Instrument

From MantidProject

What are they?

The Instrument is a geometrical description of the components that make up the beam line. The components described will generally include:

• The source
• The sample position
• Each detector 'pixel'
• Each monitor

Other components may also be included such as

• Slits
• Mirrows
• Guides
• Choppers
• Engineering obstacles in the beam path
• Link between log-files and variable parameters of the instrument (such as the height of a detector table)

An instrument is described using an instrument definition file.

The Mantid geometry is further explained here.

Why do we have a full instrument description, and not just a list of L2 and 2Theta values?

A list of L2 and 2Theta values will provide information to perform unit conversions and several other algorithms, however a full geometric instrument description allows much more.

• Visualization of the instrument internals with data overlays
• Complex absorption corrections
• Montecarlo simulations of experiments
• Updating the instrument geometry according to values stored in ISIS log-files