Tutorial: BOOTSJ Calculation

This tutorial will walk the user through running the BOOTSJ code. For this example the National Compact Stellarator Experiment (NCSX) configuration will be used. This machine is stellarator symmetric with a periodicity of three. To generate the necessary files see the tutorials VMEC Fixed Boundary Tutorial and Boozer Transform Tutorial. You will need a 'boozmn' file to run this simulation and the VMEC 'input' file.

__Edit the input namelist text file.__ > The BOOTSJ code will look in the input file for the BOOTIN namelist. We will make use of the TEMPRES variable to choose the temperatures to be consistent with the VMEC pressure profile. Thus the density will be constant.

#!fortran
&INDATA
  MGRID_FILE = 'none'
  LFREEB = F
  DELT =   9.00E-01
  TCON0 =   2.00E+00
  .
  .
  .
  RBC(1,10) = -1.08453911913102E-06     ZBS(1,10) =  8.60890353665843E-05
  RBC(2,10) =  1.04051545504927E-04     ZBS(2,10) = -2.17661420286656E-04
  RBC(3,10) = -5.21965328013036E-04     ZBS(3,10) = -2.67111216700977E-04
  RBC(4,10) = -4.95991087393098E-04     ZBS(4,10) =  2.43875640076056E-05
  RBC(5,10) = -1.94520415280627E-04     ZBS(5,10) =  1.55759001593971E-04
  RBC(6,10) = -6.94143617569942E-05     ZBS(6,10) =  4.40565098025554E-05
/
&BOOTIN
  MBUSE = 72  ! From Boozer Transformation
  NBUSE = 24  ! From Boozer Transformation
  ZEFF1 = 1.0
  DAMP_BS = 0.001 
  TEMPRES = 1.0 ! Coefficient Te=P^TEMPRES
  TETI    = 1.0 ! Te/Ti
  DENS0   = 1.0 ! 10^20 [m^-3]
/

__Edit the input text file__ You will also need to create a test file with the extension of the Boozer transformation run and the surfaces on which you wish to compute the bootstrap current.

ncsx_c09r00_fixed
2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 
32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 
60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 
88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99

__Execute the code.__ You simply need to pass input text filename on the command line to BOOTSJ. You will need to make sure you have the 'boozmn' file in the directory as well.

~/bin/xbootsj bootsj_in.ncsx_c09r00_fixed
 Start BOOTSJ: Version 7.01 
 mbuse =           72 nbuse =           24 nthetah =          192  nzetah =           96
 Total bootstrap current =   0.0162554 MA
 Finished BOOTSJ, time =   119.740  sec

__Examine the output.__ This simulation outputs three files: answers.<ext>, answers_plot.<ext> and jBbs.<ext>. These files contain various tables in text form relating to the bootstrap current and run parameters.