Defining Material properties

gd1 does find an error in our inputfile. It complains:

 eigenvalues>     solutions= 15
 eigenvalues>     estimation= 2e9   # the estimated highest frequency
 eigenvalues>     doit
 *** material 10 is used in item 4, but is undefined..
 *** material 10 is used in item 6, but is undefined..
 *** errors in settings
 *** Since this not seems to be an interactive session,
 *** I decide to treat this as a fatal error.
 *** Fix the input.
 stop

gd1 complains that we used a material index of '10' to model our plungers. The properties of this material '10' have not yet been defined. We doit by editing our inputfile, such that before the eigenvalue computation starts, we have:

 -material           # enter the section "-material"
     material= 10    # the properties of material "10" shall be changed.
     type= electric  # shall be treated as perfect electric conducting
                     # for the field computation

We did use the materials '0' and '1' as well. We did not define the properties of them, but the default values of these materials are what we want (material '0' is vacuum, material '1' is copper, and material '2' is perfect magnetic conducting).