Production and characterization of intercalated graphite crystals for cold neutron monochromators

The preparation of intercalated graphite compounds is now well established at the Institut Laue Langevin (ILL). We are able to manufacture several types of intercalated crystals, such as KC8, RbC8, KC24 and RbC24 compounds, in large quantities and in a reproducible manner. Even though the mosaic distribution is large, these compounds exhibit a high neutron peak reflectivity of about 70% at a neutron wavelength of 9.8 Å. The production of such intercalated graphite crystals allows us to build efficient neutron monochromators for wavelengths in the range 6-15 Å.