Hot Source
The hot neutron source uses a graphite block of 14 kg weight as moderator. This is well insulated and heats up to about 2300 K (2000 °C) due to the gamma radiation arising in the fuel element from the uranium fission. The hot source also heats the thermal neutrons to speeds up to several thousand kilometres per second. These hot neutrons are passed through beam pipe 9 for both the Single Crystal Diffractometers HEiDi and POLI.