Multinucleon transfer reactions are considered as a possible pathway to synthesize new heavy and superheavy nuclei. Regarding the expected small yields of exotic transfer products, efficient ...separation and detection techniques, which allow the identification of single nuclei, are mandatory. Our approach is to use a velocity filter for separation of (super)heavy transfer products. Respective experiments which we performed at GSI Helmholtz Center revealed promising results. The method allowed us for the first time a discovery of new transuranium isotopes produced in transfer reactions, the observation of the so far heaviest and most neutron-rich transfer product 260No, related with the so far smallest measured transfer cross-section of 0.5 nb.
How does one populate still vacant areas on the chart of nuclides? Mainly on the neutron-rich side several thousand further isotopes are expected to exist, including most of the nuclei along the ...astrophysical r-process path. The standard nucleosynthesis reactions, which are fragmentation, fission and fusion, are reaching their limits. Therefore, other pathways to exotic nuclei are needed. Years ago, the idea arose to revive multinucleon transfer reactions to progress toward the neutron-rich side of heavy and superheavy nuclei. Meanwhile, this option is investigated in nuclear physics labs worldwide. Beside new studies of transfer product kinematics and cross-sections, the development of suitable separation and detection techniques for heavy transfer products is ongoing. But how promising are these new advances? So far achieved results allow us to get an impression on the potential which multinucleon transfer reactions provide for nucleosynthesis.
We present new results on multi-nucleon transfer reactions in low-energy collisions of
48
Ca
+
238
U
measured at the velocity filter SHIP of GSI Helmholtz Centre, where we observed around 90 ...different nuclides from Tl to Am (
Z
=
81–95). We followed the idea to use uranium targets for the synthesis of neutron-rich MNT products, particularly in the region below lead, which was triggered by model calculations. The
γ
,
α
and spontaneous fission activities of the populated nuclides have been analyzed for their identification. The cross-sections of the observed isotopes for elements
Z
=
81–93 as a function of their mass number have been investigated. Excitation energy, total kinetic energy and the influence of nuclear shell effects on the production cross-sections of the observed transfer products have been studied. Also we present a compact review and comparative analysis of various multi-nucleon transfer and fragmentation reactions which are aimed at the synthesis of neutron-rich nuclides along the
N
=
126
shell closure in heavy nuclei.
In deep inelastic multinucleon transfer reactions of 48Ca + 248Cm we observed about 100 residual nuclei with proton numbers between Z=82 and Z=100. Among them, there are five new neutron-deficient ...isotopes: 216U, 219Np, 223Am, 229Am and 233Bk. As separator for the transfer products we used the velocity filter SHIP of GSI while the isotope identification was performed via the α decay chains of the nuclei. These first results reveal that multinucleon transfer reactions together with here applied fast and sensitive separation and detection techniques are promising for the synthesis of new isotopes in the region of heaviest nuclei.
The current work discusses the experimental evaluation technique for the prompt neutron multiplicity distribution (PNMD) emitted is the spontaneous fission (SF). The restoring technique for the ...detector efficiency correction is shown as well as the comparison of two regularization parameter choice methods. The shape of the PNMD helps to achieve the information according the dynamic of the SF. The work also compiles all currently published PNMDs in the transfermium (Z > 100) region and discusses their shapes, providing a physical interpretation of the distortion of these distributions.
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•Facile and ecofriendly bio synthesis route is used to prepare TiO2 NPs from fungal mass route.•Structural, optical and morphological analysis were carried out in detail. The prepared ...NPs exhbits superior antimicorbial activity, cytotoxic, antiplatelet and anticoagulant properties.
In the present report, biocompatible fabrication of TiO2 nanoparticles (NPs) are fabricated from biomass of Alternaria solani. The prepared TiO2 NPs are well characterized by sophisticated techniques such as, powder X-ray diffraction (PXRD), diffuse reflectance spectra (DRS), Fourier infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM) Techniques. The anatase phase of the TiO2 NPs is confirmed by the PXRD patterns. The DRS studies revealed the wide, intense peak centered at ~330 nm and band gap energy are found to be ~3.5 eV. Ti-O vibration modes centered at 648 cm−1 are confirmed by the FTIR spectra. Morphological features of biosynthesized TiO2 NPs are depicted in the SEM images and it is found that agglomeration in the prepared particles is observed due to the binding between the biomolecules of the biomass. The antimicrobial activity of TiO2 NPs are tested using the well-known agar well diffusion method and it is found that, the significant zone of inhibition in Klebsiella aerogenes, Candida albicans and Escherichia coli is found to be superior is when compared to Staphylococcus aureus and Pseudomonas desmolyticum. It is observed that the augmented clotting time for the bio-synthesized TiO2 NPs ranges between the 165–440 s in platelet-rich plasma (PRP). Likewise, the platelet-poor plasma (PPP) exhibiting the clotting factor is increased from control 175 to 450 s, which reveals the superior anticoagulant properties. Further, the antiplatelet activity of the prepared NPs is tested using the adenine diphosphate (ADP) as agonists and the platelet aggregation and inhibition is found to be ~68.18% and 31.82% respectively. In addition to this, the haemolytic activity of the prepared NPs did not hydrolyse the RBCs. The fabricated NPs also showed significant cytotoxicity against cancer cell lines, both human lung cancer cell lines (A549) when compared to human breast cancer (MCF-7). The obtained results indicate that, the fungal mediated synthesis of TiO2 NPs is simple, eco-friendly and exhibits multi-functional properties.
The standard reaction methods, such as fragmentation, fission or fusion used to synthesis exotic nuclei have reached their experimental limits. Multi-nucleon transfer (MNT) reactions are discussed as ...the potential method to reach the still unknown region of exotic proton/neutron rich heavy and superheavy nuclei. Studies of MNT reactions to follow this goal are presently a hot topic in diverse laboratories worldwide. At the velocity filter SHIP of GSI Darmstadt, our high sensitivity lead for the first time in collisions of
48
Ca +
248
Cm to the discovery of five new isotopes with
Z
92 produced in MNT reactions. As well, it enabled the observation of three nuclei of the quite heavy and neutron-rich isotope
260
No. These results are very promising for further studies of MNT reactions for the synthesis of new heavy and superheavy nuclei. The implementation of improved detection efficiency, a faster data acquisition system, the use of various actinide targets, a longer irradiation time along with optimal field settings will be beneficial. This additionally allows to suppress high background and to observe new neutron-deficient nuclides in the
Z
92 region of interest with a half-life of up to microseconds, also several above target nuclides located close to the border in the present nuclear chart are possible to reach. In this context, first experimental tests for separation of the transfer products with the use of velocity filter SHELS at Flerov Laboratory of Nuclear Reactions, Joint Institute for Nucler Research, Dubna was performed. The applied fast detection systems assured its best possible performance similar to SHIP, for the future investigation of deep inelastic transfer collisions. In this review article, our results are discussed together with previous measurements, and perspectives will be given for the application of multi-nucleon transfer reactions to produce new heavy and superheavy isotopes. The project of new kinematic separator dedicated for the MNT reactions studies is also discussed. We plan to implement a project together with modernization of U400 cyclotron (U400R).
An experimental study of 256Rf spontaneous fission following the fusion reaction of 50Ti+208Pb was performed using the velocity filter SHELS of the Flerov laboratory at JINR. The average number of ...neutrons of ν‾=4.30±0.17 and variance of σν2=3.2 from the prompt neutron multiplicity distribution were obtained. The alpha decay branching ratio of bα=0.003−0.003+0.005 and the half-life of T1/2=(6.7±0.2) ms of the isotope were determined. For the first time, our neutron detector system allowed us to extend investigation of the prompt neutron multiplicity study to the superheavy element region.
.
Recently, we reported the observation of several new isotopes with proton numbers
in low-energy collisions of
48
Ca +
248
Cm . The peculiarity is that the nuclei were produced in multinucleon ...transfer reactions, a method which is presently discussed as a possible new way to enter so far unknown regions in the upper part of the Chart of Nuclides. For separation of the transfer products we used a velocity filter, the Separator for Heavy Ion Reaction Products SHIP at GSI. The resulting strong background suppression allowed us to detect nuclei with cross-sections down to the sub-nanobarn scale. Beside the new isotopes we identified about 100 further target-like transfer products and determined their cross-sections. The results together with previous measurements strongly indicate that multinucleon transfer reactions are a viable pathway to the production of new transuranium isotopes.
After more than 45 years of successful operation of the GSI velocity filter SHIP in heavy and superheavy element research, it is time for the development of a next-generation in-flight separator. In ...frame of our Manipal-GSI-Giessen collaboration we designed a velocity filter which is intended for (super)heavy fusion and multinucleon transfer products. In this article we will present the design of the new in-flight separator and related detection techniques, as well as further activities of our collaboration.
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