4 October 2011

Four physicists have a combined 100 years anniversary

A strong group of physicists can now celebrate that they have been employed for 25 years in service to the government and the Niels Bohr Institute – all are professors and heads of research groups, one is the head of them all. Two are named Hansen – it is almost a tradition for particle physicists. Two others have nano-versions in the form of a suffix – hans'l and ultra nano with the initial letter H – and then we’re over in a completely different form. They are John Renner Hansen, Peter Hansen, Robert Feidenhans'l and Per Hedegård.

The path of physics with experiments and leadership:

John Renner Hansen

John Renner Hansen,
Professor of particle physics, Head of Institute

"I have worked with the Standard Model throughout my professional career, from data collection, to analysis and interpretation. Research leadership was also an early part of every day life as a physicist”, explains John Renner Hansen, who has been the Head of the Niels Bohr Institute since 2005, the first two years under the old university law and from January 2007 as the leader of the institute.

John Renner started his career with six years at CERN from '80 – '86, and has since been working at the Niels Bohr Institute. As a researcher he has helped to discover the W- and Z0-bosons in the UA2 experiment at CERN, and he took part in the ALEPH-experiment, where the objective was to test the Standard Model, in part through a detailed study of the properties of the Z0-particle. Since '83 he has been involved with the planning of the Large Hadron Collider and the LHC-experiment ATLAS, which the Niels Bohr Institute is a very strong participant in.

The leadership positions have come ‘bit by bit’, as John Renner puts it. From '99 – 2005 he was a member of the Danish Natural Science Research Council, the last 4 years as the chairman. He has twice been the deputy director of NBI. He sits on one of the panels of the European Research Council, which awards junior grants – from 2011 as chairman. He expressed enthusiastically that “it is exciting to help shape the profession and work for Danish science in general”. Right now a lot of time is spent shaping the future research environment in the new Niels Bohr Science Park and providing the appropriate framework for the Danish contribution to the new European neutron source in Lund, ESS.

A journey through the evolution of particle physics:

Peter Hansen

Peter Hansen, Professor, Head of the Discovery Center for Particle Physics

"I have been extremely lucky and have been at the right place at the right time”, explains Peter Hanson about his life with particle physics. The large experimental research centres are the focal points for their work. Peter Hansen started as a graduate student at CERN in 1975. He worked with experiments in Chicago at the University of Michigan from '78 to '80. He was at CERN again for some years and in 1986 returned to NBI, where the CERN experiments were also the focal point. First with the SPS-collider, which was a great success and where they found clear evidence that the quarks in protons collided in proton collisions and the W and Z bosons were found, as was predicted by the Standard Model. Then came the LEP-collider, where they showed that there are 3 neutrinos and no more. This meant that there had to be 3 families of the other particles. Now it is the Large Hadron Collider, LHC, which surpasses the energy levels of all previous experiments. "The coming years will be very exciting – there we will find out if the Higgs particle exists”, predicts Peter Hansen.

Research into solid matter with sound and spin:

Per Hedegård

Per Hedegård, Professor of nanophysics

“Basically, my field is describing solid matter and molecules using quantum physics”, explains Per Hedegård. He has a licentiate in solid-state physics from Aarhus University and then went to New York in '84 and worked at IBM, where he did basic research – which was IBM’s way of showing their might. In '85 went Per Hedegård to Nordita and then to the Physics Laboratory, which in '93 – when all physics at KU was combined – became the Niels Bohr Institute.

He has been on the board of NBI, and from 2001 – 2004 he was deputy director. In terms of research he has been working on superconductivity for many years. He is also involved in an EU-network for the development of spintronics. Electronics are based on electrons, but if you base the technology on electron magnetism – the so-called spin – this is spintronics. Spintronics will make it possible to manufacture hard drives for quantum computers that can store information in individual atoms.

Just now he is researching phononics – a technique that is based on the exchange of quantized sound. Under the right circumstances a molecule can function as a kind of ‘sound-laser’, that emits a very specific tone from one molecule to another. “If one could communicate between molecules with precise, quantized high frequency sounds transmitted through wires, you could create a kind of quantum communication”, explains Per Hedegård, who is working to develop a molecular transistor based on phononics in collaboration with chemists and experimental physicists in Göteborg and Holland.

X-ray vision for advanced material research

Robert Feidenhans'l

Robert Feidenhans'l, Professor of nanophysics

Robert Feidenhans'l studied at Aarhus University and has a licentiate in surface physics, which is a research field that has since evolved into nanophysics. In '83 he arrived at Risø and began to research surface physics using X-ray radiation. “It was brand new and have been at the forefront of the field”, explains Robert Feidenhans'l, who was at Risø until 2005, when he came to NBI.

Research into surface physics using radiation requires sophisticated experiments in large research facilities and he has travelled a great deal to the synchrotron facilities in Grenoble in France, PSI in Switzerland and DESY in Hamburg.

“We want to be able to understand how new advanced materials are made so that we can see the structure down to the atomic level and reveal their properties”, says Robert Feidenhans'l and explains that new materials can do things that other materials cannot. For example, he has been involved in investigating nanothreads, which can be used for solar cells and LEDs. Recently, he has begun to study Imaging, that is to say the imaging of meat – both the meat that we eat, but also human tissue. In collaboration with the Copenhagen University Hospital, they are looking at lymph nodes and cancerous tumours.

“We can see details that are invisible with a normal CT scan”, explains Robert Feidenhans'l about the Imaging-method, which is very promising. He has a leading post as chairman of the big European research centre XFEL in Hamburg. He is also the chairman for the PhD committee at the faculty, as well as the deputy head of research at NBI.