SAXS/ASAXS
Small Angle X-ray Scattering
Methods
Remote access
not possible
| Station data | |
|---|---|
| Temperature range | 50 - 1450 K |
| Pressure range | |
| Detector | Multiple scattering detectors available |
| Manipulators | See sample environments |
| Sample holder compatibility | |
| Additional equipment | |
| Source type | 7 tesla cryogenic wiggler |
| Energy range for SAXS | 3.8 keV to 27.5 keV |
| Energy resolution | ΔE / E ~ 2·10-4 |
| Scattering Detectors | 1. Multi-wire proportional counter gas detector, 20 * 20 cm2 2. Mar CCD165 |
| Sample – detector distance | 0.78 - 3.75 m (continuously variable) |
| Beam size at sample; typically | 300 x 300 μm2 |
| Flux | 3*10^12 at 300 mA, 10keV photons/s |
| q-range | 0.05 – 3.6 (at 5 keV) nm-1 0.10 – 7.2 (at 10 keV) nm-1 0.25 – 18.4 (at 25 keV) nm-1 |
| Dimensions | 1.8 - 125 (at 5 keV) nm 0.9 - 62 (at 10 keV) nm 0.4 - 25 (at 25 keV) nm |
| Sample environments | 1. Multi-sample changer under vacuum environment (main setup) 2. Multi-sample changer under air condition 3. Sample furnace on a sample changer: T= 25 °C – 700 °C; usable under vacuum or under air conditions 4. High temperature furnace: T= 300 °C – 1200 °C; usable under vacuum and some gas atmospheres 5. Cryo-furnace: T= -195 °C – 50°C; vacuum conditions 6. Sample changer for capillaries with a thermostat -20 °C to 90 °C 7. GISAXS setup under air condition 8. Free places for user-owned sample environments |
| Special environments of users | 1. Ultrasonic trap 2. Different electrochemical cells for catalysis 3. Microfluidic setup 4. GISAXS in combination with a furnace and an ellipsometer |
Small Angle X-ray Scattering
The SAXS instrument is designed for Anomalous Small Angle X-ray Scattering (ASAXS) and also for Grazing Incidence SAXS (GISAXS). A combination of both techniques is possible.
The ASAXS instrument is a moveable station at the monochromatic branch of the 7T-MPW beamline (more information about the 7T-MPW beamline can be found here).
The main features of the SAXS instrument construction (patented) are an optical bench that can be tilted and a continuously varying sample-detector distance. Both movements are independent and automated. An edge welded bellow system between the sample position and the area detector is a main construction detail. Installed references allow easy and fast positioning without losing the alignment. Available area detectors are currently a low-noise gas delay line detector and a Mar CCD 165. The entire instrument can be moved easily in and out of beam position on an own air cushion system.
Monitor counters and diodes for absorption measurements are critical components for successful ASAXS measurements. Therefore, the instrument has different windowless diodes to measure the beam intensity after the sample and an ionization chamber is used as beam monitor, thereby allowing precise transmission measurements with accuracy better than 10-4.