Journal of Vacuum Science & Technology A, Vol.15, No.6, 2998-3004, 1997
Kinetics of Adsorption and Photodesorption of Hydrogen on Copper Surfaces
The kinetics of adsorption and photodesorption of hydrogen on a Cu surface is discussed for the next generation of high energy proton colliders. The equilibrium solution of a rate equation describing the surface kinetics leads to an expression for the gas pressure, which we estimate to be about 10(-8) Torr for proton beam colliders like the now defunct 20-TeV superconducting super collider. Using classical molecular dynamics simulations with reliable interatomic potentials we find the fractional energy loss of hydrogen on Cu(100), for incident energies ranging from 0.1-1.0 eV, to be between 1%-6%. This leads to an estimate of 10(-4) s for the average lifetime of the hydrogen molecule in the beam tube.