Tevatron: Day of Doom

[beamjockey]

The final store is now circulating in the Tevatron. At breakfast, it was just below 100E30 luminosity units (per square centimeter per second).

The Tevatron's final crew is on shift. It will be a long day for them; after the 2 PM ceremony, after the officials and camera crews and Tevatron designers have left the Main Control Room for the party, the crew will be putting the Tevatron into standby, as well as continuing to operate other accelerators.

Picnic tents are up in the Horseshoe. TV cameras are in place in Ramsey Auditorium and the MCR. Lighting has been adjusted and links have been tested. An absurdly large TV has been placed in the MCR, so that the people there may see people speaking on the Auditorium stage.

Fermilab endures. Here are plans for the future.

Tevatron fact sheet.

About the shutdown process.

The original 1979 plan: A Report on the Design of the Fermi National Accelerator Laboratory Superconducting Accelerator. Dr. Helen Edwards, one of its co-authors, will be performing the shutdown.

Comments

[neowolf2.livejournal.com]

How much induced radioactivity is there in the tunnel? Will the magnets/etc. have to be treated as low level radioactive waste?

[beamjockey.livejournal.com]

It varies, but generally only components in direct contact with the beam show measurable residual radioactivity, not tunnel walls or floor. For (at a guess) 99% of the components in the ring, the amount is mild.

In limited areas, components have a somewhat higher level of activity and might need special attention in planning their removal.

Everyone who enters the tunnels has suitable training and dosimetry equipment or, in rare cases such as film crews or touring ambassadors, is accompanied by a qualified radiation worker.

Tevatron components will for the most part be left in place for more than a year, after which their radioactivity will be considerably lower. Activity is dominated by relatively short-lived isotopes.

The Director is talking about opening detector halls and a portion of the tunnel to public tours at some point in the future. Radioactivity in these halls and tunnels is already quite low, and before the public was invited in, Fermilab staff would measure and document activity to confirm that it was within allowable limits.

[mbumby.livejournal.com]

I've been hearing about the planned tours for a while. If there were a special tour that would have a bunch of my favorite people attending, I might be more interested in attending that than a generic one...

[neowolf2.livejournal.com]

I bet the targets in fixed target experiments get a lot more activation.

Fun fact learned while browsing the FNAL web site: the LSND experiment at Los Alamos put nearly a gram of 800 MeV protons into its target during its run. I imagine the high intensity plans you all have will go even higher.

[minnehaha.livejournal.com]

So, are you still shooting neutrinos at the basement of the Soudan Mine or no?

K.

[beamjockey.livejournal.com]

You betcha!

Well, not right NOW, because today that beam is shut off to change the polarity of the focusing horn. But when it turns on again, the Main Injector will be shooting neutrinos at the basement of the Soudan Mine.

Unless we were already shooting neutrinos at Soudan, before the polarity change. In which case, we will now be shooting antineutrinos at Soudan. I'm not keeping track.

[mmcirvin.livejournal.com]

Well, heck, if they're violating Lorentz invariance they might violate CPT too; you never know what difference it could make!

[neowolf2.livejournal.com]

So you're reversing the polarity of the neutrino flux?

I'm sorry, Star Trek is suing you for copyright infringement.

("In our defense, we claim neutrinos are Majorana particles...")

[isherempress.livejournal.com]

Interesting that ~1,000 students received their PhDs for work done on the Tevatron. That's a lot of (ahem) inbreeding, isn't it? Or maybe the study options for particle physicists are somewhat limited...

The most important thing about all of this to me is simple: will you, and our other friends, continue to be employed at FermiLab? xoxo

[wcg.livejournal.com]

I'm sure it's a sad day for you Bill. You've been part of something really amazing. I'm sure you have more amazing things ahead of you, but it's still sad to see something like this end.

[qnofhrt.livejournal.com]

It's a sad day for high energy physics.

[mihai-lado.livejournal.com]

Well, one of the many books you need to write is about a career full of interesting stories at Fermilab.
(Personally, I would call it "Never Stop Accelerating."

[acmespaceship.livejournal.com]

What's that I hear softly in the distance? Daisy... Daisy... give me your answer... do...

[dave-ifversen.livejournal.com]

One of the nonsensical, never-gonna'-happen things that were talked about in the control room was to set up the beam abort button so that when Helen pushed it, a voice would come through the speakers saying "I'm sorry, Helen, but I can't let you do that."

[acmespaceship.livejournal.com]

That would have been epic.

[beamjockey.livejournal.com]

What I wanted to do was push the Tevatron to its design energy. It has been operating at 980 GeV, and never went to 1000 GeV, because reliability was thought to be better a little below that. Nobody wanted to run the risk of damage that might keep the machine off for days or weeks--perhaps merely a quench, perhaps a breakdown that would require replacing one or more magnets.

The alternatives were considered, and the lab management declined a go-for-broke lunge for higher energy. Instead, the Tevatron ran smoothly and gave productive data up until its very last moment.

Another idea Operations had, according to Dave, was to conduct a "24-house quench," which would have made a big noise around the entire ring. But it also would have involved what one cryo expert liked to call "giving the helium back to God."