The Diffractive Quantum Limits of Particle Colliders
Abstract
Quantum Mechanics places limits on achievable transverse beam spot sizes of particle accelerators. We estimate this limit for a linear collider to be \Delta x > \hbar c f/E\delta_0 where f is the final focal length, E the beam energy, and \delta_0 the intrinsic transverse Gaussian width of the electron wave-function. \delta_0 is determined in the phase space damping rings, and we find \delta_0 \approx \sqrt{\hbar c /eB} where B is the typical wiggler magnetic field strength in this system. For the NLC \delta_0 = 25 nm, and \Delta x = 0.06 nm, about two orders of magnitude smaller than the design goal. We can recover a crude estimate of the classical result when we include radiative relaxation effects. We also consider a synchrotron and obtain \Delta x > \sqrt{\hbar c f/E} = O(1.0) nm. We discuss formulation of quantum beam optics relevant to these issues.
Cite
@article{arxiv.hep-ph/0002230,
title = {The Diffractive Quantum Limits of Particle Colliders},
author = {Christopher T. Hill},
journal= {arXiv preprint arXiv:hep-ph/0002230},
year = {2007}
}