[thedoc (OP)]

Jonathan McClain asked the Naked Scientists:
   I have been following the news about the EMdrive and I cannot help but wonder about Dr. Harolds remark in the 2014 Nasa AMES Director Colloquium about the importance of a dielectric in the tapered section of the cavity. My question is has anyone tested any better quality dielectric within a similar cavity, and has anyone tested a more energetic EM wave or is it known that this phenomenon is only observed with microwaves?

 For example has someone used Calacium Copper Titanate has the dielectric and/or used a frequency of EM radiation outside that of microwaves like visible light and if so would could be used as the dielectric for such an experiment? Possibly a plasma isolated within an EM field with a critical frequency greater than that of say x rays, would it not state to reason that more energetic EM waves would cause a greater effect provided an adequate dielectric?
What do you think?