Making a splash

A good cannonball can soak spectators, and a beam splash in CMS can soak scientists with good data. Physicists can use the data to verify detector calibration and make sure the electronics are synchronized with the beam.

From my Uncle Eddy's first cannonball into the pool each summer, to singer Susan Boyle's now-legendary performance, to make a splash means to be noticed. Recent splashes at CMS have highlighted the return of beam at the LHC and, believe me, CMS scientists noticed.

In the fall of 2008, an electrical arc substantially damaged the LHC accelerator. During the last year, accelerator scientists repaired the damage and have made some modifications to prevent such incidents from happening again. It's been a year marked by growing anticipation for the return of the beam. The wait is now over.

In recent weeks, the LHC accelerator team has been turning the accelerator complex back on, first bringing the beam to the entrance of the LHC and then guiding the beam around longer and longer fractions of the accelerator ring. Between Nov. 7-9, they successfully steered the beam around half of the ring, bringing it to the very doorstep of CMS. The beam collimators were intentionally closed, thus stopping the beam from actually passing through the detector. This was done as a safety precaution so that scientists could check the beam's trajectory before allowing it to enter the detector.

While the collimators stopped the beam from directly entering CMS, the debris caused by the beam hitting the collimators passed through the detector. Like with the splash caused by my Uncle Eddy soaking bystanders, the particle splash thoroughly penetrated the CMS detector.

The beam was run into the collimators more than 1,100 times, bathing the detector in particles. Using the splash, which deluged the detector with far more particles than during ordinary operations, CMS scientists were able to study their equipment and verify it worked under very extreme conditions.

During the next few weeks, scientists will open the collimators and circulate beam around the entire ring. A few days later, CMS scientists will make two counter-rotating beams of protons collide in the center of the LHC's various detectors.

The era of the LHC is fast approaching.

— Don Lincoln

CMS physicists celebrate the return of beam in the time-honored way of drinking good champagne out of bad glasses in the middle of the night.

This colorful image is an example of how CMS responds to beam splash. The beam entered from the right, lighting up the detectors.

Virtually attend SC09

Can't attend SC09 next week, and eager to hear what's going on in the world of supercomputing?

You can attend virtually via international Science Grid This Week's iSGTW@SC09 page, which goes live tomorrow.

Here's how:

• Follow our team Twitter account, @isgtw, for pint-size live updates on the conference.
• Whether you use Twitter or not, you can follow our updates between 8:30 a.m. and 6 p.m. Tuesday through Thursday on our Web page.
• Keep up with SC09 blogs, courtesy of our partners at GridCast.

Fermilab asking for neighbors' input in planning

From the Daily Herald, Nov. 12, 2009

Fermilab is looking for advice from its neighbors.

It is compiling a community advisory board to help make plans for the accelerator laboratory's future, particularly when its famous Tevatron accelerator ceases operations in 2010.

The panel will meet starting in January. Nomination forms are available at fnal.gov/pub/neighbors/CAB, or by calling (630) 840-3351. Nominations are due Dec. 7.

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Did a time-traveling bird sabotage the collider?

From Time, Nov. 11, 2009

Sometime on Nov. 3, the supercooled magnets in sector 81 of the Large Hadron Collider (LHC), outside Geneva, began to dangerously overheat. Scientists rushed to diagnose the problem, since the particle accelerator has to maintain a temperature colder than deep space in order to work. The culprit? "A bit of baguette," says Mike Lamont of the control center of CERN, the European Organization for Nuclear Research, which built and maintains the LHC. Apparently, a passing bird may have dropped the chunk of bread on an electrical substation above the accelerator, causing a power cut. The baguette was removed, power to the cryogenic system was restored and within a few days the magnets returned to their supercool temperatures.

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