In order to be able to feed a wide range of scientific instruments, the energetic specter of generated neutrons needs to be enlarged. This is the function of secondary moderators like the Hot neutron Source (HS) that modify the local distribution of neutron speeds.

The Hot neutron Source

The Hot neutron Source (HS) of the ILL reactor is a graphite cylinder, 20 cm in diameter and 30 cm in height, heated to more than 2000 K (about 1700°C) by nuclear agitation.
This secondary moderator has the role of locally reinforcing the neutron flux by supplying extra hot neutrons.