Message by **Hodong Lee**:

In addition to the previous question of CEX,

I also have a problem with too slow simulation speed.

I am running SPIS 6.0.0 with 24 GB RAM, but what bothers me is too small simulation dt while running the simulation.

The number of tetrahedrons in the mesh I made is about 65,000, with a not bad mesh quality.

I want to simulate a relatively short duration of 1 ms for a hall thruster, but simulation dt is in the range of 10^(-10) ~ 10^(-9).

I tried to decrease the number of avPartNbPerCell to 2.0, and change electronDistrib and ionDistrib as UnlimitedGlobalMaxwellBoltzmannVolDistrib, with other particles related to thruster (Xe+, CEX Xe+, etc) as PIC.

Are there other parameters I should change in order to get a reasonable simulation speed?

Or, is it originally (inevitably) so slow?

I am desperately waiting for a reply.

The following information is the parameters I used in my simulation:

About maximum intergration time step

electron dt: 1.0E-7

electron duration: 2.5E-7

ion dt : 1.0E-6

ion duration : 5.0E-6

plasma dt: 5.0E-7

plasma duration: 1.0E-6

simulation dt: 1.0E-5

simulation dt init: 1.0E-6

duration: 1.0E-3

VolInteract Parameters

parameter1VolInteract#:0.05

parameter2VolInteract#:0.2

parameter3VolInteract#:1.0

parameter4VolInteract#:2.9E-4

volInteract#: 0.5

crossSectionVolInteract1 (for Xe+): 8.0E-19

crossSectionVolInteract2 (for Xe++): 2.0E-19

About Poisson Equation:

iterGradient: 1500

iterGradientNI: 2000

iterLinearSys: 10000

iterNewton: 200

regular Poisson computation

tolGradient:1.0E-5

tolGradientNI: 1.0E-5

TolLinearSys: 1.0E-12

tolNewton: 0.005

variableTe:1

variableTeConstant: 6.07E-4

variableTegamma:1.23

Thank you.

Hodong Lee.