Exotic Nuclei, pp. 158-166 (2002) No AccessLATEST RESULTS FROM HENDES COLLABORATION: FINE STRUCTURE IN FRAGMENT MASS-ENERGY DISTRIBUTIONW. H. TRZASKA, YU. V. PYATKOV, YU. E. PENIONZHKEVICH, V. A. MASLOV, O. I. OSETROV, A. A. ALEXANDROV, I. A. ALEXANDROVA, J. ÄYSTÖ, K. -TH. BRINKMANN, S. V. KHLEBNIKOV, V. F. KUSHNIRUK, A. V. KUZNETSOV, V. G. LYAPIN, M. MUTTERER, Z. RADIVOJEVICH, V. A. RUBCHENYA, YU. G. SOBOLEV, V. G. TISHCHENKO, G. P. TIOURINE and D. N. VAKHTINW. H. TRZASKADepartment of Physics of University of Jyväskylä, Finland, YU. V. PYATKOVMoscow Engineering Physics Institute, Russia, YU. E. PENIONZHKEVICHFlerov Laboratory of Nuclear Reactions, JINR, Dubna, Russia, V. A. MASLOVFlerov Laboratory of Nuclear Reactions, JINR, Dubna, Russia, O. I. OSETROVKhlopin Radium Institute, St. Petersburg, Russia, A. A. ALEXANDROVFlerov Laboratory of Nuclear Reactions, JINR, Dubna, Russia, I. A. ALEXANDROVAFlerov Laboratory of Nuclear Reactions, JINR, Dubna, Russia, J. ÄYSTÖDepartment of Physics of University of Jyväskylä, Finland, K. -TH. BRINKMANNTechnical University Dresden, Germany, S. V. KHLEBNIKOVKhlopin Radium Institute, St. Petersburg, Russia, V. F. KUSHNIRUKFlerov Laboratory of Nuclear Reactions, JINR, Dubna, Russia, A. V. KUZNETSOVKhlopin Radium Institute, St. Petersburg, Russia, V. G. LYAPINDepartment of Physics of University of Jyväskylä, Finland, M. MUTTERERTechnical University Darmstadt, Germany, Z. RADIVOJEVICHDepartment of Physics of University of Jyväskylä, Finland, V. A. RUBCHENYADepartment of Physics of University of Jyväskylä, FinlandKhlopin Radium Institute, St. Petersburg, Russia, YU. G. SOBOLEVFlerov Laboratory of Nuclear Reactions, JINR, Dubna, Russia, V. G. TISHCHENKOMoscow Engineering Physics Institute, Russia, G. P. TIOURINEDepartment of Physics of University of Jyväskylä, FinlandKhlopin Radium Institute, St. Petersburg, Russia and D. N. VAKHTINDepartment of Physics of University of Jyväskylä, FinlandKhlopin Radium Institute, St. Petersburg, Russiahttps://doi.org/10.1142/9789812777300_0012Cited by:0 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail Abstract: Existence of a new feature in fragment mass-energy distribution is reported. Careful analysis of the data obtained in the reaction 238U + 40Ar (275 MeV) shows that small but statistically significant ripples visible already in the gross mass spectrum come from extended and regular 2D patterns in the TKE vs. mass matrix. Intensity distributions of these patterns coincide with the location of heavy clusters such as 78Ni, 108Mo, or 132Sn. Presumably, the observed patterns show the dominant trajectories in the elongation vs. mass-asymmetry space of the decaying system. This information, unknown in the past, can shed a new light even on the previously well-studied reactions. FiguresReferencesRelatedDetails Exotic NucleiMetrics History PDF download

The results of experimental and theoretical studies of the double-differential proton and neutron spectra measured in coincidence with fission fragments in the deuteron-induced reaction on a 238 U target at E d =65 MeV are presented. These spectra measured in the forward direction are analyzed in the plane-wave Born approximation by using the modified model of stripping into a continuum. The pre-neutron emission fission fragment mass distributions were measured for the ( d , f ), ( d , pf ), and ( d , nf ) reaction channels. The enhancement of highly asymmetric mass division in the ( d , pf ) channel for the low-energy part of the breakup proton spectrum was observed. The ( d , pf ) channel can be used to imitate the neutron-induced fission at intermediate energy. The fission characteristics were analyzed in the model taking into account nuclear friction and relevant fission modes.

A pronounced fine structure (FS) in the form of distinct peaks was observed in neutron gated mass spectra from the decay of the 278110 composite system produced in the reaction 238U + 40Ar (243 MeV) at an initial excitation energy E* > 70 MeV. The FS peaks are located in the vicinity of mass numbers 70-80, 100, and 130, which correspond to those of magic nuclei (clusters). In the data there is also evidence for a new type of decay -- collinear cluster tripartition of an excited nucleus.

The results of studies of fission fragment mass distributions in deuteron-induced fission of U-238 for (d,f), (d,pf), and (d,nf) reaction channels at deuteron energy E-d = 65 MeV are presented. The double differential proton and neutron spectra in coincidence with fission fragments have been measured. Enhancement of fragment yield in the highly asymmetric mass region had been observed in (d,f), (d,pf), and (d,nf) reaction channels. The U-238(d,pf) reactions channel can be used to imitate the neutron induced fission at intermediate energy.

Existence of a new feature in fragment mass-energy distribution is reported. Careful analysis of the data obtained in the reaction 238U + 40Ar (275 MeV) shows that small but statistically significant ripples visible already in the gross mass spectrum come from extended and regular 2D patterns in the TKE vs. mass matrix. Intensity distributions of these patterns coincide with the location of heavy clusters such as 78Ni, 108Mo, or 132Sn. Presumably, the observed patterns show the dominant trajectories in the elongation vs. mass-asymmetry space of the decaying system. This information, unknown in the past, can shed a new light even on the previously well-studied reactions.