The NA62 Gigatracker: detector properties and pixel read-out architectures

Abstract

The beam spectrometer of the NA62 experiment has to sustain high and non-uniform beam rate (∼1.5 MHz/mm 2 in the hot center and 0.8-1.0 GHz in total, hence the name Gigatracker) and should preserve beam divergence and limit beam hadronic interactions. The Gigatracker has to provide precise momentum, time and angular measurements on every single track of the secondary 75 GeV/c hadron beam with a timing precision of 150 ps (rms). To meet these requirements, three hybrid silicon pixel detector stations will be installed in vacuum. An adequate strategy to compensate the discriminator time-walk must be implemented and R&D investigating two different options is ongoing. Two prototypes have been designed in order to have an experimental comparison of the performances: one approach is based on the use of a constant-fraction discriminator followed by an on-pixel TDC, while the other one is based on the use of a Timeover-Threshold circuit followed by a TDC shared by a group of pixels.

Detection systems for mass spectrometry imaging: A perspective on novel developments with a focus on active pixel detectors

“…Up to now, only few CMOS active pixel detectors with timing capabilities on the pixel level have been developed. Table compares the Timepix chip with the NA62 collaboration's timing chip …”

Emerging technologies in mass spectrometry imaging

“…Very few active pixel detectors with comparable functionality are currently available. An interesting alternative chip is currently being developed by the NA62 collaboration at CERN [86][87][88][89][90]. This read-out chip achieves a timing resolution of about 100 ps and is designed to accommodate about 73k hits per second per pixel.…”