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Dear friends
With the hot weather upon us in Geneva we also have ‘hot’ news from the CMS experiment!
In this edition, you can follow the progress of the Combined Computing Readiness Challenge, CCRC for short. The purpose of this world-wide exercise was to check the readiness of our computing infrastructure for LHC data taking. Our second featured challenge is the trial installation of the Forward Pixel detector, a delicate operation that was successfully performed at the beginning of May.
In the 'People' section this week you can read about someone who doesn't actually work for CMS but sounds like he would like to! Mike Einzinger, guitarist for the multi-platinum selling rock band Incubus, visited CMS on 13th June, discussing his passion for physics and forthcoming science symphony.
Finally, taking advantage of the sunny weather, those of you who are here (or will be before the end of July) can take a stroll down the banks of Lake Geneva and enjoy an impressive exhibition of pictures taken by German photographer, Peter Ginter, featuring the LHC, CMS and the other experiments. Take a look at the “CMS Outreach, Visits and Media” section for more details.
With kind regards
Marzena Lapka
Elizabeth Gibney
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June
- Beam pipe bakeout
- EE+ installation
- Insert pixel and BCM
- Phase 2 of Cosmic Run at Zero Tesla (CRuZeT)
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July
- Phase 3 of CRuZeT
- EE-/ES installation
- Close CMS
- CRAFT - cosmic run at four tesla
- HF and Totem
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Updated information should be sent to
cmstimes@cern.ch |
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The Sound of Physics
Mike Einzinger performing in 2004 |
Some people find answers to their most profound questions in physics. Some find it in music. For others, like Mike Einzinger of the multi-platinum, Grammy- nominated rock band, Incubus, it takes both. Currently writing an orchestral symphony inspired by high-energy physics, Einzinger visited CMS on Friday 13th June to see first hand the experiments he has been in awe of for many years.
The US guitarist’s interest in physics was sparked many years ago in high school: “I had this great teacher who was really smart. He gave me A Brief History of Time [by Stephen Hawking, 1988] to read and I was hooked – the stuff was mind blowing. But then my band got this record deal and, you know, that was it.”
Whilst securing a record deal is probably not a problem most of us identify with, youthful excitement about physics is quite familiar. And getting more young people involved in physics is one of Einzinger’s goals. “It’s a huge passion of mine. I think that it can be easy to get young people into science if they can just access it.” And he lives up to his word. The “band website” section of his myspace page (where he lists physics, cosmology, and the theories of relativity, gravity and electricity among his interests) actually links to the LHC homepage. “If they do get to hear about it of course they think it’s amazing. I mean quantum physics, particle physics – this stuff is better than the movies and it’s real.”
For Einzinger, what holds back kids in his own country is a fear of science: “I think there’s a growing problem. Religion especially seems to be scared of science. Many of the older generation have a fear of it and the younger generation are born into that and don’t even realise. We all saw the debates over evolution, and I think that’s happening again with the Big Bang. And I just don’t think it’s fair that kids could be denied this.”
Mixing music and physics is one way that Einzinger hopes to inspire people. His own reconnection with the subject came after surgery on his hand left him temporarily unable to play the guitar but with time to ponder his former passions. “I really had time to think and I decided that some kind of musical piece inspired by physics was something that I’d like to do. It’s almost ready to go now. It’s about the struggle for the mind to get around these kinds of problems and how humble it can make you feel. But it’s not about fear; it’s about the amazing scale of this kind of physics and just being in awe. Hopefully I can capture that.”
Einzinger and CMS's Chad Jarvis (UCLA) admire the Point 5 timeline |
Einzinger will ensure his symphony becomes reality when he goes to university for the first time in September, at age 32. “I’m going to Harvard. I’m going to be majoring in music, but hopefully there will be scope to take a few physics classes. I’m really looking forward to bugging all the fantastic professors and picking their brains.”
And what does he think of CMS, his first LHC experiment? “It’s just amazing. I can’t get over the size of it.” Then somebody tells him that CMS is supposed to be “compact”. “Oh. In that case what should I say, it’s cute?” he laughs. “I just think this whole place is phenomenal. I’m trying to get my head around it all and I’m starting to understand it. It’s better than science fiction; you couldn’t make it up. And I hope that I can get other people to discover it too.”
http://profile.myspace.com/index.cfm?fuseaction
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| Submitted by: |
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| Elizabeth Gibney |
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From STOP.hu (Hungary), 6 June 2008:
Magyarok is vadasznak az isteni reszecskere!
Iden kezdheti meg mukodeset a vilag legnagyobb reszecskegyorsitoja, a Nagy Hadron Utkozteto (LHC), amely az europai reszecskekutato kozpontban, a CERN-ben talalhato, Genftol nem messze, a fold alatt, s a szenzacios vallalkozasban nyolcvan magyar szakember is reszt vesz...
Read the full article:
http://www.stop.hu/articles/article.php?id
=333473
From Science.gouv.fr (France), 16 June 2008:
LHC: le nouvel accélérateur du CERN
D'ici la fin de l'année, le plus grand laboratoire de physique des particules du monde entrera en service au CERN, près de Genève. Sa mission : atteindre des énergies faramineuses pour mettre la matière en miettes et repousser ainsi les frontières de la connaissance. Un nouvel élan pour la physique du XXIè siècle...
Read the full article:
http://www.science.gouv.fr/index.php?
qcms=dossier,view,2882,view,154,2882,,,,
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From Naver (Korea), 18 June 2008:
Read the full article:
http://news.naver.com/main/read.nhn?
mode=LS2D&mid=sec&sid1=105&sid2=
228&oid=028&aid=0001955721
CERN through the lens of Peter Ginter
Exhibition on the Geneva Lake banks, opposite Palais Wilson. In collaboration with the City of Geneva (from Thursday, 29 May to end of July 2008)
Particle physics is not only fascinating but also very photogenic. Peter Ginter followed the great human and scientific adventure of the construction of the LHC accelerator and its experiments.
Fifty of his photographs, accompanied by explanations that can often be as astonishing as the images themselves, are currently on display on Wilson Quay, between La Perle du Lac gardens and Mont Blanc bridge, the location kindly provided by the City of Geneva.
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The highlight of last few days has certainly been the successful completion of the CMS beam pipe bake out by our colleagues of AT-VAC. The vacuum analysis is now being performed and we have still to await the final results to be able to celebrate. However, the fact that the thermal cycles were performed without any problems is in itself a great achievement.
The test of the CO2 fire fighting system |
The first tests of the CO2 fire fighting system have been successfully performed on a sample TK rack and we are now looking forward to installing this new hardware on all TK racks.
The HF+ has been moved further into the UXC55 to enable the opening tests to be performed.
Large amount of hardware has been delivered to Point 5 for the DAQ room in the SCX5.
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Analysis PCs delivery to SCX5 |
The backup TK chiller is now fully installed, connected to the CV room and ready to be used if the need arises.
The second of the CRUZET2 commissioning exercise ended on 14/06. In addition to the very interesting outcome for the commissioing of CMS, some required adjustements in the Control Room infrastrure have also been highlited and are currently being undertaken.
The Barrel - End Cap seal is being installed. This activity has to be complete before the closing of CMS and has therefore been given high priority.
| Submitted by |
Martin Gastal |
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During May CMS participated in the second phase of the Combined Computing Readiness Challenge (CCRC) together with all other LHC experiments. The purpose of this world-wide exercise was to check the readiness of our computing infrastructure for LHC data taking. CSA and CRUZET were also running in May and CCRC augmented the load on computing with additional tests to validate and stress-test all CMS computing workflows at full data taking scale.
We ran a wide range of tests, exercising most aspects of the CMS computing model. While CMS was running at full blast other experiments were also testing, however not all the time, and not all possible interferences between experiments on shared computing infrastructures have yet been tested.
The CMS tests were comprehensive. During May we moved more than 3.6 Petabytes among more than 300 links in the complex Grid topology - that's more data than CMS is expected to take during a full year. We demonstrated that we can safely move data out of CERN to the Tier-1s, sustaining the required rate of more than 600 MB/s as a daily average for more than seven days in a row, with enough headroom and with hourly peaks of up to 1.7 GB/s.
We ran hundreds of simultaneous jobs at each Tier-1 site and up to 3000 at Fermilab, re-reconstructing and skimming hundreds of millions of events. After re-reconstruction the fresh AOD (Analysis Object Data) has to be synchronized between Tier-1 centers. We demonstrated that the required inter-Tier-1 transfers are possible and finished within a few days. We also showed that skimmed analysis data sets can be transferred to Tier-2s for analysis with sufficient rate, regionally as well as inter-regionally. This extended the February tests to the full mesh of Tier-1 and Tier-2 centers. We achieved all our goals in over 90% of the ~200 links, with headroom of up to a factor of ~40.
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Submitted jobs per day, with peaks up to 200k
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Simultaneously we also ran a large Tier-2 analysis exercise. Realistic analysis jobs were submitted to a large set of Tier-2 sites by a large number of people to produce a “chaotic” workload across the systems. We had more than 400 analysis users in May. Taken all together CMS routinely achieved submission of ~100k jobs/day, with peaks up to 200k jobs/day, which is shown in the picture.
It looks as if CMS is getting ready to do analysis of real data on our world-wide Grid of computing centers!
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Lothar
Bauerdick |
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Daniele Bonacorsi |
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A trial installation and removal of the CMS barrel and forward pilot run pixel detectors was successfully conducted at Point 5 between 5th and 7th May.
Barrel Pixels installed and ready for Forward Pixels |
The detector was transported to P5 on April 30th in a special vibration installation frame and craned into the cavern on May 3rd. The installation of the pixel detectors presents a special challenge as they must be installed with the beam pipe in place. The pixel detectors are installed inside the silicon strip tracker cavity by sliding the detectors on precision alignment rails, milled into the carbon fiber of the inner strip tracker surface. Since the beam pipe has vertical support wires that cannot be removed inside the central tracker volume, both barrel and forward pixel detectors are split into two sections in phi. The forward pixels are additionally split into a +Z and -Z component, and are inserted on their respective sides. Each section is mounted on a carbon fiber service half cylinder, which contains readout electronics and delivers power and cooling to the detectors.
Positioning the Transport Frame |
One of the main goals of the installation test was to insure that the pixels could be safely installed without damage occurring to the beam pipe. The forward pixels must be installed extremely close (on the order of 10mm) to the beam pipe and both detectors require substantial hardware infrastructure for safe transport and installation alignment. Both the forward and barrel pixel detectors utilize integrated transport/installation frames that protect the detectors during transport and allow the pixels to be installed directly from the transport vessel. Given the delicate nature of the beam pipe and its utmost importance to the entire LHC community, beam pipe safety was on everyone's mind. (My personal plan if I broke something: change my name and join an outlaw motorcycle gang. Failing that, switch to theory.) It is with pleasure that I report that the extensive engineering efforts on the installation infrastructure with respect to beam pipe safety were met with complete success.
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Among the many challenges is the forward pixel installation process. The two half-disks of the forward pixel detector converge in the installation rails as they move into the tracker such that the two halves mesh together (providing full coverage in phi) after they pass the beam pipe support wire obstruction. At the final insertion point there is only 1mm of clearance between the two half disks, requiring both half disks to stay precisely aligned in the Z direction as they travel down the insertion rails. It is not possible to see the half disks as they are inserted, so an ohmmeter is used to detect if the support rings make any contact during installation.
Following the successful installation of the pixel detectors and the beam conditions monitor, the forward pixel pilot run detectors were cabled into the DCS and DAQ system. Several readout tests and calibrations were performed successfully, ensuring that the pixels had not been damaged in transit.
Forward Pixels halfway installed |
The next day both pixel detectors were removed from the tracker volume. The removal tasks were completed within the time budgeted, and many additional improvements have been proposed that will help refine the procedure for future removals. Minimizing removal time will be very important during future CMS upgrades, as the pixel detector will be irradiated and personnel will need to minimize direct exposure.
The successful pixel insertion test has shown that the pixel detectors can be safely and quickly installed, which will be invaluable in the hectic final days before the closure of CMS. Many congratulations are due to the many people that worked very hard to make this test a success.
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| Evan Friis |
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