LEP achieves its first century

On 2 August, a decade after the initial commissioning at 45 GeV per beam, CERN’s LEP storage ring has collided 100 GeV beams of electrons and positrons, giving a total energy of 200 GeV and a healthy luminosity (a measure of the collision rate) of 6 x 10³¹ cm^-2 s^-1.

This year, LEP supplied colliding beams initially at 96 GeV, and then at 98 GeV. However, the 100 GeV per beam figure was always on the cards following the delivery by LEP of a single 100 GeV electron beam in a debut 1999 high-energy run.