A high-resolution tracking hodoscope based on capillary layers filled withliquid scintillator

Results are given on tests of a high-resolution tracking hodoscope based on layers of 26-mum-bore glass capillaries filled with organic liquid scintil lator (1-methylnaphthalene doped with R39). The detector prototype consiste d of three 2-mm-thick parallel layers, with surface areas of 3.1 x 21 cm(2) . The layers had a centre-to-centre spacing of 6 mm, and were read by an op toelectronic chain comprising two electrostatically focused image intensifi ers and an Electron-Bombarded Charge-Coupled Device (EBCCD). Tracks of cosm ic-ray particles were recorded and analysed. The observed hit density was 6 .6 hits/mm for particles crossing the layers perpendicularly, at a distance of 1 cm from the capillaries' readout end, and 4.2 hits/mm for particles a t a distance of 20 cm, A track segment reconstructed in a single layer had an rms residual of 20 mum, and allowed determination of the track position in a neighbouring layer with a precision of similar to 170 mum. This latter value corresponded to an rms angular resolution per layer of about 30 mrad , A comparison is made between capillary layers and silicon microstrip plan es. (C) 2001 Elsevier Science B.V. All rights reserved.