A plasma lens for linear collider final focus

Summary Form only given, as follows. Recent experimental and theoretical effort has been directed at designing a plasma lens for the Stanford Linear Collider final focus. Plasma lens of the type under consideration work on the principle that the self-forces of a beam pulse can be used to pinch the beam if electrostatic neutralization by the plasma is partially or wholly realized. It is predicted that the luminosity could be increased severalfold by such a lens. The plasma would be provided by a laser-ionized gas pulse. The operating modes of the lens are constrained by conflicting requirements of minimizing background and sensitivity to beam fluctuations. Preliminary focusing experiments using a 20-MeV linac and tests of a high-speed, pulsed valve for gas injection have been carried out.<>