Abstract
Reflectivity in Saclay is a long story starting in 1984 with the first measurements [1] performed by B. Farnoux on a small angle scattering spectrometer. A few years later, a dedicated time offlight spectrometer called DESIR gave new results [2]. At that early time, focus was already made on liquid interfaces. In 1992, EROS, a similar multipurpose reflectometer, started operation [3]. In order to study magnetic layers, another polarized spectrometer using a constant wavelength was used. Called PRISM, it has been upgraded recently and presented in this magazine [4]. The DESIR prototype of the early days is now decommissioned and all the experiments on liquid interfaces are performed on the EROS instrument.