First Collisions of Run 2

This morning in Geneva saw the first collisions in the revamped LHC, there’s an event display from ATLAS here, CMS here.

These collisions are just at the injection energy of 450 GeV/beam, but over the past few weeks beams have been successfully ramped up (without intentional collisions, although see page 23 here) to the planned 6.5 TeV/beam. 6.5 TeV beams have been accelerated not just with probe intensity, but with nominal bunch intensity and squeeze. They are roughly halfway through a planned 8 week beam commissioning process and on schedule, with stable beams for physics collisions still planned for around June 1. For quite a while now, 6.5 TeV/beam collisions have been possible, but no word yet on when this is planned for, I assume there will be some sort of media event at that time.