“…Some of the past experimental investigations of this type were performed by Giordmaine and Wang (1960), Hanes (1960), Jones et al (1969), Steinruck and Redulic (1986), McGilp (1986, 1988), and, more recently, Buckman et al (1993). Most of these measurements have used large separations between the source and the detector (40 cm or greater); however, the most recent of these, by Jones et al (1969), , and Buckman et al (1993), obtained distributions for single capillary and multi-capillary arrays at separations of as little as 1.5 mm from the source tube. A summary of these experiments is given in table 1.…”