Hawking Partly Wrong
NewsHammer Exclusive Peter Higgs with CERN's Tejinder Virdee and get-this: Under the hood of the giant solenoid CMS 12,500 tonne detector behind them you've got a radiator leaking water like a '72 Chevy. The new and mighty CMS, our favorite experiment, one of 4 beautiful cathedral-size detectors or reactors, but CERN won't call them that, has 272 zones of corrosion. Plus unlike any Chevy anywhere it even leaks its coolant directly into the engine. But that was December, a cold month, about 25 gallons or a 100 liters of water with the CMS plugged in, CMS On, spilling inside. See the candid report in the CMS Times, "CMS Winter Shutdown Adventure".
Don't worry, none of the 1,000,000 signal channels were affected. CERN didn't really say one way or the other, but not saying exactly anything at CERN always means there are no safety issues. Damage of course was minor. I suppose we are being asked to theorize a quick wipedown by CERN technicians insured a total recovery of all systems, even unaffected systems that might have been at risk. Though how did the technicians get inside? It took them 10.5 days to break in, a bit late for a quick wipedown. Though with a lot of official CERN hot air always present at the LHC, it could have been easily diverted directly into CMS. The blow-dry operation would be the intervention of choice for the "incident", as CERN hot air is considered very hot in comparison to other smaller collider PR.
CMS is maybe still down for 272 corrosion repairs due to other leaks, spotted once technicians got inside for the quick wipedown. A second burst pipe and flooding of the CMS Control Room two years running has been fixed again. 4,000 fault-prone connectors mistakenly installed in a new giant safety system, to replace an old system that failed in 2008, the nQPS or new Quench Protection System, have been replaced. That's why in part, the collider hasn't been going anywhere over the very long and bumpy "Technical Stop" since December in case you were wondering what happened to $10 Billion and 10,000 physicists trying to hitch a ride on the LHC Eurostar.
That's the latest from CERN, a fast train as an equivalent to an LHC beam. Not the power of 1700 Nuclear Power Plants, as discussed in "Fantastic LHC Energies May Be Higher Than Expected". By the way, the Two Mosquitoes Line, a long-running embarrassment bewildering even for collider kids, was shutdown and deleted from all CERN websites in a surprising retreat from CERN hot air physics. Looks like the CERN-EuroDisney merger is at a "Technical Stop".
Leaky CMS/ First Quantum Bench Test
Results not in.
Anyway, why leaks, especially water leaks in a new CMS that cost a fortune to build? The CMS gets very hot when it powers down. At its ordinary field strength of 3.8 Tesla it operates at about 18,000 Amps. It's supposed to power down gradually, but sometimes it can crash, like when there's a power failure. Then it can get hot enough to smoke.
During a crashdown test a couple of years ago, you could see a cloud of steam rising in a series of CERN photos which used to be available from CMS. That in itself could have damaged water lines and caused the later big spill and corrosion.
Other though unplanned "incidents" might have contributed:
Monday [August 3, 2009] at 2:19 PM, when a power cut on the CERN general network caused a slow discharge that turned into a fast dump a few seconds later. Investigations are ongoing to understand the switching from the preferred slow discharge to the faster dump which, while being a throughly tested part of the CMS operations, raises the temperature of the coil to 70K, thus requiring three days to cool down again to 4K before current can be injected again.
"5am 9 Nov [2009]: “Glitch” in CMS solenoid cryogenics system caused magnet to ramp down to 2.3T."
"[as of December 7, 2009] CERN power outage Tuesday night . . . trip of tracker cooling plant. . . . 3 or 4 cases . . . CMS solenoid magnet cryo dry compressors stopped. Field dropped from 3.8 T to 3.5 T. . . . slow current dump of CMS solenoid. Went down to 2.7 T. . . . Down most of today due to another power glitch"
Mounting Radiation Hazards In Cooling Water
Not that everything has been going smoothly. A lot of water is used as coolant at the LHC, including for some Septum Magnets that suffered heavy radiation damage and had to be replaced in 2004, "SEPTUM MAGNET MNP-23 FOR THE CERN PS EXPERIMENTAL AREA
AND ITS FAST INTERLOCK SYSTEM". With the recent revelations about mounting radiation hazards during collider operations, ignored for 10-15 years in ring tunnels according to Steve Meyers Head of Accelerators, in "Large Hadron Collider Waiting For Doomsday", it looks like some people in CERN Maintenance were well aware of the potential problems. Doesn't anybody at CERN read CERN docs?
That also means mounting radiation hazards in many LHC cooling water systems, including the colossal CMS solenoid surprisingly also partly cooled by water, and leaking too. Hope there's a new study and some action on this, before radioactive waste water finds itself in nearby Lake Geneva.
The LHC Collimator System where relatively exposed beams are focused is also cooled by water in part, though like in the CMS system it's hard to imagine an idea like this being approved by a CERN Committee of Experts. Here's the full January report from Chamonix, "Summary of the Collimation Upgrade Plans" and the smoking gun slide on P38.
Perhaps it's time for a little more foresight.
LHC On Target Again For Re-ReStart
Late January, February, Mid-February, March, February 20th (Official), February 25 (Rumor), After Monday but no firm date (Official, sometime after Monday February 22)
Jump to 3.5 TeV, no back to injection energy 0.45 TeV. Slow ramp? Not perfectly clear yet. A good idea I'd say. One of those 3.5 TeV beams will be very hard to handle if the collider has another bad day.
Next in NewsHammer, more on CMS in The Strange Case Of The Misbehaving Magnet At The LHC
--Alan Gillis
This is Part 3 of a series on machine safety and potential risks of expected Collider Objects like mBH at the LHC when the collider jumps to very high unknown energies this March. "Doomsday Report: New Physics At The LHC" will appear in The Science of Conundrums.
NewsHammer Part 1: Large Hadron Collider Waiting For Doomsday
NewsHammer Part 2: Fantastic LHC Energies May Be Higher Than Expected
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