Patent ID: 8344237

Claim:
A power system comprising: a primary optical element that defines a first opening therein; a secondary optical element positioned relative to said primary optical element to direct energy from said primary optical element to said first opening; and a thermal absorber comprising: a housing that defines an internal volume and a second opening into said internal volume, wherein said second opening is connected to said first opening; a window sealingly connected to said second opening to enclose said internal volume; a barrier wall that divides said internal volume into at least a hot chamber and a cold chamber; and at least one alkali metal thermal-to-electric converter (“AMTEC”) cell, said AMTEC cell having a first portion received in said cold chamber and a second portion received in said hot chamber; said window positioned to directly transmit said energy into said hot chamber and direct said energy from said secondary optical element into said hot chamber to heat said hot chamber sufficiently to vaporize alkali metal in said hot chamber to interact with said AMTEC cell.