We consider a conducting and a permeable plate immersed in the vacuum of a scalar field. We calculate the photon production rate when two plates at a distance $H$ oscillate with a frequency ${\omega }_p$. For $H{\omega }_p∕\left(\pi c\right)<2$, the angular spectrum and photon production rates are significantly different from those of a conventional cavity with two conducting or two permeable plates.

• Received 4 March 2007

DOI:https://doi.org/10.1103/PhysRevA.75.055802