VITESS Tool Direct View

With this tool, it is possible to determine, whether the curvature of a bender
or guide is sufficient to prevent direct view.

Three different situations are treated:
1. The beamline starts with a curved guide and has a straight section behind it
2. The beamline starts with a straight guide, then a curved section follows;
   and it ends with another straight part.
3. The last set-up consists of three straight parts (of different lengths)
   with an angle alpha between first and the second as well as between the second
   and the third.

After starting the tool you have to choose one of these 3 cases and give
information about the sizes and the curvature of the guide. Then you are
given the mimimal length of the last (straight) part that is necessary to
avoid direct view. If the curvature is so small that particles are able to
fly parallel to the guide in the straight section (after passing the curved
section), the minimal length is unlimited. In this case, the message of the
program will be "curvature too small".

All guides and benders are thought to be circle segments.