APPENDIX IIT THE GAUSSIAN CURVE GENERATOR The Gaussian curve generator consisted of a Gaussian template mounted on a lucite disk which in turn was mounted like a wheel on the shaft of a potentiometer, With a bate tery to provide voltage and another potentiometer to vary the amount of voltage across the main potentiometer, the pen of " the X-Y recorder was caused to move along the X axis as the wheel was turned. The range of the pen'’s motion during one revolution of the wheel was governed by the setting of the secondary potentiometer. A photovoltaic cell "looking" at a light througn the template was connected to the Y axis of the X-Y recorder with another potentiometer controlling its range. As the wheel was turned by hand and the amount of light reaching the cell was varied by the template, a Gaussian curve of height and width, as determined by the range-controlling potentiometers, was drawn on the recorder paper. The template was made of thin, opaque sheet metal and its shape was determined by plotting a Gaussian curve on polar graph paper. By this method several hundred Gaussian curves were drawn of various heights for each width. The widths were chosen to correspond to the widths at half maximum for the actual energies present in. the fallout spectra as determined ei, from the resolution versus energy curve.