[ Identification | Description | Input parameters | Links ]

The Pol_simpleBfield Component

Identification

• Site:
• Author: Erik B Knudsen, Peter Christiansen and Peter Willendrup
• Origin: RISOE
• Date: July 2011

Description

Region with a definable magnetic field.

The component is nestable. This means that it requires a

// START MAGNETIC FIELD
COMPONENT msf =
Pol_simpleBfield(xwidth=0.08, yheight=0.08, zdepth=0.2, Bx=0, By=-0.678332e-4, Bz=0)
AT (0, 0, 0) RELATIVE armMSF

// HERE CAN BE OTHER COMPONENTS INSIDE THE MAGNETIC FIELD

// STOP MAGNETIC FIELD
COMPONENT msf_stop = Pol_simpleBfield_stop(magnet_comp_stop=msf)
AT (0, 0, 0) RELATIVE armMSF

In between the two component instances the propagation routine
PROP_DT also handles spin propagation.
The current algorithm used for spin propagation is:
SimpleNumMagnetPrecession
in pol-lib.

Example: Pol_simpleBfield(xwidth=0.1, yheight=0.1, zdepth=0.2, Bx=0, By=1, Bz=0)
Pol_simpleBfield(xwidth=0.1, yheight=0.1, zdepth=0.2,
filename="bfield.dat", fieldFunction=table_magnetic_field)

The magetic field may be given as any definable c-function with a specific footprint:
int func(double x, double y, double z, double t, double *bx, double *by, double *bz, void *data)
where the magnetic field at coordinates (x,y,z, t) is returned in the variables
pointed to by bx,by, and bz. Additional parameters to be handed to the function
should be handed to the function using the pointer data.

Functions supplied by the system are:
1. const_magnetic_field: Constant field (Bx,By,Bz) within the region
2. rot_magnetic_field: Field is initially (0,By,0) but after a length of zdepth
has rotated to (By,0,0)
3. majorana_magnetic_field: Field is initially (Bx,By,0) liearly transforms to
(-Bx,By,0) after zdepth where By<

Input parameters
Parameters in boldface are required;
the others are optional.


 
Name
Unit
Description
Default


 
fieldFunction
pointer
Function describing the magnetic field.
const_magnetic_field

 
xwidth
m
Width of opening.

 
yheight
m
Height of opening.

 
zdepth
m
Length of field.

 
Bx
T
Parameter used for x composant of field.

 
By
T
Parameter used for y composant of field.

 
Bz
T
Parameter used for z composant of field.

 
filename
file where the magnetic field is tabulated.
"bfield.dat"




  

  
AT (
  
, 
  
, 
  

  
) RELATIVE
  

  

    Generate
  
  
  

  
ROTATED (
  
, 
  
, 
  

  
) RELATIVE
  



Links


  
 Source code for Pol_simpleBfield.comp.
  



 [ Identification
 | Description
 | Input parameters
 | Links ]



Generated on 2024-01-03 11:47:43