Photofission of heavy nuclei at energies up to 4 GeV.
Total photofission cross sections for 238U, 235U, 233U, 237Np, 232Th, and natPb have been measured simultaneously, using tagged photons in the energy range Egamma=0.17-3.84 GeV. This was the first experiment performed using the Photon Tagging Facility in Hall B at Jefferson Lab. Our results show that the photofission cross section for 238U relative to that for 237Np is about 80% over the entire energy range, implying the presence of important processes which compete with fission. If we assume that for 237Np the photofission probability is equal to unity, we observe a significant shadowing effect, starting below 1.5 GeV.
Cetina
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C
Center for Nuclear Studies, Department of Physics, The George Washington University, Washington, D.C. 20052, USA.
Berman
B L
BL
Briscoe
W J
WJ
Cole
P L
PL
Feldman
G
G
Heimberg
P
P
Murphy
L Y
LY
Philips
S A
SA
Sanabria
J C
JC
Crannell
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H
Longhi
A
A
Sober
D I
DI
Kezerashvili
G Y
GY