Pressure loss in a PX-3A alkali metal thermo-electric converter (AMTEC) cell was investigated by varying the heat radiation between the beta alumina solid electrolyte (BASE) and the condenser. Chevron radiation shields were used to change the heat radiation between the BASE and the condenser in different numbers and at different angles. Results show that the pressure losses and also the pressure on the cathode side increase using chevron shields. The cell electrical power output and the cell efficiency decrease as the pressure on the cathode side increases when chevron shields are placed. The power output and efficiency increase as the chevron angle increases up to a certain limit. (C) 2001 Elsevier Science B.V. All rights reserved.