A position sensitive high resolution hodoscope for particle unstable intermediate mass fragments

A position sensitive high resolution hodoscope was developed to detect particle unstable intermediate mass fragments and to resolve the individual excited states of these nuclei. The hodoscope consists of 13 telescopes, four of these telescopes were designed to isotopically resolve fragments with 3 ≦ Z ≦ 10 and the other nine to resolve hydrogen and helium isotopes. In order to optimize the excitation energy resolution of the hodoscope, each telescope contains an x − y position sensitive gas proportional counter. A position resolution better than 0.5 mm is obtained for 5.8 MeV α-particles. This position sensitivity also allows compensation for the thickness nonuniformity of the nonplanar silicon detectors incorporated in the nine light particle telescopes. For proton decay channels of the particle unstable nucleus 14N∗ produced in 14N induced reactions on natAg at EA = 35 MeV, the hodoscope provides an excitati energy resolution of about 60 keV (FWHM).