Cadmium mass spectrum

Figure 2 shows a mass spectrum of cadmium spiked with enriched 106Cd. The solid line at position 106 represents the 106Cd spike, and the dashed lines represent the relative abundance for the other cadmium isotopes. The dashed line at juxtaposition at 106 is the relative abundance of 106Cd as it occurs in nature. Table I shows the IBM 1130 computer-programmed output for a typical isotope dilution analysis. The program... 

Both compounds crystallize with the cadmium diiodide structure (space group P3ml) as previously reported on polycrystalline samples.3 For platinum disulfide, ao = 3.542(1) A and c0 = 5.043(1) A, and for platinum ditelluride, a0 = 4.023(1) A and c0 = 5.220(3) A. Direct chemical analysis for the component elements was not carried out. Instead, precision density and unit-cell determinations were performed to characterize the samples. The densities of both compounds as determined by a hydrostatic technique with heptadecafluorodeca-hydro-l-(trifluoromethyl)naphthalene as the density fluid4 indicated that they are slightly deficient in platinum. For platinum disulfide, = 7.86 g/cm3 and Pmeas = 7.7(1) gm/cm3, and for platinum ditelluride, p = 10.2 gm/cm3 and Pmeas = 9.8(1) gm/cm3. In a typical experiment an emission spectrum of the platinum disulfide showed that phosphorus was present in less than 5 ppm. A mass spectroscopic examination of the platinum ditelluride revealed a small doping by sulfur (less than 0.4%) and traces of chlorine and phosphorus (less than 100 ppm). 

The SSR operates with a neutron energy spectrum quite unlike any gas-cooled reactor concept studied during the past 20 years. Nuclear data evaluations for uranium, carbon, oxygen, and cadmium isotopes for the epithermal and fast energy ranges must be reviewed, probably reevaluations performed, and likely additional cross section measurements made. Because the concept relies on low excess reactivity, the predicted critical mass should be confirmed. The value of the temperature coefficient must be confirmed. Subcriticality under accident conditions should be assured through applicable benchmark experiments. 

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