MX Series X-ray Detector System

MX-225 CCD Detector: MX Series CCDs, MX-225, MX-300, MX-325, MX225, MX300, MX325, MarMosaic, Mar Mosaic, Mar325, Mar225, Mar300, CCD225, CCD300, CCD325

Our MX Series X-ray detectors offer the largest active areas available, combined with the highest performance available, for protein crystallography and diffraction.

These detectors are now also offered in high efficiency (HE) versions using back-illuminated CCD chips.

Detector Configurations

Detector	Active Area	Configuration	Resolution*
MX-225	225mm x 225mm	3 x 3 (9 CCDs)	3072 x 3072
MX-300	300mm x 300mm	4 x 4 (16 CCDs)	4096 x 4096
MX-325	325mm x 325mm	4 x 4 (16 CCDs)	4096 x 4096

*All specifications are for standard 2x2 binned readout mode unless indicated. 1x1 (unbinned) readout available as a special option, with resolution 6144x6144 for MX-225, 8192x8192 for MX-300 and MX-325.

Seamless multi-element ccd technology

The MX series of detectors use 3 x 3 or 4 x 4 arrays of tiled fiber optic taper elements to make a very large active area for detection. But unlike other multi-element detectors, the images produced have no inactive strips between each of the fiber optic tapers. How is this accomplished? Our innovative design includes tapers that are tiled and machined together as one block, with effectively no gaps between the elements (less than about half of a pixel distance between any neighboring elements). During our calibration process, we measure the amount of signal over the entire detector, and thus are able to correct for the signal incident on every pixel.

Fast readout, Low Noise

Every CCD chip is read out through two channels simultaneously. Thus the 3 x 3 MX-225 detector is read out of 18 channels in only 1 second, and the 4 x 4 MX-300 and MX-325 are read out of 32 channels in 1 second at the standard readout resolution. Multiple readout channels allow high speed readout, while maintaining a modest 500kHz pixel readout rate from each channel. Keeping the single channel readout rates slow reduces the read noise.

High Dynamic range

In order to make sensitive comparisons of both low-intensity and high-intensity data possible in a single frame, a detector must have a high dynamic range. Demanding applications like macromolecular crystallography require this. The MX detectors, designed with this in mind, have appropriate gain, full-well capacity, low read noise, and linearity to yield a true 16-bit dynamic range.

On-chip Binning

Binning on the chip before readout minimizes noise compared to binning in software, because read noise for a group of pixels is introduced by the read amplifier only once. If binning is done in software, each pixel has read noise introduced separately, and the signals (already made noisy) are summed later. All MX detectors use on-chip binning, enabling the high dynamic range as specified.

New High Efficiency (HE) Models Available

Rayonix is pleased to announce the first X-ray mosaic detectors to use thinned, back-illuminated CCD chips. All of the standard MX detectors (3x3 225; 4x4 300 and 325) are available in High Efficiency (HE) versions that use this different CCD chip, but have the same active area and resolution.

Because these back-illuminated CCDs have twice the quantum efficiency of standard front-illuminated chips, and very low noise readout electronics, our HE detectors offer 4X to 8X higher signal to noise ratio at the lowest photon counts. The image at the right displays this rather dramatically—the fact that the back-illuminated chip is nearly black is due to its ability to absorb incident light more efficiently. In addition, these back-illuminated CCDs offer excellent linearity, compared to other high-gain CCD options on the market that we have tested.

The MX HE series were specifically designed with several applications in mind, which require the ability to image and discriminate both weak and strong X-ray signals. These applications include protein crystallography of micro-crystals, low energy X-ray crystallography, small angle X-ray scattering (SAXS), and measurements of other weakly scattering samples, such as protein solutions and thin fibers.

Lowest CCD Operating Temperature

The CCDs are operated at a temperature of -70C or below, giving them negligible dark current for any application. The dark current is so low that dark frames of equal integration time as the data frame never need to be recorded; only occasional bias frames of zero integration time are recorded.

Low-maintenance Cooling by Refrigeration

Simple closed-cycle refrigeration, similar to a refrigerator or air-conditioner, is used for cooling: a refrigerant gas expands to cool the cooling head, and then the expanded gas is compressed in an external compressor. No water or other liquids are used for cooling the MX detectors.

High Production Standards

Each of the CCD chips in all MX systems undergoes a series of tests and are selected for low dark current, minimal defects, and high performance. We use fiber optic tapers that have strict quality control for high transmission efficiency, low distortion, and minimal shear effects.

Detector Interface With Only One Computer Workstation

Images are transferred directly from the detector to the computer workstation with full-frame DMA (Direct Memory Access) via a single fiber optic cable. No intermediary computers or other equipment are necessary.

Permanent Factory Calibration

Our scientists understand the methodology of proper detector calibration. Like other Mar detectors, our factory calibration is permanent and routine recalibration is not required.

Putting Together a Beamline

One of the crucial items in the design and running of a beamline for X-ray diffraction is the detector. We recognize this and strive to provide detectors that have the most up-time and reliability, have the best data quality, and are the easiest to use.

Knowledgeable scientists are available to help choose the right options, and then help smoothly integrate our detector hardware and software into the beamline. Data collection options include either using our versatile software interface to control the detector, shutter, and/or goniostat, or using your custom control software to operate the entire experiment, including the detector.

In addition, we offer the MX-225 detector with the MarDTB goniostat and the MarCSC Cryogenic Sample Changer as a complete turn-key endstation for crystallography.