Penning ion source performance for neutron generator applications is characterized by the atomic ion fraction and beam current density, providing two paths by which source performance can be improved for increased neutron yields. We have fabricated a Penning ion source to investigate novel methods for improving source performance, including optimization of wall materials and electrode geometry, advanced magnetic confinement, and integration of field emitter arrays for electron injection. Effects of several electrode geometries on discharge characteristics and extracted ion current were studied. Additional magnetic confinement resulted in a factor of two increase in beam current density. First results indicate unchanged proton fraction and increased beam current density due to electron injection from carbon nanofiber arrays.

This article describes an rf ion source with a back-streaming electron dump. A quartz tube, brazed to a metal plug at one end, is fused in the center of a flat quartz plate. rf power (at 13.6 MHz) is coupled to generate hydrogen plasma using a planar external antenna bonded to the window. Bonding the water-cooled rf antenna to the quartz window significantly lowers its temperature. The water-cooled metal plug serves as the back-streaming electron dump. At 1800 W, the current density of extracted hydrogen ions reaches approximately 125 mA/cm(2).

Geometry tagging is an experimental technique for selecting event samples where one can, on a statistical basis, control the geometry of the collision in order to make more incisive physics measurements. Several physics measurements at the EIC would benefit significantly from the use of this technique, including studies of gluon anti-shadowing, studies of parton propagation, attenuation and hadronization in the nucleus, and ultimately the search for parton saturation. The JLEIC full-acceptance detector, with full acceptance to forward-going neutrons, protons and nuclear fragments and a high data-taking rate is ideally suited to such geometry tagging. We improve, tune, and apply existing modeling codes, BeAGLE, Sartre, and GEMC, and detector descriptions to study this physics.