2018 Impact factor 2.481
Hadrons and Nuclei
Eur. Phys. J. A 16, 495-507 (2003)
DOI: 10.1140/epja/i2002-10122-9

Charge distribution studies in the fast-neutron-induced fission of $\chem{^{232}Th}$, $\chem{^{238}U}$, $\chem{^{240}Pu}$ and $\chem{^{244}Cm}$

H. Naik, R.J. Singh and R.H. Iyer

Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085, India

rhiyer@magnum.barc.ernet.in

(Received: 26 July 2002 / Revised version: 13 November 2002 / Published online: 3 April 2003)

Abstract
Charge distribution studies for heavy-mass fission products were carried out in the fast-neutron-induced fission of $\chem{^{232}Th}$, $\chem{^{238}U}$, $\chem{^{240}Pu}$ and $\chem{^{244}Cm}$ using radiochemical and gamma-ray spectrometric techniques. The width parameter( $\sigma_Z /\sigma_A $), the most probable charge/mass ( $Z_{\rm P} / A_{\rm P}$), the charge polarization ( $\Delta Z$) and the slope of charge polarization [ $\delta (\Delta Z)/\delta A^\prime$] as a function of the fragment mass ( $A^\prime$) were deduced. The average charge dispersion parameter ( $\langle \sigma_Z \rangle $) and proton odd-even effect ( $\delta_{\rm p}$) were also obtained for these fissioning systems. The $\langle \sigma_Z \rangle $ and $\delta_{\rm p}$ values in the fissioning systems $\chem{^{241}Pu}$ $^{\ast}$ and $\chem{^{245}Cm}$ $^{\ast}$ were determined for the first time. The $\delta (\Delta Z)/\delta A^\prime$ value is also determined for the first time in the fissioning systems $\chem{^{239}U}$ $^{\ast}$, $\chem{^{241}Pu}$ $^{\ast}$ and $\chem{^{245}Cm}$ $^{\ast}$. These data along with the literature data for even- Z fissioning systems such as $\chem{^{230}Th}$ $^{\ast}$, $\chem{^{232}Th}$ $^{\ast}$, $\chem{^{233}U}$ $^{\ast}$, $\chem{^{234}U}$ $^{\ast}$, $\chem{^{236}U}$ $^{\ast}$, $\chem{^{238}U}$ $^{\ast}$, $\chem{^{239}Pu}$ $^{\ast}$, $\chem{^{240}Pu}$ $\ast$, $\chem{^{242}Pu}$ $^{\ast}$, $\chem{^{246}Cm}$ $^{\ast}$, $\chem{^{250}Cf}$ $^{\ast}$ and $\chem{^{252}Cf}$(SF) are discussed in terms of nuclear structure effect and dynamics of descent from the saddle to the scission point. The role of the excitation energy in low-energy fission is also discussed.

PACS
25.85.Ec - Neutron-induced fission.

© Società Italiana di Fisica, Springer-Verlag 2003