Exotic Nuclei

The following sections are included:

• PREFACE

• WELCOME – JINR: BRIEF INTRODUCTION INTO HISTORY, PRESENT STATUS AND FUTURE DEVELOPMENT

• CONTENTS

The following sections are included:

• Introduction

• Knockout reactions under the microscope

• Nuclear structure under the microscope

• Conclusion

• Acknowledgments

• References

A short review of recent nuclear astrophysics experiments performed at GANIL is given. These experiments used radioactive beams produced by the SPIRAL facility or the LISE separator.

Spectra of unbound states of helium isotopes ^8,9,10He were studied in the one- and twoneutron transfer reactions with the use of the ^6,8He secondary beams and a cryogenic tritium/deuterium target. Analysis of angular correlations of decay products allowed us to define spin-parities of the states observed in the experiments. In disagreement with shell model expectations the established level ordering in ^9,10He testifies the shell breakdown in these nuclei. Angular correlations measured for a decay of the well-known 2+ state of ⁸He were applied for the verification of the experimental approach used in this work.

A review of recent experiment including those performed by our collaboration is given. The main accent is done to unique information which is extracted from the measurements of the inelastic scattering cross-sections using the Modified diffraction model (MDM). The enhancement of the radii of some highly excited cluster states of ¹²C, ¹¹B and ¹³C was definitely observed. The radii values are in general 20-30% larger than those of the corresponding ground states but much less than those predicted by the model of alpha particle condensation. A rotational band based on the 0⁺₂ (Hoyle) state in ¹²C is identified.

-decay in the neighborhood of ¹⁰⁰Sn was studied at the National Superconducting Cyclotron Laboratory (NSCL). The new half-lives of ^96,97Cd, along with several new -delayed proton emission branching ratio for nuclei in this region have an impact on the composition of type-I X-ray burst ashes predicted by network calculations.

The knowledge of spin and parity of excited levels in exotic nuclei revealed exciting phenomena appearing only in nuclei with extreme N/Z ratios. Excited levels in nuclei are mainly depopulated by competitive processes between gamma-emission and internal electron conversion. The spin and parity of the initial and final state for a given Z and gamma energy could be deduced by knowing the ratio between the emitted conversion electrons and gamma particles. By measuring the internal conversion coefficient α_k or the ratio α_k/α_L we can extract the multipolarity of the transition. This paper will present preliminary results concerning the evolution of g_9/2 orbital with increasing number of neutrons in the vicinity of N=40 nuclei.

The following sections are included:

• Introduction

• Coulomb dissociation of ³⁶Ca and ²⁷P

• Proton elastic scattering of ²⁶Si

• Direct measurement of the ¹⁸Ne( ,P) reaction

• References

We report on the spectroscopic quadrupole moment of the 7/2- isomer state [E*=320.5(5) keV, T_1/2=415(5) ns, |Q_s|=23(3) efm²] in the neutron-rich ⁴³S nucleus, using the Time Dependent Perturbed Angular Distribution (TDPAD) method at RIKEN. The measured |Q_s| is larger than that expected for a single particle state. Comparison to shell model calculations performed using the SDPF-U interaction, show that correlations drive the isomeric state away from a purely spherical shape.

Thanks to its record spatial resolution and sensitivity, nuclear track emulsion technique allowed one to carry out a "tomography" for light neutron deficient nuclei. It is found that for the ¹⁰C nucleus the fraction of the coherent dissociation events 2a + 2p is about 80%. About 30% of them belong to the channel ⁹B_g.s. + p with a subsequent decay ⁸Be + p. There are no obviously leading channels in the coherent dissociation of ¹²N. At the same time there is an intensive formation of fragments with a charge exceeding 3. Most probably, the role of the ¹²N core can be attributed to the ⁷Be nucleus.

By using the ¹H(⁶Li,⁶Be)n charge-exchange reaction, population of continuum states in ⁶Be was observed up to 16 MeV above its three-body decay threshold. In kinematically complete measurements performed by detecting α+p+p coincidences The spectrum provides detailed correlation information about the 0+ ground state and first excited 2⁺ state. Influence of reaction mechanism on formation of observed spectra is discussed.

The results of the experiment performed by Kurchatov – Tsukuba – Almaty collaboration at the tandem of Tsukuba University are presented. All the known states of ⁹Be up to the excitation energies ~ 12 MeV were observed. It is possible, all the low laying ⁹Be states could be decomposed into three rotational bands, each having cluster structure ⁸Be core plus a valence neutron in one of the orbits: p_3/2-, s_1/2+ and p_1/2-.

The U120M cyclotron in NPI ASCR, Rez, delivers light particle beams that can be used for different indirect methods to reach experimentally the Gamow region. ANC Asymptotic Normalization Coefficient method and THM Trojan Horse method are used to extract information on astrophysical S-factors in the above mentioned region. Key parameters of the U120M cyclotron are presented, a review of recent experiments concerning problems of nuclear astrophysics is given.

The sub-barrier fusion experimental data have been inspected. A strong correlation between fusion cross-sections at sub-barrier energies and the fusion Q values has been found. A simple energy scaling is suggested to comply Compound Nucleus available phase-space. An experimental verification of the scaling is proposed…

The following sections are included:

• Introduction

• Elastic scattering cross section

• Breakup cross section

• Momentum distributions of fragments

• Conclusions

• Acknowledgments

• References

The joint analyze of experimental data of interactions deuterons on nuclei ⁶Li, ¹⁶O, ³²S, ⁵⁰V, ⁵¹V, ⁷⁰Ge, ⁷²Ge, ⁹⁰Zr, ¹¹⁶Sn in range of Coulomb barrier till 200 MeV is presented. The global parameters as mass and energy dependence of deuterons with energies till 200 MeV by macroscopically optical model of deuterons were analyzed.

Time-dependent Schrodinger equation is numerically solved by difference method for external neutrons of nuclei ⁶He, ¹⁸O, ⁴⁸Ca, ²³⁸U at their grazing collisions with energies near to a Coulomb barrier. The spin-orbital interaction and Pauli's exclusion principle were taken into consideration during the solution.

In the experiments carried out by ion beam ⁶He of the cyclotron complex DRIBs (JINR) and ³He beam cyclotron U-120M of the NPI, Czech Academy of Sciences have been investigated reaction ⁴⁵Sc+³He,⁶He and ¹⁹⁷Au+³He,⁶He in the energy range near the Coulomb barrier. It were obtained the experimental values of the cross sections for complete fusion reactions and direct reactions for formation of the isotopes ⁴³Sc, ⁴⁴Sc and ⁴⁶Sc also ¹⁹⁶Au and ¹⁹⁸Au as a function of the bombarding ³He and ⁶He energy. Despite the low binding energy of ³He and the positive Q-values leading to the formation of isotopes ⁴⁴Sc and ⁴⁶Sc also ¹⁹⁶Au and ¹⁹⁸Au, the behavior of the excitation functions with the formation of these isotopes is different from the excitation functions for d, ⁶He.

Structure of the excited states and resonances with different isospin quantum numbers in halolike nuclei is discussed. It is shown that IAS, DIAS, and CS can simultaneously have nn, np, and pp halo components in their wave functions.

During the last decade the elements hassium (Hs, Z=108), copernicium(Cn, Z=112), and flerovium (Fl, Z=114) have been studied for the first time by chemical means. Hassium as a member of group eight of the periodic table proved to form a volatile molecule with oxygen, HsO₄. Copernicium and flerovium both behaved like a volatile noble metal. While HsO₄ turned out to be less volatile compared to the nearestby homologue in the same group of the periodic table, OsO₄, Cn and Fl were both significantly more volatile compared to their homologues Hg and Pb, respectively, in their elemental state. All first ever chemical studies were performed with very few atoms: seven in case of Hs, five with Cn and three with Fl, respectively.

Several aspects of the structure of exotic nuclei are discussed. Some problems interesting for the experimental investigations are considered.

Collisions between ²⁴⁸Cm and ⁴⁸Ca are systematically investigated by time-dependent density functional calculations with evaporation prescription. Depending on the incident energy and impact parameter, fusion, deep-inelastic and fission events are expected to appear. In this paper, a microscopic method of calculating the fissibility of compound nuclei is presented.

The discovery of new higher Z elements and the determination of their decay properties provide important insights into our understandings of the behaviour of nuclear matter under extreme conditions of high Z and important tests of the prediction of an island of stability around N=184 and high Z (114 or even 120-126). The synthesis of odd-Z superheavy nuclei provides more detailed information than even-Z nuclei about the nuclear structure of these nuclides because of their longer decay chains as a result of strong fission hindrance caused by the unpaired nucleons. For the first time the Z=115 nuclei and their odd-Z decay products including Z=113 isotopes were observed in 2003 [1,2]. Three decay chains of ²⁸⁸115 ²⁸⁴113 ²⁸⁰Rg …²⁶⁸Db and one decay chain of ²⁸⁷115 ²⁸³113 ²⁷⁹Rg …²⁶⁷Db were discovered in the ²⁴³Am(⁴⁸Ca,3-4n) complete-fusion reaction. In 2006 two decay chains of the lighter isotope ²⁸²113 were synthesized in the ²³⁷Np(⁴⁸Ca,3n) reaction [3]. The discovery of element 117 [4,5] has been reported using the ²⁴⁹Bk+⁴⁸Ca reaction; five decay chains of ²⁹³117 ²⁸⁹115 …²⁸¹Rg and one chain of the heaviest isotope ²⁹⁴117 ²⁹⁰115 …²⁷⁰Db were observed in 2009–2010. A relatively high stability of all these odd-Z activities is caused by the influence of presumably spherical nuclear shells at Z=114-126 and N=184. The sequential a decays of the isotopes ²⁸²113, ^287,288115 and ²⁹⁴117 lead to ^266-270Db (N=161–165) that are already located in the vicinity of deformed nuclear shells at Z=108 and N=162…

A possibility of the formation of superasymmetric fission fragments caused by the nuclear shells at Z = 20, 82 and N = 28, 126 is investigated. The mass-energy distributions of fission fragments of ²⁶⁰No compound nucleus formed in the reaction ¹²C + ²⁴⁸Cm have been measured. The increase of fragment yields in the mass region around 52/208 u that corresponds to the formation of fissioning pair of two double magic nuclei Ca/Pb was observed. At excitation energy of 50 MeV the yield of these fragments is about 0,001%.

The following sections are included:

• Introduction

• Experimental setup

• Experiments and future plans

• Acknowledgments

• References

Using HF+BCS method with Skyrme forces we analyze the neutron drip line. It is shown that around magic and new magic numbers the drip line may form stability peninsulas. It is shown the location of these peninsulas does not depend on the choice of Skyrme forces. It is found that the size of the peninsulas is sensitive to the choice of Skyrme forces and the most extended peninsulas appear with the SkI2 set.

At the present time, a great interest is paid to the research of the properties of atomic nuclei (isotopes) located far from the beta stability line. Neutron-rich osmium isotopes of multi-nucleon transfer reactions investigated in this work. The reaction ¹³⁶Xe+²⁰⁸Pb with energy near Coulomb barrier is used for production osmium isotopes. The CORSAR-V setup was created in framework of our investigations. Method of separation volatile reaction products from non-volatile products was realized from experimental setup. The fist experimental results were obtained at this time.

The possibility of superheavy elements production in high intensive neutron fluxes is being studied. A model of the transuranium isotopes production under conditions of pulse nucleosynthesis in a neutron flux with densities of up to ~10²⁵ neutron/cm² is considered. The pulse process allows us to divide it in time into two stages: the process of multiple neutron captures (with t < 10^-6 s) and the subsequent β-decay of neutron-rich nuclei. The modeling of the transuranium yields takes into account the adiabatic character of the process, the probability of delayed fission, and the emission of delayed neutrons. A target with a binary composition of ²³⁸U and ²³⁹Pu, ²⁴⁸Cm, and ²⁵¹Cf isotopes is used to predict the yields of heavy and superheavy isotopes.

Time-dependent Schrödinger equation for external neutrons of deformed nucleus ²³⁸U is numerically solved by difference method for collisions ^40,48Ca+²³⁸U with energies in vicinity to a Coulomb barrier. The spin-orbital interaction were taken into consideration during the solution. The probabilities of transfer of neutrons are determined as function on minimum internuclear distances and quantum numbers of initial neutrons states.

Several self-consistent observations have led to the conclusion that long-lived multi-core systems (nuclear molecules) exist. This conclusion is based on next results:…

The level structures of ^108,110,112Ru (Z=44) and ^{112,114,115,116,117,118}Pd (Z=46) have been significantly expanded through studies of prompt γ-γ-γ coincidences observed with Gammasphere following the spontaneous fission of ²⁵²Cf. The softness to triaxiality perturbs the band structures of ¹⁰⁸Ru and even-N Pd isotopes. Two sets of odd-parity bands are identified in ^112,114,116Pd similar to but different from those in ^110,112Ru. These differences can be accounted for by interferences of the chiral doubling and softness to triaxiality. Also in ¹¹²Ru, evidence for wobbling motion is found in the behavior of the γ vibrational band. Similar evidence for wobbling motion is found in ¹¹⁴Pd, the N = 68 isotone of ¹¹²Ru.

Negative-parity bands in deformed nuclei have traditionally been interpreted in terms of octupole excitations, but interest in these bands has been revived recently by predictions of tetrahedral shape. The level schemes of numerous nuclei in the mass 160 and 230 regions have been studied at iThemba LABS. In particular we look at the results for ¹⁵⁸Dy. B(E1)/B(E2) ratios for transitions from the odd and even-spin negative parity bands to the ground bands were measured and are compared with Cranked Random Phase Approximation calculations. The results support an interpretation in terms of aligned octupole vibrations.

A finite rank separable approximation for the quasiparticle random phase approximation with Skyrme interactions is applied for the case of charge-exchange nuclear modes. The couplings between one- and two-phonon terms in the wave functions are taken into account. First, we check that the approximation reproduces reasonably well the full charge-exchange RPA results for the spin-dipole resonances in ¹³²Sn. As an illustration of the method the phonon-phonon coupling effect on the β-decay half-live of ⁷⁸Ni is considered.

The dynamical dipole mode was investigated in the mass region of the ¹⁹²Pb compound nucleus, by using the ⁴⁰Ca + ¹⁵²Sm and ⁴⁸Ca +¹⁴⁴Sm reactions at Elab = 11 and 10.1 MeV/nucleon, respectively. The -ray energy spectra at various polar angles were obtained for fusion-evaporation and fission events by detecting the high energy -rays with the MEDEA experimental apparatus in coincidence with evaporation residues and fission fragments. Our results show that the dynamical dipole mode survives in reactions involving heavier nuclei than those studied previously. However, its yield is lower than that expected within BNV calculations.

Reactions induced by photons may be used as a probe for bonds and correlations between nucleons inside a heavy target nucleus. Electromagnetic radiation perturbs the nucleons only slightly unlike the influence of strongly interacting particles. The yield of (γ, α) reactions could be used to test theoretical models assuming a complete α-clustering, or multi-quark objects in heavy nuclei. Relative yields of (γ, n), (γ, p), and (γ, α) reactions have been measured at the bremsstrahlung end-point energy of 23 MeV with several targets. Much lower probability of (γ, α) compared to (γ, p) reactions is proved despite practically similar threshold and spin factors for both types of reactions. Alpha clustering in heavy targets is not supported. The mechanism of particle release in nuclear reactions is discussed and some details are clarified.

Preliminary results of the analysis of the rectangular structures in the mass correlation distributions of the fission fragments from ²⁵²Cf (sf) are presented. The structures lie in the region of big missing mass and are connected with the multi-body decay of the mother system. The ternary chain-like prescission configuration seems to be too compact and could decay due to tunneling only. More elongated four-body configuration leading to the quaternary decay let meet energy conservation law in the scission point.

Relativistic exotic nuclei have been produced via uranium projectile fragmentation and fission and investigated with the in-flight separator FRS directly, or in combination with either the storage-cooler ring ESR or the FRS Ion Catcher. 60 neutron-rich isotopes have been discovered in the element range from Nd to Pt and their production cross sections have been measured. In another experimental campaign the fragments were separated in flight and injected into the storage-cooler ring ESR for accurate mass and lifetime measurements. Pioneering experiments have been carried out with the FRS Ion Catcher. Results from these different FRS experiments will be presented in this overview together with perspectives for the next-generation facility Super-FRS.

The following sections are included:

• Introduction

• Experiment

• Results and discussion
  • Momentum distributions
  • Production cross section

• Production cross section for the next calcium isotopes

• Summary

• Acknowledgments

• References

The following sections are included:

• Introduction

• Development of shape coexistence theory in Pb region

• Important experimental findings

• In-beam γ-ray spectroscopy of 184Pb – probing non-yrast states beyond the N=104 midshell

• Summary

• References

The study of the properties of neutron-rich nuclei far from stability is one of the most intriguing areas of modern research in nuclear physics. A plenty of the joint GANILFLNR experiments were devoted on study of neutron rich unstable nuclei with neutron numbers near the magic shells N=20 and N=28. A lot of interesting results on stability and properties of nuclei in this region were observed during these experiments, mainly performed at GANIL.

Yields of reactions resulting in formation of exotic nuclei during uranium photofission are measured. The nuclei are identified and their yields are found by the method based on measurement of γ ray spectra from their radioactive decay. The nuclei for investigation are produced using the microtron bremsstrahlung beam and their γ spectra are measured at the HPGe detector. The optimum conditions for production of exotic nuclei in photonuclear reactions are discussed.

The new PreSPEC project is aimed at nuclear structure and reaction studies using radioactive isotope beams. At the SIS/FRS facility at GSI exotic beams at relativistic energies were employed for Coulomb excitation and secondary fragmentation experiments. High-resolution gamma-ray spectroscopy is the main tool to investigate the shell evolution far off stability, proton-neutron interaction, symmetries and nuclear shapes. Compared to the former RISING set-up an advanced particle (LYCCA) and γ-ray (AGATA) detection system are used. At the future FAIR facility, these tools will be employed by the High-resolution In-flight SPECtroscopy (HISPEC) project. The improvements in the experimental set-ups, together with the opportunities to be opened, are discussed.

The following sections are included:

• Introduction

• Accelerator facility NICA

• Nuclotron-M & NICA project

• Collider luminosity

• NICA cryogenic system

• The BM@N experiment

• The MPD experiment

• Detector for the second IP

• References

The following sections are included:

• Introduction

• ACCULINNA fragment separator and collaboration

• Dripline research at ACCULINNA. Novel experimental approaches for low-energy direct reactions

• Scientific motivation for ACCULINNA-2

• On the way to ACCULINNA-2

• Welcome

• References

The Helmholtzcenter for Heavy Ion research (GSI) is focusing on the Facility of Antiproton and Ion Research (FAIR) strongly. Providing highest energy beams the new facility will offer outstanding research opportunities and discovery potential in future [1]. Nevertheless, regarding the public impact the discovery of new elements is next to the cancer therapy with heavy ions still the flagship of GSI. It is an ongoing process to keep the super heavy element (SHE) program at GSI together with its international collaborations competitive on a high level. Providing high primary beam intensity by a dedicated accelerator is one import part therefore. A cost-benefit analysis has shown, that a superconducting (sc) continuous-wave (cw) linear accelerator (LINAC) in combination with the upgraded GSI High Charge Injectior (HLI) fits the requirements for the GSI SHE program at best [2]. A predicted increase of the beam intensity by a factor of 10 to 20, depending on the ion and charge state, would keep the successful and popular SHE program competitive with remarkable reduced operational costs in comparison with the existing accelerator at GSI. In the following the status of the cw LINAC project is reported and its perspectives are discussed.

A new plunger device has been designed and built to measure the lifetimes of unbound states in exotic nuclei beyond the proton drip-line. The device is designed to work in both vacuum and dilute-gas environments made possible through the introduction of a lowvoltage piezoelectric motors. The differential plunger for unbound nuclear states, DPUNS, will be used in conjunction with the gas-filled separator RITU and the vacuum separator MARA at the accelerator laboratory of the University of Jyväskylä, Finland, to measure the lifetimes of excited states with low population cross-sections. This is achieved by eliminating the need for a carbon foil to isolate the helium gas of RITU from the beam line thus reducing the background from beam-foil reactions. The plunger will be used to address many key facets of nuclear structure physics with particular emphasis on the effect of deformation on proton emission rates.

The following sections are included:

• Introduction

• Incorporation of the gas catcher technique
  • Gas catcher technique advantages
  • Primary beam pre-separator
  • Evaporation-residue fusion reactions
  • Electrostatic pre-separator
  • Modification of the mass spectrometer MASHA

• Application for studying multinucleon transfer (MNT) reactions
  • MNT reaction features
  • Transport line to deliver primary beams up to the gas catcher

• Conclusion

• References

Beta decay properties are among the easiest and therefore, the first ones to be measured to study new neutron rich isotopes. Eventually it could be sufficient just a few number of nuclei to estimate its lifetime and neutron emission probability. With the new radioactive beam facilities which have been commissioned recently (or will have been constructed shortly) new areas of neutron rich isotopes are becoming reachable. To study beta decay properties of such nuclei at IPN Orsay in the frame of collaboration with JINR, Dubna a new experimental setup including the neutron detector TETRA of high efficiency was developed and commissioned.

A neutron detector array-Multi-Neutron Correlation Spectrometer (MuNCoS) composed of 80 detector modules was constructed at Peking University in order to measure simultaneously multi-neutrons with excellent cross-talk rejection capability. MuNCoS was configured in a special spacing setup and applied firstly in a test experiment with 11Be@37A MeV beam at HIRFL-RIBLL facility. Some preliminary results concerning the performance of the spectrometer are obtained and reported here.

After more than 25 years of the successful operation of SHIP in heavy-and superheavy element research, it is due time for the development of a next-generation in-flight separator for fusion and transfer products, primarily for heavy and superheavy elements. This work is triggered by new developments including accelerators for beams of highest intensity, the availability of strong beams of radioactive isotopes at near Coulomb barrier energies, and the recent developments for efficient ion catcher-cooler systems with the capability of mass identification and measurement.

A novel method, SCRIT (Self-Confining Radioactive isotope Ion Target), forms a target of short-lived RI (Radioactive Isotope) ions inside an electron scattering ring, which makes electron scattering experiments for short-lived nuclei possible. The SCRIT electron scattering facility is under construction at RIBF in RIKEN to realize electron scattering experiment for short-lived nuclei for the first time. The facility consists of a 150-MeV microtron, an electron storage ring equipped with a SCRIT device and an ISOL involving a low energy RI beam generator. Stable nuclei, ¹³³Cs and ¹³²Xe, were used as targets to evaluate the performance of this facility. Elastically scattered electrons from the targets were clearly observed and the luminosity was found to reach nearly 10²⁷ cm^-2s^-1 at the electron beam current ~200 mA, which is the required luminosity to determine the charge density distribution of the target nucleus.

European plans for the construction of a deep underground science facility for neutrino physics and proton decay are presented and discussed. The new facility should host a very large volume neutrino detector of the next generation that would work also as a far detector for the very long baseline flavor oscillations with neutrino beams from CERN and possibly also from Protvino. The Pyhäsalmi mine in Finland is currently the strongest contender.

This paper intends to give a short overview of the ELI-NP facility in the context of the ELI Project and to provide to date information about its status. More detailed information can be found on the sites: www.extreme-light-infrastructure for the ELI Project in general and www.eli-np.ro for ELI-NP.

In our experiments carried out so far multiple manifestations of the new multi-body decay of ²⁵²Cf (sf) were observed. Principal result obtained in the missing mass approach consists in revealing of the rectangular like structures bounded by magic clusters in the fission fragments correlation mass distributions. The result is confirmed by the direct registration of three decay partners. Further development of the experimental methodic is planning to provide in three different directions, namely, by increasing of both aperture and granularity of the COMETA mosaic setup, by using of the electrostatic guide based system at the IBR-2 reactor and developing flesh-ADC based technique.

Our recent experiments dedicated to study of the CCT of ²⁵²Cf (sf) were carried out at the COMETA setup based on the mosaics of PIN diodes and special array of ³He filled neutron counters. Principal peculiarity of the experiment consists in measuring of the heavy ions masses in the frame of the TOF-E (time-of-flight vs. energy) method in the wide range of masses and energies and almost collinear recession of the decay partners. The methodical questions of such experiment are under discussion here.

It is proposed a new setup to produce and investigate heavy neutron rich nuclei located along the neutron closed shell N=126. This "blank spot" of the nuclear map can be reached neither in fusion-fission reactions nor in fragmentation processes widely used nowadays for the production of exotic nuclei. A new way was recently proposed for the production of these nuclei via low-energy multi-nucleon transfer reactions. The estimated yields of neutron-rich nuclei are found to be rather high in such reactions and several tens of new nuclides can be produced in the near-barrier collision of ¹³⁶Xe with ²⁰⁸Pb, for instance. This setup could definitely open a new opportunity in the studies at heavy-ion facilities and will have significant impact on future experiments.

The VME based data acquisition system for the first time was fully tested in the recent experiment [1] with the ³H(⁸He,p)¹⁰He reaction on the ACCULINNA fragment separator [2]. This DAQ allowed us to combine in the same experiment several types of detectors: multiwire proportional chambers, silicon detectors, CsI detectors and stilbene detectors. The DAQ system includes a RIO-3 processor connected with CAMAC crate via GTB resources, TRIVA-5 master trigger, standard VME units ADC, TDC, QDC (about 250 parameters in total) and various software (Multi Branch System – MBS version 5.0, based on CERN ROOT Go4 version 4.4.3 and real time OS LynxOS version 3.3.1). The new DAQ is faster and more flexible than the old system based on CAMAC and provides possibility to use in the future new VME modules (for instance digitizers).

The experimental method and set-up based on 4 n-Υ-technique for direct and modelindependent measuring of the total reaction cross section σ_R have been presented. The excitation function σ_R(E) for ⁶He+¹⁹⁷Au reaction at the Coulomb barrier energy region has been measured. The measured data are compared with the summarized cross section which has been prepared by summing of measured cross sections of main reaction channels: 1n-transfer and ¹⁹⁷Au(⁶He, xn)^203-xnT1 with x = 2÷7 evaporation reaction channels.

Dear Chairman, ladies and gentlemen, dear colleagues! It is a great honor for me to speak before you at the opening ceremony of the international Symposium on exotic nuclei. I welcome you in this beautiful hall, belonging to the Far Eastern Federal University and thank you that you have responded to our invitation and were able to arrive to our city in order to discuss the latest achievements in the field on nuclear physics. This is the first major scientific event, which takes place in the new University campus, where only a few weeks ago ended the APEC summit…

RIKEN Radio Isotope Beam Factory RIBF is currently providing the world most powerful heavy-ion beams up to uranium. The status of RIBF is presented together with its prospect for coming five years.

The advent of high power light and heavy ion accelerators producing intense secondary radioactive ion beams (RIB) made possible the exploration of a new territory of nuclei with extreme in Mass and/or N/Z ratios. To pursue the investigation of this "terra incognita" several projects, based on second generation accelerators producing intense stables and RIB, all aiming at the increase by several orders of magnitude of the RIB intensities are now under construction and/or planned for the end of this decade in the world. RIB production at SPES@Legnaro, SPIRAL2@GANIL, ALTO@Orsay, ISAC@TRIUMPF and HIE-ISOLDE@CERN are based on the ISOL method, RIBF@RIKEN, FRIB@MSU-NSCL, FAIR@GSI with the new Super-FRS fragment - separator takes advantage of the "In Flight" technique. Projects of high intensity heavy ions, and low energy drivers (< 10 MeV/n) are also foreseen at Flerov Laboratory@DUBNA, GSI, RIKEN and GANIL. Technical performances, innovative new instrumentation and methods, and keys experiments in connection with these second generation high intensity facilities will be reviewed.

Exotic nuclei and superheavy element research is in a transition phase from experiments at the existing facilities of GSI towards the construction and exploitation of new instruments at the international facility FAIR. Prospective physics opportunities are outlined and illustrated by highlight results from the ongoing research programme together with novel instrumental developments and strategies.

This paper highlights some of the exotic nuclei studies at Lawrence Livermore National Laboratory (LLNL) within the Experimental Nuclear Physics (ENP) group. The work at LLNL concentrates on investigating nuclei at the extremes. The ENP group performs research to improve our understanding of nuclei, nuclear reactions, nuclear decay processes and nuclear astrophysics; an expertise utilized for important laboratory national security programs and for world-class peer-reviewed basic research.

The observation of atomic numbers Z that are 40% larger than that of Bi, the heaviest stable element, is an impressive extension of nuclear survival. Although the super heavy nuclei (SHN) are at the limits of Coulomb stability, shell stabilization lowers the groundstate energy, creates a fission barrier, and thereby enables the SHE to exist. The fundamentals of the modern theory concerning the mass limits of nuclear matter have been experimentally verified. We are going to upgrade an active cyclotron U-400 for the purpose of creation a SHE-factory for the further synthesis of superheavy nuclei and investigating of their properties.

The following sections are included:

• LIST OF PARTICIPANTS

• AUTHOR INDEX