ATLAS completes world's largest jigsaw puzzle

Celebrations are underway in the ATLAS Experiment, as the final element of the detector was lowered into the cavern on Friday February 29th, 2008. The second “small wheel” is also the final part of the muon subsystem, but the wheels themselves are small in name only. At 9.3 metres in diameter, and weighing in at 100 tons each, moving them from their construction warehouse, at the north-west tip of the CERN site in Geneva, to the underground ATLAS cavern was a challenge which was anything but small.

News | 29th February 2008

Intrepid Rappellers Descend Into ATLAS Cavern

It could be a scene from a James Bond movie. But this action shot of two intrepid rappellers (abseilers) was in fact taken in the ATLAS experimental cavern one night in December. François Butin, the ATLAS experimental area manager, tells the story behind the photograph.

News | 15th February 2008

Cables: The “blood vessels” of ATLAS

The cables within the ATLAS detector may be thought of as the blood vessels and nervous system of the experiment; they carry power to the detector, they deliver messages to control its functions and they relay the data taken, ready for analysis. Just as blood vessels and nerves criss–cross and connect the organs and tissues of the human body, cables penetrate the whole of the ATLAS volume, reaching each and every one of its elements.

News | 15th January 2008

Dress Rehearsal for ATLAS debut

Dave Charlton and his team have a mammoth job on their hands; Charlton has been tasked with coordinating the Full Dress Rehearsal (FDR) of the computing and data analysis processes of the ATLAS experiment, a run–through which he describes as "essential, almost as much as ensuring the detector itself actually works".

News | 15th December 2007

Norwegian teachers visit ATLAS

"It's amazing that you have to build something so huge to measure such extremely small things," said Tom Christiansen from Telemark in Norway, after visiting the ATLAS cavern. His sentiment about the size of the ATLAS detector was shared by the thirty–one other physics teachers who, together with Tom, attended the first Norwegian Teacher Programme run at CERN, in November 2007.

News | 11th December 2007

Progress on Toroid Magnets

The magnets on either end of the ATLAS detector (called end–cap toroid magnets) dominated November’s work in the experimental cavern. The ATLAS magnet team took a significant step towards finishing work on the ATLAS detector as testing of the magnets began.

News | 10th December 2007

The pixels find their way to the heart of ATLAS

Leading up to the lowering of the pixel detector into the ATLAS cavern, final preparations were proceeding quickly.

News | 28th June 2007

ESA/NASA astronaut Christer Fuglesang visits the ATLAS cavern

On 14 June, 2007, ESA/NASA astronaut Christer Fuglesang visited the ATLAS cavern. A former CERN fellow working on ATLAS, Christer went on to become the first Swedish astronaut and participated in the STS-116 Space Shuttle mission to the International Space Station last December.

News | 14th June 2007

The complex and spectacular lowering into the cavern of the huge end-cap toroid magnet on side A

On 13 June 2007 the first of two giant toroid magnet end-caps was lowered into the ATLAS cavern on the A side. This complex and spectacular operation was completely successful.

News | 13th June 2007

Triggering and measuring bent cosmic muon tracks with the muon spectrometer barrel for the first time

Data have recently been collected with the toroidal magnetic field will provide for the first time the measurement of the cosmic ray muons' momenta in the ATLAS experiment and allow studies on trigger optimization, chamber calibration, chamber alignment and magnetic field maps. More than one million events were acquired. They are now being analyzed by enthusiastic members of the collaboration.

News | 22nd December 2006

The ATLAS Detector safety system

The ATLAS Detector safety system (DSS) has the mandate to put the detector in a safe state in case an abnormal situation arises which could be potentially dangerous for the detector. It covers the CERN alarm severity levels 1 and 2, which address serious risks for the equipment.

News | 15th December 2006

Development of the ATLAS control room

The ATLAS control room will become the brain of the detector operations. At the moment six of the final fifteen stations are already in place.

News | 15th December 2006

First combined SCT/TRT end-cap cosmic rays seen in building SR1

Following the successful combined SCT/TRT barrel test in the Spring 2006, a similar combined SCT/TRT endcap test is currently being performed in the SR1 building on the ATLAS experimental site at CERN. One quadrant of the SCT and two sectors of the TRT have been cabled up and are used in this test. The data taking and combined testing is expected to last until December 11th.

News | 9th December 2006

The pixels system: last but not late!

After almost 15 years of R&D and prototyping, the ATLAS pixel detector is finally almost ready for installation in ATLAS, and its first rendez-vous with colliding beams!

News | 4th December 2006

Barrel toroid magnet fully charged to nominal field, and it works!

After a few weeks of testing up to intermediate currents, finally, on Thursday evening November 9, the current in the Barrel Toroid was pushed up to its nominal value of 20500 A and even 500 A beyond this value to prove that we have some margin. It went surprisingly well.

News | 1st December 2006

First physics pulses in the barrel electromagnetic calorimeter with cosmic rays

The electromagnetic barrel calorimeter was installed in its final position in October 2005. Since then, the calorimeter is being equipped with front-end electronics. Starting in April 2006, electronics calibration runs are taken a few times per week to debug the electronics and to study the performance in the pit (stability, noise). Today, 10 out of the 32 Front End crates are being read out, amounting to about 35000 channels.

News | 20th November 2006

Progress on the level-1 calorimeter trigger

The level-1 calorimeter trigger (L1Calo) has recently passed a number of major hurdles. The various electronic modules that make up the trigger are either in full production or are about to be, and preparations in the ATLAS pit are well advanced.

News | 3rd November 2006

ATLAS copies its first PetaByte out of CERN

On 6th August ATLAS reached a major milestone for its Distributed Data Management project - copying its first PetaByte (1015 Bytes) of data out from CERN to computing centers around the world. This achievement is part of the so-called 'Tier-0 exercise' running since 19th June, where simulated fake data is used to exercise the expected data flow within the CERN computing centre and out over the Grid to the Tier-1 computing centers as would happen during the real data taking.

News | 1st November 2006

Inner detector barrel installed in cryostat

Wednesday 23rd August was a memorable day for the Inner Detector community as they witnessed the transport and installation of the central part of the inner detector (ID-barrel) into the ATLAS detector.

News | 23rd October 2006

First operation of the central solenoid

A new phase for the ATLAS collaboration started with the first operation of a completed sub-system: the central solenoid. It was cooled down from the 17th to 23th May 2006, and the first kA was put into it the same evening as it was cold and superconductive. That makes our solenoid the very first cold and superconducting magnet to be operated in the LHC underground areas.

News | 15th October 2006

Successful mapping of the solenoid magnet

The ATLAS solenoid coil is about 5.3m long, has a diameter of 2.5m and is designed to deliver a magnetic field of approximately 2T for the ATLAS inner detector. The superconducting solenoid coil has been integrated inside the LAr barrel cryostat and was installed at its final position inside the cavern in November 2005. This summer - after completion of the extended barrel calorimeters and before the installation of the inner detector - the end cap calorimeters (LAr end caps and Tile extended barrels) were moved for the first time into their final position in order to create conditions as close as possible to final for the solenoid tests and for mapping the field inside the solenoid bore.

News | 5th October 2006

Progress with the muon end-cap

After completing the preparation of the sectors of the wheels TGC-1 (first layer of trigger chambers) and MDT (precision chambers) for the side C of ATLAS last spring, the work in building 180 has advanced quickly during the summer: all the sectors for TGC-2-C have been completed during the month of August; currently, two sectors for TGC-3-C are complete, and work is underway for three others. Similarly, assembly, integration and commissioning have progressed well also with the precision chambers, with 12 of the 16 sectors for MDT-A being complete now, and the end of this significant phase of work is only a few weeks ahead of us.

News | 2nd October 2006

Professor Stephen Hawking visits the ATLAS cavern

On Tuesday 26 September 2006 the ATLAS Collaboration was honoured by a very special visit to the detector in the underground cavern by Professor Stephen Hawking, the famous cosmologist holding the post of Lucasian Professor of Mathematics at Cambridge University (position held by Isaac Newton in the 17th century).

News | 27th September 2006

Final components of the semi-conductor tracker (SCT) arrrive at CERN

The first few months of 2006 saw the delivery to CERN of the final components of the ATLAS semi-conductor tracker (SCT), namely the completed SCT end-caps.

News | 23rd May 2006

The SCT barrel inserted into the TRT

The SCT barrel was inserted in the TRT on 17 February, just missing Valentine's day. This was a change of emphasis for the two detectors. In the preceeding months there had been a lot of focus on testing their performance. The TRT had been observing cosmic rays through several sectors of the barrel. The two detectors had to be painstakingly aligned to be concentric to within a millimetre.

News | 22nd February 2006