-15- UCRL-6491 Rev. II FIGURE CAPTIONS Fig. 1. Yield (atoms per hundred fissions) of fission products of various masses plotted against mass-to-charge ratio of fragments for various assumed values of the ionic charge. It can be seen that only the curve for charge 1 (extreme right-hand curve in the figure) is essentially free of overlap with curves for other charges. omitted for clarity. Curves for charges higher than 4 are All such curves would lie between existing curves and the vertical axis, with a great deal of overlap on the charge 3 and 4 curves, Fig. 2. Schematic views of the essential parts of the Thomson parallel field mass analyzer. Fig. 3. Fission-fragment analyzer used to obtain the data in this report. Fig. 4. Outline of autoradiograph of collector foil from fission-fragment analyzer. Circular area at right represents the undeflected beam. Dotted line indicates position of one of the coordinate axes. flection is horizontal (leftward), Magnetic de- electric deflection is vertical (downward). In the original autoradiograph faint smudges representing lower-charged fission fragments could be seen to the right of the large irregular area. The ellipsoidal areas labeled HI, LI, and so on are the resolved low-charge beams. H indicates "heavy fragment"; L indicates "light fragment."’ The numeral next to each letter indicates the assumed fragment ionic charge. Fig. 5. A line from the point (-x,, 0) to the parabola at the point (xy, y;) is tangent to the parabola at that point. This line therefore represents an approximation to the parabola in the neighborhood of (x, y,). Fig. 6. Method of cutting collector foil for radiochemical analysis. The trapezoidal sections are rough approximations to parabolic arcs passing through the origin and through the centers of the trapezoids. 90018u4