Speaker
Description
For the high-luminosity phase of the Large Hadron Collider (HL-LHC), at the
expected position of the innermost pixel detector layer of the CMS and ATLAS
experiments, the estimated equivalent neutron fluence after 3000 fb$^{-1}$
is 2$\cdot$10$^{16}$ n$_{eq}$/cm$^2$, and the IEL (Ionizing Energy Loss) dose
in the SiO$_2$ is 12 MGy. The optimisation of the pixel sensors and the
understanding of their performance as a function of fluence and dose makes a
radiation damage model for TCAD simulations, which describes the available
experimental data, highly desirable. The currently available bulk-damage
models are not able to describe simultaneously the measurements of dark
current (I-V),capacitance-voltage (C-V) and charge collection efficiency (CCE) of pad diodes for fluences $\ge 1\cdot 10^{15}$ n$_{eq}$/cm$^2$.
Therefore, for the development and validation of a new accurate bulk damage model
we use I-V, C-V and CCE measurements on pad diodes available within
the CMS-HPK campaign and data from samples irradiated recently with 24 GeV/c protons. For the determination of the radiation-induced damage parameters we utilise the "optimiser" of Synopsys TCAD, which allows the minimisation of the difference between the measured and simulated I-V, C-V and CCE. The outcome of this optimisation, the Hamburg Penta Trap Model (HPTM), provides a consistent and accurate description of the measurements of diodes irradiated with protons in the fluence range from
3$\cdot$10$^{14}$ n$_{eq}$/cm$^2$ to 1.3$\cdot$10$^{16}$ n$_{eq}$/cm$^2$.
