On the Margin

On the Margin
October 19, 2012

The primary component of Jefferson Lab’s mission is nuclear physics - to explore the nature of nuclear matter and to explore fundamental symmetries. This dominance is reflected in the budgets we receive, and in what we do on a daily basis. In many ways, the whole laboratory revolves around the operation of the nuclear physics accelerator.

However, when we make presentations about the laboratory, we usually talk about our activities in much broader terms. There are several reasons for that. One reason is that there are technologies that are vital to the execution of our primary mission, which are quite exotic and very exciting to work with. Another reason is that some of what we do has the potential to have a large societal impact. Often this can arise as a result of the ability to apply our science and technology. Conversely, we are often very quick to apply technologies developed for other purposes. But often, we talk about these broader aspects because we are just "very good" at it. I’d like to take this opportunity to talk about some of our activities within this broader framework.

On a routine basis we work a couple of Kelvin above absolute zero temperature and for the special polarized targets we get down to 30 milliKelvin. In either case, these are exotic conditions. In both cases, the ability to manipulate the conditions and to understand the way the world behaves under these extreme conditions is special. Our cryogenics group is sought by many to help them with their projects. Recently, the group completed a project for NASA that involved helping to create conditions that will be experienced by the James Webb Telescope when it is launched into outer space.

The motivation for the 2 Kelvin helium is to make our niobium radiofrequency cavities become superconducting. This reduces dramatically the power consumption and increases the energy that can be achieved by the accelerators. During the course of the year, one of our cavities held the world record performance for a while, and the ensemble of cavities prepared for our 12 GeV Upgrade project is the basis for confidence in our ability to build the next generation of machines.

As a result of these SRF skills we have a second accelerator on site. We label it with its characteristic output. It is the basis for a Free-Electron Laser, in fact, two of them. The first, which operates in the infrared region of the electromagnetic wave spectrum, has capabilities that encourage some to imagine a device to intercept and destroy missiles. Funding for the relevant R&D was provided by the Office of Naval Research. The second laser is in a different part of the spectrum, the ultraviolet, and among other things can be used for incredible micro-machining of hard materials, an application that interests the Air Force, which wants to build midget satellites. Â Both FELs offer significant possibilities for breakthrough scientific research on materials and the electron beam may be useful for several significant nuclear physics experiments.

Medical Imaging
In order to measure the radiation, the debris from a nuclear collision, we have developed generations of detectors starting, perhaps, with photographic film, which was used with X-rays to examine the bones inside our bodies, looking for breaks and cracks. In recent years, positron-electron tomography is one of the modern generation of medical imaging techniques. Our own medical imaging group, which developed the basis for a commercial mammography unit, is already applying silicon photomultipliers to plant and animal imaging. This is a technology that will be deployed on a large scale in the GlueX experiment being assembled in the new Hall D.

Advanced Computing
Our theorists are the opportunists. Our lattice gauge group is almost always the top user for any new supercomputer introduced by the Office of Science. When they received ARRA funding to improve the local cluster of computers, they increased the computing they were able to usefully get out of the fixed dollars by purchasing arrays with graphical processing units originally developed for game playing applications.

Let me finish with our education group. Note that our lab is supported by the Department of Energy, not the other DOE, the Department of Education. Nevertheless, the work we do puts us at the pinnacle of the education hierarchy. There are relatively few places in the world with doctoral scientists and technologists in the numbers we have. The place is overrun by the species. And our education group has recognized that this is an opportunity. They feed off the nuclear science, the research that we are trying to do, and they take the food into the schools and bring the schools into the lab. A couple of weeks ago, our education group received a plaque from the Secretary of Energy commemorating a Secretary of Energy Achievement Award. We all smiled and felt proud.

It was just like May 19, when 7,000 people visited this year’s Open House and not just for the nuclear physics; it’s pretty exciting what we do on the margin!