Passive beam sprending systems and light-weight gentries for synchrotron based hadron therapy

Hadron therapy is a promising technique that uses beams of protons or light ions for the treatment of cancer. In order to open this technique to a wider application, hospital based treatment centres are now needed. The extbf{P}roton- extbf{I}on extbf{M}edical extbf{M}achine extbf{S}tudy (PIMMS) in CERN is concerned with the design of such a centre that would use both protons and light ions. The dual species operation makes it preferable to base the centre on a synchrotron. The present thesis is concerned with the beam delivery for the protons. After introducing the basic vocabulary of linear beam optics, the feasibility of a light-weight gantry with passive beam spreading fed by a synchrotron is investigated. The device is a non-linear magnetic structure, which can be described as a emph{magnetic guide} or as a emph{proton pipe}. Detailed studies show that while it is possible to design an optically stable 270$^circ$ section, which would be necessary for a gantry, the properties do not fulfil the requirements of a gantry for medical purposes...