LHC - Large Hadron Collider (ATLAS/CMS/ALICE)


Program Description: The High Energy Physics (HEP) community has largely driven network backbone capacity to current levels -- 40 -100G + (TB in Europe). HEP is the set of scientists who design, execute, and analyze experiments requiring use of the Large Hadron Collider (LHC) facility at CERN. There is only one such place in the world, so those who want to participate in the experiments and results have over 20+ years formed an international, well-organized community around these experiments. The computational people within the HEP community are called CHEP – they are computer scientists, programming physicists, experimental equipment designers/operators & so forth. The community shares the Large Hadron Collider (LHC) instrument, located near Geneva and spanning the Franco-Swiss border, about 100m underground. It is a particle accelerator used by physicists to study the smallest known particles – the fundamental building blocks of all things. Major experimental groups are the ATLAS Experiment, CMS, and ALICE.

Organization Description: The community is a collaboration of 10,000 scientists and engineers from over 100 countries, organized around the six types of experiments at the LHC. Each experiment is distinct, characterized by its unique particle detector.

Data Description: Because the LHC is a scarce resource, experiments are scheduled years in advance (way past 2020) and they know already how much data will be produced and distributed as a result of those experiments. The community has a well established Tiered Model for data distribution, currently more of an inherited situation than a technical necessity. Up until recently, CalTech was responsible for planning and implementing network connections for HEP. CERN (Tier 0) transfers data to “Tier 1” facilities (Brookhaven and Fermi National Labs); from there, data is re-distributed to “Tier 2” facilities, located at universities. The community is moving unevenly to more of a mesh; sites don’t need to specialize in one kind of data/one kind of analysis. A MonaLisa repository maintained at CalTech monitors all data flowing over all relevant backbone segments. Traffic graphs show most data movement is Tier 2 to Tier 2 now. HEP currently maintains ~30PB of data (20PB of which are on-line accessible); in comparison, NETFLIX has only 12TB of data and comprises 30% of all traffic on the commercial Internet. HEP’s on-line data is used at an average of 0.8Tbps. The community’s expectations are that a 5 minute delay is acceptable; bandwidth required is 2 Gbps average and 10 Gbps max.

Project Type: Instrument

Project Domains: Math and Physical Sciences

Budget: 7.5 Billion Euros

Federal Funding: NSF, DOE

Program Data

Location Lat/Lon Coordinates Location Type Data Type Data Generation Single Data Instance Size (TB) Estimated Daily Data Size (GB) Estimated Annual Data Size (PB) Average Sustained Throughput (Gbps) Maximum Sustained Throughput (Gbps) Online Repository Size (PB) Total Repository Size (PB) Delay Tolerance (minutes) Jitter Sensitive? Uses the Cloud?
CERN, Switzerland 46.2,6.14 Instrument Data Scheduled 15.00 2.00 10.00 20.00 64.00 5.00 - -
CalTech, United States 34.14,-118.13 Monitor Data Scheduled 15.00 2.00 10.00 20.00 64.00 5.00 - -
Brookhaven Lab, United States 40.87,-72.89 Data Repository Data Scheduled 15.00 2.00 10.00 20.00 64.00 5.00 - -
Fermi Lab, United States 41.85,-88.23 Data Repository Data Scheduled 15.00 2.00 10.00 20.00 64.00 5.00 - -