Beam test results from the SPAKEBAB electromagnetic calorimeter

We present the results of beam tests with high energy (6–150 GeV) electrons and muons of a new type of electromagnetic calorimeter, consisting of very thin interleaved lead and scintillator plates and read out by means of a large number of wavelength shifting fibers. A crucial feature of this detector is the absence of physical boundaries between the readout towers. We have measured the effects of crosstalk between cells that results from this feature and more common calorimeter properties such as the energy and position resolutions, signal linearity, signal uniformity and light yield. The results are among the very best ever obtained for sampling calorimeters.