Commun. Comput. Phys., Notice: Undefined index: year in /var/www/html/issue/abstract/readabs.php on line 20 Notice: Undefined index: ppage in /var/www/html/issue/abstract/readabs.php on line 21 Notice: Undefined index: issue in /var/www/html/issue/abstract/readabs.php on line 23 Volume 4. Particle-in-Cell with Monte Carlo Collisions Gun Code Simulations of a Surface-Conversion H^- Ion Source E. Chacon-Golcher 1*, K. J. Bowers 21 Los Alamos National Laboratory, Los Alamos, NM 87545, USA. 2 Los Alamos National Laboratory Guest Scientist, currently at D.E. Shaw and Company, New York, NY 10036, USA. Received 31 October 2007; Accepted (in revised version) 15 December 2007 Available online 21 April 2008 Abstract We present an extended update on the status of a particle-in-cell with Monte Carlo collisions (PIC-MCC) gun code developed at Los Alamos for the study of surface-converter $H^-$ ion sources. The program is fully kinetic. Some of the program's features include: solution of arbitrary electrostatic and magnetostatic fields in an axisymmetric ($r$,$z$) geometry to describe the self-consistent time evolution of a plasma; simulation of a multi-species ($e^-$, $H^+$, $H_2^+$ , $H_3^+$ , $H^-$) plasma discharge from a neutral hydrogen gas and filament-originated seed electrons; full 2-dimensional ($r$,$z$) 3-velocity ($v_r$, $v_z$, $v_\phi$) dynamics for all species; detailed collision physics between charged particles and neutrals and the ability to represent multiple smooth (not stair-stepped) electrodes of arbitrary shape and voltage whose surfaces may be secondary-particle emitters ($H^-$ and $e^-$). The status of this development is discussed in terms of its physics content and current implementation details. Notice: Undefined variable: ams in /var/www/html/issue/abstract/readabs.php on line 163 PACS: 52.65.-y, 52.65.Pp, 52.65.Rr, 52.80.Vp, 29.25.Ni Key words: Negative hydrogen ion source simulation, particle-in-cell with Monte Carlo collisions, low temperature plasma simulation. *Corresponding author. Email: edcg@lanl.gov (E. Chacon-Golcher), kevin.j.bowers@ieee.org (K. J. Bowers)