ID2 Detectors

1. FReLoN Kodak CCD: This is the principal SAXS detector which is a fiber optically coupled FReLoN (Fast-Readout, Low-Noise) CCD based on Kodak KAF-4320 image sensor. The detector has an input field of 100mm x 100mm, nominal dynamic range of 16bit (15 bit above the noise floor) and full frame rate of 3 frames/sec (2048 x 2048). With 2x2 binning, the readout rate is about 5 frames/sec, and at still higher binning (8x8) (and high speed mode) up to 15 frames/sec can be obtained. The spatial resolution determined by the point spread function (PSF) is about 80 µm. The effective gain of the system is optimized to obtain the single photon level above the readout noise of the CCD. This good sensitivity together with the high count rate capability makes this system suitable for millisecond range time-resolved stroboscopic experiments. In order to cover a wider q range, the detector can be displaced both in the horizontal and vertical directions.
2. AVIEX PCCD-4284: This is the main WAXS detector (commissioned in June 2009) which is based on a large Dalsa sensor (FTF7040M).  The detector has 1:1 oblique fiber optic coupling that allows to pass the SAXS intensity nearly unhindered. The detector has an input field of about 84 mm x 42 mm, nominal dynamic range of 16 bit (20,000 above the noise floor), and full frame rate of 1 frame/sec (3584x2048). With 8x8 binning and high speed mode, up to 6 frames/sec can be acquired.  The nominal pixel size is about 24 µm and the real spatial resolution determined by the point spread function is about 60 µm. In the low speed mode, the average single X-ray photon level is well above the noise floor of the CCD. This high sensitivity together with the good spatial resolution makes this detector excellent for combined SAXS/WAXS experiments. The detector is mounted in an erected configuration without requiring any special geometrical or distortion corrections. There is sufficient overlap in the SAXS and WAXS q ranges for the shortest SAXS sample-detector distance. The possibility for installing two identical WAXS detectors along the meridional and equatorial directions is foreseen in the near future.
   
3. MCP-Sensicam CCD: This system is used as a WAXS detector and it comprises a Micro Channel Plate (Proxitronic) based XRII lens coupled to a low noise cooled Sensicam 12 bit CCD (11 bit above noise floor). The input conversion stage consists of a demagnifying (3:1) fiber optic taper having a sensitive area of size ~75 mm. The MCP is gated allowing electronic shuttering and the gain can be varied by 3 orders of magnitude. Therefore, the WAXS signal can be adjusted to be in tandem with the SAXS intensity. At the maximum MCP gain, up to 6 counts per incident X-ray photon can be obtained. Therefore, the single photon signal can be set to well above the CCD noise. The CCD has 1024x1280 pixels, however to match the frame rate of the SAXS detector, only the central region of 640x1280 can be used in time-resolved experiments.   
   
4. For experiments requiring better spatial resolution, image plates (A3 size) with an offline scanner can be used. The scanner is out of order at the moment. 
5. Avalanche Photodiode: This is the principal detector for the Bonse-Hart setup. The photodiode together with the NIM fast counter allows count rates up to 2x 10⁷ cps. 

Further Information

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