The term “hybrid” stems from the fact that the two main elements from which these devices are built, the semiconductor sensor and the readout chip (also known as application-specific integrated circuit or ASIC), are manufactured independently and later electrically coupled by means of a bump-bonding process.
Ionizing particles are detected as they produce electron-hole pairs through their interaction with the sensor element, usually made of doped silicon or cadmium telluride.
The readout ASIC is segmented into pixels containing the necessary electronics to amplify and measure the electrical signals induced by the incoming particles in the sensor layer.
[3][4][5] Using silicon pixel detectors as part of their inner tracking systems, these experiments are able to determine the trajectory of particles produced during the high-energy collisions that they study.
The main reasons for the success of HPC detectors are the direct detection of individual photons and the accurate determination of scattering and diffraction intensities over a wide dynamic range.