The front-end electronics of silicon detectors are typically designed to ensure optimal noise performance for the expected input charge. A combination of preamplifiers and shaper circuits result in a ...nontrivial response of the front-end to injected charge, and the magnitude of the response may be sizeable in readout windows subsequent to that in which the charge was initially injected. The modulation of the discriminator threshold due to the superposition of the front-end response across multiple readout windows is coined "threshold bounce". In this paper, we report a measurement of threshold bounce using silicon modules built for the Phase-II Upgrade of the ATLAS detector at the Large Hadron Collider. These modules utilize ATLAS Binary Chips for their hit readout. The measurement was performed using a micro-focused 15 keV photon beam at the Diamond Light Source synchrotron. The effect of the choice of photon flux and discriminator threshold on the magnitude of the threshold bounce is studied. A Monte Carlo simulation which accounts for the front-end behaviour of the silicon modules is developed, and its predicted hit efficiency is found to be in good agreement with the measured hit efficiency.
Single Event Effects (SEEs) - predominately bit-flips in electronics caused by particle interactions - are a major concern for ASICs operated in high radiation environments such as ABCStar ASICs, ...which are designed to be used in the future ATLAS ITk strip tracker. The chip design is therefore optimised to protect it from SEEs by implementing triplication techniques such as Triple Modular Redundancy (TMR). In order to verify the radiation protection mechanisms of the chip design, the cross-section for Single Event Upsets (SEUs), a particular class of SEEs, is measured by exposing the chip to high-intensity particle beams while monitoring it for observed SEUs. This study presents the setup, the performed measurements, and the results from SEU tests performed using the latest version of the ABCStar ASIC (ABCStar V1) using a 480 MeV proton beam.
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