Just as a reference to others who might reply, here are some links to previous
posts by Goher on the same subject -
Here is a magnetron datasheet, if it is of any use to you -
Otherwise, you have probably exhausted Google searches to no avail,
so anything I (we) find you have already seen.
Maybe one last resort, if you have not already
done so, is to call Ansoft of some other EM software company and ask for suggestions.