A scaled, circular‐emitter penning sps for intense H− beams

The Los Alamos versions of the Penning Surface‐Plasma Source (SPS) routinely generate H− ion beams with pulsed currents over 100 mA. However, these sources employ geometries that result in the extraction of slit beams (0.5×10 mm2). Our modeling with the SNOW code indicates that the beam from a 5.4‐mm‐diam circular emitter will have lower emittance and divergence for transport to and injection into our radio‐frequency quadrupole (RFQ) accelerator. This paper describes a newly constructed Penning SPS that has most of its discharge chamber dimensions scaled up by a factor of 4 to accommodate this circular emitter.