Precision calibration of calorimeter electronics in the D0 liquid argon/uranium particle detector

The calibration system built for the D0 experiment has been shown to provide the necessary stability and uniformity across the entire calorimeter. However, during its engineering evolution, many compromises have been made, such as the inverting transformer and the 50- Omega pulser, filter, and attenuator. The system is used to deliver and distribute a 300-ns pulse across 50000 channels of electronics with better than 0.25% difference between channels from a location more than 200 ft away. The system is used for both cross-calibration and functionality checking (i.e., missing channels). Design of a fixed-width pulse generator of high stability is presented as a key ingredient in the system´s overall performance. In addition, the design of a controlled impedance distribution system is discussed.<>