International Workshop on Fusion Dynamics at the Extremes : Dubna, Russia, 25-27 May 2000 = Fusion dynamics at the extremes

376 Pages·2001·6.034 MB·English

by  Yu Ts Oganessian, V I Zagrebaev

International Workshop on
Fusion Dynamics
at the Extremes
<
Editors
Yu. Ts. Oganessian
V. I. Zagrebaev
World Scientific
International Workshop on
Fusion Dynamics
at the Extremes

International Workshop on
Fusion Dynamics
at the Extremes
Dubna, Russia 25-27 May 2000
Editors
Yu. Ts. Oganessian
V. I. Zagrebaev
Flerov Laboratory of Nuclear Reactions
Joint Institute for Nuclear Research
Dubna, Russia
Vkfe World Scientific
wb Singapore • New Jersey • London • Hong Kong
Published by
World Scientific Publishing Co. Pte. Ltd.
P O Box 128, Farrer Road, Singapore 912805
USA office: Suite IB, 1060 Main Street, River Edge, NJ 07661
UK office: 57 Shelton Street, Covent Garden, London WC2H 9HE
British Library Cataloguing-in-Publication Data
A catalogue record for this book is available from the British Library.
Cover Design: V. Zagrebaev
FUSION DYNAMICS AT THE EXTREMES
Copyright © 2001 by World Scientific Publishing Co. Pte. Ltd.
All rights reserved. This book, or parts thereof, may not be reproduced in any form or by any means,
electronic or mechanical, including photocopying, recording or any information storage and retrieval
system now known or to be invented, without written permission from the Publisher.
For photocopying of material in this volume, please pay a copying fee through the Copyright
Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, USA. In this case permission to
photocopy is not required from the publisher.
ISBN 981-02-4617-X
This book is printed on acid-free paper.
Printed in Singapore by Uto-Print
V
PREFACE
The aim of the Workshop was to bring together theoreticians and
experimentalists who work in the field of near-barrier nuclear fusion, synthesis and
investigation of properties of superheavy elements (SHE). The progress made lately
by the experimentalists who have very closely approached the possibility of testing
the hypothesis of the existence of "islands of stability" in the region of superheavy
and exclusively stable by the nuclear standards nuclei, met with a similar activity of
theoreticians. It turned out that both communities have accumulated a large arsenal
of ideas and solutions after a long period of evolution and acquiring new
knowledge, when production of individual atoms of new elements was taking years
and years.
Even without clear understanding of complex fusion-fission dynamics in
extremely heavy nuclear systems the experimentalists took the risk of departing
from traditional methods of synthesis of new elements and made a number of
attempts to advent into unexplored areas, which had earlier been regarded as non-
promising and doubtful. They decided to fortify this intervention by setting up new
experiments devoted to the study of nuclear fusion-fission reactions, choosing as
objects of investigation such combinations, which potentially lead to the synthesis
of SHE.
On the other hand, theoretical models of the atomic nucleus and, in
particular, methods of calculation of masses and decay properties of nuclei far from
the stability line have progressed substantially, interalia in connection with the
development of physics of radioactive beams and prospects offered by the
acceleration of neutron-rich fission fragments in the near future. Application of
these achievements to superheavy nuclei leads to several possibilities in predicting
the SHE properties depending on the used model of the nuclear matter structure.
That is why we invited to our Seminar all leading physicists, theoreticians and
experimentalists, who work in the field of physics of SHE. The majority of them,
whose names you can see in the list of speakers, accepted our invitation and came to
Dubna.
In discussing the problems of near-barrier fusion of complex nuclei, the
competition between different reaction channels and their coupling, it was
interesting to understand what new information can be extracted in the case of using
radioactive ion beams (RIB), in particular beams of neutron-rich nuclei. That is why
a large number of contributions were devoted to the reactions induced by
radioactive nuclei, that is to the line in the investigations which will be developing
in the future in connection with the realization of big projects on the creation of
facilities for the production of high-intensity RIBs.
We express gratitude to all our guests and wish them further fruitful work.
Yu. Ts. Oganessian
V.I.Zagrebaev

VII
CONTENTS
Preface v
Aspects of Fusion, Fission and Cluster Radioactivity 1
W. Greiner
Current Problems of Superheavy Nuclei 21
/. Muntian, Z. Patyk and A. Sobiczewski
Structure of Super-Heavy Nuclei in Mean-Field Models 31
K. Rutz, T. Burvenich, M. Bender, P.-G. Reinhard,
J.A. Maruhn and W. Greiner
Superheavy Nuclei in Deformed Mean-Field Calculations 39
T. Burvenich. J.A. Maruhn, W. Greiner and P.-G. Reinhard
Extrapolation of Mean-Field Models to Superheavy Nuclei 51
M. Bender
The Synthesis of Superheavy Nuclei in the 48Ca+244Pu Reaction 65
Yu.Ts. Oganessian, V.K. Utvonkov. Yu.V. Lobanov, F.Sh. Abdullin,
A.N Polyakov, I.V. Shirokovsky, Yu.S. Tsyganov, G.G. Gulbekian,
S.L. Bogomolov, B.N. Gikal, A.N. Mezentsev, S. Iliev, V.G. Subbotin,
A.M. Sukhov, O.V. Ivanov, G.V. Buklanov, K. Subotic, M.G. Itkis,
K.J. Moody, J.F. Wild, N.J. Stoyer, M.A. Stoyer and R.W. Lougheed
Experiments on the Synthesis of Superheavy Elements with 48Ca Beams 81
at the Separator VASSILISSA
Yu.Ts. Oganessian, A.V. Yeremin. A.V. Belozerov, M.L. Chelnokov,
V.I. Chepigin, V.A. Gorshkov, A.P. Kabachenko, S.P. Korotkov,
O.N. Malyshev, A.G. Popeko, J. RohdC, R.N. Sagaidak,
S. Hofmann, G. Miinzenberg, M. Veselsky, S. Saro, N. Iwasa,
K. Morita and G. Giardina
Fusion-Fission of Superheavy Nuclei at Low Excitation Energies 93
M.G. Itkis. Yu.Ts. Oganessian, A.A. Bogatchev, I.M. Itkis,
M. Jandel, J. Kliman, G.N. Kniajeva, N.A. Kondratiev,
I.V. Korzyukov, E.M. Kozulin, L. Krupa, I.V. Pokrovski,
V.A. Ponomarenko, E. V. Prokhorova, A. Ya. Rusanov,
V.M. Voskresenski, F. Hanappe, B. Benoit, T Materna,
N. Rowley, L. Stuttge, G. Giardina and K.J. Moody
VIII
Survival Probability for Heavy Compound Nuclei 110
M. Ohta
Theoretical Estimation of Evaporation Residue Cross Section for 123
Production of Superheavy Elements in the Framework of Fluctuation-
dissipation Model
Y. Aritomo. T. Wada, M. Ohta and Y. Abe
Fusion Probability and Survivability in the Reactions Leading to the 135
Production of Heavy and Superheavy Nuclei
R.N. Sasaidak. V.I. Chepigin, M.G. Itkis, A.P. Kabachenko,
O.N. Malyshev, Yu.Ts. Oganessian, A.G. Popeko, J. Rohdd
andA.V. Yeremin
Decay Properties of Superheavy Elements (Theory and Experiment) 148
Yu.Ts. Oganessian
Semi-Bubbles and Bubbles: A New Kind of Superheavy Nuclei 155
K. Dietrich
Reaction Theory for Synthesis of the Superheavy Elements 162
Y.Abe
The Dinuclear System Concept for the Complete Fusion Process 174
V.V. Volkov
Calculation of Formation and Decay of Heavy Compound Nuclei 186
E.A. Cherepanov
Formation of Superheavy Elements 200
R. Smolanczuk
Production of Superheavy Elements in Heavy Ion Reactions 203
V.Yu. Denisov
Fusion-Fission Dynamics of the Synthesis of Superheavy Nuclei 215
V.I. Zagrebaev
IX
Fusion and Alpha Emission within a Liquid Drop Model 232
and Heaviest Element Formation and Decay
G. Rover and R.A. Gherghescu
On Scission Configuration in Ternary Fission 243
V.G. Kartavenko. A. S&ndulescu and W. Greiner
Fusion of Weakly Bound Stable Nuclei - What Can We Learn? 254
M. Dasgupta. A.C. Berriman, R.D. Butt, D.J. Hinde, C.R. Morton,
J.O. Newton, R.M. Anjos, P.R.S. Gomes, S.B. Moraes, N. Carlin,
A. Szanto de Toledo
Spin and Excitation Energy Dependence of Fission Survival: 264
A New Probe for the Fusion Fission Dynamics
S.K. Hui, A.K. Ganguly, C.R. Bhuinya, N. Madhavan, J.J. Das,
P. Sugathan, S. Muralithar, L.T. Baby, V. Tripathi, A.K. Sinha.
A.M. Vinodkumar, D.O. Kataria, N.V.S.V. Prasad,
P. V. Madhusudhana Rao and Raghuvir Singh
Sub-Barrier Fusion and Multi Nucleon Transfer in Medium-Heavy Nuclei 274
F. Scarlassara. S. Beghini, G. Montagnoli, G.F. Segato,
L. Corradi, A.M. Stefanini, A.M. Vinodkumar
Interplay between Fusion, Transfer and Breakup Reactions at 284
Near-Barrier Energies
P.R.S. Gomes, J. Lubian, S.B. Moraes, J.J.S. Santos,
A.M.M. Maciel, R.M. Anjos, I. Padron, C. Muri, R. Liguori Neto
and N. Added
Mechanisms of Sub-Barrier Fusion Enhancement 296
N. Rowley
Fusion Enhancement Above the Barrier for the 6He + 209Bi-Reaction 308
Yu.E. Penionzhkevich. Yu.A. Muzychka, S.M. Lukyanov,
R. Kalpakchieva, N.K. Skobelev, V.P. Perelygin, L.V. Mikhailov,
Yu.G. Sobolev, Z. Dlouhy, Ya. Mrazek, J. Vincour, N.O. Poroshin,
F. Oliveira de Santos, L. Kostov, N.A. Demekhina and F. Negoita