Recently I came across something and I was surprised. I always thought that huge amount of energy is required to accelerate particles in the accelerator in the particle physics.But looks like no. The peak energy of proton beams at the LHC now is around 7 trillion electron Volts (TeV), which is only like 0.00000121J. So energy involved in particles accelerators is not that much then or am I missing something.? May be since the mass of these partciles is so small, their velocity needs to really high to get this much energy and may be that is the big deal.?
Yes, you are missing something. First, 7 TeV is the energy of each proton. The LHC beam contains 300 trillion protons! Second, the protons continuously lose energy as they radiate synchrotron radiation, so you have to continuously put in energy just to keep them going around at the same speed.
A particle accelerator does not work with one particle at a time. At any moment, there will be billions of particles distributed into a beam (usually with bunches in it). Because they are charged, the particles in the beam represent a current. Electrical power is (current x voltage) and as such the beam packs enough wallop to tear holes in the beam tube and wreak havoc upon the equipment nearby if it gets out of control.
From Wikipedia: "While operating, the total energy stored in the magnets is 10 GJ (2,400 kilograms of TNT) and the total energy carried by the two beams reaches 724 MJ (173 kilograms of TNT)"