ATLAS Pixels

Sebastián Grinstein

The Pixel group develops new silicon detector technologies for high energy physics experiments and other applications. After making key contributions to the ATLAS IBL and AFP sub-detectors the group aims to play a leading role in the HL-LHC upgrades. In parallel the group is developing smart silicon sensors for neuromonitoring and exploring new materials for radiation detection.

3D Pixel Sensors for the HL-LHC

After IFAE demonstrated the radiation hardness capabilities of 3D sensors (which surpass any other sensing technology), ATLAS selected these sensors for the innermost layer of the pixel tracker for the high-luminosity era. IFAE is now qualifying it’s assembly line to produce 3D modules for the most challenging detector instrument of ATLAS.

Low Gain Avalanche Detectors (LGAD)

During 2019 the group made important advancements in the HGTD activities. In-deep studies of LGAD sensors before and after irradiation to understand the limitations of the technology were carried out. These studies include performance of different bulk-doping options in terms of gain and timing resolution in laboratory and beam tests, and also voltage stability and geometry optimization. Furthermore, ALTIROC1 devices (with a 5x5 pixel matrix) were fully assembled at IFAE with CNM and HPK LGAD sensors. The group is leading the digital design of the final HGTD readout chip (the ALTIROC2). The TDR of HGTD is to be submitted in April 2020.

CMOS Monolithic devices

The CMOS effort during 2019 concentrated in the development of a prototype for the CEPC vertex detector. The TaichuPix1 was partially designed by IFAE and is now being characterized in our lab. Furthermore, the group started exploring the usage of HV-CMOS sensors beyond high energy physics. Early in 2019, the BIST Ignite award was obtained to explore the usage of CMOS SPADs for neuromonitoring, in a coordinated project of IFAE and ICFO.
Figure 1: The pixel group has been exploring the usage of silicon detectors beyond high energy physics. One interesting application of the HV-CMOS technology is for neuromonitoring.