ATLAS at the starting line

The start of the 2017 run marks the conclusion of a maintenance period known as the Extended Year-End-Technical-Stop (EYETS). This upkeep is vital for the health and well-being of the detector, ensuring that ATLAS can thrive for the months of high-intensity operation that follow.

19th May 2017

Review before Run 2

ATLAS is ready for Run 2 of the Large Hadron Collider (LHC) where proton beams will be collided together at a higher centre of mass collision energy of 13 TeV, and reach higher luminosities than ever before.

1st June 2015

Shots from the Long Shutdown

As ATLAS gears up to record data from proton collisions delivered by the Large Hadron Collider (LHC) at an unprecedented energy level, here are glimpses from the last two years of preparations.

8th April 2015

The Ties That Bind

A few weeks ago, I found myself in one of the most beautiful places on earth: wedged between a metallic cable tray and a row of dusty cooling pipes at the bottom of Sector 13 of the ATLAS Detector at CERN. My wrists were scratched from hard plastic cable ties, I had an industrial vacuum strapped to my back, and my only light came from a battery powered LED fastened to the front of my helmet. It was beautiful.

15th January 2015
15th January 2015

Handing In the ATLAS Keys

After completing more than 250 work packages concerning the whole detector and experimental site, the ATLAS and CERN teams involved with Long Shutdown 1 (LS1) operations are now wrapping things up before starting the commissioning phase in preparation for the Large Hadron Collider's restart. The giant detector is now more efficient, safer and even greener than ever thanks to the huge amount of work carried out over the past two years.

8th December 2014

"Dirt Detectives"

For five days last week, 110 ATLAS collaborators worked in 10 different shifts to help clean and inspect the detector and the cavern that houses it before the toroid magnets are turned on.

5th December 2014
5th December 2014

Identity problems

An obligatory eye scan is required for all ATLAS underground personnel entering the experimental cavern. The iris recognition is performed by the IrisID iCAM7000. Its only point in life is to keep track of who enters and leaves the Zone. It sounds like a simple task for such an advanced technology, but -- like most things in the world of research -- it's never without some hiccups.

25th July 2014
25th July 2014

A New Sub Detector for ATLAS

Closest to the beam pipe where particle collisions will occur in the very heart of ATLAS, a new sub-detector – the Insertable B-Layer – was put in place on 7 May. The IBL team had been developing and practicing the insertion procedure and tooling for two years because of the operation’s delicate nature.

2nd June 2014

Notes from Underground: Servicing Silicon

We physicists refer to the vast underground cavern that houses the ATLAS experiment as ‘the pit’. That may be a strange term to use for a marvel of civil, mechanical and electrical engineering, but nonetheless there are parallels to what you might imagine a ‘pit’ to be. Working inside the ATLAS detector in the pit can be dark, sometimes hot and not suited to those with claustrophobia. It often involves climbing several sets of makeshift steps and gantries and crawling flat on your stomach through narrow gaps to get to the part of the detector where you need to be. You will be wearing a safety helmet with mounted lamp, steel toe-cap shoes, one or more dosimeters to monitor radiation exposure and even a harness, if working at heights. Not to mention tools, laptop and any equipment you need to do your job. You tend to recognize the experimental physicists, engineers and technicians who have just come up from the pit – they stand blinking in the sunlight with a tired and rather sweaty appearance.

14th May 2014

Dealing With Data

In the first run of the Large Hadron Collider, almost a billion proton-proton collisions took place every second in the centre of the ATLAS detector. That amounts to enough data to fill 100,000 CDs each second. If you stacked the CDs on top of each other, in a year it would reach the moon four times. Only a small fraction of the observed proton–proton collisions have interesting characteristics that might lead to discoveries. How does ATLAS deal with this mountain of data?

16th January 2014
16th January 2014

Full Coverage for ATLAS Muons

Hold out your hand and in one minute hundreds of muons will have passed through your palm. Muons are one of the high-energy cosmic ray particles that can pass through most solid structures – even the ATLAS detector’s calorimeter, which is designed to absorb particles and measure their energy. A specific system is required to measure muons. Until now, the ATLAS muon system was almost completed, but not quite. The last of the 62 chambers in the Extended Endcap (EE) region was installed just before summer this year.

29th October 2013

Approaching the End...and a New Beginning

This Tuesday, if all goes according to plan, will mark the end of a very long journey for many High Energy Physicists. The first 7 TeV Collisions will signal the end of the the commissioning period of the LHC and its experiments.

28th March 2010

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.

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.

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.

15th January 2008

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.

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.

28th 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.

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.

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.

15th 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!

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.

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.

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.

3rd 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.

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.

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.

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.

2nd October 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.

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.

22nd February 2006

2005: a busy year for ATLAS

During 2005, the preparation of the ATLAS Experiment has proceeded smoothly and many results were achieved.

15th December 2005