Maybe a bug in garfield++

when i used garfield++ to calculate gas properties like ElectronVelocity, ElectronDiffusionL, ElectronDiffusionT, ElectronTownsend, ElectronAttachment. while the electricfield is set as from 50V/cm to 1000V/cm,as calculating the 700.0000 VOLTS/CM points, the errors occured:

“WARNING ENERGY OUT OF RANGE,INCREASE ELECTRON ENERGY INTEGRATION RANGE”

but when the electricfield is set as from 650V/cm to 850V/cm, everything works ok.

What is the gas mixture you are using and for what pressure are you running the calculation?

The gas is CH4 + Ar, the ratio of CH4 is from 0 to 50%,the pressure is 760 mm Hg

Thanks. At what fraction of CH4 specifically do you get this error message?

CH4 is 0%, Ar is 100%

Hi,
running Magboltz for pure Argon at atmospheric pressure and 700 V/cm, I can’t reproduce the problem. Is one of the parameters different in your program?

          PROGRAM MAGBOLTZ 2 VERSION 11.13

          MONTE CARLO SOLUTION FOR MIXTURE OF  1 GASES.
     ------------------------------------------------------

       GASES  USED                 PERCENTAGE USED 

      ARGON ANISOTROPIC    2014      100.0000


  GAS TEMPERATURE =  20.0 DEGREES CENTIGRADE.
  GAS PRESSURE =   760.0 TORR.
  INTEGRATION FROM 0.0 TO    11.31 EV.  IN 4000 STEPS. 

 PENNING EFFECTS NOT INCLUDED

 ANISOTROPIC SCATTERING TYPE 2 (OKHRIMOVSKYY) USED IF AVAILABLE

 LONG DECORRELATION LENGTH =2000000 COLLISIONS.


 THERMAL MOTION OF GAS NOT INCLUDED

  ELECTRIC FIELD =    700.0000 VOLTS/CM.
  MAGNETIC FIELD =     0.0000 KILOGAUSS.
  ANGLE BETWEEN ELECTRIC AND MAGNETIC FIELD =    90.000 DEGREES.
  CYCLOTRON FREQ. =   0.000D+00 RADIANS/PICOSECOND

  INITIAL ELECTRON ENERGY =   0.226 EV.

  TOTAL NUMBER OF REAL COLLISIONS =  400000000

I will reply you later.

GASES USED PERCENTAGE USED

  ARGON ANISOTROPIC    2014      100.0000

GAS TEMPERATURE = 20.0 DEGREES CENTIGRADE.
GAS PRESSURE = 760.0 TORR.

INTEGRATION FROM 0.0 TO 11.31 EV. IN 4000 STEPS.

PENNING EFFECTS NOT INCLUDED

ANISOTROPIC SCATTERING TYPE 2 (OKHRIMOVSKYY) USED IF AVAILABLE

LONG DECORRELATION LENGTH =2000000 COLLISIONS.

THERMAL MOTION OF GAS NOT INCLUDED

ELECTRIC FIELD = 700.0000 VOLTS/CM.
MAGNETIC FIELD = 0.0000 KILOGAUSS.
ANGLE BETWEEN ELECTRIC AND MAGNETIC FIELD = 90.000 DEGREES.
CYCLOTRON FREQ. = 0.000D+00 RADIANS/PICOSECOND

INITIAL ELECTRON ENERGY = 0.226 EV.

TOTAL NUMBER OF REAL COLLISIONS = 400000000

NULL COLLISION FREQUENCY AT 8 EQUALLY SPACED ENERGY INTERVALS (*10**12/SEC)
0.111D+02 0.111D+02 0.111D+02 0.111D+02
0.111D+02 0.111D+02 0.111D+02 0.111D+02

REAL COLLISION FREQUENCY AT 8 EQUALLY SPACED ENERGY INTERVALS (*10**12/SEC)
0.958D-01 0.741D+00 0.171D+01 0.291D+01
0.447D+01 0.632D+01 0.834D+01 0.103D+02

VEL      POS        TIME      ENERGY   COUNT   DIFXX     DIFYY     DIFZZ

 3.84  0.690D-01  0.180D+08   3.8728    20     4042.5    4778.6       0.0

WARNING ENERGY OUT OF RANGE,INCREASE ELECTRON ENERGY INTEGRATION RANGE
(base) root@llh-virtual-machine:/home/llh/Garfield/Patent/build#

And, just to be sure, you are also using the HEAD version of Garfield++, i. e. the first line of the Magboltz output is this one?

sorry, the first line of my Magboltz output is this one:
PROGRAM MAGBOLTZ 2 VERSION 11.11

Can you update your installation of Garfield++ to the latest version from the repository, re-build the project and try again?

yes, i will update my program

sorry, the same problem occurs:
PROGRAM MAGBOLTZ 2 VERSION 11.13

      MONTE CARLO SOLUTION FOR MIXTURE OF  1 GASES.
 ------------------------------------------------------

   GASES  USED                 PERCENTAGE USED 

  ARGON ANISOTROPIC    2014      100.0000

GAS TEMPERATURE = 20.0 DEGREES CENTIGRADE.
GAS PRESSURE = 760.0 TORR.

INTEGRATION FROM 0.0 TO 11.31 EV. IN 4000 STEPS.

PENNING EFFECTS NOT INCLUDED

ANISOTROPIC SCATTERING TYPE 2 (OKHRIMOVSKYY) USED IF AVAILABLE

LONG DECORRELATION LENGTH =2000000 COLLISIONS.

THERMAL MOTION OF GAS NOT INCLUDED

ELECTRIC FIELD = 700.0000 VOLTS/CM.
MAGNETIC FIELD = 0.0000 KILOGAUSS.
ANGLE BETWEEN ELECTRIC AND MAGNETIC FIELD = 90.000 DEGREES.
CYCLOTRON FREQ. = 0.000D+00 RADIANS/PICOSECOND

INITIAL ELECTRON ENERGY = 0.226 EV.

TOTAL NUMBER OF REAL COLLISIONS = 400000000

NULL COLLISION FREQUENCY AT 8 EQUALLY SPACED ENERGY INTERVALS (*10**12/SEC)
0.111D+02 0.111D+02 0.111D+02 0.111D+02
0.111D+02 0.111D+02 0.111D+02 0.111D+02

REAL COLLISION FREQUENCY AT 8 EQUALLY SPACED ENERGY INTERVALS (*10**12/SEC)
0.958D-01 0.741D+00 0.171D+01 0.291D+01
0.447D+01 0.632D+01 0.834D+01 0.103D+02

VEL      POS        TIME      ENERGY   COUNT   DIFXX     DIFYY     DIFZZ

 3.84  0.690D-01  0.180D+08   3.8728    20     4042.5    4778.6       0.0

WARNING ENERGY OUT OF RANGE,INCREASE ELECTRON ENERGY INTEGRATION RANGE
root@llh-virtual-machine:/home/llh/Garfield/Patent/build#

i meant:

while the electricfield is set as from 50V/cm to 1000V/cm,the error is produced.

but:
while the electricfield is set as from 650V/cm to 850V/cm, everythings work well.

the increments are all 50V/cm.

Sorry for my late reply. That’s strange, the calculation of the energy range for a given electric field should normally be independent of the previously set electric field. Will try if I can reproduce this.

As a pragmatic short-term solution, you could generate separate gas files: one covering the range of electric fields from 50 V/cm to 600 V/cm and one covering the range 650 - 1000 V/cm. And then merge the two gas files (see the section “Merging gas files” on this page).