A scintillator hodoscope for experiments at proton storage rings

A versatile scintillator hodoscope with two dimensional position sensitivity and good time resolution has been installed at the CELSIUS ion storage ring of the The Svedberg Laboratory. It is designed to be easily inserted into a package of range-measuring hodoscopes. We report on resolution and efficiency features that have been studied with reaction products from stored protons of energies 1360 and 1450 MeV impinging on a proton or deuteron pellet target. Among first applications are reconstructions of missing masses in pp reactions and of neutrons in η meson production via pd → pn η p s with a spectator proton p s .