collisions

Beams return to the ATLAS Experiment

With the year’s first proton beams now circulating in the Large Hadron Collider, physicists have today recorded “beam splashes” in the ATLAS experiment

29th April 2017

Counting collisions

Whether searching for signs of new physics, or making precise measurements of known interactions, it is essential to know the total number of proton-proton collisions that the LHC delivers in ATLAS. This parameter, known as “luminosity”, is a vital part of ATLAS analysis.

27th October 2016
27th October 2016

ATLAS begins recording physics data at 13 TeV

Today ATLAS and other particle physics experiments at CERN's Large Hadron Collider (LHC) began recording physics data from 13 TeV proton collisions, which allow for precision studies of the Higgs boson and other Standard Model particles, as well as the search for new particles with higher masses. The new data will bring a deeper understanding of nature.

3rd June 2015

ATLAS records first test collisions at 13 TeV

On 20 May at around 22:24, ATLAS recorded the first 13 TeV test collisions delivered by the Large Hadron Collider. The proton collisions set a new high energy record, marking the beginning of ATLAS' journey into unexplored physics frontiers as we prepare for production data-taking, scheduled to start in early June.

22nd May 2015

Coordination for collisions

There is the Large Hadron Collider and then there are its experiments. When the collider is ready to circulate proton beams, the experiments have to be ready to receive them.

14th May 2015

First collisions at injection energy

On the morning of 5 May 2015, ATLAS recorded the first scheduled proton beam collisions since the Large Hadron Collider and its experiments started up after two years of maintenance and repairs.

8th May 2015

ATLAS reaches milestone: 5 inverse femtobarns of data!

In an amazing year that has exceeded our expectations, the Large Hadron Collider has delivered, and ATLAS has recorded, over 5 inverse femtobarns (fb-1) of collisions. These units correspond to having 3.4 x 1014 or 340 000 000 000 000 total collisions. Most analyses presented at the last major conference (the Lepton Photon Symposium in August in Mumbai) made use of about 1 fb-1, so this is a big jump.

28th October 2011

Increasing collision rate

Many collisions will be needed to unveil the secrets eventually hidden at the 7 TeV energy regime.

1st April 2010

First 7 Tev collisions have been recorded in ATLAS

After ramping of the beams to 3.5 TeV and tuning, final checks, and some emotions due to an unforeseen beam dump, the 7 TeV collisions finally appeared on the on-line monitors of the ATLAS Control Room.

30th March 2010

More collisions at 2.36 TeV

This early morning Dec.14 at 2.40, after a 8 minutes ramp, the energy of the two LHC beams has been brought up to 1.18 TeV again.

14th December 2009

Just a taste

At 21:32 pm on December 8th, the LHC did something that no other accelerator has ever done before.

11th December 2009
11th December 2009

First collisions with the pixel detector

It's been a busy weekend for ATLAS. Last night, well, actually early this morning, we received the "stable beam" flag from the LHC.

7th December 2009

First collisions in ATLAS

A few days ago, loud cheers and happy faces filled the ATLAS Control Room while the whole detector lit up: protons are back at the experiment's door, and everybody forgot in a second the long year of waiting for the Large Hadron Collider (LHC) to resume operation.

23rd November 2009

LHC beams and events back in ATLAS

Loud cheers and happy faces fill the ATLAS Control Room while the whole detector lights up: protons are back today at the experiment's door, and everybody forgets in a second the long year of waiting for the Large Hadron Collider (LHC) to resume operation.

21st November 2009

ATLAS preparing for collisions in mid-2009

The full ATLAS Experiment has been operational and taking cosmic ray data since September 2008, and high-energy collisions are scheduled for late summer 2009. Data from cosmic rays that hit the ATLAS detector are valuable to calibrate and synchronize the many detector elements. Even more exciting were the so-called “splash events” that occurred as the LHC was being tuned up starting 10 September 2008.

15th December 2008