Speaker
Description
Extensive efforts at INFN Pisa have been devoted to the characterization of MICROMEGAS detectors operated at low pressures down to a few tens of mbar, together with the development of a simulation framework capable of accurately reproducing and predicting their performance. While MICROMEGAS technology is intrinsically well suited to low-density gas operation thanks to its tunable amplification gap, reduced-pressure conditions enhance secondary processes, such as photon- and ion-mediated feedback, leading to increased discharge probability, gain instabilities, degraded energy resolution, and longer signal formation times that ultimately affect timing performance. These effects motivate a dedicated and systematic investigation, supported by simulation, to identify stable and optimized operating conditions.
Four detector prototypes have been studied, including one specifically designed for gain measurements and equipped with a tunable amplification gap. This configuration enabled a detailed characterization of gain as a function of gap width, electric field, and gas pressure. The detector response has been probed using both X-rays, under well-controlled calibration conditions, and low-energy ions, which represent the primary particle species of the intended physics applications.
Particular emphasis is placed on the detector response to low-energy ions and on the time development of the corresponding signals. Dedicated readout electronics have been developed to acquire high-fidelity preamplifier waveforms, enabling direct comparison with simulations that incorporate electron transport, avalanche development, secondary processes, and the effect of the resistive anode plane.
The experimental results have been used to iteratively refine the simulation, leading to substantially improved agreement with data. The resulting framework provides a robust predictive tool for extrapolating detector performance beyond the explored parameter space and for identifying optimal working points, in terms of gas mixture, pressure, and electric field, for low-energy ion detection.
| Name of the speaker | Federico Pilo |
|---|---|
| Eligible for the Georges Charpak Young Scientist Award. | no |