DFG Forschergruppe 1123

Physics of Microplasmas
Modeling and Simulation of high-frequency driven Plasmas at medium and high Pressure 

Pro­ject B1
Project leader: Dr.-Ing. Thomas Mussenbrock, Prof. Dr. Ralf Peter Brinkmann

Re­cent ex­pe­ri­men­tal stu­dies and nu­me­ri­cal si­mu­la­ti­ons of high-fre­quen­cy dri­ven plas­mas at me­di­um and high pres­su­res have re­vea­led that the spa­tio-tem­po­ral be­ha­vi­or of these de­vices can be sur­pri­sin­gly com­plex. Alt­hough some in­roads were made, a com­ple­te un­der­stan­ding of the re­gime has not yet been es­ta­blis­hed. The pro­ject aims to achie­ve in­sight into the phy­sics of high-fre­quen­cy dri­ven plas­mas at me­di­um and high pres­su­re on the basis of a sys­te­ma­tic mo­de­ling ap­proach. Using the me­thods of scale ana­ly­sis i) a con­sis­tent model of a the high-fre­quen­cy dri­ven plas­ma boundary she­ath at me­di­um and high pres­su­re and ii) a model of the di­sch­ar­ge (as a whole in­clu­ding the matching net­work) will de­ve­lo­ped. Of par­ti­cu­lar in­te­rest is the dy­na­mics of the sys­tem, i.e., the hea­ting of the di­sch­ar­ge and its re­la­ti­on to the di­sch­ar­ge sustain­ment and sta­bi­li­ty. Con­cepts of preven­ting "-tran­si­ti­on" will be wor­ked out. The mo­de­ling and si­mu­la­ti­on work will be done from the out­set in close con­nec­tion with the re­la­ted ex­pe­ri­ments in order to gain be­ne­fit from the me­thods of "mo­del-ba­sed plas­ma dia­gnostics".

Kintic modeling of microplasma discharges 
Pro­ject B2
Project leader: Dr.-Ing. Thomas Mussenbrock, Prof. Dr. Ralf Peter Brinkmann

Pro­ject B2 will in­ves­ti­ga­te the sta­tio­na­ry and dy­na­mi­cal be­ha­vi­or of micro­plas­mas with par­ti­cu­lar focus on pla­nar micro­di­sch­ar­ges and micro hol­low-ca­tho­de di­sch­ar­ges (µHCs). The pro­ject con­sists of three parts: First, a con­sis­tent ki­ne­tic de­scrip­ti­on will be es­ta­blis­hed which takes into ac­count all re­le­vant spe­cies in the plas­ma (elec­trons, ions, ex­ci­ted and non-ex­ci­ted neu­trals) and their mu­tu­al in­ter­ac­tion (elas­tic and in­elas­tic col­li­si­ons, Cou­lomb in­ter­ac­tion, emis­si­on and ab­sorp­ti­on of ra­dia­ti­on, in­ter­ac­tions with the walls). In the se­cond part, mathe­ma­ti­cal tools will be de­ve­lo­ped which allow to eva­lua­te the de­scrip­ti­on and to ob­tain phy­si­cal in­sight. It is pl­an­ned to es­ta­blish both a spa­ti­al­ly aver­a­ged glo­bal model and a spa­ti­al­ly re­sol­ved Par­ti­cle-In-Cell/Monte Carlo si­mu­la­ti­on. Fi­nal­ly, ex­ten­si­ve stu­dies of dif­fe­rent pa­ra­me­ter re­gimes will be con­duc­ted, with the goal to un­co­ver the exact ope­ra­ti­on me­cha­nism of the di­sch­ar­ges – of par­ti­cu­lar in­te­rest will be the elec­tron ki­ne­tics. Also sca­ling rules will be es­ta­blis­hed.

Projektpartner: Fa­kul­tät für Phy­sik