90 likes | 180 Views
Learn about Babar Cherenkov Detector utilizing DIRC technology to detect internally reflected Cherenkov radiation generated as charged particles pass through insulator at superluminal speeds. Babar detector employs 144 quartz bars arranged in a 12-sided polygon around the beamline.
E N D
The Babar Cherenkov DetectorDetection of Internally ReflectedCherenkov Yuen-Jung Chang
Cherenkov radiation Charge particle passes through an insulator at a constant speed greater than the speed of light in that medium. The charged particles polarize the molecules of that medium, which then turn back rapidly to their ground state, emitting prompt radiation cosθ = 1/βn
Quartz Bars Material is actually synthetic fused silica (n = 1.473 ) Cross section 17.25 mm x 35.0 mm. Four 1.225 m long bars glued together make one 4.9 m long DIRC bar. DIRC uses as a radiator 144 quartz bars arranged in a 12-sided polygon around the beam line