科研之友
微信
新浪微博
Facebook
分享链接
摘要
We present the characteristics and performances of the time-of-flight EROS reflectometer, located at Laboratoire Leon Brillouin (Saclay, France), which operates on the high-flux Orphee reactor. It is a versatile spectrometer with a horizontal geometry enabling air/liquid, air/solid and solid/liquid measurements. It is mostly dedicated to soft matter projects but welcomes also studies on thin solid films. It is equipped with a multi-disc chopper providing a tunable delta lambda/lambda resolution, a collimation system with two deviating supermirrors and slits with flexible apertures allowing any given delta theta/theta higher than 0.007, a large sample area, and a detector (either single tube or positioning sensitive detector). The accessible Q(min) is 0.0026 angstrom(-1) and the accessible Q(max) is 0.36 angstrom(-1) in air/solid or solid/liquid geometries and 0.21 angstrom(-1) in air/liquid geometry. The spectrometer has been upgraded during the last decade in order to reach a gain in flux of similar to 50 from its original version. In air/solid geometry, we reach R(min) - 2 x 10(-5) in 1 hour, R(min) = 8 x 10(-7) in 4 hours and R(min) = 4 x 10(-7) in 12 hours on a sample of similar to 20 cm(2) with EROS II, while it was difficult to go below 10(-5) with the initial version dating from 1992. In air/liquid or solid/liquid geometries, we show that the main limitation to reach very low reflectivities is the incoherent scattering of the liquid solvent (D(2)O). For such geometries, we obtain R(min) of 5 x 10(-6) in 4 hours after incoherent background subtraction. The rejuvenated EROS allows thus measurements of 15-20 samples of a few tens cm(2) in a span of 4 days, which corresponds to the minimum time allocated to external users for a given experiment.
- 出版日期2011-11
- 单位中国地震局
