Beam Position Monitors

A beam monitor acts on the beam like a drift space. In addition it serve records the beam position for closed orbit corrections. Four different types of beam position monitors are recognised:

HMONITOR

Monitor for the horizontal beam position,

VMONITOR

Monitor for the vertical beam position,

MONITOR

Monitor for both horizontal and vertical beam position.

INSTRUMENT

A place holder for any other type of beam instrumentation. Optically it behaves like a drift space; it returns no beam observation. It represents a class of elements which is completely independent from drifts and monitors.

label:HMONITOR,  TYPE=string,APERTURE=real-vecto,L=real;
label:VMONITOR,  TYPE=string,APERTURE=real-vecto,L=real;
label:MONITOR,   TYPE=string,APERTURE=real-vecto,L=real;
label:INSTRUMENT,TYPE=string,APERTURE=real-vector,L=real;

A beam position monitor has one real attribute:

L

The length of the monitor (default: 0 m). If the length is different from zero, the beam position is recorded in the centre of the monitor (except for the INSTRUMENT element).

Examples:

MH:HMONITOR,L=1;
MV:VMONITOR;

The reference system for a monitor is a Cartesian coordinate system.