Doppler-shift Correction of Emitted 
-Rays
Figure 1: Experimental set-up with double ionization chamber
and Ge-detector positioned at 
.
A.) special geometry: Ge-detector at 
Doppler-shift correction:
where 
is the measured Doppler-shifted -ray energy
for an excited fragment in det-1
for an excited fragment in det-2
is the polar emission angle of excited fragment
and 
the fragment velocity
B.) general case: Ge-detector at 
Doppler-shift correction:
where is the measured Doppler-shifted -ray energy
for an excited fragment in det-1 and in det-2, respectively.
is the polar emission angle of excited fragment
and the fragment velocity
Figure 2: Fragment mass selected -ray spectra: no Doppler-shift
correction (top), Doppler-shift correction for the light fragment mass (center)
and Doppler-shift correction for the heavy fragment mass (bottom).