Iron liquid-argon and uranium liquid-argon calorimeters for hadron energy measurement

The authors studied, with a specially designed hadron calorimeter, the contributions of different mechanisms affecting the energy resolution of such instruments. It is shown that in ordinary materials the resolution is dominated by 'nuclear fluctuations'. Measurements with a uranium calorimeter show that these fluctuations can be effectively compensated by the amplifying effect of nuclear fission in uranium. The resolution at low energies is good ( sigma =9.6% for 10 GeV/c pions) and improving with energy. (12 refs)