Pictorial Tour of World's Longest Linear Accelerator

Wired has a great pictorial tour of their recent visit to Stanford University's linear accelerator, the longest in the world. The accelerator has been the vehicle upon which three Nobel Prizes were earned and a the next big project will boast an electron laser roughly 10 billion times more powerful than existing x-ray sources.

Re:SLAC is great, but...

[bcdm]

125 staff members at SLAC have been let go this year (so far), and 200 projected layoffs at Fermilab by the end of the summer. Wired has the fuller scoop. [wired.com]

Re:Not a dupe per se...

[eecue]

Yeah that was also an interesting article, my photo editor pointed it out to me after we had wrapped up the captioning process. I think we saw a somewhat different side of SLAC (although we got the klystron gallery shot of course)

Microwave ovens do *NOT* have a klystron inside.

[Anonymous Coward]

Picture 8 has a description that starts with: "Your microwave oven has a klystron inside" which is wrong. All modern microwave ovens have a cavity magnetron inside not a klystron.

Re:SLAC is great, but...

[niklask]

Well thats what happens when you mostly do "B" physics.

High-energy physics, like the BaBar experiment, is only a fraction of what SLAC does these days. SLAC is heavily involved in photon science and particle astrophysics.

Re:SLAC is great, but...

[Anonymous Coward]

Yeah but from my understanding, Belle just had them beat (mainly due to that long safety related shutdown which pretty much killed BaBar's competitiveness). Coupled with CDF/D0 and soon LHCb (I'm aware the these are hadron collider experiments and are therefore more complimentary than direct competitors but still...), there just wasnt much of a physics program left that wasnt being done better elsewhere or hadnt already been measured by BaBar and Belle to great precision.

I would be interested in hearing from some of my SLAC colleagues if I'm very much mistaken which I may be to some degree.

Re:Richard Feynman Was There

[Guy Harris]

For the benefit of those who think "Dolly" when they hear "Parton", the parent artice is presumably talking about the parton model [wikipedia.org], devised by Feynman to explain some high-energy collision results; as the article says, eventually the partons Feynman talked about were identified with the quarks [wikipedia.org] that Gell-Mann [wikipedia.org] and Zweig [hhttp] proposed, and the gluons [wikipedia.org] that bind them together in hardons^Whadrons [wikipedia.org]. (Oh, and "Bjorken" is James Bjorken [wikipedia.org].)

Re:SLAC is great, but...

[Anonymous Coward]

The safety shutdown didn't help get experimental results faster, but I think you're overstating the effect. Belle/KEK-B was designed from the beginning to deliver more luminosity than BaBar/PEP-II -- particularly as the IP for Belle was designed for the bunches to rotate ("crab crossing") to improve the beam-beam parameter. BaBar/PEP-II was actually ahead in integrated lumi. for quite a while, but that was because Belle/KEK-B's program was more ambitious (and IIRC more expensive), and so it took longer to work the kinks out.

I'm out of touch now, but IIRC the two experiments' total lumi. is still within a factor of two, so the two experiments are actually still fairly competitive -- especially when a physicist at one or the other finds some new resonance or thinks of a particularly good technique to reduce systematics. Either site could be upgraded to a Super-B factory, but around 2003 (or so) the HEP community decided to push for the ILC instead. Of course, now there is no funding in the US for either. I hear rumors that physicists in Japan still hope for a Super-B factory, but I don't know how realistic that is.

Coupled with CDF/D0 and soon LHCb (I'm aware the these are hadron collider experiments and are therefore more complimentary than direct competitors but still...), there just wasnt much of a physics program left that wasnt being done better elsewhere or hadnt already been measured by BaBar and Belle to great precision.

Yeah, and of course any experiment that collects data at a constant rate will tend to see diminishing returns simply because of sqrt(N). I really don't think CDF/D0 are direct competitors to BaBar/Belle. B physics there has turned out to be pretty difficult. BTev was expected to handle B physics at the Tevatron anyway. In terms of comparing one class of results, I believe the B factories have produced much tighter constraints than CDF/D0. Of course B_s results are impossible with the B factories' Y(4S) data, so there is certainly a place for B physics at the Tevatron!

Anyway, I do think it is quite reasonable to wind down BaBar/PEP-II, and since around 2004-2005, it was already expected to stop taking data sometime during 2008-2009. (IIRC, the original proposal was to 2010, though in principle it could have been extended.) What's disappointing to me is not that BaBar stops, but that there is no Super-B nor ILC work to replace it, nor even any prospect thereof, thanks to the US Congress.

I've been out of the business for a while, so I welcome any factual corrections to the above...