Opening session

Welcome Lecture
"Semiconductor Detectors in the Low Countries"
In the first half of the 20th century experiments with ionizing radiation have been essential for the understanding of the electronic structure of semiconducting crystals, and therefore it is no wonder that semiconductors from the beginning have been used the other way round to characterize radiation. The photoelectric effect prompted van Heerden here in Utrecht to manufacture the first semiconducting X-ray and electron detector in the middle of the 2nd World War, around 1943. Rapidly improving materials technology favored progress in a highly industrialized environment like at Bell-Labs, where germanium and silicon detectors were perfected soon afterwards. Application at the Oak Ridge nuclear facility was immediate. An important step towards imaging detectors was made in the Philips Research Lab in Amsterdam, where ideas about segmented monolithic silicon devices were put into practice around 1965, with the 'checker board' detector for the ambitious 3-D project: BOL. Around 1970 the BBD and the CCD, respectively in Philips-Eindhoven and Bell- Murray Hill were attempts to combine imaging and charge readout in the same device, although not aimed at detection of ionizing particles. After intensive development of CMOS manufacturing technology the widespread use of CCD would only begin 20 years later, even though the CCD is a simple concept. Much more sophisticated electronic functions have then been integrated from 1988 onwards in particle physics silicon pixel tracker arrays. This now results in new approaches in X-ray imaging. Processing functions in microscopic segments eventually will allow images by selective counting of photons. Philips supplied a variety of semiconductor detectors between 1965 and 1979. Since 1984 Canberra Semiconductor, one of the largest suppliers of silicon detectors, is actually situated in Flanders, mainly because it was drawing on expertise in the Leuven Research Center IMEC. Some of the most important developments in semiconductor detectors, both in the early years and later on, have been linked to the 'Low Countries'.
Erik Heijne CERN CH-1211 Genève 23 Switzerland Tel +41 22 76 73946 Fax +41 22 76 73394 Email: erik.heijne@cern.ch
Erik Heijne is an Instrumentation Physicist at CERN since 1973, and has initiated the famous RD19 Collaboration that pioneered the use of pixel detectors in particle physics. He obtained his PhD from the University of Amsterdam (1983) and has worked on semiconductor technology, especially on silicon detectors since 1970. The introduction of radiation resistant pixel detector readout circuits in deep submicron technology (~1997) is a step in the progress towards full integration of sensor elements and readout functions. He spends part of his time at NIKHEF to strengthen the R&D activities on semiconductor detectors. In collaboration with various universities around Europe, he has supervised a score of PhD students on detector technology and applications. He published over a hundred papers on semiconductor detectors and electronics and organised several symposia and workshops on semiconductor detectors. Erik Heijne is a member of the Dutch Physical Society NNV, and of the international societies MRS, SPIE and a senior member of the IEEE. In the NPSS of IEEE he is elected chair of the TransNational Committee, and as such also member of the NPSS Administrative Committee. He is NPSS Liaison in the IEEE Sensors Council.

Opening Lecture
"A Personal Perspective on the Evolution of Radiation Detectors"
While there have been many significant innovations in the design of instruments for the detection of ionizing radiation in research applications, the choices available to "the common man" for routine applications in industry or medicine have changed more slowly. Some of the most important detectors in these fields have evolved very little from their form 30 or 40 years ago., and relatively few are based on recent inventions. Some promising technologies will be briefly mentioned. There has, however, been a dramatic change in the electronic units available to process the output of all types of detectors. The advances in digital pulse processing and microelectronics now permit modes of operation that were impossible just a few years ago. With these tools, detectors can be used in ways that extend their operating range, extract additional information from signals, and permit their use in entirely new applications. Some examples are given of the evolution of both sensors and processing electronics in these directions.
Glenn F. Knoll Department of Nuclear Engineering and Radiological Sciences University of Michigan 2355 Bonisteel Blvd. Ann Arbor, MI 48109-2104 Phone: 734 936-0121 Fax: 734 763-4540 Email: gknoll@srvr5.engin.umich.edu
Glenn F. Knoll is Professor Emeritus of Nuclear Engineering and Radiological Sciences at the University of Michigan. He joined the Michigan faculty in 1962, and served as Chairman of the Department of Nuclear Engineering from 1979 to 1990 and as Interim Dean of the College of Engineering from 1995-96. His research interests have centered on radiation measurements, nuclear instrumentation, and radiation imaging. He is author or co-author of over 170 technical publications, 8 patents, and 2 textbooks. Prof. Knoll has been elected a Fellow of the American Institute for Medical and Biological Engineering, the American Nuclear Society, and the Institute of Electrical and Electronics Engineers. He has been selected to receive three national awards given annually to a single recipient for achievements in engineering and education: the 1979 Glenn Murphy Award from the American Society for Engineering Education, the 1991 Arthur Holly Compton Award of the American Nuclear Society, and the 1996 Merit Award of the IEEE/Nuclear and Plasma Sciences Society. He was one of about 1% of IEEE members selected to receive the Third Millennium Medal in the year 2000 from the society. He is one of five receiving editors for Nuclear Instruments and Methods in Physics Research, Part A, and a past or present member of Editorial Boards for Nuclear Science and Engineering, IEEE Transactions on Medical Imaging, and Physica Medica. In 1999, he was elected to membership in the U.S. National Academy of Engineering. He was selected for the 2000 Stephen S. Atwood Award, the highest faculty achievement award of the University of Michigan College of Engineering.