A.K. Nandi

Some Hadron Calorimeter Properties Relevant to Storage Rings

At wide angles in a storage ring environment, a substantial part of the energy seen by a hadron calorimeter can be in the form of very low momentum particles such as jet fragments or resonance cascade decay products. Data are presented on the deviations from Gaussian resolution and linear response for such low momentum particles. The differing responses to incident e-, μ-, π+-, K+-, p and at momenta below 10 GeV/c are also compared. In addition, we discuss the significance of angle effects for a 4π calorimeter, and the problems of combining data from calorimeters with different physical characteristics. Experimental data are presented on the difference in hadron response between a fine grain (electromagnetic) lead calorimeter and a coarser (hadron) iron calorimeter, and on the dependence of the response on the energy sharing between the two calorimeters.

The UA1 calorimeter trigger

Abstract We describe the design, construction and performance of the fast calorimeter trigger used in the UA1 experiment on the CERN p p collider. Calorimeter energy signals are digitized rapidly and used to trigger on possible electrons, hadronic jets, total transverse energy and missing transverse energy, with many possible options. We also describe the minimum-bias pretrigger, based on scintillator hodoscopes.

Performance of a UA1 Hadron Calorimeter Prototype

The hadron calorimeter for the UA1 experiment at the CERN SPS proton-antiproton collider consists of a lead-scintillator sandwich plus an iron-scintillator sandwich with wavelength shifter readout. We have tested prototype modules in muon and hadron beams in the momentum range from 0.7 to 90 GeV/c. For several angles of incidence, we have studied the uniformity of the response to hadrons as a function of position. This has included regions where there is reduced sensitivity due to mechanical constraints and the presence of the wavelength shifter readout. The response, resolution and degree of shower containment were measured as a function of incident momentum.

Central Hadron Calorimeter of UA1

Abstract An iron—scintillator sampling calorimeter is described, which measures hadronic energy in proton-antiproton interactions at the CERN 540 GeV SPS collider. Construction details are given of the instrumentation of the magnet pieces of the UA1 experiment and of the methods used to measure the calorimeter response and resolution. The system of lasers and quartz fibres, which allows long term monitoring of the calorimeter response, is also described.