The focusing DIRC with waveform digitizing electronics

We have tested a novel Cherenkov imaging detector called the Focusing DIRC (FDIRC) with waveform digitizing electronics. The prototypeʹs concept is based on the BaBar DIRC with several important improvements: (a) much faster, pixelated photon detectors, (b) a mirror that makes the photon detector smaller and less sensitive to background in future applications, and (c) electronics capable of measuring single photon resolution to σ ≈ 150 ps , which allows for correction due to chromatic error. In this test, the prototype has been instrumented with seven Hamamatsu H-8500 MaPMTs. Waveforms from ∼ 450 pixels are digitized with waveform sampling electronics based on the BLAB2 ASIC, operating at a sampling speed of ∼ 2.5 GSa / s . This version of the FDIRC prototype was tested in a large cosmic ray telescope providing muon tracks with ∼ 1 mrad angular resolution and a muon momentum cutoff of ≥ 1.6 GeV / c .