Automatic generation of IGUN(C) input files for enhanced mesh resolution at the plasma meniscus.

The plasma-beam interface (meniscus) is highly nonlinear and its correct simulation needs a mesh resolution of the order of the Debye length. In high intensity ion sources, the plasma density is usually too high and the Debye length is too small for a sufficient mesh resolution. A well established method to overcome this dilemma is the use of a field line and an equipotential line to be created in a first run, in order to dissect the simulation problem into a plasma part with much higher mesh resolution and a transport part with usual resolution. In the past many users of IGUN have found it difficult to perform this dissection. Therefore, a new feature has been added to IGUN to automatically write new input files for the dissected areas. For this a field line starting point needs to be defined as well as the potential of a pseudo electrode. The field line then is used for the plasma part as a slanted and curved Neumann boundary, while the pseudo electrode will act as the extraction electrode. The trajectory end data then are used in the automatically generated concatenating run as ion starting input without any need for the user to adjust for positions or different mesh resolutions. Here we show as an example the simulation of the well-known CHORDIS ion source, the calculated field line, the pseudo equipotential line, and the resulting simulations for the automatically generated input files for the plasma and the transport parts.

Electron beam ion source and electron beam ion trap (invited).

The electron beam ion source (EBIS) and its trap variant [electron beam ion trap (EBIT)] celebrated their 40th and 20th anniversary, respectively, at the EBIS/T Symposium 2007 in Heidelberg. These technologically challenging sources of highly charged ions have seen a broad development in many countries over the last decades. In contrast to most other ion sources the recipe of improvement was not "sorcery" but a clear understanding of the physical laws and obeying the technological constraints. This review will report important achievements of the past as well as promising developments in the future.