Getting to the starting line
November 12, 2009
There are some analogies that keep on turning up when we describe what is going on either in the world or in our lives. The analogy of a race is one of those. When we achieve a great victory or complete a project, we may speak of crossing the finishing line. However, it is also recognized that it’s often an achievement just to get to the starting line.
About a year ago, we discussed with the Science Council what was happening with the free- electron laser effort at the lab.
You will recall that the big news of the summer of 2008 had been what is called a Broad Agency Announcement, a BAA, of a Request for Proposals to further develop the technology of the high-power, infrared free-electron laser. Prior to this, high-power infrared FEL development work was primarily done at Jefferson Lab. Now, ONR wants to push for an FEL with a factor of 10 increase in power, a 100 kW machine, with a longer view to a megawatt-class FEL. The announcement made it clear that the Office of Naval Research was looking to industry and that some of the work would be classified.
We were encouraged to seek a way forward with the accelerator research and to explore aggressively the potential of the Jefferson Lab FEL to support a science program. This had been tried before in some sense, but (possibly because of competition from tabletop lasers in the same wavelength and also with significant power) this had never "developed legs." So, to respond to the Science Council’s challenge, it was clear that a new approach was needed. The FEL team led by George Neil with his deputy Gwyn Williams spent the winter months working the options. From my point of view they gradually came to recognize a couple of things:
- They had tried the infrared and the terahertz path several times with modest success.
- If we were to obtain support from Basic Energy Sciences (BES), we needed a product that BES and BES-supported scientists would support.
- Several reports of studies commissioned by various agencies across the world, including BESAC, started to appear, all with the similar theme: next generation X-ray photon sources are needed.
With support from the U.S. Air Force, interested in its machining capabilities, the FEL group was constructing an ultraviolet FEL line for operation late in 2009. Given the high power level in the fundamental lasing frequency, it seemed that the higher harmonics of that device would also provide substantial power, and at the shorter wavelengths being sought. It was a possible step in the right direction. Further, the advances in the superconducting radiofrequency technology could now offer upgrades to the FEL cryomodules, which would provide more than 300 MeV in electron energy in a single pass.
And so a concept was born. An upgrade to the Jefferson Lab FEL which for some amount of money could operate, using the high-frequency continuous wave, hallmark approach, at very high power with photon energies beyond 100 eV in the higher harmonics with a continuous/average brightness greater than that of the FLASH facility at DESY. Further it looked as if we would be able to use the device to do some vital accelerator science, essential for any construction of a next generation machine. We developed a plan to write a proposal for submission to BES. We included the idea in our presentation to the Office of Science of our strategic plan for the lab. The audience, including Steve Koonin, Bill Brinkman, Pat Dehmer and Harriet Kung, did not pooh-pooh the idea.
We laid out a timeline to invite a top-of-the-line team to review the machine, and then to help us with the physics case. In the end, we split that task across two different groups. The first provided valuable criticism of several aspects of the machine. The second was fired with enthusiasm about what physics could be done IF we could build the machine.
Along the way, the FEL group came up with a name, Jefferson Lab AMPlifier ( JLAMP ).The draft proposal/white paper was completed in September and, after a little polishing, we offered it to the BES team and asked its members to have a look. Whether we pulled the thought out of the air or not, I am not sure, but we and others would repeat that it would be better for BES to invite us to submit a proposal rather than for us to drop one on them.
We gave JLAMP some "air time" when Brinkman, the director of the Office of Science, visited. Then a week ago, we met with Kung, who is the associate director for Basic Energy Sciences, and two of her lieutenants. They told us what our document was missing to be considered as a proposal and told us that if we did the work, they would subject it to peer review.
The starting line!
This was a great effort from George and his FEL team; all were involved. Their reward is to do more work. Now, we must really make sure we have checked all our assertions, and there is no guarantee that the reviews will be good. But we now know we will get to run the race!