Starting a space-charge calculation.
There are two methods of assigning the space-charges of the rays) -the 'tube' method (the usually preferred method) and the 'cell' method- and so the user has to choose one of these.
One error that occurs rarely in space-charge simulations concerns running a simulation initially without space-charge and then running it afterwards with space-charge but without first deleting the processed data file that was created during the earlier run. The program looks for some relevant data in the processed data file, but does not find it. The program therefore deletes the processed data file and asks the user to start again.
Deleting the processed data file is also a solution for other very rare crashes in space charge simulations.
See also the note on details of space-charge calculations.
For users who are editing or constructing an 'input data file' without the use of the data-builder -that is, pre-processor:
But Manual editing is certainly not recommended -it is a relic from the time when the databuilder was not available All users are strongly encouraged to use the databuilder, which always gives the correct formats and which has many options for which the formats are not described or easily deduced.
Enter either 'y' for the cell method or 'Y' for the tube method, and then follow with the line specified in the notes on the cell method or the tube method,
or enter anything else for a non-space-charge calculation, and then follow with the line specified in the note on ray reflections.