Theory design of proton imaging magnetic lens for hot spot measurement in inertial confinement fusion

The magnetic lens used in high energy proton radiography system can alleviate the degradation of resolution which is induced by multi scattering of protons. A magnetic lens used for 3.6 MeV protons produced from DD fusion reactions in the implosion region is designed based on the scaling law of beamline design. A similar object-image relationship as in geometrical optical is deduced. 3D particle tracing simulation is also carried out to demonstrate the object-image relationship of the magnetic lens.