An attempt has been made to understand the effect of transfer channels on reaction dynamics for the O-16+Ho-165 system through the measurement of a quasi-elastic excitation function at backward angles, which was translated to the corresponding barrier distribution. The results were explained in light of coupled channel calculations performed with the inclusion of different possible coupling schemes describing the structure of the projectile and target nuclei. Analysis reveals that the rotational coupling of the target nuclei along with the coupling due to the 2n-transfer (pick-up) channel satisfactorily reproduces the experimental data.

The electromagnetic structure of Sc-45 at low excitation energy was investigated via low-energy Coulomb excitation at the Heavy Ion Laboratory (HIL) of the University of Warsaw and at the Inter-University Accelerator Centre (IUAC) in New Delhi. A set of reduced E2, E3, and M1 matrix elements was extracted from the collected data using the GOSIA code. The reduced transition probability B(E2; 11/2(-) -> 7/2(-)) has been determined, allowing us to deduce the lifetime of the 11/2(-) state at 1237 keV. In addition, the upper limit on the reduced transition probability B(E3; 7/2(-) -> 5/2(+)) has been determined for the first time. New large-scale shell-model and beyond-mean-field calculations were performed to interpret the structure of this nucleus.

The pre-scission and post-scission neutron multiplicities are measured for the O-18 + W-184 reaction in the excitation energy range of 67.23-76.37 MeV. Langevin dynamical calculations are performed to infer the energy dependence of fission decay time in compliance with the measured neutron multiplicities. Different models for nuclear dissipation are employed for this purpose. Fission process is usually expected to be faster at a higher beam energy. However, we found an enhancement in the average fission time as the incident beam energy increases. It happens because a higher excitation energy helps more neutrons to evaporate that eventually stabilizes the system against fission. The competition between fission and neutron evaporation delicately depends on the available excitation energy and it is explained here with the help of the partial fission yields contributed by the different isotopes of the primary compound nucleus.

Fusion excitation functions have been measured for O-16+Ni-61 and O-18+Ni-61,Ni-62 systems around the Coulomb barrier (approximate to 0.7V(B)-1.3V(B)) using the recoil mass spectrometer, heavy ion reaction analyzer. The ground state Q value for two neutron stripping is positive for both systems with O-18 as the projectile. Strong enhancement of the experimental fusion cross sections were observed below the barrier for all the systems compared to that of the predictions of the one-dimensional barrier penetration model. To understand such enhancement, a coupled-channels formalism has been used. A comparative study of these systems indicated that the coupling of two neutron transfer channels with the collective excitations could play the role behind the sub-barrier fusion enhancement for O-18 induced reactions. However, the sub-barrier enhancement for O-16 + Ni-61 is found to be due to the coupling of quadrupole vibrations of both the interacting nuclei. Also after comparing these systems with other systems of different Ni isotopes, we have found that the signature of the role of coupling to neutron transfer channels due to ground state positive Q value for neutron transfer is ambiguous.

yy A Coulomb-excitation measurement to study low-energy electromagnetic properties of Sc-45 has been performed at the IUAC facility in New Delhi, India using a 70 MeV S-32 projectile from the 15UD tandem accelerator. The preliminary value of the reduced transition probability B(E2; 11/2(-) -> 7/2(-)) and the resulting lifetime for the 11/2(-) state at 1237 keV were determined using the GOSIA code.

Background: In heavy-ion-induced fusion reactions, cross sections in the sub-barrier region are enhanced compared to predictions of the one-dimensional barrier penetration model. This enhancement is often understood by invoking deformation and coupling of the relative motion with low-lying inelastic states of the reaction partners. However, effects of nucleon transfer on fusion below the barrier, especially for the systems having positive Q value neutron transfer (PQNT) channels, are yet to be disentangled completely. Purpose: We intend to study the role of the PQNT effect on the sub-barrier fusion of the O-18 +/- Sn-116 system having positive Q value for the two-neutron stripping channel. Also we reflect on the interplay of couplings involved in the system around the Coulomb barrier. Method: The fusion excitation function was measured at energies from 11% below to 46% above the Coulomb barrier for O-18 +/- Sn-116 using a recoil mass spectrometer, viz., the Heavy-Ion Reaction Analyser (HIRA). Fusion barrier distributions were extracted from the data. Results from the experiment were analyzed within the framework of the coupled-channels model. Results: Fusion cross sections at energies below the Coulomb barrier showed strong enhancement compared to predictions of the one-dimensional barrier penetration model. The fusion process is influenced by couplings to the collective excitations with coupling to singleand two-phonon vibrational states of the target and the projectile respectively. Inclusion of the two-neutron transfer channel in the calculation along with these couplings could reproduce the data satisfactorily. Conclusions: The significant role of PQNT in enhancing the sub-barrier fusion cross section for the chosen system is not observed. It simply reduced the sub-barrier fusion cross section. Therefore, a consistent link between PQNT and sub-barrier fusion enhancement could not be established vividly while comparing the fusion excitation function from this work with the same from other O-16,O-18-induced reactions. This clearly points to the need for more experimental as well as theoretical investigation in this field.

Barrier distributions for the (28)si+Nd-142,Nd-150 systems were extracted from large-angle quasielastic scattering measurements. The measurements were carried out over a wide range of incident beam energies around the Coulomb barriers. The experimental results were compared with the predictions from coupled-channels calculations carried out using different coupling schemes. Reasonable agreement between the experimental and theoretical results was obtained. The role of coupling effects of the various excitation modes of the projectile and target on the observed barrier distributions is discussed. The sensitivity of the quasielastic scattering process on the mode of projectile excitation is clearly been seen from the use of two different types of targets, Nd-142 and Nd-150 U having spherical and deformed shapes at the ground state, respectively.

Barrier distributions for the $^{28}\mathrm{Si}+^{142,150}\mathrm{Nd}$ systems were extracted from large-angle quasielastic scattering measurements. The measurements were carried out over a wide range of incident beam energies around the Coulomb barriers. The experimental results were compared with the predictions from coupled-channels calculations carried out using different coupling schemes. Reasonable agreement between the experimental and theoretical results was obtained. The role of coupling effects of the various excitation modes of the projectile and target on the observed barrier distributions is discussed. The sensitivity of the quasielastic scattering process on the mode of projectile excitation is clearly been seen from the use of two different types of targets, $^{142}\mathrm{Nd}$ and $^{150}\mathrm{Nd}$, having spherical and deformed shapes at the ground state, respectively.

Ni system Nabendu Kumar Deb1,∗ Harun A. Rashid, Amar Das, Kushal Kalita, Subir Nath, Pankaj K. Giri, Rudra N. Sahoo, N. Madhavan, J. Gehlot, Rohan Biswas, N. K. Rai, A. Parihari, T. Varughese, B. J. Roy, Saumyajit Biswas, Anjali Rani Department of Physics, Gauhati University, Guwahati 781014, Assam, India Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067, India Department of Physics, Central University of Jharkhand, Ranchi 835205, Jharkhand, India Department of Physics, Indian Institute of Technology, Ropar,Punjab 140001, India Department of Physics, Banaras Hindu University, Varanasi, Uttar Pradesh-221005, India Nuclear Physics Department, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India Department of Physics,Visva Bharati, Santiniketan, West Bengal-731235, India Department of Physics & Astrophysics, Delhi University, Delhi-110007, India

Institute of Nuclear Physics Polish Academy of Sciences, Kraków, Poland Heavy Ion Laboratory, University of Warsaw, Warszawa, Poland Inter University Accelerator Centre, New Delhi, India Department of Physics and Astrophysics, University of Delhi, New Delhi, India Department of Physics, Aligarh Muslim University, Aligarh, India Department of Physics, Bareilly College, Bareilly, India Department of Pure and Applied Physics, Guru Ghasidas University Bilaspur, India, National Institute for Physics and Nuclear Engineering (IFIN-HH) Bucharest-Măgurele, Romania Faculty of Physics, University of Warsaw, Warszawa, Poland Department of Physics, Indian Institute of Technology Roorkee, Roorkee, India Department of Nuclear and Atomic Physics, TIFR, Mumbai, India Department of Physics, Banaras Hindu University, Varanasi, India Department of Physics, Indian Institute of Technology Ropar, Rupnagar, India GSI, Darmstadt, Germany

The barrier distribution of a system can be extracted from excitation function data obtained either through fusion reaction or through quasi-elastic scattering measurement. In the present work, the quasi-elastic excitation function has precisely been measured at back angle for the Si-28 + Nd-142 system at energies around the Coulomb barrier and the corresponding experimental barrier distribution has been extracted. The experimental data has been interpreted in the frame work of the coupled channel calculations which include couplings to different possible modes of excitations of the interacting target-projectile combination. The possible effect of the nature of projectile excitations on the derived barrier distribution has been presented.

In the present work, the pre- and post-scission neutron multiplicities were measured for the reaction O-18 + W-186 at different excitation energies populating the compound nucleus Pb-204, using the National Array of Neutron Detectors (NAND) facility at IUAC, New Delhi, India. Here, we investigated the entrance channel effect on the nuclear dissipation involved in the heavy ion fusion-fission dynamics. The statistical model analysis was performed using the code VECSTAT. The prescribed reaction O-18 + W-186 had similar value of the mass asymmetry as the system O-16 + Ta-181 studied earlier, populating the compound nucleus Tl-197. Specifically, we observed the similar behavior from both the systems against the nuclear dissipation, with the similar value of the mass asymmetry. The role of the entrance channel parameters on the nuclear dissipation was also discussed in the present work.

In this article, we present the nuclear excitation functions of the fast neutron-induced reactions 52Cr(n,p)52V, 52Cr(n,α)49Ti, 52Cr(n,2n)51Cr, 56Fe(n,p)56Mn, 56Fe(n,α)53Cr, and 56Fe(n,2n)55Fe, because these measurements are critical to estimate the level of the neutron activation for the fusion reactor structural materials. The theoretical computer codes TALYS-1.8 and EMPIRE-3.2.2 have been used for the calculation of the excitation functions. The theoretical calculations consider different nuclear reaction models, level density models and optical model potentials. The calculated excitation function results are compared with the existing experimental data obtained from the IAEA-EXFOR database, as well as with those available in the TENDL-2017 and ENDF/B-VIII.0-evaluated nuclear data libraries. The obtained results show the variation in excitation functions for different level density models. Moreover, we have studied the contribution from different reaction mechanisms in total reaction cross-section which varies with the incident neutron energy. These excitation function results can be useful to estimate the important parameters of nuclear reactors, such as nuclear heating, nuclear transmutation rates, and waste management etc. This kind of information can enhance the basic understanding of the mechanism of the fast neutron-induced nuclear reactions.

In order to gain further information on the electromagnetic properties of the low-lying states in Sc-45, a Coulomb excitation measurement was carried out at the IUAC, New Delhi. The Sc-45 target nuclei were Coulomb excited by the 70 MeV S-32 beam from the 15UD tandem accelerator. The gamma-rays depopulating Coulomb excited states in Sc-45 were detected by four Clover detectors in coincidence with the forward scattered ions. The main aim of the experiment was to determine the B(E3; 7/2(-) -> 3/2(+)) and B(E3; 7/2(-) -> 5/2(+)) transition probabilities, as well as the transitional electromagnetic matrix elements for low-lying intruder states.

The cross sections of 67 Zn, 92,96 Mo, 208 Pb(n,p) and 70 Zn, 100 Mo(n,2n) reactions have been evaluated using statistical nuclear model codes EMPIRE 3.2.2 and TALYS 1.8 at the neutron energy range from reactions threshold to 20 MeV. The variation in cross section with different optical model potential, level density models, and nuclear reaction models have been investigated at neutron energy 14.5 MeV. In this work, the pre-equilibrium emission contribution in the total cross section has also been verified in the neutron energy of 14.5 MeV. The calculated results were also compared with the experimental data being taken from EXFOR database.

In heavy-ion fusion reactions, the energy of the projectile couples with the intrinsic degrees of freedom of the target during the collision process and this leads to a dissipative phenomenon. Consequently, the dissipation in the system causes the angular momentum hindrance during the fusion process. In this work, we have focused on the dissipative behavior of the fusing nuclei and its dependency on the incident energy. The dissipative evolution of the system depends not only on the entrance channel mass asymmetry but also on the incident energy, which was not mentioned in earlier studies. Moreover, the dissipative behavior of the fusing nuclei is also compared with respect to the entrance channel parameters like mass asymmetry a and the Coulomb interaction term Z(p)Z(T). The dissipation phenomenon decreases when the mass asymmetry increases and it increases when the Coulomb interaction term Z(P)Z(T) increases.

V.M. Bystritsky, Yu.N. Kopatch, V.R. Skoy, I.N. Ruskov, T.Yu. Tretyakova3,∗ N.A. Fedorov1,4,† D.N. Grozdanov, A. Gandhi, F.A. Aliyev, C. Hramco, W. Dongming, Yu.N. Barmakov, E.P. Bogolyubov, A. Kumar, V. Kumar, V. Mishra, and N. K. Rai Joint Institute for Nuclear Research (JINR), Dubna, Russia Institute for Nuclear Research and Nuclear Energy (INRNE), BAS, Sofia, Bulgaria Skobeltsyn Institute of Nuclear Physics (SINP), MSU, Moscow, Russia Faculty of Physics, Lomonosov Moscow State University (MSU), Moscow, Russia Departmen of Physics, Banaras Hindu University, Varanasi, India Institute of Geology and Geophysics (IGG), ANAS, Baku, Azerbaijan Institute of Chemistry (IC), Academy of Science of Moldova, Chisinau, Republic of Moldova School of Energy and Power Engineering, Xian Jiaotong University, Xian, China and All-Russia Research Institute of Automatics (VNIIA), Moscow, Russia

A. Gandhi,* D. N. Grozdanov , F. A. Aliyev , W. Dongming , N. A. Fedorov , Yu. N. Kopatch, V.R. Skoy, V.M. Bystritsky, I. N. Ruskov , C. Hramco , E. P. Bogolyubov, Yu. N. Barmakov, V. Kumar, V. Mishra, N. K. Rai, and A. Kumar Department of Physics, Banaras Hindu University, Varanasi – 221005, INDIA Joint Institute for Nuclear Research (JINR), Dubna, Russia Institute for Nuclear Research and Nuclear Energy (INRNE), BAS, Sofia, Bulgaria Institute of Geology and Geophysics (IGG), AAS, Baku, Azerbaijan Faculty of Physics, Lomonosov Moscow State University (MSU), Moscow, Russia Institute of Chemistry (IC), Academy of Science of Moldova, Chisinau, Republic of Moldova All-Russia Research Institute of Automatics (VNIIA), Moscow, Russia School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, China. . * email: gandhiaman653@gmail.com

Abhishek Yadav, A. Jhingan, M. Kumar, N. Saneesh, Indu Bala, K. S. Golda, Md. Moin Shaikh, Tathagat Banerjee, G. Kaur, R. Dubey, C. Yadav, R. N. Sahoo, A. Sood, K. Rani, H. Arora, N. K. Rai, P. P. Singh, M. K. Sharma, B. P. Singh, R. Prasad, and P. Sugathan NP-Group: Inter-University Accelerator Centre, New Delhi-110 067, Delhi, India Physics Department, Panjab University, Chandigarh-160 014, Punjab, India Nuclear Physics Group, iThemba Lab, Somerset West 7129, Capetown, South Africa Physics Department, Indian Institute of Technology Ropar, Roopnagar-140 001, Punjab, India Physics Department, B. H. U., Varanasi-221 005, Uttar Pradesh, India Physics Department, S. V. College, Aligarh-202 001, Uttar Pradesh, India and Physics Department, Aligarh Muslim University, Aligarh-202 002, Uttar Pradesh, India