Generating Gas Tables in GARFIELD:

Gas files are produced to save computation time when running GARFIELD. Once a Gas file is produced for a specific Gas, Pressure, Magnetic Field, and Temperature, then it can be re-used over and over in the generation of GARFIELF Drift Time Tables.

Click  here  to see a sample input file for generating a Gas Data file.
 

Last Update: August 7, 2001 by Roy Wilds

Sample Input file for generating GAS DATA file:

***
*** Program simulates gas data for 3 E/p ranges (linear scale):
*** 0.01 - 9.99 V/cm/Torr (500 points, step 0.02 V/cm/Torr);
*** 10.0 - 19.95 V/cm/Torr (200 points, step 0.05 V/cm/Torr
*** 20.0 - 600 V/cm/Torr (291 points, step 5 V/cm/Torr)
***

*** Enter gas mixture and fraction and gas id for data set file name

Global GAS=`DME 1.0`
*Global GAS=`ARGON .25 ISO .75`
*GLOBAL GAS_ID=`Ar25_Iso`

*Global GAS=`HE .70 ISO .30`
*GLOBAL GAS_ID=`HE70_ISO`
Global GAS_ID=`DME`

*** Enter values of the magnetic field (Tesla), temperature (K),
*** pressure (Torr), ion mobility (cm**2/V*us), average number of clusters
*** per cm (mean)

GLOBAL B=0.0
GLOBAL t=299
GLOBAL p=760
GLOBAL mean=15

** Mobilities for ions:
**
**
**Average number of clusters (MEAN) for some gas mixtures:
**
**

* GLOBAL cluster=
* { 0. 78.2 7.4 2.1 1.4 0.8 0.7 0.6 0.8 1.1 1.2 0.9 0.7 0.5 0.4}
 

&magnetic
components 0. {B} 0. tesla

&gas
* magboltz HE .7 ISO .3
* write "{GAS_ID}_B{B*10}_P{p}_T{t}.DAT"
*&quit
 opt gas-pl
 pressure {p}
 temperature {t}
 Heed DME 100

 magboltz {GAS} E/P-RANGE 0.1 600. N-E/P 20
*      angle-range 0. 90. n-angles 10
      orders 1 iter-alpha noswitch
 interpolations drift-velocity newton 2 townsend newton 2
 extrapolations high-drift-velocity linear low-drift-velocity constant
 extrapolations high-long-diff constant high-ion-mobility constant
* parameters mean {mean}
* cluster
* 0. 78.2 7.4 2.1 1.4 0.8 0.7 0.6 0.8 1.1 1.2 0.9 0.7 0.5 0.4

 write "{GAS_ID}_B{B*10}_P{p}_T{t}.DAT"

&quit