Archives of ATLAS Collaboration records

Identity Statement [Top]

Reference code(s)



Archives of ATLAS Collaboration records


1988 - 2009

Level of description


Extent of the unit of description

259 boxes; 494 files, 29 linear meters

Context [Top]

Name of creator

ATLAS Collaboration, CERN

Administrative history

The ATLAS project consists of the designing, construction and use of a particle detector named "A Toroidal LHC Apparatus" (abbreviated ATLAS) at the Large Hadron Collider (LHC). It is one part of the five experiments (ATLAS, CMS, ALICE, LHCb, TOTEM) to be performed at the LHC.

Here are some of the steps accomplished by the ATLAS collaboration from 1992 onwards. For a description of the work in progress detailed by detector component, see the CERN Annual Reports from 1994 onwards.

The ATLAS collaboration writes a Letter of Intent (CERN/LHCC/92-4) in which the building of a general purpose proton-proton detector for the Large Hadron Collider (LHC) is proposed.

The ATLAS collaboration submits a Technical Proposal (CERN/LHCC/ 94-43) in December.

The ATLAS collaboration shapes its management structure. The Executive Board (EB) starts functioning. The first ATLAS Resource Review takes place. The LHC Committee and the Research Board recommend approval of the ATLAS project, together with the plans, including milestones, leading to subsystem Technical Design Reports (TDR).

The calorimeter Technical Design Reports (TDR) are submitted in December.

The Technical Design Reports (TDR) for the inner tracking detector (except the pixel detectors), the muon instrumentation and the magnets are submitted and reviewed, resulting in approvals for construction.

The Technical Design Reports (TDR) for the first-level trigger and pixel detector are submitted and reviewed, resulting in approvals for construction. The ATLAS Memorandum of Understanding, which specifies the contributions expected from each participating institute, is signed by most funding agencies. The construction sites are under preparation and are being tested-out by producing module-0s.

The Technical Design Reports (TDR) for the Technical Coordination and also a two-volume Technical Design Report (TDR) documenting the expected physics performance are submitted and reviewed.

The Memorandum of Understanding is signed by all participating funding agencies. Most detector systems enter the construction phase.

Most detector systems continue construction. A new estimate of cost to completion is made, showing that supplementary funding of the order of 20% is required. A staging scenario giving an initial detector consistent with the needs of the initial low-luminosity physics run is integrated in the work schedule.

Half of the construction milestones are met, and 65% of the construction payments made.

* Sources: documents cited with reference in brackets; CERN Annual Reports, from 1994 onwards.

Immediate source of acquisition or transfer

Peter Jenni, ATLAS spokesperson

Content & Structure [Top]

Scope and content

The ATLAS detector has been designed to cover the largest possible range of LHC physics: searches for Higgs bosons and alternative schemes for the spontaneous symmetry-breaking mechanism; searches for super-symmetric particles, effects from extra dimensions, new gauge bosons, lepto-quarks, and quark and lepton compositeness indicating extensions to the Standard Model and new physics beyond it; studies of the origin of CP violation via high-precision measurements of CP-violating B-decays; high precision measurements of the third quark family such as the top quark mass and decay properties, rare decays of B-hadrons, spectroscopy of rare B-hadrons, and [Bs0]-mixing.

The ATLAS detector consists of four major components:

  • the inner tracker measures the paths of electrically charged particles,
  • the calorimeter measures the energies of charged and neutral particles,
  • the muon spectrometer measures muon paths to determine their momenta with high precision,
  • the magnet system bends charged particles for momentum measurement.

The particle interactions in the ATLAS detector will create an enormous dataflow which will be digested by:

  • the trigger system, selecting 100 interesting events per second out of 1000 million others,
  • the data acquisition system, channeling the data from the detectors to the storage,
  • the computing system, analyzing 1000 million events recorded per year.

ATLAS collaboration

The ATLAS collaboration consists of CERN and a group of institutions from CERN Member and non-Member States that have proposed the ATLAS experiment. The institutions are universities and laboratories (150 in 2004), with about 2000 scientific collaborators from 34 countries. The project is financed by Funding Agencies which are government departments, laboratories or universities connected to or identical with the collaborating institutions. A list of these Funding Agencies can be found in the Memorandum of Understanding mentioned below ("Sources"). The main policy-making powers are the Resource Review Board (RRW), the Plenary Meeting (PM) and the Collaboration Board (CB). The Resource Review Board (RRW) is the body where the ATLAS resources are approved upon proposals from the ATLAS collaboration, and monitored. It is chaired by the CERN Director of Research and composed of representatives of the national funding agencies, the CERN management and the ATLAS management. The Plenary Meeting (PM) is the general forum of the collaboration. All major ATLAS decisions concerning physics objectives and results, hardware and software design, and organizational matters are discussed there. The Collaboration Board (CB) is the policy deciding body. Each institution collaborating in the project is represented in it and has one vote. The Plenary Meeting (PM) and the Collaboration Board (CB) assemble at the ATLAS Weeks, week-long meetings of the ATLAS collaboration, four times a year.

The main executive powers are the ATLAS management, the Executive Board (EB) and the ATLAS Systems. The ATLAS management is composed of the Spokesperson, the Deputy Spokesperson, the Technical Coordinator and the Resource Coordinator. The Spokesperson is the highest level executive of ATLAS, and as such has the overall responsibility of the ATLAS execution. He or she represents the ATLAS executive branch at the Collaboration Board (CB). The Executive Board (EB) is the main body for directing the execution of the ATLAS project and for direct communication between the ATLAS management and the ATLAS Systems. It is composed of the ATLAS management, the System Project leaders, the Magnet Project Leader, Technical coordination staff, the Collaboration Board (CB) Chairperson and Deputy, and up to two additional individuals. The ATLAS Systems (Inner Detector, Magnets, Liquid Argon Calorimeter, Tile Calorimeter, Muon Spectrometer, Shielding, Trigger/ DAQ/ DCS) correspond to performance tasks, major activities involving sets of institutions which will produce hardware and software. Each System includes a Steering Group and an Institute Board. the Steering Group takes decisions on technical execution matters and makes recommendations to the Institute Board. The Institute Board takes decisions on major technical choices and on sharing of resources and responsibilities. Each ATLAS System is chaired by a Project Leader.

The material collected so far was created by Peter Jenni, the ATLAS Spokesperson. It documents the activity of the ATLAS Collaboration in the managerial, scientific and technical areas. For an overview of the topics handled, see section 'System of arrangement'.

* Sources: CERN Annual Report 2003; web-site [consulted in May 2004]. 
* Sources: Memorandum of Understanding for Maintenance and Operation of the ATLAS Detector CERN-RRB-2002-035 (28 March 2002); [consulted in May 2004]; ATLAS Internal Note GEN-NO-009 (16 September 1994); ATLAS Internal Note GEN-NO-015 (29 November 1996); ATLAS Internal Note GEN-NO-016 (16 December 1996).

Appraisal, destruction and scheduling information

Nothing was destroyed.


Further accruals are expected.

System of arrangement

The original order has been preserved. The main categories are as follows:

CERN-ARCH-ATLAS-001 EAGLE and ATLAS: official documents
CERN-ARCH-ATLAS-002 Collaborations matters
CERN-ARCH-ATLAS-003 Non Member States
CERN-ARCH-ATLAS-004 Technical Matters
CERN-ARCH-ATLAS-005 LHC General Detector Studies
CERN-ARCH-ATLAS-008 Calorimeter
CERN-ARCH-ATLAS-009 Inner Tracking Detector
CERN-ARCH-ATLAS-010 Trigger/ Data Acquisition (DAQ)/ Detector Control System (DCS)
CERN-ARCH-ATLAS-011 Computing
CERN-ARCH-ATLAS-013 Physics Working Group
CERN-ARCH-ATLAS-014 Semi-Conductor Tracker - SCT
CERN-ARCH-ATLAS-016 ATLAS Executive Board
CERN-ARCH-ATLAS-017 Management Meetings
CERN-ARCH-ATLAS-018 Plenary Meetings
CERN-ARCH-ATLAS-019 Financial Matters
CERN-ARCH-ATLAS-020 United States (USA) ATLAS groups
CERN-ARCH-ATLAS-021 Russian Funding
CERN-ARCH-ATLAS-022 Working notes and Management
CERN-ARCH-ATLAS-023 Conference Speakers
CERN-ARCH-ATLAS-024 Forward Physics Panel
CERN-ARCH-ATLAS-026 Milestones
CERN-ARCH-ATLAS-028 Internal notes

Conditions of access and use [Top]

Conditions governing access

See file level description and the CERN operational circular No 3: rules applicable to archival material and archiving at CERN. In general, records on any subject that are over 30 years old, and all records of a purely scientific nature, may be consulted.

Conditions governing reproduction

Copyright is retained by CERN, no reproduction without permission.

Language / scripts of material

Most of the material is written in English.

Finding aids

Listed to file level in the CERN Archives Database.

Description control [Top]

Archivist's note

Description prepared by Sara Eusebio, Sylvain Féjoz and Caroline Hofer.

Date(s) of description

Geneva, the 28th September 2005, Revised 2007 and 2013.