Heart of SuperSUN: superfluid injector and UCN extraction unit

a:  the 100-L liquid helium bath
b: the needle valve
c: the 1-K pot<
d: the 4He superleak
e: the 3He pumping column
f: the 3He impedance
g: the 3He/4He heat exchanger
i: the conversion volume at 0.6 K
k: the UCN extraction system