Propagation of an intense charge-neutralized ion beam transverse to a magnetic field

Abstract

It is shown experimentally that an intense, pulsed, charge-neutralized proton beam (140 kV, 10 A/cm2, 800 nsec) will pass through a region of transverse magnetic field of up to 2 kG without being significantly deflected. Electric probe measurements show that within the magnetic field a polarization electric field E is set up such that E+v×B=0, where v is the beam velocity and B is the applied magnetic field. Data for propagation are consistent with the polarization drift model of Schmidt which applies to plasmas having a dielectric constant ε≫1; however, propagation was not observed unless ε≳400.