&CELL: PLANE

direction

Specifies which coordinate is constant along the plane. Can have one of the following 4 values:

Direction	Meaning	Coordinate system
`X`	Plane parallel with the y-axis	Cartesian
`Y`	Plane parallel with the x-axis	Cartesian
`R`	Circular plane	Polar
`PHI`	Plane through the origin	Polar

coordinate

The coordinate at which the plane is located, in cm for X, Y and R and in degrees for PHI.

The r coordinate must be strictly positive (non-zero).

[No default, the coordinate is mandatory.]

potential

Optional indication of the potential, in Volt, of the plane.

[Default: an earthed plane, at 0\ V.]

label

A label by which the plane can be referenced in SELECT statements, for instance when computing signals induced in the plane by moving charges.

The label is a single alphabetic upper case character. You may type a longer string, but only the first character will be stored.

A label is not mandatory, but signals induced in a plane are only computed if the plane can be selected, and this can only be done if the plane has a label.

[By default, no label is assigned to a plane.]

STRIP

Anticipates read-out of a part of the plane.

Signals in strips are computed with weighting fields that are exclusively valid for parallel plate chambers without wires. This can perhaps most easily be seen in an MWPC where the weighting field (orange in the figure) of the strip (in red, covering -0.1\ <\ x\ <\ 0.1\ cm) is not influenced by the wires (purple) - while in reality, the influence of the wires is of course highly significant.

The reason for this limitation is that no exact weighting fields for strips are known for general wire-plane layouts. Should expressions be known for the particular case that interests you, then these can of course be added on demand.

See the weighting_field example for the FIELD-MAP command of the optimisation section for a method to address this using the finite element technique.

Subdivisions are permitted as follows:

Subdivision	Permitted with	Unit
`R-STRIP`	PLANE PHI=...	cm
`PHI-STRIP`	PLANE R=...	degrees
`X-STRIP`	PLANE Y=...	cm
`Y-STRIP`	PLANE X=...	cm
`Z-STRIP`	all planes	cm

strip_min

Indicates the starting point of the strip.

The location should be given in degrees for \φ-sectors, in cm for all other strips.

[Mandatory parameter, no default provided.]

strip_max

Indicates the end point of the strip.

The location should be given in degrees for \φ-sectors, in cm for all other strips.

[Mandatory parameter, no default provided.]

strip_label

A label by which the strip can be referenced in SELECT statements, when computing signals induced in the strip by moving charges.

The label is a single alphabetic upper case character. You may type a longer string, but only the first character will be stored.

A label is not mandatory, but signals induced in a strip are only computed if the strip can be selected, and this can only be done if the strip has a label.

[By default, no label is assigned to a strip.]

gap

Indicates the gap width to be used when computing the weighting field for the strip.

The gap is specified in cm for strips in x-, r- and y-planes, and in degrees for strips in \φ-planes.

[By default, this is taken to be the distance to the parallel plane, if there is one, otherwise the distance from the plane to which the strip belongs to the nearest electrode.]

representations

The planes will be displayed using the PLANES representation.

Strips, if any, are shown with the STRIPS representation.

Go to the top level, to &CELL, to PLANE, to the topic index, to the table of contents, or to the full text.

Formatted on 21/01/18 at 16:55.