This is a guest post by Anna Wilson and Eleanor Harris, who spent a week interning with CMS in April 2015.
More than half a year, a school trip to CERN, and a round of 13TeV collisions later, the week-long internship we completed at CMS over Easter is still the most awe-inspiring experience of our lives so far.
Long Shutdown 1 (LS1) — the two-year period of maintenance, consolidation and upgrades to prepare the LHC and its particle detectors for collisions at an energy of 13 TeV — recently came to an end as the LHC was successfully restarted earlier this year. Although the term “shutdown” seems to imply a quiet period, this interpretation couldn’t be farther from the truth. Below we present in no particular order some highlights from what was a very productive two years at the CMS experimental site, as we take the final steps towards analysis data at the new energy frontier.
Yesterday was an exciting day! While many people were hunting for eggs in their gardens and enjoying a nice Easter-Sunday lunch, physicists and engineers from CMS congregated in their control room near Cessy in France to partake in their own hunt: for the first signs of particles from the LHC in the CMS detector for two and a half years. In the morning the LHC operators started to thread the protons beams around the 27km ring, sector by sector. They first tried with "beam 2", the anti-clockwise beam.
After a two-year hiatus, proton beams will soon start to circulate in the LHC and, in a couple of months from now, we will have the first collisions at 13 TeV, nearly twice as much as in the first run of the LHC back in 2010-2012. Many things have improved in the LHC, to allow this higher energy, but many things have also happened in the CMS detector too. Some changes and repairs of hardware have been made, along with many improvements to "firmware" - the computer programs embedded in the custom-made electronics that control the detector - and software.