This year’s major accelerator conference covered impressive progress in the field, and featured events celebrating the World Year of Physics. Norbert Holtkamp reports.
The 2005 Particle Accelerator Conference (PAC05) took place on 16-20 May, at the Knoxville Convention Center in Knoxville, Tennessee. The conference was jointly hosted by the Oak Ridge National Laboratory Spallation Neutron Source (SNS) – the largest accelerator construction project in the US – and the Thomas Jefferson National Accelerator Facility (JLab), Newport News, Virginia. As usual, the conference covered new developments in all aspects of the science, technology and use of particle accelerators. Unique to PAC05, however, was the special theme of the World Year of Physics, as declared by the United Nations in honour of the centenary of Albert Einstein’s annus mirabilis, when he published his three papers on light quanta, Brownian motion and the special theory of relativity. These discoveries had a remarkable impact on science which continues to this day.
With its exciting programme, the conference attracted more than 1400 accelerator specialists to Knoxville during the week, making it the second largest PAC ever. Geographically, 59% of the attendees were from the US, 25% from Europe, 15% from Asia and 1% from the Middle East, South America and as far away as Australia. Nearly 1400 papers were processed during the conference and will soon be published on the Joint Accelerator Conferences Website, located at www.JACoW.org.
Accelerators present and future
Phil Bredesen, governor of Tennessee and a physicist with a background in accelerators from his student years, welcomed delegates to the conference. The governor talked about the significance of science as a driver of economy and wealth, as well as the importance of continuously supporting education. He was followed by Cecilia Jarlskog from Lund, whose colourful presentation included information about Einstein, the Nobel prize and accelerators. Barry Barish, chair of the International Technology Recommendation Panel for the proposed International Linear Collider (ILC), then explained the technology choice made last year for the machine and outlined his role as the new director of the ILC Global Design Effort to design the accelerator while involving all regions of the world.
The Monday morning plenary session included highlights from other accelerators, such as the luminosity records of the Tevatron at Fermilab, achieving more than 1 × 1032 cm-2 s-1; the outstanding performance of Brookhaven’s Relativistic Heavy Ion Collider, with its polarized beams; and the race between the B-factories (KEKB in Japan and PEP II at SLAC in the US). The closing plenary session on Friday afternoon included talks on nuclear-physics topics such as the Rare Isotope Accelerator proposed in the US and the Facility of Antiproton and Ion Research (FAIR) project at GSI, as well as accelerator-based materials-science research, and neutrino and high-energy physics. The talks focused on projects that have paved the way for the accelerators that need to be built to address today’s pressing questions in all areas of science, and they demonstrated yet again how accelerators have become crucial research tools over the past 50 years.
Synchrotron light sources of all sizes and flavours once again dominated the papers presented at the conference, demonstrating how quickly the field is still growing, especially in energy-recovery linacs and short-pulse coherent light sources, i.e. X-ray free-electron lasers (FELs) including the use of self-amplification of spontaneous emission (SASE). Sixteen oral presentations and more than 100 papers were presented on these facilities alone. Vibrant research and planning for new projects are ongoing, with the Linac Coherent Light Source under construction at SLAC and the EUROFEL moving from planning to construction at DESY, as well as the Spring-8 Compact SASE Source in Japan.
Einstein was ever-present throughout PAC05, with the conference website incorporating an Einstein quotation on every page, and several special activities during the week. These events began with a violin and piano concert by Jack Liebeck and Inon Barnatan on the Tuesday evening, which recognized Einstein’s love of the violin and was introduced by Brian Foster from Oxford University. Then on Wednesday afternoon, the US, Asian and European PAC series joined forces in a special session, “Einstein and the World Year of Physics”, organized by Swapan Chattopadhyay from JLab. The session was chaired by Bill Madia of Battelle and included four presentations relating present-day research to Einstein’s legacy, by Michael Turner from the National Science Foundation (NSF), Makoto Kobayashi of KEK, Yoichiro Suzuki of Tokyo and Carlo Rubbia from ENEA/CERN.
Einstein in the City
To draw the public’s attention to the World Year of Physics, an “Einstein in the City” festival followed the session. Organized with the City of Knoxville, the festival drew conference participants and several hundred others to the World’s Fair Park, outside the convention centre. Part of the festival was a science fair for local high-school students, with cash prizes of between $200 and $5000 awarded to projects judged by a team of conference participants. A special panel of four physicists, moderated by Madia, answered science-related questions from the public for about an hour. Questions covered everything from “Why is science useful?” to “How many stars are in the universe?” to “What does an accelerator do?”. Other activities included an appearance by “Einstein the Bird” – a talking parrot from the local zoo – and bluegrass music from a local band, as well as plenty of good food and drink.
Another highlight of the conference was the now customary prize session, in which the winners of several accelerator prizes are recognized and have the opportunity to report on their research. The session chair, Nan Phinney of SLAC, congratulated recipients individually and presented some of the awards. Among them was Keith Symon of the University of Wisconsin-Madison, winner of the American Physical Society’s prestigious Robert R Wilson Prize “for fundamental contributions to accelerator science, including the FFAG concept and the invention of the RF phase-manipulation technique that was essential to the success of the ISR and all subsequent hadron colliders”. The other APS prize was for an outstanding doctoral thesis by Eduard Pozdeyev from JLab, who performed his doctoral work at Michigan State University. Ron Davidson of Princeton and Tom Roser of Brookhaven National Lab were awarded the Particle Accelerator Science and Technology Award from the Nuclear and Plasma Science Society of the Institute of Electrical and Electronics Engineers. Wim Leemans of the Lawrence Berkeley National Laboratory (LBNL) and Anton Piwinski of DESY were presented with the US Particle Accelerator School Prize for Achievement in Accelerator Physics and Technology.
While PAC05 ended officially on Friday afternoon, about 400 participants extended their stay by a day to visit the SNS site at Oak Ridge. The SNS is entering its last year before the first beam is scheduled to hit the mercury target and the first neutrons channelled to instruments. So far the beam has been commissioned to the end of the normal conducting linac, up to 157 MeV, and soon the superconducting linac will be turned on to boost the energy to 1 GeV. Later this year the compressor will be commissioned in preparation for user operation, to begin next summer. Tour participants were therefore among the last people to get a glimpse of what has been going on at the site over the past five years, before much of the facility is closed to visitors.
