Dipole Field Example


Upcoming in the next release.

This field example displays an ideal transverse dipole field from gmultipoles. It is useful for checking the field association on a single volume and the visual field-line startup options.


Quickstart

Copy the example to your current directory, build the geometry database, and open the field display:

cp -r $GEMC_HOME/examples/fields/dipole .
cd dipole
./dipole.py
gemc dipole.yaml -gui


Geometry

The geometry is defined in dipole.py. The world volume root contains one transparent box, dipole_field_box, with its mfield property set to dipole.


Field Definition

The YAML file defines a 2 T dipole rolled by 30 degrees about the z axis:

gmultipoles:
  - name: dipole
    pole_number: 2
    strength: 2
    rotaxis: z
    rotation_angle: "30*deg"

The display options request 80 field lines and auxiliary geometry edges:

show_field_lines: 80
show_auxiliary_edges: true


Field Display

Dipole field display: a transparent field box with ideal transverse field lines.


Usage

The file dipole.yaml sets n: 0, so no /run/beamOn is needed for this display scene. Add -fieldAt to inspect the configured field at a point:

gemc dipole.yaml -fieldAt="0*cm 0*cm 0*cm"