Tens of thousands of these silicon components could be used at CERN in the near future. The detectors improve on prior devices in several respects. They are not only more economical to produce than previous sensors, which measured up to six inches. The components also stand up better to constant radiation and thus age slower than the previous generation. Planned experiments, such as those probing then highest energies for evidence of dark matter, will scarcely be possible without resistant sensors.
The experiments at CERN are analyzing the structure of matter and the interplay among elementary particles: Protons are accelerated almost to the speed of light and then made to collide, giving rise to new particles whose properties can be reconstructed with various detectors. “In particle physics and cosmology, there are many questions that are still open and to which mankind still has no answer,” says Dr. Manfred Krammer, head of the Experimental Physics Department at CERN. “To make new advances in these areas, we need a new generation of particle sensors. Cooperation with high-tech companies like Infineon allows us to develop the technologies we need for that.”
Two of the detectors for which the use of the Infineon sensors is currently being tested are named ATLAS (A Toroidal LHC Apparatus) and CMS (Compact Muon Solenoid). Particle physics experiments are huge cameras: When particles penetrate the silicon detectors, it registers them. With twenty meters (ATLAS) respectively fifteen metres (CMS) height both experiments are located 100 meters below ground. They have been in almost round-the-clock operation for years, carrying out 40 million individual experiments each second. The participants are currently discussing possible production of chips with a total area of up to 1,000m².
Details of the detector technology was not available at the time of publication, but prior technology has employed a scintillator layer (converting incident particle to flashes of light) atop a photo-sensitive matrix. Moving to a larger single detector may also simplify creating detector arrays that cover the maximum possible area (detecting surface vs. ‘dead’ space) around the particle events.
Infineon speculates that the technology developed for CERN could help cancer patients in less than ten years: several groups of researchers are currently testing proton computed tomography. The medical imaging procedure [that would be required for that technology] is based on the same fundamentals as the chip technology for CERN. Large silicon detectors like the ones Infineon and HEPHY are developing could supply tomographic images during therapeutic radiation. This would better determine the position of the tumour, allowing less damage to be done to healthy tissue than is possible with conventional X-rays. It would reduce the radiation load by a factor of 40.
Illustrations show, respectively; Elementary particle strip sensor with a size of 15 cm x 10 cm in the center of the wafer (source; Infineon); Elementary particle strip sensor with a size of 15 cm x 10 cm (Infineon); One end-cap of the CMS tracker is opened during installation work (CERN); First half of CMS inner tracker barrel (CERN).