Absolute integral cross sections have been measured for Dndash;H2at primary particle velocitiesv=7730 m/s and 9580 m/s with a 77thinsp;deg;K target. The number density of target particles was determined with an absolute accuracy of 1percnt; by the method of dynamic expansion. The overhyphen;all error in the absolute cross sections is estimated to be about 1.5percnt;. All available measurements of integral cross sections as a function of velocity were used to test literature potentials in a khgr;2procedure. A new Bornndash;Mayerndash;Splinendash;Van der Waals (BMSV) potential is proposed that is in reasonable agreement with recentabinitiocalculations. The potential is also consistent with the differential total cross section measurement of Geddes, Krause, and Fite. This justifies the use of the new potential together with the differential measurements to perform an absolute calibration of the cross section for the D+H2rarr; HD+H reaction. The calibrated reactive cross section is found to be in reasonable agreement with measured bulk rate constants.
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