A SCREENING PROBLEM WITH APPLICATION TO THE THETATRON

摘要

An investigation is made of the amount by which the y component of electric field due to two Lecher Wires parallel to the x-axis, through z = 0, y = ± b, can be screened inside a cage consisting of wires parallel to the z-axis in the planes y = ± a, and short circuited by conducting plates in the planes z = ± d.nIt is shown that the reduction in Ey within the cage is of order 4d2/λ2, where λ is the wavelength, whilst the magnetic field is little affected ifλ » d.nThis result would appear to have application to a proposed type of "thetatron", in which the primary current is of radio frequency and flows in a loop of wire, whilst the cage might consist of a set of wires along the generators of a cylinder coaxial with the loop. The unwanted radial electric field Er is then reduced in about the same ratio.