Photons R Us

December 5, 2008

This one is especially for my condensed matter readers, of whom I know there are at least two …

SLAC is undergoing a transformation, from particle science to photon science. This includes both catching photons (astronomy) and shooting photons (light sources). I guess I am part of the trend on the catching-photons side. A few years back, someone like me would probably not have thought of Stanford for a sabbatical; but now it seems like a happening place, with Fermi flying, the LSST camera being built and the database under design, and AGN types to hang out with, like Roger Blandford and Greg Madjewski. On the shooting-photons side, there is of course a long synchrotron science tradition, with SSRL; but now the big new thing, the world beating monster, the core of the new SLAC, is LCLS, the Linac Coherent Light Source. Today, along with other SLAC employees, I got the chance the tour the beast.

This was both depressing and inspiring. Depressing because it starts in the historic Linear Accelerator, a stark reminder of how PEP II and BaBar are dead. The BaBar kit sits there still, waiting for a bright idea. But of course visiting LCLS was also inspiring, just like it always is when visiting a huge telescope or a monumental building; you marvel at the scale, the ambition, and the amazing detail attended to throughout the vast space. Like the LHC, like the VLT, like the cathedral at Chartres, the LCLS is a triumph of human co-operation.

Electrons are accelerated to 13 GeV in an underground tunnel; then they coast through a tiny pipe four football fields long while a sequence of devices align and squeeze the beam; then into another huge tunnel with temperature controlled to a tenth of a degree, where magnets wiggle the beam by a few microns; the accelerating electrons radiate; the electric field of the emitted light bunches the electrons; and lo there is lasing … two football fields later, the electrons are pulled down into The Dump and the light sails on, where samples and detectors await their arrival. Well, free electron lasers have been made before, but not at X-ray wavelengths, not with such intensity, and not in such short bursts. The pulse time is shorter than the chemical reaction time of most molecules, so a protein wacked by the X-rays doesn’t have time to change before the diffraction image is complete.

At least thats the plan … the first electron beam run is in a few days, but the undulator magnets don’t go in until March; first light, as it were, will be next summer. (Anybody want to tell me how this all compares to Diamond ? Back in the Yookay, do we have the next great thing, or the great white elephant ?)

A cynic might watch the transformation of SLAC as the B mesons fade away, and see an organisation trying to preserve itself even when its purpose has gone.  So whats wrong with that ? Its one of the world’s great labs. It has expertise and skills in engineering, project management, computing, and accelerator physics. It has a working culture, and a proud esprit de corps. How dumb would it be to waste all that ? Today’s tours had secretaries, lab technicians and scientists, and whether they were involved in LCLS or not, you could see their chests swelling as they thought “Hey, we did this. It was us.”

Hey, it could have been different. SLAC could have become a Science and Innovation Campus while Fermilab got all the new toys…


Angels over Stanford

September 5, 2008

I had lunch today at the Quadrus cafe, just across the road from SLAC. This is where the angels eat. Years back, Sand Hill Road was buzzing with busy Venture Capitalists, shovelling their money into computer startups. Apparently they are still there, but now they are for looking for alternative energy technologies. Steve Kahn told me that office rental is six times higher around here than in Palo Alto.  This makes SLAC folks nervous. Will Stanford keep backing them when they could flog the land instead ?

On the way back I picked up Symmetry, the PR magazine for Fermilab and SLAC combined. By PR mag standards, its actually a pretty good read. The editorial took me by surprise – it was labelled “Positive News for Particle Physics”. (I wouldn’t have been surprised if I’d kept up with Mark Lancaster’s web page or read this Physics World article )

Back before Christmas, panic and despondency hit US physics at pretty much the same time as the STFC crisis blew up in the UK. Work on the ILC and ITER was cut right back, and almost three hundred redundancies (“layoffs” in US-speak) planned between SLAC and Fermilab. Now it seems Congress has “appropriated” an extra $32M, and the President has announced a supplemental budget. The planned Fermilab layoffs have been halted. Its too late for 125 people laid off by SLAC, but apparently they might want to re-apply …

So how come Parliament can’t vote us some extra money ? Tough guy Willis wrote a stinging report … but he didn’t get us any money. Or did he ? Its pretty hard to tell in the UK system. It could well be that behind the scenes DIUS and the Treasury are doing what they can for STFC, slipping over extra LFCF or TSB money, so they can save money in their main budget etc etc .. but how would we know ? The only rule is that the Minister cannot imply that the Government made a mistake. There simply cannot be any publicly announced rescue. We all know that. But why not ?  Cue the Watcher to tell us its because the Government believes you mustn’t give in to children with tantrums.


The Pale Face of Stanford

July 6, 2008

Your correspondent is now in Silicon Valley. My tour of duty as Head of Physics is now over, and I am starting a year long sabbatical at SLAC. My main aim is to kick-start some collaborations with LSST folk, especially on the database side, but its also exciting to be here just after the launch of the gamma-ray space telescope, GLAST . Meanwhile I will also keep working on the VO. AstroGrid has a tradition of being more or less location independent, and it has been noted that I will be working in the same time zone as our official night-owl, Dave Morris.

The story at SLAC these days is in some ways similar to STFC-land, and in others very different. They have had to lay off 200 staff, the B-factory has closed down, work on the ILC has been halted, and the famous tunnel, the straightest object in the world, has been turned into a light source, the LCLS . Less particle physics, more chemistry, biology and materials physics. However they are also diversifying into astrophysics, which is why I am here. This builds on their experience – the GLAST Large Area Telescope (LAT) is really like a particle physics detector in space, with silicon strip trackers and a calorimeter, and the LSST data rate is a drip compared to Babar, let alone the LHC.

Here is another interesting distinction. A Senior Person told me he gets worn down by endless reviews of SLAC, which go on and on and nobody really takes any decisions. Much of our problem with STFC has I think been that the decision making has been too brash and bold….

Meanwhile, we are under pressure to prove our economic worth, as discussed in various comments on this blog over the last few days. Well, SLAC didn’t invent the Web, but it was the first meeting place of the Homebrew Computer Club which is where Jobs and Wozniak got started, and to whom Bill Gates addressed his Open Letter to Hobbyists. The street that SLAC is on, Sand Hill Road, contains an amazing density of venture capitalists. And of course Stanford as a whole is a hot house of ideas moving out from science to industry. Brin and Page built the Googleplex as close as they could to the Alma Mater.

Stanford itself originates from sentimental philanthropy. Leland Stanford was a self made California millionaire. The Stanfords were the Posh and Becks of their day, with newspapers full of stories of their opulent lifestyle in San Francisco. They also had a huge farm down south of the city in nowhere land. Tragedy struck the family in 1884 when their son died of Typhoid on a trip to Florence. So in the spirit of the times, they created the Leland Stanford Junior University in his memory.

So of course I knew none of this three days ago, but the mythology and historical resonances of a place like this are a kind of vapour that you can’t avoid breathing. Gets a bit mawkish sometimes though … Exploring the campus, I found the Cantor Art Centre. It has some good stuff, and a room full of Stanford memorabilia, including Leland Junior’s plaster death mask. It just sits there on the wall reminding you of the Victorian image of death. Milky white, hair neat, eyes closed.