A large area liquid scintillation multiphoton detector

A 60 layer lead-liquid scintillator shower detector, which we call the SLIC, has been used for multiphoton detection in the Fermilab tagged photon spectrometer. The detector has an unimpeded active area which is 2.44 m by 4.88 m and is segmented, by means of teflon coated channels, into 3.17 cm wide strips. The 60 layers in depth are broken into three directions of alternating readouts so that three position coordinates are determined for each shower. At present the readouts are made by 334 photomultiplier tubes coupled to BBQ doped wavelength shifter bars which integrate the entire depth of the detector. It is relatively straightforward to increase the number of readouts to include longitudinal segmentation and to increase the segmentation of the outer region which are at present read out two strips to a readout. The energy and position resolutions of isolated showers are about and 3 mm., respectively. The SLIC has been used to study the K⁻π⁺π⁰ decay of the D⁰ [1], as well as for electron and muon identification in ψ → e⁺e⁻ and ψ → μ⁺μ⁻ plus π⁰ identification in γp → ψχ [8].