We measured the mean and FWHM for two lines which were identified by Reference ??? as being the result of fission events in cf-252
FWHM= 0.9 +/- 0.1 keV => [math]\sigma = \frac{FWHM}{2\sqrt{2ln(2)}}[/math] = 0.39 +/- 0.043 keV
Max Energy shift = 23 keV
Predicted a Max Energy shift due to doppler effects of 172 keV