On 23rd November the LHC collided 450 GeV beams of protons for the first time (see here) but only for a short period as a trial. The first real period of collisions started on 6th December. The aim for the coming days is to accumulate about 100000…

Today LHC delivered to CMS a total of about 5 hours of clean collisions and we have recorded about 11000 min bias BSC triggers. The quality of the data produced and the performance of the Tracker together with the exceptional speed with which we…

This morning between 8:20 and 8:50 for the first time the full Tracker (Strips and Pixel) was turned ON and successfully collected data in Global run with a quiet single beam running in LHC. This is a major achievement. Everything seems all right…

Only TOB was turned ON today after LHC Opearation declared stable beams for a while. Below is a 900 GeV p-p collision event seen by the TOB in Run 122314, Evt 8605569.

TOB was turned ON today after LHC Opearation declared stable beams for a while. Here are images showings possible tracks from inelastic collisions detected by TOB in run 122294, lumi section 37

Following the "splash" events of 6th/7th November (see here) the time has come to circulate the proton beams all around the LHC. This started in the early evening (Geneva time) on friday 20th and by midnight the beam had been circulated in both…

On the weekend of 6th & 7th November the LHC beam was injected and arrived near the CMS experiment, before being "stopped" by a large amount of material known as a "collimator". The interaction of the protons with the dense material produced "…

After further maintenance work on the detector here are 4 new cosmic events from run 119013

After further maintenance work on the detector here a few event display animations (make sure your Browser settings allow image animations and click on each image to animate them!).

After the refurbishment of the Cooling plants (see next article) and 5 weeks of intense re-commissioning work, last night the Tracker joined the MW Global Run at zero tesla. Here are 4 cosmic muon events. A few modules appear a bit noisy still, so…

A series of important milestones have been passed during the last 3 months. With the delivery of refurbished cooling systems, pixels and strip systems have been brought back into operation after long shutdowns. Pixels has been operating since…

In July of last year we successfully inserted the pixel detector inside CMS and successfully integrated and operated it with the rest of the CMS detector during the CRAFT run. Despite the excellent detector performance some problems arose after…