The target's temperature directly affects the efficiency of polarization. The temperature's effects are easily seen in a graph of polarization over time. As inevitable beam trips occur, the polarization rises as the heat load of the beam is removed. When the beam comes back, the polarization drops a few percent simply due to the heat load. An example diagram of the pumps and fridge which create and maintain the low temperature is shown to the right, although the precise pumps used in the hall are slightly different.
The fridge, magnet, and liquid nitrogen shield are hung in the "target can" which is held at vacuum by a di pump. The liquid nitrogen shield, seen in the diagram in green, protects the liquid helium components from heat radiation from the room temperature can.
The cryogenic Evaporation Fridge is designed to provide high cooling
power (1 W) at 1 K.