Comparison of fission modes in {sup 252}Cf, {sup 257}Fm, and {sup 260}Md

Journal Article · Thu Oct 01 04:00:00 EDT 1998 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.56741· OSTI ID:308195

van Aarle, J ^[1]; Siemon, K; Patzelt, P ^[2]; Wild, J F; Lougheed, R W ^[3]; Westmeier, W ^[4]

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1. Laboratory for Materials Behaviour, Paul Scherrer Institute, CH-5232 Villigen-PSI (Switzerland)
2. Philipps University, FB 15---Kernchemie, D-35032 Marburg an der Lahn (Germany)
3. University of California, Lawrence Livermore National Lab., Livermore, California 94551 (United States)
4. Dr. Westmeier GmbH, Moellnerweg 32, 35085 Ebsdorfergrund-Moelln (Germany)

Although the spontaneous-fission properties of heavy actinides have been studied for well over 35 years, many interesting and informative details continue to come into light. During the last decade, the spontaneous fission of {sup 252}Cf, {sup 257}Fm and {sup 260}Md has been extensively investigated at the Philipps University of Marburg (1{endash}4), by means of a gadolinium-doped liquid scintillation tank for neutron counting and surface barrier detectors for fission fragment detection. The three nuclides represent the transition from the well-known asymmetric fission yield distribution, as it is characteristic for {sup 252}Cf, to a much more symmetrical one, found in the fission of {sup 260}Md. Therefore, trends in the dynamical changes of fission properties have been derived from these studies. For the spontaneous fission of {sup 252}Cf and {sup 260}Md, it was already shown that different fission modes, as proposed by theoretical calculations of Brosa et al. (5), could be separated, using the correlation between the neutrons emitted in a fission event and both the observed fission-fragment mass and the total kinetic energy (1, 2). In the case of {sup 257}Fm, no theoretical calculations for fission modes exist. However, from the fission properties of the two surrounding actinides, one can expect at least three different fission modes, namely two {open_quotes}standard{close_quotes} and the {open_quotes}supershort{close_quotes} mode. In this paper, results from the recent {sup 257}Fm experiment will be presented and compared to systematics extracted from the fission properties of other heavy actinides. {copyright} {ital 1998 American Institute of Physics.}

• Sponsoring Organization: USDOE
• OSTI ID: 308195
• Report Number(s): CONF-980457--
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 447; ISSN 0094-243X; ISSN APCPCS
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CALIFORNIUM
CALIFORNIUM 252
CROSS SECTIONS
FERMIUM
FERMIUM 257
KINETIC ENERGY
MASS SPECTRA
MENDELEVIUM
MENDELEVIUM 260
NEUTRON SPECTRA
SPONTANEOUS FISSION
SPONTANEOUS FISSION RADIOISOTOPES