LOW-POWER HIGH-RESOLUTION TDC WITH FAST DATA CONVERSION FOR BALLOON-BORNE EXPERIMENTS

A new low power CAMAC TDC module with a resolution of 26 psec and fast data conversion for time-of-flight measurement on a balloon-borne par ticle detector is described. The module incorporates sixteen TAC chann els in single CAMAC width, and the total power consumption is 0.8 W/ch . Temperature coefficient of the conversion gain is typically 20 ppm/d egrees C so that an influence of a wide variation of the ambient tempe rature during the flight could be reduced. Each channel has a hit regi ster scanned by a sequencer and digitizations of non-stopped channels are skipped, thus minimizing the conversion time and the data volume.