A transient electromagnetic signal is recorded in an earth formation in the presence of a pipe having a finite conductivity. The invention includes a pump adapted to couple to a processing chamber and adapted to draw effluent from the processing chamber; a reaction chamber coupled to the pump and adapted to receive the effluent from the pump; and a turbine coupled to the reaction chamber and adapted to be driven by combustion gases from the reaction chamber. A first plurality of ribs is formed on an inside surface of the cassette pod body, each having a predetermined depth sufficient to support an edge portion of a wafer.