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.