The SELEX phototube RICH detector

Abstract

In this article, construction, operation, and performance of the RICH detector of Fermilab experiment 781 (SELEX) are described. The detector utilizes a matrix of 2848 phototubes for the photocathode to detect Cherenkov photons generated in a 10 m Neon radiator. For the central region an N 0 of 104 cm −1 , corresponding to 13.6 hits on a β = 1 ring, was obtained. The ring radius resolution measured is 1.6 %.

Measurement of the charged kaon mass with the MIPP RICH

“…The following section summarizes the principle of operation of RICH counters, and the description and construction of the MIPP RICH as described in [16,15,14].…”

“…Both tests showed that the window material is both gas and light tight [16]. Each mirror was polished such that an image size of a point source illuminating the mirror was less than 1 mm.…”

“…The FEU60 tubes have a glass entrance window and are coated with a wavelength shifter so as to achieve sensitivity over the same range of wave-lengths as the R760 tubes. Thickness of the wavelength shifter was found not to be critical to performance, based on tests made in a vacuum reflectometer using a Deuterium light source [16].…”

“…They also have an order of magnitude greater noise than the R760 tubes. Quantum efficiencies were measured, as described in [16], relative to a standard R760 tube, of which the absolute quantum efficiency was known only approximately. This …”

“…It provides a gas seal between the phototube and the carbon dioxide radiator gas. Gas tightness was checked with a helium leak detector, and any windows found to leak were replaced [16]. Any residual glue was cleaned off each window, and transmission was checked with a spectrometer [16].…”