(No/%), the ratio of estimated absorption peak counts to primary flux for axial incidence, was determined in the laboratory for several energies using standard 137cs, 24Na, 113sn, and 226Ra sources and for other energies by comparison with our previously well calibrated 5" x 3" detector using 40x, 85sr and 232qh sources of unknown intensity. These results are given in Table I. (NF/No), the angular correction factor for 0.61 MeV and for 1.76 MeV y-rays was obtained by numerical integration over the measured angular response of the detector for these energies and the calculated angular primary flux distribution from a uniformly distributed source. The measured angular response of the 4" x 4" detector to y-rays of these energies was much flatter than for the 5" x 3" detector and thus the corresponding angular correction factors were much smaller. The angular corrections for other energies and other source distributions were estimated on the basis of these two calculations. Due to the flatness of the angular response the errors involved in these estimates are negligible. (¢/I), the ratio of primary flux to total dose rate, is the same as given in HASL-150 except for the case of the 1.76 Mev 214Bi photopeak used for the dose rate estimate of the 238U series. This particular ratio was revised slightly based on further analysis of existing 214Bi decay schemes and y-ray intensity measurements. The final field spectra conversion factors (Np/I), absorption peak counts per ur/hr, are given in Tables II and III. These values were verified by direct field comparison with the 5" x 3" detector at a large number of locations. The values of (Np/I) for the three natural emitters, 40x, the 238y series, and the 232TH series, are significantly higher than the corresponding values for the 5" x 3" NaI(Tl) detector. Thus, estimates of peak areas should be affected less by errors in estimating the continuum resulting in more precise dose rate estimates. The (Np/I) for the various fallout emitters are also slightly higher. This increase in response is due primarily to the improved geometrical configuration, which results in a larger intrinsic peak efficiency for higher energy y-rays and an improved angular response at all energies. In addition, the improved resolution allows a better estimate of the 1.76 MeV 214Bi absorption peak, even in the presence of a large 1.46 MeV 40K peak. -4-