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Item | Unit |
---|---|
Attachment coefficient | 1/cm |
Drift velocity | cm/microsec |
Ion mobility | cm2/microsec.V |
Longitudinal diffusion | cm for 1 cm of drift |
Lorentz angle | degrees |
Townsend coefficient | 1/cm |
Transverse diffusion | cm for 1 cm of drift |
quantity | scaling | enter |
---|---|---|
drift velocity | v vs E/p | v |
ion mobility | mu vs E/p | mu |
diffusion coefficients | sigma.sqrt(p) vs E/p | sigma.sqrt(p) |
Townsend coefficient | alpha/p vs E/p | alpha/p |
Attachment coefficient | beta/p vs E/p | beta/p |
Lorentz angles | - | angle |
Example: the diffusion coefficient varies approximately with pressure according to the formula:
sigma(p=p1)=sigma(p=p0)*sqrt(p0)/sqrt(p1)
hence sigma.sqrt(p) is approximately constant.
Assigning the transverse diffusion:
table e/p trans-diff long-diff 1 0.1 0.1 2 0.1 0.2 3 0.1 0.3
Not assigning the transverse diffusion:
table e/p dummy long-diff 1 0.1 0.1 2 0.1 0.2 3 0.1 0.3
Alternatively, you could have kept the original table followed by a RESET TRANS-DIFF command.
[By default: 0.1 to 100 V/cm.Torr in 20 logarithmic steps.]
[By default: 20 points covering E/p from 0.1 to 100 V/cm.Torr]
Formatted on 0099-12-08 at 15:52.