  A Hollow Electron Lens (HEL) has been proposed in order to improve
performance of halo control and collimation in the Large Hadron Collider in
view of its High Luminosity upgrade (HL-LHC). The concept is based on a beam of
electrons that travels around the protons for a few meters. The electron beam
is produced by a cathode and then guided by a strong magnetic field generated
by a set of superconducting solenoids. The first step of the design is the
definition of the magnetic fields that drive the electron trajectories. The
estimation of such trajectories by means of a dedicated MATLAB tool is
presented. The influence of the main geometrical and electrical parameters are
analysed and discussed. Then, the main mechanical design choices for the
solenoids, cryostats gun and collector are described. The aim of this paper is
to provide an overview of the preliminary design of the Electron Lens for LHC.
The methods used in this study also serve as examples for future mechanical and
integration designs of similar devices.
