Total photofission cross sections for {sup 237}Np, {sup 233}U, {sup 235}U, {sup 238}U, {sup 232}Th, and {sup nat}Pb have been measured simultaneously, using tagged photons in the energy range E{sub {gamma}} = 0.17-3.84 GeV in Hall B at Jefferson Lab. The fission fragments were detected using parallel-plate avalanche detectors. Our results show that, of these nuclei, {sup 237}Np has the largest photofission cross section per nucleon, and that the photofission cross section for {sup 238}U relative to that for {sup 237}Np is about 80% over the entire energy range. The relative photofission cross sections per nucleon increase with the fissility parameter Z{sup 2}/A, approaching an apparent asymptote at the Z{sup 2}/A value for {sup 237}Np, and they do not depend strongly on the incident photon energy over this entire energy range. These results, together with a comparison of the {sup 237}Np photofission cross section per nucleon with total photoabsorption data, indicate that the photofission probability for {sup 237}Np is almost unity. If we make this assumption, we observe a significant shadowing of the interior nucleons starting below 1.5 GeV, so that the photoabsorption cross section decreases by 20% near 4 GeV.
Cetina, C, et al. "Photofission of Heavy Nuclei from 0.2 to 3.8 GeV." Physical Review C, vol. 65, no. 4, Mar. 2002. https://doi.org/10.1103/PhysRevC.65.044622
Cetina, C, Heimberg, P, Berman, B L, Briscoe, W J, Feldman, G, Murphy, L Y, Crannell, Hall, Longhi, A, Sober, D I, Sanabria, J C, & Kezerashvili, G Ya (2002). Photofission of Heavy Nuclei from 0.2 to 3.8 GeV. Physical Review C, 65(4). https://doi.org/10.1103/PhysRevC.65.044622
Cetina, C, Heimberg, P, Berman, B L, et al., "Photofission of Heavy Nuclei from 0.2 to 3.8 GeV," Physical Review C 65, no. 4 (2002), https://doi.org/10.1103/PhysRevC.65.044622
@article{osti_813950,
author = {Cetina, C and Heimberg, P and Berman, B L and Briscoe, W J and Feldman, G and Murphy, L Y and Crannell, Hall and Longhi, A and Sober, D I and Sanabria, J C and others},
title = {Photofission of Heavy Nuclei from 0.2 to 3.8 GeV},
annote = {Total photofission cross sections for {sup 237}Np, {sup 233}U, {sup 235}U, {sup 238}U, {sup 232}Th, and {sup nat}Pb have been measured simultaneously, using tagged photons in the energy range E{sub {gamma}} = 0.17-3.84 GeV in Hall B at Jefferson Lab. The fission fragments were detected using parallel-plate avalanche detectors. Our results show that, of these nuclei, {sup 237}Np has the largest photofission cross section per nucleon, and that the photofission cross section for {sup 238}U relative to that for {sup 237}Np is about 80% over the entire energy range. The relative photofission cross sections per nucleon increase with the fissility parameter Z{sup 2}/A, approaching an apparent asymptote at the Z{sup 2}/A value for {sup 237}Np, and they do not depend strongly on the incident photon energy over this entire energy range. These results, together with a comparison of the {sup 237}Np photofission cross section per nucleon with total photoabsorption data, indicate that the photofission probability for {sup 237}Np is almost unity. If we make this assumption, we observe a significant shadowing of the interior nucleons starting below 1.5 GeV, so that the photoabsorption cross section decreases by 20% near 4 GeV.},
doi = {10.1103/PhysRevC.65.044622},
url = {https://www.osti.gov/biblio/813950},
journal = {Physical Review C},
number = {4},
volume = {65},
place = {United States},
year = {2002},
month = {03}}
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 457, Issue 1-2https://doi.org/10.1016/S0168-9002(00)00765-8
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 440, Issue 2https://doi.org/10.1016/S0168-9002(99)00784-6
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 441, Issue 3https://doi.org/10.1016/S0168-9002(99)00857-8