Search for dynamical effects in the fission decay in the 240 MeV $\chem{^{32}S+\,^{100}Mo}$ reaction

G. La Rana; A. Brondi; R. Moro; E. Vardaci; A. Ordine; A. Boiano; M.A. Di Meo; A. Scherillo; D. Fabris; M. Lunardon; G. Nebbia; G. Viesti; M. Cinausero; E. Fioretto; G. Prete; N. Gelli; F. Lucarelli

doi:doi:10.1140/epja/i2002-10091-y

2022 Impact factor 2.7

Hadrons and Nuclei

Eur. Phys. J. A 16, 199-207 (2003)
DOI: 10.1140/epja/i2002-10091-y

Search for dynamical effects in the fission decay in the 240 MeV $\chem{^{32}S+\,^{100}Mo}$ reaction

G. La Rana¹, A. Brondi¹, R. Moro¹, E. Vardaci¹, A. Ordine¹, A. Boiano¹, M.A. Di Meo¹, A. Scherillo¹, D. Fabris², M. Lunardon², G. Nebbia², G. Viesti², M. Cinausero³, E. Fioretto³, G. Prete³, N. Gelli⁴ and F. Lucarelli⁴

¹ Dipartimento di Scienze Fisiche, Università di Napoli "Federico II" and Istituto Nazionale di Fisica Nucleare, Via Cinthia, 80126 Napoli, Italy
² Dipartimento di Fisica and Istituto Nazionale di Fisica Nucleare, Padova, Italy
³ Laboratori Nazionali di Legnaro dell' Istituto Nazionale di Fisica Nucleare, Legnaro (Padova), Italy
⁴ Dipartimento di Fisica and Istituto Nazionale di Fisica Nucleare, Firenze, Italy

moro@na.infn.it

(Received: 6 August 2002 / Published online: 4 February 2003)

Abstract
Light particles in coincidence with evaporation residues and heavy fragments have been measured by a 4 $\pi$ charged-particle detector at the INFN Laboratori Nazionali di Legnaro (Padua) for the 240 MeV ³²S + ¹⁰⁰Mo reaction leading to the ¹³²Ce composite system at 152 MeV of excitation energy. Energy spectra of the alpha-particles in coincidence with fission fragments were extracted for many correlation angles both in plane and out of plane. A prominent out-of-plane emission was observed, consistent with the pattern for the near-scission emission. From the fit to the spectra, the pre-scission alpha-particle multiplicity of $0.040 \pm 0.006$ was obtained. This value is reproduced by the code PACE2 without the inclusion of a delay time for fission. The presence of fast fission, which could be responsible for this result, is discussed.