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Notes:
In case Maxwell Field Simulator has been used to generate the maps, identifying the mesh directory is recommended. The contents is optional for all other types of data written by Maxwell programs.
A warning is issued if the file contains other data than the declared contents.
Currently, the following contents types are recognised:
Name | Used to compute |
---|---|
B-FIELD (=MAGNETIC-FIELD) | Drift lines |
ELECTRIC-FIELD | Drift lines, various other plots |
D-FIELD | Epsilon by comparing E and D |
MATERIAL (=D-FIELD) | Drift line termination |
MESH | Always needed with Maxwell Field Simulator |
POTENTIAL (=VOLTAGE) | Contour maps |
WEIGHTING-FIELD | Induced signals |
The label is a single character.
No label should be assigned to other fields than the weighting fields.
[By default, the label "S" is assigned to weighting field maps, which makes these maps are part of the initial, default, selection.]
With the exception of Tosca, all formats are automatically recognised, and a format doesn't have to be specified therefore.
Recipes for creating field maps with these programs are given in the sub-topics.
Additional information on:
There are 3 ways to select the drift medium:
Beware: DRIFT-MEDIUM 3 is not the same as DRIFT-MEDIUM 3.0 ! In the first case, the medium with the 3rd dielectric constant or the 3rd conductivity will be selected. In the second case, the medium with the dielectric constant or the conductivity closest to 3 will be taken.
When using the DC conduction mode, it may be more natural to use the keywords SMALLEST-SIGMA, SECOND-SMALLEST-SIGMA, SECOND-LARGEST-SIGMA and LARGEST-SIGMA which are treated as synonyms of the keywords listed in the command description.
[By default, the medium with the lowest dielectric constant or the lowest conductivity is assumed to be the drift medium.]
[This is the default.]
The length of one period is taken to be the maximum extent in x of the field map.
A cell can not be both X-PERIODIC and X-MIRROR-PERIODIC, but can be X-AXIALLY-PERIODIC in addition to being translation periodic in the x-direction.
[By default, a field map is not assumed to be periodic.]
A cell can not be both X-PERIODIC and X-MIRROR-PERIODIC, but can be X-AXIALLY-PERIODIC in addition to being translation periodic in the x-direction.
[By default, a field map is not assumed to be periodic.]
The length of one period is deduced from the field map, and is therefore not specified on the FIELD-MAP statement.
The symmetry axis must pass through y=z=0.
A cell can not be both X-PERIODIC and X-MIRROR-PERIODIC, but can be X-AXIALLY-PERIODIC in addition to being translation periodic in the x-direction.
[By default, a field map is not assumed to be periodic.]
[This is the default.]
The length of one period is taken to be the maximum extent in y of the field map.
A cell can not be both Y-PERIODIC and Y-MIRROR-PERIODIC, but can be Y-AXIALLY-PERIODIC in addition to being translation periodic in the y-direction.
[By default, a field map is not assumed to be periodic.]
A cell can not be both Y-PERIODIC and Y-MIRROR-PERIODIC, but can be Y-AXIALLY-PERIODIC in addition to being translation periodic in the y-direction.
[By default, a field map is not assumed to be periodic.]
The length of one period is deduced from the field map, and is therefore not specified on the FIELD-MAP statement.
The symmetry axis must pass through x=z=0.
A cell can not be both Y-PERIODIC and Y-MIRROR-PERIODIC, but can be Y-AXIALLY-PERIODIC in addition to being translation periodic in the y-direction.
[By default, a field map is not assumed to be periodic.]
[This is the default.]
The length of one period is taken to be the maximum extent in z of the field map.
A cell can not be both Z-PERIODIC and Z-MIRROR-PERIODIC, but can be Z-AXIALLY-PERIODIC in addition to being translation periodic in the z-direction.
[By default, a field map is not assumed to be periodic.]
A cell can not be both Z-PERIODIC and Z-MIRROR-PERIODIC, but can be Z-AXIALLY-PERIODIC in addition to being translation periodic in the z-direction.
[By default, a field map is not assumed to be periodic.]
The length of one period is deduced from the field map, and is therefore not specified on the FIELD-MAP statement.
The symmetry axis must pass through x=y=0.
A cell can not be both Z-PERIODIC and Z-MIRROR-PERIODIC, but can be Z-AXIALLY-PERIODIC in addition to being translation periodic in the z-direction.
[By default, a field map is not assumed to be periodic.]
This method can be applied to all field maps.
[By default, the highest order method permitted by the field map will be used.]
This method can only be applied to field maps with additional nodes halfway the vertices. This information is present in for instance all Maxwell field maps.
[By default, the highest order method permitted by the field map will be used.]
This method can only be applied to field maps with additional nodes at 1 third and at 2 thirds between the vertices. There are currently no field map formats with which this interpolation order can be used.
[By default, the highest order method permitted by the field map will be used.]
Removes the excluded parts of the background from the field map.
[This option is on by default.]
A triangle or a tetrahedron is eliminated whenever one of its vertices is located outside the window.
This argument is ignored if the field map is 3-dimensional.
[By default, the cell is assumed to go from -50 cm to +50 cm in the z-direction.]
The option has effect only if material properties have been entered, either as a map of dielectric constants or as maps of both D and E.
The materials are distinguished by their dielectric constant, which must therefore have been entered with the FIELD-MAP command. This can be done with an explicit map of dielectric constants, but also by a comparison of maps of E and D.
The material with the smallest dielectric constant is shown with representation MATERIAL-1. The medium with the next highest dielectric constant with MATERIAL-2 etc. The drift medium is never shown.
Elements of a 2D field map are only shown in X-Y views and in CUT views at a constant z. The cross sections of the viewing plane with the elements of a 3D field map are shown in X-Y, X-Z, Y-Z and CUT views, but not in 3D views.
Field maps do not usually cover areas filled with conducting material since there is no field inside these. To visualise these, one has to enter them manually with the SOLIDS command. SOLIDS doesn't interfere with PLOT-MAP.
This option can also be switched on and off with the PLOT-MAP option of the AREA command.
[By default, the map is shown.]
Tetrahedrons and triangles with large aspect ratios can be a sign that the mesh is of poor quality. When using Maxwell, one should consider adding dummy volumes which constrain the mesh elements (contact CERN Maxwell support or Ansoft for further information).
Tetrahedrons with a very large volume and triangles with a very large surface are likely to cause problems while drifting particles since the E field inside is linear, without guaranteed match with neighbouring elements.
[These histograms are not made by default.]
Formatted on 0099-12-08 at 15:52.