A “dwarf ball”: Design, instrumentation, and response characteristics of a 4 π light charged-particle multidetector system

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 264; no. 2; pp. 319 - 326
• Main Authors: Sarantites, D.G., Sobotka, L.G., Semkow, T.M., Abenante, V., Elson, J., Hood, J.T., Li, Z., Nicolis, N.G., Stracener, D.W., Valdes, J., Hensley, D.C.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.02.1988
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/0168-9002(88)90921-7

A 4 π light charged-particle spectrometer is described. The spectrometer consist of 72 fast-low plastic scintillator phoswiches closely packed in a 4 π arrangement. The device is small enough to be enclosed in the spin spectrometer scattering chamber. For each detector that fires, the fast ΔE and slow E pulse heights and a time for each group of 16 detectors are recorded. From this information protons and α particles can be identified and their energies measured over a large dynamic range. The geometry, construction, electronics and data acquisition system are discussed. Examples are given of the performance of this spectrometer from an experiment in which Si ( ΔE, E) heavy-ion telescopes were used as event triggers and the spin spectrometer detected γ rays and neutrons.