Speaker
Description
Optical readout Micromegas detectors offer high spatial resolution and simplify readout electronics by directly imaging avalanche-induced scintillation light, making them attractive for various applications, including dark matter search and rare event detection. However, long-term stability under high-rate or continuous operation remains a critical challenge due to discharge risks and gain fluctuations. We present a resistive optical readout Micromegas that incorporates a resistive glass plate with a volume resistivity of 10⁹ Ω·cm as the readout anode to suppress discharges and enhance operational stability. We measured the visible-light transmittance of three anode materials including resistive glass with Indium-Tin Oxide layer, normal glass and Diamond-Like Carbon layer. The results show that the resistive glass provides sufficient visible-light transmittance, significantly higher than that of the Diamond-Like Carbon layer, making it suitable for optical readout Micromegas detectors. In addition, the resistive glass detector demonstrates beneficial effects on gain and stability. Compared to the non-resistive Indium-Tin Oxide-based Micromegas design, the resistive-glass design increases the gas gain from below 10,000 to over 40,000, with significantly improved stability. Using an 8 keV X-ray source at a gain of approximately 4000, counting rate tests show sustainable operation at 200 kHz – 300 kHz. Further fundamental performance studies and practical characteristic evaluations, including the dependence of resistivity on temperature and working parameters, are currently in progress.
| Name of the speaker | Cong Liu |
|---|---|
| Eligible for the Georges Charpak Young Scientist Award. | no |