of Da Lat, to check the possibilities of donating our “retired” neutron generator to the university, and to install it there.

In addition to science and research, Gudmar had also many private interests, such as music, wood-carving, writing, literature and photography. Among others, he was an active and very appreciated member and Indiana Order of Odd Fellows. He was also on the Board of directors of the Church of Nödinge, and during a short period Chairman of Environmentalists for Nuclear Power. He had a very humble and helpful attitude, and his support and guidance both to his younger colleagues, as well as to the functioning of the department, was invaluable and much appreciated. With his passing away has Reactor Physics/Nuclear Engineering at Chalmers lost both of its founders. We remember Gudmar for his kind and helpful personality, his scientific excellence, and for his seminal role in the history of our department. 

Read more
Those who want to enjoy Gudmar’s unique narrative style and read many entertaining stories in Swedish about Chalmers and Reactor Physics when it all started, mixed with Gudmar’s own personal reminiscences including his adventurous trips, all illustrated with photos, can find these under

Text: Imre Pázsit​

Sidansvarig Publicerad: må 17 aug 2020.