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LHC@home logo transparent.png
Initial releaseSixTrack: 1 September 2004
Test4Theory: 1 August 2011
Development statusActive
Operating systemCross-platform
As ofApril 2021
Average performance144 TFLOPS[1]
Active users9,309[1]
Total users174,625[1]
Active hosts18,391[1]
Total hosts507,826[1]
Websitelhcathome.cern.ch/lhcathome/ Edit this at Wikidata

LHC@home is a distributed computing project for particle physics based on the Berkeley Open Infrastructure for Network Computing (BOINC) platform.[2] The project's computing power is utilized by physicists at CERN in support of the Large Hadron Collider and other experimental particle accelerators.[3]

The project is run with the help of over 9,300 active volunteer users contributing more than 18,300 computers processing at a combined 144 teraFLOPS as of April 2021.[1] The project is cross-platform, and runs on a variety of computer hardware configurations.


The LHC@home project currently runs four applications—Atlas, CMS, SixTrack, and Test4Theory—which deal with different aspects of research conducted in LHC like calculating particle beam stability and simulating proton collisions. Atlas, CMS, and Test4Theory use VirtualBox, an x86 virtualization software package.[3][4] In 2017, all of the Virtualbox Projects were moved over to LHC@home to join SixTrack.


Atlas uses volunteer computing power to run simulations of the ATLAS experiment. It can be run in VirtualBox or natively on Linux.


Beauty (LHCb[5]) compared the decay of bottom quarks (
) and bottom antiquarks (
), which also known as beauty quarks. The participation of volunteers in the application was suspended indefinitely on 19 November 2018.[5]


The CMS application (formerly a standalone project called CMS@Home) allows users to run simulations for the Compact Muon Solenoid experiment on their computers.[6]


SixTrack was first introduced as a beta on 1 September 2004 and a record 1000 users signed up within 24 hours. The application went public, with a 5000 user limit, on September 29 to commemorate CERN's 50th anniversary. Currently there is no user limit and qualification. Data from the application is utilized by engineers to improve the operation and efficiency of the accelerator, and to predict possible problems that could arise from adjustment or modification of the LHC's equipment.

SixTrack simulates particles accelerating through the 27 km (17 mi)-long LHC to find their orbit stability. In one workunit, 60 particles are simulated travelling 100,000 or 1,000,000 loops, which would take about 10 seconds in an actual run. The orbit stability data is used to detect if a particle in orbit goes off-course and runs into the tube wall—if this happened too often in actual running, this would cause damage to the accelerator which would need repairs.


The Test4Theory application allows volunteers to run simulations of high energy particle collisions on their home computers. These simulations use theoretical models based on the Standard Model of particle physics, and are calculated using Monte Carlo methods. The theoretical models have adjustable parameters and the aim is that a given set of parameters (called a "tune") will fit the widest possible range of experimental results.

The Test4Theory results are therefore submitted to a database which contains a very wide set of experimental data from many accelerator experiments worldwide, including of course experiments at the Large Hadron Collider. The database and the theoretical fitting process is part of the project MCPLots, based in the Theory Unit at CERN.

See also[edit]


  1. ^ a b c d e f "Server Status". LHCAtHome.CERN.ch. CERN. Retrieved 11 April 2021.
  2. ^ "BOINC projects list". Retrieved 30 April 2020. CS1 maint: discouraged parameter (link)
  3. ^ a b "LHC@home". LHCAtHome.CERN.ch. CERN. Retrieved 23 December 2020. CS1 maint: discouraged parameter (link)
  4. ^ "Applications". LHCAtHome.CERN.ch. CERN. Retrieved 11 April 2021.
  5. ^ a b Roiser, Stefan (19 November 2018). "Pausing Submission of LHCb Applications". LHCAtHome.CERN.ch. CERN. Retrieved 22 December 2020.
  6. ^ "CMS@Home". LHCAtHome.Web.CERN.ch. CERN. Retrieved 11 April 2021.

External links[edit]

LHC@home projects[edit]