TA-DPG-2017-009

The PANDA experiment at the future FAIR facility will use antiproton annihilations to investigate open questions in hadron physics in the momentum range of 1.5-15 GeV/c.
Two DIRC detectors will be built for the PANDA target spectrometer in order to achieve excellent charged particle identification (PID), which is needed to cleanly separate $\pi/K/p$.
The Barrel DIRC will surround the interaction point and perform $\pi/K$ separation for polar angles between $22^{\circ}$ and $140^{\circ}$ and momenta between 0.5 GeV/c and 3.5 GeV/c.
It is based on the successful BaBar DIRC detector, but with several key improvements to perform a better-than $3\sigma$ $\pi/k$ separation between 0.5 GeV/c and 3.5 GeV/c.
In the (forward) endcap region, the Disc DIRC will be placed to cover the angular range from $5^{\circ}$ to $22^{\circ}$ to cleanly separate $\pi$ from K for momenta up to 4 GeV/c. Both DIRC counters will use enhanced-lifetime MCP-PMTs for photon detection in combination with fast readout electronics. The radiators are made from highly polished synthetic fused silica to ensure that photons, propagating through the radiators by total internal reflection, conserve the Cherenkov angle and reach the photon detection plane without angular distortions. Geant4 simulations and tests with several prototypes at various test beam facilities have been used to evaluate the designs and validate the expected PID performance of both PANDA DIRC counters.