Neutron induced pulses in CDF forward hadron calorimeter

The use of calorimeters with very small energy sampling fractions (of the order of a few percent or less) can result in small energy fluctuations in the showers which are interpreted as large equivalent energy depositions in the calorimeter. The authors studied the nature of such fluctuations in the forward hadron calorimeter system of the collider detector at Fermilab (CDF). The results are consistent with the hypothesis that the fluctuations are due to interactions of low-energy neutrons produced in the hadronic showers of the absorbed particles with the hydrogeneous material which makes up the calorimeter´s structure or filling. These neutrons elastically scatter the protons in these hydrogen compounds, which heavily ionize the active media of the calorimeter, creating additional observed energy. The authors present the characteristics of the energy fluctuations and calculate an effective cross section for their production using data available from neutron source measurements and text beam and colliding beam runs