Soudan 2 detector as a time-projection calorimeter

The Soudan 2 Nucleon Decay Detector uses Hytrel plastic tubes to cause ionization electrons to drift up to 50 cm prior to gas multiplication and collection. The drift tubes are embedded in a matrix of thin steel sheets. Readout is accomplished by flash digitizers in a system with distributed intelligence. This design is usable as a general-purpose calorimeter in which 3 spatial coordinates and pulse height are measured at all points where ionization occurs. Several 4.3 ton modules of this detector have now been studied in detail. We will present information about the detector performance and its dependence on manufacturing tolerances.