• Number 300  |
• November 23, 2009

LHC restart produces first particles in CMS detector

Preparations for the restart of the Large Hadron Collider in Europe are in full swing. On Saturday, Nov. 7, scientists taking shifts in the LHC Remote Operations Center at DOE’s Fermi National Accelerator Laboratory witnessed the first beam of protons knocking on the door of the CMS particle detector. LHC accelerator operators sent low-energy protons half way around the 17-mile LHC ring, stopping the protons with a collimator just upstream of the CMS cavern. The CMS detector recorded so-called splash events—the tracks created by secondary particles emerging from the collimator and penetrating the detector from the side. Over the next few weeks, scientists will use the LHC to accelerate two proton beams in opposite direction around the ring and make the protons collide at the centers of four particle detectors, including CMS. Physicists from institutions across North America come to the Remote Operations Center at Fermilab and help monitor the performance of the detector and its data acquisition systems in Europe.

[Kurt Riesselmann, 630/840-5681,
kurtr@fnal.gov]