You might want to read this article that describes how the protons are accelerated.

The LHC uses eight 2MV RF cavities. Assume that the electron gets the full benefit of this (it doesn't - see below) so the energy of a circulating proton increases by 16MV with each circuit. The protons complete about 11,000 circuits per second, so their energy increases by about 0.18TeV per second and it would take about 40 seconds to accelerate to the full design energy of 7TeV.

It actually takes a lot longer than this (about 20 minutes according to the article I linked). The 2MV is the maximum field strength in the RF cavities, but the protons don't feel the full 2MV for their whole passage through the cavity.

A little while ago I answered a question about RF cavities, Accelerating electrons via microwaves, and you might find this interesting.

You might want to read this article that describes how the protons are accelerated.

The LHC uses eight 2MV RF cavities. Assume that the electron gets the full benefit of this (it doesn't - see below) so the energy of a circulating proton increases by 16MV with each circuit. The protons complete about 11,000 circuits per second, so their energy increases by about 0.18TeV per second and it would take about 40 seconds to accelerate to the full design energy of 7TeV.

It actually takes a lot longer than this (about 20 minutes according to the article I linked). The 2MV is the maximum field strength in the RF cavities, but the protons don't feel the full 2MV for their whole passage through the cavity.

A little while ago I answered a question about RF cavities, Accelerating electrons via microwaves, and you might find this interesting.