A ring imaging Cherenkov detector, the DELPHI Barrel RICH Prototype: Part A: Experimental studies of the detection efficiency and the spatial resolution

Abstract

We discuss in two parts A and B [Nucl. Instr. and Meth. A270 (1988) 289] the latest DELPHI Barrel RICH Prototype test results. The first part A, after a technical description of the prototype, is devoted to detailed experimental studies of the multiwire detector response, associated analog electrons and of the photoelectron collection in the drift volumes. Emphasis is given to the single electron detection efficiency problem and to the accuracy of the three-dimensional photoconversion space point reconstruction. Limitations of the technique and their solution are discussed. These results are used as input data to a Monte Carlo prototype simulation, in part B, to interpret the ring imaging beam tests therein. Finally a measurement of the longitudinal diffusion coefficient for several gas mixtures is given.