Investigation of Resistive Magnetic Field Generation by Intense Proton Beams in Dense Plasmas

Abstract

Charged particle beam transport through matter is a fundamental process in many high energy density science scenarios, including applications such as isochoric heating, secondary particle generation, and inertial confinement fusion. The propagation of intense charged particle beams through solid density plasmas can induce resistive electromagnetic fields, triggering collective effects such as resistive collimation. While these effects have been theorized 1 and observed with hot electron beams 2 , laser-driven proton beams are now approaching current density regimes (~10 10 A/cm 2 ) in which collective effects become significant. Here, we present a theoretical model for the proton beam-driven generation of resistive magnetic fields in solid density plasmas. A comparison of the essential heating mechanisms which play a crucial role in field generation is made between intense proton beams and hot electron beams. Using an analytic model for resistivity 3 and stopping power 4 that span cold to hot plasma regimes, the theoretical evolution of the magnetic field profile is compared with 2-D hybrid-PIC simulations and shows good agreement. Finally, the roles of various beam parameters are explored for both monoenergetic and Maxwellian proton beams, and a simple model to compute the maximum magnetic field is given.