SPUD Receiver Cross Section


 Outer vaccum vessel houses
 Babushka doll of progressively
 colder layers.

 Microwaves enter through
 foam "window" and are
 focused by plastic lenses onto
 super cooled focal plane.

 Pulse tube cooler gets down
 to 4K using 10kW of electric
 power (no more liquid
 helium)

 3He fridge gets down to
 0.25K!