X-Ray Imatek's technology is mainly based in the Medipix2/Timepix chip, a photon-counting electronics characterized by a modular design that provides size flexibility and costs reduction while improving image quality and the possibility to use different semiconductor materials, depending on the field of application, minimizing the radiation dose.
The Medipix2/Timepix CMOS ASIC is a photon counting chip developed by an international Collaboration consisting of 17 research institutes and over 75 scientists at CERN, Switzerland. X-Ray Imatek span off IFAE, one of the initial members of the Medipix Collaboration.
It is a pixel-detector readout chip consisting of 256 x 256 identical elements, each working in single photon counting mode for positive or negative input charge signals. Each pixel occupies a total area of 55μm x 55μm where a 20μm octagonal opening connects the detector and the amplifier via bump bonding.
Pixel Operation Modes
One of the main advantages of the Medipix2 is its versatility, due to the possibility of working in three different counting modes.
Medipix: The counter is incremented by 1 count for each particle detected above a user-defined energy threshold.
Timepix: The counter is incremented continuously from the time the first particle arrives to the end of the shutter (one value per pixel) to provide timing information useful in tracking applications.
Time-Over-Threshold: The counter is incremented continuously as long as the signal generated by the incoming particle is above a certain threshold to provide energy information.
Photon counting electronics can distinguish between photons of different energies. Therefore, only photons above a certain threshold are used to form the image eliminating the error introduced by dark currents. This improves significantly the image contrast of the image taken.
Low Dose Radiation
By direct capturing the photon in the semi-conductor material, our technology uses all of the information contained in that photon.
Different kinds of semi-conductor materials are now available in the market although this is an emerging sector and many more will become available in the future.
Bump-bonding the semi-conductor material to the pixel electronics allows us to employ different kinds of detector material depending on the application.
By improving the DQE of the detector in each application we can significantly reduce the radiation dose when needed, specially in medical applications.
Most Common Applications
• Particle Physics