POROREEO IRE SEI SM a re pe ee ee ye a ane Aen “a CHAPTER 5 DISCUSSION 5.1 DISCUSSION OF ERRORS The statistiesl errors in.the counting rates have been minirized vbenever possible by reading the activities at specified tires from smooth decoy curves. The omission of a self-absorption - selfascattering correction in the reduction of the analytical data for Sr 9, 2x95 pal40, and Celhas introduced additional errors. The maximum possible veriation, or spread, in the data that this omission can produce is $.5 per cent for Sr89, 4.6 per cent for Zr95, 2.7 pvr cent for Bal40, and 10 per cent for Celt44¥, These maximum percent2ces were calculated by taking the difference between the extreme self-cbserptione self~scattering correctionsfor 211 the samples and dividing by the ° average of these two corrections. The self-absorption-self-src.ttering corrections were estimezted from the data presented by Engels-+reir et al.18/ In all cases the errors among the four aliquots of any ore sample are much smaller than the maximum possible error presented here, These two sources of errors are combined in the estinate of tha totel error for each analysis. These estirates are reported as syresds in Table 5.1. ° As in the calculation of the maxirum possible error tie to self-absorption - self-scattering effects, the spread = highest valua ~ lowest value average velue x 100 In general the spreads are approximately twice the stendard ‘eviattions, In the calculations of the S-~values the spreads are comround.1 ‘y tre equation where ‘ 2/2 SR = (sf2. + 332. + 332, + si) Sp = Spread of the R-value Sy, S2, 33, and Sy = the spreads of the individual analyses for the mclides in question (Cf, definition of ?-valse section 4,1) 35 SECRET — RESTRICTED DATA