Managing Across Boundaries
University of Illinois, Urbana-Champaign (Champaign, IL)
Partner Institution: St. Petersburg Nuclear Physics Institute, Gatchina, Russia
Precision Measurement of the Singlet mu-p Capture Rate in Hydrogen Gas
October 8, 2005
Interview by: Kelly Cooper
Thanks in part to a cooperative grant provided by the U.S. Civilian Research and Development Foundation (CRDF) in 2003, a team led by professors David Hertzog and Peter Kammel from the University of Illinois at Urbana-Champaign has been working closely with a group of Russian scientists from the St. Petersburg Nuclear Physics Institute to determine to high precision the muon capture rate on the proton in hydrogen gas. The joint U.S.-Russian team is part of the larger international MuCap Collaboration that includes researchers from six partner institutions: the Paul Scherrer Institute (Switzerland), the University of California, Berkeley, the Université Catholique de Louvain (Belgium), the Technische Universität München (Germany), Boston University, and the University of Kentucky. Every year, team members from each institution meet at the Paul Scherrer Institute to discuss their research and carry out joint experiments. The Russian and American scientists had worked together for some years prior to receiving the grant; however, with the aid of CRDF funding a new team of Russian scientists could join the collaboration to construct a critical and unique component of the experiment by combining Russian expertise and Western technology. Fortunately, the Russian scientists do not have to worry about funding difficulties any time in the near future. The team recently learned that the CRDF award has been renewed for an additional two-year period, a clear endorsement of this project’s success so far.
The Project:
The CRDF supported team, includes three Americans and ten Russians, some of whom once developed and tested missile guidance systems for the Soviets. Their special skills are being used in the MuCap experiment to provide the ultra-pure "protium" gas—hydrogen gas depleted of impurities to an unprecedented level. The MuCap Collaboration uses the pure hydrogen gas to answer a scientific dilemma that has plagued intermediate energy physicists for several decades – the discrepancy between the theoretical prediction and the precision measurement of the muon capture rate on the proton. The prediction for this rate is based on a very solid theoretical foundation; therefore, a difference between the theory and the measurement—if confirmed—could signal that there is "something new to discover."
But the process of discovery is not always a simple one. In this case, says Hertzog, "the idea is easy but technically difficult to put into action." Hertzog credits his colleague Kammel with devising the innovative experimental design to test the muon capture rate on the proton in hydrogen gas, which must be specially processed to attain ultra purity. The Russian scientists’ expertise in processing and maintaining the purity of the gas has been a major factor in the team’s success.
Perhaps an even more valuable asset to the team was the Russians’ ability to build and assemble the necessary technical components from scratch, providing a cost-effective alternative to professionally manufactured equipment that has also further enabled the Russians to monitor and even enhance its performance as required by the experience gained during joint experimental runs.
Why Russia?
Hertzog and Kammel are encouraged by the team’s successes so far, stating that, "the Russians are critical to the project", further explaining that the Russians are highly regarded in the field for their expertise and dedication. The Russians have "realistic goals" and are consistently "on budget," says Kammel, noting that the research carried out by his overseas colleagues would be far more expensive if conducted in the United States due to the comparatively high salaries paid to Western scientists and expensive technical equipment required.
Beyond the fundamental importance of their experiments for particle physics, this team’s efforts help to ensure that former weapons scientists in Russia use their expertise to further the public good, not to aid terrorists in obtaining weapons know-how – a win-win situation for everyone involved.