Related press releases
Related research
Terabytes of Data Network Behind the Cern in Preparation for World's Largest Particle Accelerator
:: 16 July, 2008
Enough information to fill multiple CDs every second is flowing across the world on a network one thousand times faster than home broadband.
Terabytes of data are streaming through dedicated fibre optic links between laboratories and universities globally in preparation for the world's largest particle accelerator, the Large Hadron Collider (LHC), being switched on in August at Cern in Geneva, Switzerland.
The Large Hadron Collider Computing Grid (LCG), a super high bandwidth network, will channel about 15 petabytes - 15 million gigabytes - of data from the LHC to about 5,000 scientists in 500 institutions every year for at least 10 years.
The particle accelerator will smash sub-atomic particles, protons, into each other at 99 per cent of the speed of light, spraying huge amounts of energy and particles into its detectors.
The LCG will allow researchers to tap into the distributed processing power of almost 100,000 CPUs, crunching through vast amounts of data from the detectors and speeding their hunt for clues about the fundamental nature of the universe.
Rutherford Appleton Laboratories (RAL), near Oxford, has a 10-gigabit connection to Cern capable of 1,250Mbps upstream and downstream that will pipe in almost raw data from the LHC via the UK part of the LCG - the GridPP.
Andrew Sansum, tier one manager at RAL, said its connection with Cern is about 1,000 times faster than the download speeds on a home broadband connection.
He said it may be less than two decades before commercial networks catch up: "Video and other media services are going to push the speed of consumer network connections up as the demand is going to be huge.
"We were at today's speed of about 10Mbps about 10 to 15 years ago, so you could take that as a precedent for how long it will take for the commercial networks to catch up with us today."
RAL and other "tier one" sites across the world in the LCG will shape the mass of data from the LHC into chunks that can be usefully analysed by physicists and pass it on to hundreds of "tier two" universities and laboratories in their respective countries.
Sansum said: "The LHC experiment would not be possible without the power and throughput of the LCG. Cern has not got the capacity to solely process the vast amount of data on site. The tier one sites will be busy refining the data and enhancing the software that analyses it, growing the processing operations of the grid.
"Our role is to make sure that those physicists are getting the most useful and relevant data. Grid technology is transforming the way that experiments are being carried out, 10 years ago these institutions were working on there own, now they work closely together."
Sansum said RAL and the GridPP are prepared for the LHC going live: "We have run it up to 250 to 300 Mbps each way sustained over several days so far. We are in the final shakedown at the moment and seem to be in good shape to face the challenges the LHC will throw at us.
"But there are bound to be surprises around the corner, the biggest challenge is for the software to work out which of the 200 or so tier two sites has which data. You need to be able to move vast amounts of data from site to site, check it has all got there, flag up any problems and correct those immediately - it quickly gets immensely complicated."
A wide range of projects are already tapping into the vast number crunching capabilities and fat pipes of the GridPP during its downtime, including those searching for anti-malarial drugs, combating avian flu and an image search engine.
There are various grid projects around the world analysing weather data, collaborating on other scientific and academic projects but none match the scale and sustained throughput of the LCG.
Grid technology will continue to grow in use, according to Sansum, linking up diverse data, such as climate information and localised cancer rates, and offering insight and driving scientific progress forward in ways never before possible.
About Large Hadron Collider
The Large Hadron Collider (LHC) is a particle accelerator complex intended to collide opposing beams of 7 TeV protons. Its main purpose is to explore the validity and limitations of the standard model, the current theoretical picture for particle physics. This model is known to break down at a certain high energy level.
The LHC is being built by the European Organization for Nuclear Research (CERN), and lies under the Franco-Swiss border near Geneva, Switzerland. The LHC will become the world's largest and highest-energy particle accelerator. It is funded and built in collaboration with over two thousand physicists from thirty-four countries as well as hundreds of universities and laboratories.
The collider is currently undergoing commissioning while being cooled down to its final operating temperature of approximately 2 K (−271.15 °C). The first particle beams are due for injection in August 2008, with the first collisions planned to take place about two months later.
When activated, it is theorized that the collider will produce the elusive Higgs boson, the observation of which could confirm the predictions and "missing links" in the Standard Model of physics and could explain how other elementary particles acquire properties such as mass. The verification of the existence of the Higgs boson would be a significant step in the search for a Grand Unified Theory, which seeks to unify three of the four known fundamental forces: electromagnetism, the strong nuclear force and the weak nuclear force, leaving out only gravity. The Higgs boson may also help to explain why gravitation is so weak compared to the other three forces. In addition to the Higgs boson, other theorized novel particles that might be produced, and for which searches are planned, include strangelets, micro black holes, magnetic monopoles and supersymmetric particles.
The collider is contained in a circular tunnel with a circumference of 27 kilometres (17 mi) at a depth ranging from 50 to 175 metres underground.[6] The 3.8 metre diameter, concrete-lined tunnel, constructed between 1983 and 1988, was formerly used to house the LEP, an electron-positron collider. It crosses the border between Switzerland and France at four points, although most of it is in France. Surface buildings hold ancillary equipment such as compressors, ventilation equipment, control electronics and refrigeration plants.
The collider tunnel contains two adjacent beam pipes, each containing a proton beam (a proton is one type of hadron). The two beams travel in opposite directions around the ring. Some 1232 bending magnets keep the beams on their circular path, while an additional 392 focusing magnets are used to keep the beams focused, in order to maximize the chances of interaction between the particles in the four intersection points, where the two beams will cross. In total, over 1600 superconducting magnets are installed, with most weighing over 27 tonnes. Approximately 96 tonnes of liquid helium is needed to keep the magnets at the operating temperature, making the LHC the largest cryogenic facility in the world at liquid helium temperature.
About LHC Computing Grid
The LHC Computing Grid is a distribution network designed by CERN to handle the massive amounts of data produced by the Large Hadron Collider (LHC). It incorporates both private fiber optic cable links and existing high-speed portions of the public Internet.
The data stream from the detectors provides approximately 300Gb/sec, which is filtered for "interesting events", resulting in a "raw data" stream of about 300Mb/sec. The CERN computer center, considered "Tier 0" of the LHC Computing Grid, has a dedicated 10Gb/sec connection to the counting room.
The project is expected to generate 27 TB of raw data per day, plus 10 TB of "event summary data", which represents the output of calculations done by the CPU farm at the CERN data center. This data is sent out from CERN to eleven Tier 1 academic institutions in Europe, Asia, and North America, over dedicated 10Gb/sec links. Over 150 Tier 2 institutions are connected to the Tier 1 institutions by general-purpose national research and education networks.
The Tier 1 institutions receive specific subsets of the raw data, for which they serve as a backup repository for CERN. They also perform reprocessing when recalibration is necessary.
Distributed computing resources for analysis by end-user physicists are provided by the Open Science Grid, Enabling Grids for E-sciencE, and LHC@home projects.
Tags: The 15-petabyte network behind the Cern atom smasher , Grid technology , Large Hadron Collider , Large Hadron Collider Computing Grid , sub-atomic particles , protons , Rutherford Appleton Laboratories (RAL) ,
