Speaker
Description
The Proximity Focusing RICH (pfRICH) detector is a key sub-system fur particle identification (PID) at ePIC. It sits about 1.2 m from the interaction point in the electron-going direction, covering $-3.5 < \eta < -1.5$ in pseudorapidity and full $2\pi$ in azimuth. It will be primarily used for identification of scattered electrons from deep inelastic scattering (DIS) events, as well as for identification of charged hadrons, namely $\pi^\pm$, $K^\pm$, with $p$ and $\bar{p}$, which will be vital e.g. for semi-inclusive DIS analyses. In order to achieve the aforementioned acceptance in pseudorapidity, the pfRICH will be equipped with conical mirrors that will reflect the Cherenkov light, that would otherwise escape its volume, back onto the sensor plane. For optimal performance, these mirrors need to have reflectivity at least 90% in wavelength range from 200 nm to 600 nm. In this presentation, I will summarize current efforts in the pfRICH mirror reflectivity measurement at BNL which is a key part of the mirror development process.
