Comparative study of the fragments' mass and energy characteristics in the spontaneous fussion of 238Pu, 240Pu and 242Pu and in the thermal-neutron-induced fission of 239Pu

Schillebeeckx, P.; Wagemans, C.; Deruytter, A.J.; Barthelemy, Ramón S.

doi:10.1016/0375-9474(92)90296-v

Cited by 89 publications

(40 citation statements)

References 15 publications

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“…7 (bottom). Although a quantitative analysis is still to be done, it is already noted that the theoretical correlation shows a trend similar to the experiment [22], with a mean TKE larger for the lighest (A f h ≈ 132) heavy-fragment group, than for the heaviest (A f h ≈ 140) group. The relatively good agreement of the TKE distribution and mean value with the experiment can be considered as quite encouraging.…”

Section: Collective Model Of Fissionsupporting

confidence: 58%

Fission fragment mass and total kinetic energy distributions of spontaneously fissioning plutonium isotopes

Pomorski

Nerlo-Pomorska

Bartel³

et al. 2018

EPJ Web Conf.

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Abstract. The fission-fragment mass and total kinetic energy (TKE) distributions are evaluated in a quantum mechanical framework using elongation, mass asymmetry, neck degree of freedom as the relevant collective parameters in the Fourier shape parametrization recently developed by us. The potential energy surfaces (PES) are calculated within the macroscopic-microscopic model based on the Lublin-Strasbourg Drop (LSD), the Yukawa-folded (YF) single-particle potential and a monopole pairing force. The PES are presented and analysed in detail for even-even Plutonium isotopes with A = 236-246. They reveal deep asymmetric valleys. The fission-fragment mass and TKE distributions are obtained from the ground state of a collective Hamiltonian computed within the BornOppenheimer approximation, in the WKB approach by introducing a neck-dependent fission probability. The calculated mass and total kinetic energy distributions are found in good agreement with the data.

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Section: Collective Model Of Fissionsupporting

confidence: 58%

Fission fragment mass and total kinetic energy distributions of spontaneously fissioning plutonium isotopes

Pomorski

Nerlo-Pomorska

Bartel³

et al. 2018

EPJ Web Conf.

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“…In the case of D1S, the endpoint of this valley, located in the region Q 30 ∈ [25,50] (color online) Pre-neutron mass yields for 239 Pu(n,f). The SkM* and D1S calculations are compared with two experimental datasets [57,58]. The data from Nishio et al are plotted with their statistical uncertainties.…”

Section: Fission Yields Obtained With Skm* and D1smentioning

confidence: 99%

“…The widths of the predicted mass yields match the experiment within roughly 1 mass unit. Part of this agreement comes from the fact that both calculations and experimental data are convolutions of a raw data set with a smoothing function: The Schillebeeckx et al [57] data comes from a 2E measurement with a mass resolution of typically 4-5 mass units (FWHM) [59]. A measurement of both energy and velocity of the two fragments as the one performed by Nishio et al [58] is also expected to provide a mass resolution significantly larger than one mass unit.…”

Section: Fission Yields Obtained With Skm* and D1smentioning

confidence: 99%

Fission fragment charge and mass distributions inPu239(n,f)in the adiabatic nuclear energy density functional theory

Regnier

Dubray

Schunck³

et al. 2016

Phys. Rev. C

142

120

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Background: Accurate knowledge of fission fragment yields is an essential ingredient of numerous applications ranging from the formation of elements in the r-process to fuel cycle optimization for nuclear energy. The need for a predictive theory applicable where no data is available, together with the variety of potential applications, is an incentive to develop a fully microscopic approach to fission dynamics.Purpose: In this work, we calculate the pre-neutron emission charge and mass distributions of the fission fragments formed in the neutron-induced fission of 239 Pu using a microscopic method based on nuclear density functional theory (DFT).Methods: Our theoretical framework is the nuclear energy density functional (EDF) method, where large amplitude collective motion is treated adiabatically using the time dependent generator coordinate method (TDGCM) under the Gaussian overlap approximation (GOA). In practice, the TDGCM is implemented in two steps. First, a series of constrained EDF calculations map the configuration and potential energy landscape of the fissioning system for a small set of collective variables (in this work, the axial quadrupole and octupole moments of the nucleus). Then, nuclear dynamics is modeled by propagating a collective wave packet on the potential energy surface. Fission fragment distributions are extracted from the flux of the collective wave packet through the scission line.Results: We find that the main characteristics of the fission charge and mass distributions can be well reproduced by existing energy functionals even in two-dimensional collective spaces. Theory and experiment agree typically within 2 mass units for the position of the asymmetric peak. As expected, calculations are sensitive to the structure of the initial state and the prescription for the collective inertia. We emphasize that results are also sensitive to the continuity of the collective landscape near scission.Conclusions: Our analysis confirms that the adiabatic approximation provides an effective scheme to compute fission fragment yields. It also suggests that, at least in the framework of nuclear DFT, three-dimensional collective spaces may be a prerequisite to reach 10% accuracy in predicting pre-neutron emission fission fragment yields.

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“…1 are most closely related because both 239 Pu(n th ,f) and 240 Pu(sf) start from a compound nucleus with the same value of A 0 . The 240 Pu(sf) data were taken from a study of 238,240,242 Pu(sf) relative to 239 Pu(n th ,f) [12]. The experiment was set up next to a reactor so that 239 Pu(n th ,f) could be used as a calibrator, The product yield data are shown for 239 Pu(n th ,f) while the fragment yields are given for 240 Pu(sf).…”

Section: Mass and Charge Partitionmentioning

confidence: 99%

Event-by-event study of neutron observables in spontaneous and thermal fission

Vogt

Randrup

2011

Phys. Rev. C

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Comparative study of the fragments' mass and energy characteristics in the spontaneous fussion of 238Pu, 240Pu and 242Pu and in the thermal-neutron-induced fission of 239Pu

Cited by 89 publications

References 15 publications

Fission fragment mass and total kinetic energy distributions of spontaneously fissioning plutonium isotopes

Fission fragment mass and total kinetic energy distributions of spontaneously fissioning plutonium isotopes

Fission fragment charge and mass distributions inPu239(n,f)in the adiabatic nuclear energy density functional theory

Event-by-event study of neutron observables in spontaneous and thermal fission

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