Research Detectors Inc.

Large Area CMOS X-ray Detectors


RDI’s CMOS_1M system uses a single large CMOS sensor to create a continuous image area 147 mm x 94 mm with 1.39 million pixels. Each pixel has an active area of 100 mm2. Scattered x-rays from the sample are converted into visible light with a Gd2O2S:Tb phosphor screen and the light is then transferred to the CMOS sensor with a thin fiber optic plate. 

A special feature of CMOS sensors compared to CCD detectors is that individual pixels of the sensor can be readout while all the other pixels are acquiring data. The total read time for the detector is only 0.033 seconds. This allows the imaging system to be used for shutter-less crystallography where a series of images are collected as the crystal sample is smoothly rotated through 180 (or 360) deg. Usually each frame is taken with a 0.1 deg rotation of the crystal and an exposure time of 0.1 - 5 seconds. Therefore, a complete dataset of 1800 (or 3600) frames is collected in 3 minutes at an x-ray synchrotron or in about ½ to one hour with a laboratory source.

With our system images frames are acquired every 0.1 deg with a short exposure time while with most CCD systems images are acquired with an oscillation range of 0.5 -1.0 deg with longer exposure times per frame. When images from the CMOS system are added to simulate the data from a CCD system the data quality and dynamic range are as good or better than that from a CCD system. However, the CMOS images are usually used directly by analysis programs to give improved positioning accuacy of the diffraction peaks which results in higher resolution of the final crystal structure.  

The detector is read out using a standard 1Gig Ethernet cable into a standard Intel PC system running Windows 7. Diffraction data collected with this system can be directly analyzed with standard analysis programs (XDS, HKL2000, MOSFLM, D*Trek, etc.). The detector control software can be configured to also control an x-ray goniometer and an x-ray generator or a device driver can be provided to allow control of the detector with other software.

Here are the detailed specifications for the CMOS_1M system.

                       Feature                                    Specification
Active area (mm2) 147.6 x 94.4
Image size in pixels 1476 x 944 pixels (1.39 x 106 pixels)
Pixel size (microns)
100.1 x 100.1
Phosophor (optimized for 1 Angstrom) Gd2O2S:Tb phosophor plate
Detector window Aluminized mylar or Beryllium
Spatial Resolution (FWHM) microns 100
Dark current (e/pixel/sec) 1
Read noise (electrons) 175
Signal from one 12 keV photon (electrons)
Detector operating temperature (deg C)
Cooling type
Internal thermoelectric with external water chiller
Readout time (sec)
0.033 (simultaneous readout and acquisition)
Dimensions (cm)
20 wide x 18 high x 10 thick
Weight (kg)
Detector to PC interface
1 GigE Ethernet interface using TCP/IP
PC Computer system
8 Gybyte Intel system using Windows 7

                        Front view of system                                                            Rear view of system

The system comes with the detector, water chiller, power supplies, computer and software. Delivery is 60 days and the warranty is for one year (parts and labor). For further information please email us from the contact page or call us at 510-409-6031.