The 88 Inch Cyclotron has been generating beams of heavy and light ions since 1962. As of October 1, 2003, it ceased to be a U.S. Department of Energy (DOE) national user facility, but the venerable machine is not yet ready to go dark. A memorandum of understanding (MOU) between DOE, the U.S. Air Force (USAF), and the National Reconnaissance Office (NRO) has granted the 88 Inch Cyclotron a reprieve through at least fiscal year 2005. Under the MOU, the 88 Inch Cyclotron will be used to test electronic components for the National Security Space Community and to support a local research program in nuclear science.
"It has been a tough, up-and-down year for the staff but people have hung in and we're optimistic about the future," says Claude Lyneis, a physicist with the Nuclear Science Division who has headed the accelerator facility since 1991.
For the 88 Inch Cyclotron, the immediate future is in space-based electronics such as those in the nation's spacecraft and satellites, which are designed and built for the USAF and the NRO. Satellites in orbit are subjected to many different forms of ionizing radiation that can wreak havoc on unprotected electronic components. Heavy ions, neutrons, and protons can scatter the atoms in a semiconductor lattice, cosmic rays can blast sensitive microcircuits, and even wiring and cabling can be damaged by exposure over time.
The USAF and the NRO, through a nonprofit federal research organization called the Aerospace Corporation, have been testing space-based electronics at the 88 Inch Cyclotron since the 1980s. As one of the few machines in the world that can accelerate beams of atomic nuclei as light as hydrogen or as heavy as uranium, the 88 Inch Cyclotron is ideal for simulating space radiation. For example, it is uniquely capable of producing heavy ion cocktails -- mixtures of different ions with a nearly identical charge-to-mass ratio.
"The ions are tuned out of the source together and the cyclotron acts as a mass analyzer to separate them," explains Peggy McMahan, Research Coordinator at the cyclotron. "This allows us to quickly switch from one ion beam to another, which means that the ion and therefore the linear energy transfer (LET) delivered to an electronic component can be varied without having to re-tune the accelerator."
Heavy ion cocktails generated at the 88 Inch Cyclotron are used for testing single-event upsets. These events occur when damage results from the impact of a single energetic particle such as a trapped proton or heavy ion.
The Aerospace Corporation has been using the 88 Inch Cyclotron to investigate both commercial and military electronic components to determine if they have been sufficiently radiation-hardened. The process involves exposing a component to a particle beam while monitoring its function. By counting the number of upsets and knowing how many particles passed through the part, investigators can calculate the likelihood that a particle strike will cause a single-event effect.
Under the terms of the new MOU, the $3 million in the proposed DOE fiscal year 2004 budget that was going to be used for planning the decommissioning and decontamination of the 88 Inch Cyclotron will instead be redirected to continuing operations. In addition, the USAF and NRO pledged $2 million to meet the total $5 million needed to keep the 88 Inch Cyclotron operating. For their funding contributions, the USAF and NRO and their national space security partners will be able to use up to 2,000 hours of beam time on the 88 Inch Cyclotron without paying any fees. The rest of the beam time will be available to researchers and students at Berkeley Lab and the University of California (UC) Berkeley for a variety of nuclear physics studies.
"The staff and researchers at the 88-Inch Cyclotron are enthusiastic about the new mission," says Lyneis. "They're working to develop the cyclotron's capabilities to meet the long-term needs of the National Security Space Community."
For more than 40 years, the 88 Inch Cyclotron has been an important contributor to nuclear physics research. It gave birth to the AECR-U and VENUS ion sources, the Gammasphere, and the Berkeley Gas-filled Separator. It is where the discovery of the element that would be named Seaborgium was at long last confirmed. The 88 Inch Cyclotron's story is long and filled with accomplishment. Most importantly, this story is not yet finished.
(Reprinted with permission from "Berkeley Lab View," January 9, 2004)