14th "Trento" Workshop on Advanced Silicon Radiation Detectors

Parametrisation of the response of ALPIDE Monolithic Active Pixel Sensors to low energy nuclei

27 Feb 2019, 15:00

20m

Aula Grande (FBK, Trento)

Oral Session 10: CMOS Sensors (2)

Speaker

Ester Ricci (Universita degli Studi di Trento and INFN (IT))

Description

We report on the characterisation of the response of the ALPIDE MAP
sensor to nuclei of energy 20-220 MeV/a.m.u.. ALPIDE has been designed
for the upgrade of ALICE experiment at the LHC: the new tracker will be
fully efficient, with improved sensitivity, for particles with
transverse velocity larger than 0.7c and charge ±1. The operating regime
considered in this work is really different: slower nuclei release much
more energy in silicon, proportionally to Z2/β2, increasing signals by
up to orders of magnitude in amplitude and spatial extension. Since the
only available observable quantity is the cluster size understanding and
parametrising the response of front-end electronics for different
settings of current thresholds, bias potential and acquisition time, is
far from trivial. We provide here results from measurements taken in
Trento (protons 20-220 MeV) and in Catania (H, He, C, O nuclei 62
MeV/a.m.u.). The agreement with predictions from Geant4 Monte Carlo
simulations and TCAD calculations proved sufficiently good to
analytically parametrise the response of ALPIDE to low energy nuclei.

Presentation materials

ERicci_2019_2_27_Trento_Workshop.pdf