Name: Professor Len Culhane FRS

Job title: Professor of Physics

What education and qualifications do you have?

B.Sc. Honours: 1st in Physics, University College Dublin, 1955-59. MSc (Thesis on Properties of K-Mesons), UCD, 1959-60. Ph.D (Thesis on X-ray Astronomy of the Sun), University College London, 1960-66. Elected FRS, 1985.

Give an outline of your career so far

My Ph.D work involved the first direct demonstration, with the proportional counter spectrometer on the UK/US Ariel-I launched in 1962, that the Sun's X-ray spectrum hardened during solar flares and was due to emission from high temperature (~ 10 000 000 K) gas. In 1969, I spent a year at the Lockheed Palo Alto Lab in California where I was Principal Investigator (PI) for an advanced multi-grid imaging detector on OSO-8. Returning to UCL, I was involved with the Ariel V X-ray Astronomy project and used the proportional counter spectrometer to discover emission lines of highly ionised Iron in the the spectra of Galaxy Clusters. This showed clearly that the extended X-ray sources in Clusters were due to the presence of large volumes of hot (~ 100 000 000 K) gas. Returning to Solar work, I became PI for a series of X-ray and EUV spectrometers on NASA's SMM and Spacelab-2 and on Japan's Yohkoh mission. I have served on a number of UK Research Council and European Space Agency committees and as a member of PPARC Council. I am an Honorary Doctor of Science at Wroclaw University in Poland (1994) and a Foreign Member of the Norwegian Academy of Science (1996).

Why did you choose this career path?

While my first research was in the study of high energy particles, following a lecture in Dublin (1960) by my predecessor at MSSL, Sir Robert Boyd, I was enormously enthused by the prospect of observations from orbiting spacecraft. I joined his group at UCL in 1960 and became involved in X-ray studies of both the Sun and the Universe. It was a career choice that I have never regretted.

What does your current work involve?

Since returning to Solar Physics work, I have been involved in high resolution X-ray and EUV spectral studies of the Sun. Use of our Bragg Crystal X-ray spectrometers on the NASA Solar Maximum Mission and Japanese Yohkoh spacecraft has allowed us to understand in some detail how very high temperature gas is produced in Solar Flares. However Solar Physics now requires the simultaneous use of spectral and imaging instruments at visible, UV and X-ray wavelengths if we are to make further progress. Thus we are currently building an Extreme UV Imaging Spectrometer (EIS for which I am Principal Investigator), for the Japanese Solar-B mission. This spacecraft will also carry a large optical telescope which will provide images of ~ 150 km resolution on the Sun?s surface along with X-ray images of the Sun's corona. Combined use of this superb facility will allow us to connect the fine scale behaviour of magnetic fields on the Sun's surface with the transfer of energy to the corona and the related outbursts - flares, Coronal Mass Ejections, which can have damaging effects on spacecraft in the near-earth environment.

For the future, I am engaged in a project to process and distribute data from a NASA mission - Solar Dynamics Observatory (SDO), which when launched in 2008 will become the successor to the very successful ESA/NASA Solar Heliospheric Observatory (SOHO). Instruments on SDO will allow us to study the early evolution of magnetic activity below the Sun's surface using the techniques of Helioseismology and to image the solar corona at eight separate EUV wavelengths every ten seconds. The very large volume of data from this spacecraft - about 3 Tbytes/day, will require use of the newly developed GRID computing techniques.

Having stood down as Director, MSSL, I continue to work in Solar Physics with special focus on preparations for the launch of Solar-B - due in August 2006. I also teach the undergraduate High Energy Astrophysics course jointly with Kinwah Wu. I have become Chairman of the Science Advisory Committee for the International Space Science Institute in Bern whose role is to further interdisciplinary studies and the interpretation of experimental data from space missions.

Hobbies and interests outside work

Formula I motor racing - my 60th birthday present from MSSL was ten laps of Silverstone in a Formula Ford single seater. In spite of some car rally participation as an undergraduate, it rapidly became clear that I would never make it in Formula I! However I have enormous admiration for those who have - Fangio, Moss, Senna and latterly Schumacher. I also enjoy travel, poetry and wine!

Len at MSSL - wishing he was viewing the Sun in X-rays.

Schematic of the Japanese Solar-B spacecraft. The large central instrument is the Solar Optical Telescope (SOT). The X-ray telescope (XRT) is attached to the underside of the SOT while the EUV Imaging Spectrometer (EIS) is mounted on top. EIS is being built by an international team (UK, US and Japan) led by MSSL. The complex optical Focal Plane Package (FPP) is located on the far side of the SOT. The Solar Array Panels (SAP) are shown deployed. The spacecraft observes the Sun continuously from a sun-synchronous orbit of 800 km.