<P> On 5 April 2015 , the LHC restarted after a two - year break , during which the electrical connectors between the bending magnets were upgraded to safely handle the current required for 7 TeV per beam ( 14 TeV ) . However , the bending magnets were only trained to handle up to 6.5 TeV per beam ( 13 TeV total ) , which became the operating energy for 2015 to 2017 . The energy was first reached on 10 April 2015 . The upgrades culminated in colliding protons together with a combined energy of 13 TeV . On 3 June 2015 the LHC started delivering physics data after almost two years offline . In the following months it was used for proton - proton collisions , while in November the machine switched to collisions of lead ions and in December the usual winter shutdown started . </P>
<P> On 5 April 2015 , the LHC restarted after a two - year break , during which the electrical connectors between the bending magnets were upgraded to safely handle the current required for 7 TeV per beam ( 14 TeV ) . However , the bending magnets were only trained to handle up to 6.5 TeV per beam ( 13 TeV total ) , which became the operating energy for 2015 to 2017 . The energy was first reached on 10 April 2015 . The upgrades culminated in colliding protons together with a combined energy of 13 TeV . On 3 June 2015 the LHC started delivering physics data after almost two years offline . In the following months it was used for proton - proton collisions , while in November the machine switched to collisions of lead ions and in December the usual winter shutdown started . </P>
when is the large hadron collider being turned on
when is the large hadron collider being turned on
5 April 2015
5 April 2015