Upgrade of the time-of-flight reflectometer at LLB

Abstract

The multi-purpose time-of-flight reflectometer Eros of LLB, built in 1991, will be upgraded soon. The original design of this spectrometer was optimised to study layers of thickness ranging from 20 to 300 nm. Recent physics and chemistry research requires the study of layers as thin as 1 nm which corresponds to the measurements of reflectivity as low as 10 −8. In order to achieve this challenge, a three stages upgrade will be done on the reflectometer. A first step already realised consist in the replacement of the single disk chopper by a multidisc one. A second step, planned beginning 2004, will correspond to a shortened of the instrument, and finally, the third step will be the transfer of the reflectometer on a main guide of the Orphee reactor. A total gain reaching nearly 100 will be achieved.