Abstract: The electron beam monitor includes two long, thin foil elements which are sequentially moved through an electron beam to be measured, in directions transverse to the beam and perpendicular to one another. The electron beam striking the elements produces forward directed bremsstrahlung radiation that is detected by a series of detectors which are positioned circumferentially about the beam path. A measuring circuit measures the radiation intensity as a function of the foil position to provide beam current, profile and position information. To simultaneously monitor a second beam travelling in a direction opposite to the first beam, a second series of detectors are positioned circumferentially about the beam path to detect forward directed radiation produced by the second electron beam as it strikes the foils.

Abstract: The magnetic beam deflector system of this invention consists of two identical mirror image sections positioned about a symmetry plane. The sections are energized such that the zeroth order beam path through one section is a mirror image of the beam path through the other section resulting in a beam exit axis which is symmetrically located on one side of the symmetry plane with respect to the entry axis on the other side. In a 180.degree. deflector system, the entry and exit axes are coincident and lie in the symmetry plane. The preferred embodiment consists of four dipole magnets, forming a 180.degree. deflector system symmetrical about a symmetry plane in which the zeroth order beam path is defined by:.theta..sub.2 = .theta..sub.1 + .theta..sub.3 + 90.degree. and ##EQU1## WHERE .theta..sub.1, .theta..sub.2 AND .theta..sub.3 ARE THE BENDING ANGLES OF THE FIRST, SECOND AND FOURTH, AND THIRD MAGNETS RESPECTIVELY, .rho..sub.1, .rho..sub.2 AND .rho..sub.