Speaker
Dr
Magnus Mager
(CERN)
Description
A new Inner Tracking System based on seven concentric layers of Monolithic Active Pixel Sensors will be installed in the ALICE experiment during the second long shutdown of LHC in 2018-2019. It is based on 10m^2 of pixel sensors that will be fabricated using the 180nm CMOS Imaging process of TowerJazz. The ALPIDE design takes full advantage of a particular process feature, the deep p-well, which allows for CMOS circuitry within the pixel matrix, while retaining the full charge collection efficiency. Together with the small structure size, this allowed placing a continuously active, low-power front-end into each pixel and using an in-matrix sparsification circuit that sends only the addresses of hit pixels to the periphery. This approach led to a design with a power consumption of <40mW/cm^2, a spatial resolution of ~5um, and a peaking time of ~2us, while being radiation hard to some 10^3 1MeV n-eq, perfectly matching or superseding the requirements of ALICE.
Over the last years of R&D, several prototype circuits have been used to verify radiation hardness and to optimise pixel geometry and in-pixel front-end circuitry. The positive results led to submissions of full-scale (3x1.5 cm^2) sensor prototypes in 2014. They are being characterised in a thorough campaign that includes several irradiation and beam tests. This contribution will give a comprehensive summary of the results obtained and prospects towards the final sensor to instrument the ALICE Inner Tracking System.
Collaboration
on behalf of the ALICE collaboration
Primary author
Dr
Magnus Mager
(CERN)
