RF Pillbox cavity seems to be misconstructed

[Jochem Snuverink]

I could be wrong, but I can't find good parameters for the pillbox cavity. I have added the following to examples/features/components/rf.gmad:

rf3: rfcavity, material="copper", cavityModel = "pillbox", gradient=100.0, l=0.1*m;

pillbox: cavitymodel,
     type = "rectangular",
     equatorRadius = 10*cm,
     irisRadius = 8*cm,
     thickness = 3*cm;

Seems This results in a pillbox that can't be 'looked through', possibly there is a thin disk of material at the end.

[Laurie Nevay]

There were several reasons for this. The pale white bit is actually the vacuum volume which wasn't made invisible and the default is that pale white. The thickness of the cavity in the example was wrong led to an unphysical combination and also wasn't implemented properly in code. The defaults for the component examples were ridiculous.

All fixed now.