Here we report on the measurements of the gamma -ray strength functions and nuclear level densities of 112,114Sn performed for the first time at the 9-MV Tandem accelerator facilities at Horia Hulubei Institute for Physics and Nuclear Engineering using the Oslo method. We extract thermodynamic properties and gross and fine properties of the pygmy dipole resonance for systematic comparison in the chain of Sn isotopes. The results are compared with microscopic models implemented in the TALYS reaction code and the fully microscopic quasiparticlephonon model for the underlying nuclear structure of the dipole strength in 112,114Sn. The quasiparticle-phonon model results show the importance of complex configurations to the low-energy dipole response in the pygmy dipole resonance energy region. The experimental data are further included in the cross section and reaction rate calculations for the (n, gamma ) reaction of the p-process nuclei 112,114Sn showing a significant increase in reaction rates at high temperatures compared to existing nuclear databases.

Single-particle and collective excitations in 116Sb are studied using the reaction 115In(alpha, 3n) 116Sb at abeam energy of 40 MeV and investigated using gamma -ray spectroscopic techniques. The existing level scheme is extended with the observation of several new transitions. The previously known band structures are extended to higher spins. Measurements of the directional correlation from oriented states (DCO) ratio and polarization asymmetry of the observed gamma rays are carried out to assign the spin-parities of the excited levels, populated in the present work. New band structures are interpreted as being due to the coupling of the valence particles with the 2p-2h intruder states of the Sn core. Further, the collective band structures are discussed on the basis of their rotational properties, total Routhian surface calculations, and the triaxial projected shell model approach.

The isospin mixing was deduced in the compound nucleus 72Kr at a low nuclear temperature around 1.3 MeV, from the gamma decay of the giant dipole resonance. The gamma rays from two compound-nucleus reactions were measured: from the 32 S + 40Ca at bombarding energy of 90 MeV characterized by isospin I = 0, and from the 31 P + 40Ca at 82 MeV used as a reference. The ELIFANT array was employed at the Bucharest Tandem Laboratory, consisting of Compton-suppressed scintillator detectors. The statistical-model analysis of the measured spectra provided a mixing parameter of (3.5 +/- 0.8)%. This new point, being at the lowest temperature compared with the few other existing ones, can validate the predictions of the temperature dependence of the isospin mixing. The isospinsymmetry-breaking correction, delta c, used for the Fermi super-allowed transitions was extracted from the present result of the isospin mixing and found to be consistent with beta decay data, theoretical predictions, and previous experimental results.

. - The high-energy gamma-rays from the GDR decay of 56,60,62Ni* nuclei at finite temperature, produced in the reactions 32,34,36S + 24,26Mg at bombarding energies between 78 , 90 MeV, were measured and analyzed with statistical model using a Monte Carlo approach. It is found that the present analysis gives some evidence on the presence of an extra yield on the tail of the Giant Dipole Resonance which may be attributed to a Pygmy Dipole Resonance in an excited nucleus.

The excited states of 209Rn (Z = 86, N = 123) have been populated by the heavy -ion induced fusion evaporation reaction 198Pt (16O, 5n) 209Rn at a beam energy of 102 MeV. The de -excited gamma rays were detected with the Compton suppressed clover HPGe detectors of the Indian National Gamma Array (INGA) set-up. The high spin spectroscopic study of 209Rn has been carried out up to an excitation energy of 7.9 MeV and spin (55/2) h over bar . Spin -parity assignments of the excited levels have been determined and are confirmed on the basis of the ratio of directional correlation and polarization asymmetry measurement. The possible presence of new isomeric states has been observed and the half-lives have been estimated. A negative parity sequence of M1 transitions has been observed which exhibits the property of magnetic rotation and is interpreted in the framework of semiclassical model calculation. The large basis shell -model calculation has been performed for all the nuclear levels and is found to be in well agreement with the experimental results.

The ELIADE-y-ray spectrometer constructed at the Extreme Light Infrastructure Nuclear Physics (ELI-NP, Romania) is featured for Nuclear Resonance Fluorescent studies to be performed using a mono-energetical almost fully polarized-y-ray beam. This paper reports on the progress of implementation of ELIADE.

We have performed the measurement of the 27Al(α, n) cross section at IFIN-HH for a range of energies from 2.5 to 5.2 MeV, using an array of 28 3He counters arranged in 3 concentric rings (ELIGANT-TN). Here we present the experimental setup and discuss the role of the 13C contamination which effects the measurements in the low-energy region. Energy-dispersive X-ray spectroscopy carried out before and after the experiment suggested an increase in the 13C concentration during the experiment.

We report a dedicated setup built in-house for the annealing of the HPGe clover detectors of the ELI-NP Array of DEtectors (ELIADE) γ-ray spectrometer, as well as the post-annealing testing of these detectors with the standard 60 Co & 152 Eu radioactive calibration sources employing conventional analog electronics. Both the design and assembly of the annealing setup were performed at the Extreme Light Infrastructure — Nuclear Physics (ELI-NP) facility, Măgurele, Romania. A `radiation damage annealing assembly kit' (NRK-200 unit) from the detector manufacturer Canberra is utilized in heating and controlling the temperature of the Ge crystals of the annealed detector. The vacuum inside the detector was maintained throughout the annealing process by constantly pumping the system using a turbo-molecular pumping station. The temperature of the germanium crystals, located inside a vacuum sealed chamber, of the detector and the vacuum level of this chamber were monitored throughout the annealing process, via both in-person observation and remote (online) monitoring. The Graphic User Interface (GUI) of an underlying LabVIEW script was utilized for running the monitoring process of the temperature and vacuum pressure values via a local network. To have the option of real-time online monitoring of the temperature, vacuum pressure, we coupled the web application Grafana with the Influx DB of the annealing data, as well as the backup time information of an Uninterruptible Power Supply (UPS) unit used in system.

We have designed and constructed a high-energy gamma-ray source for detector characterisation and calibration. The source is a composite type based on a plutonium-beryllium neutron emitter embedded in a paraffin moderator, which is homogeneously mixed with nickel powder. The 9 MeV gamma-ray source produces approximately 450 photons per second in 4 pi when 2.2 x 10(5) neutrons per second are emitted, corresponding to a surface flux of 9 MeV gamma-rays of approximately 2.5 x 10(-6) cm(-2) per emitted neutron. Here we discuss the properties and design of this source, including the characterisation of homogeneity and high-energy y-ray emission spectra.

The excited states of 116 Sb have been studied using in-beam γ -spectroscopy techniques with 115 In( α , 3n) ^116 Sb reaction and Indian National Gamma Array (INGA) setup at VECC, Kolkata. Various collective structures have been populated in the α -induced fusion evaporation reaction. Two of the previously known bands based on ( πg_9/2^ - 1⊗νd_7/2^1 ) and ( πg_9/2^ - 1⊗νd_5/2^1 ) configurations are extended to (14 + ) and 16 + spin, respectively and also pair-breaking has been reported in the later. Crossover E2 transitions could also be identified in one of the bands reported earlier.

We present a liquid nitrogen (LN 2 ) cooling station for the high-purity germanium (HPGe) segmented clover detectors of the ELI-NP Array of DEtectors (ELIADE) spectrometer, including its associated filling control and monitoring systems, all designed and built in-house at Extreme Light Infrastructure - Nuclear Physics (ELI-NP), Măgurele, Romania. The automated LN 2 filling process is controlled by a CompactRIO (cRIO) system from National Instruments through a custom LabVIEW software used for monitoring both the internal germanium crystal temperatures as well as the temperatures of external Pt100 sensors (used for detection of overflow of LN 2 from detectors during a filling process). The detectors are filled with LN 2 by opening their individual filling valves (which are mounted on the cooling station) and the process is automatically stopped once an overflow condition is fulfilled by the corresponding external Pt100 sensor located downstream. A twelve-hour cycle is used to periodically fill all of the detector dewars and keep their germanium crystals cool at all times. The associated Graphic User Interface (GUI), Command Line Interface (CLI) and Text User Interface (TUI) are used for both controlling and monitoring the above mentioned process. Alert and warning email messages were also enabled via the cRIO system so that users can be alerted in real-time in the event of any cooling malfunction. In this way, any issues related to the cyclic filling procedure, as well as any abnormal observations regarding the germanium crystal temperatures can be quickly and efficiently addressed before the detectors have a chance to warm back up to room temperature. Temperature data of all the Pt100 sensors corresponding to detectors as well as to the solenoid valves are made available in an influx database by the cRIO control system. The web application Grafana access the database and plots them in real-time for online monitoring.

The excited states of 116Sb have been studied using in-beam $$\gamma $$ -spectroscopy techniques with 115In( $$\alpha $$ , 3n) $$^{{116}}$$ Sb reaction and Indian National Gamma Array (INGA) setup at VECC, Kolkata. Various collective structures have been populated in the $$\alpha $$ -induced fusion evaporation reaction. Two of the previously known bands based on ( $$\pi {\text{g}}_{{9/2}}^{{ - 1}} \otimes \nu {\text{d}}_{{7/2}}^{1}$$ ) and ( $$\pi {\text{g}}_{{9/2}}^{{ - 1}} \otimes \nu {\text{d}}_{{5/2}}^{1}$$ ) configurations are extended to (14+) and 16+ spin, respectively and also pair-breaking has been reported in the later. Crossover E2 transitions could also be identified in one of the bands reported earlier.

The excited states of 116Sb have been populated using the α induced reaction 115In(α, 3n)116Sb at a beam energy of 40 MeV and investigated via in-beam gamma spectroscopic techniques. A positive parity sequence (B1) of strong M1 transitions with relatively weak crossover E2 transitions, connected to the yrast negative parity rotational band (B2) of 116Sb, has been observed. The experimental B(M1)/B(E2) values for band B1 are found to decrease with angular momentum (I). The origin of this band (B1) has been interpreted in terms of Magnetic Rotation (MR) under the framework of Semi-Classical Model (SCM) and Shears mechanism with Principal Axis Cranking (SPAC) formalism and is assigned a four quasiparticle configuration of π(g9/2)−1 ⊗ ν(g7/2/d5/2)(h11/2)2. The yrast rotational band B2 is extended up to the band crossing region.

The excited states of 187Os have been studied via 186W(4He, 3n) 187Os reaction at a beam energy of 36 MeV. The gamma rays were detected using the Indian National Gamma Array at the Variable Energy Cyclotron Centre having seven Compton-suppressed clover high-purity germanium (HPGe) detectors and one low-energy photon spectrometer (LEPS) detector with a digital data acquisition system. The level scheme of 187Os has been extended substantially up to approximate to 3.86 MeV of excitation energy and 37/2 h over bar of spin with the placement of more than 90 new gamma rays. All known bands have been extended and new band structures have been identified. The results show evidence of triaxial shapes for different configurations of 187Os and different manifestations of nonaxial shape have been observed in the same nucleus. A comparison of the observed band crossing frequency in 187Os with neighboring nuclei gives evidence of a deformed shell gap at N = 110. The experimental results are well explained using total Routhian surface calculations.

Excited states in the $^{66}\mathrm{Zn}$ nucleus were populated via a $^{56}\mathrm{Fe}(^{12}\mathrm{C},2p\ensuremath{\gamma}$) fusion-evaporation reaction at a beam energy of $\ensuremath{\approx}62$ MeV. The deexciting $\ensuremath{\gamma}$ rays were detected using the Indian National Gamma Array (INGA). The level scheme of the $^{66}\mathrm{Zn}$ nucleus has been updated by placing several new $\ensuremath{\gamma}$ rays as well as by assigning the spin and parity of various excited states from the present spectroscopic results. The microscopic structure of the observed states have been investigated in the light of large shell-model calculations. The shape of this nucleus in the low-spin regime has been studied under the framework of total Routhian surface (TRS) calculations. The lifetime of first ${3}^{\ensuremath{-}}$ state at 2826 keV is experimentally measured using the Doppler-shift attenuation method and the deduced $B(E1)$ value indicates the presence of octupole collectivity in this nucleus.

The Hoyle analogue state in $$^{16}$$ O was explored by inelastic scattering of 45 MeV $$\alpha $$ s on a Mylar target. The break up 4 $$\alpha $$ s of $$^{16}$$ O have been detected in coincidence with the inelastically scattered $$\alpha $$ beam particle to probe the Hoyle analogue state of $$^{16}$$ O in complete kinematics, for the first time. The data have been analysed for all possible configurations and the excitation function of $$^{16}$$ O has been reconstructed directly from 4 $$\alpha $$ as well as for specific decay channels like $$^{12}$$ C(0 $$^{+}_{2}$$ ) + $$\alpha $$ , $$^{12}$$ C(3 $$^{-}_{1}$$ ) + $$\alpha $$ and $$^{8}$$ Be + $$^{8}$$ Be. Several previously known states have been observed above the $$4\alpha $$ break-up threshold (14.44 MeV) in the above mentioned decay channels. However, the signature of the 15.1 MeV state, most preferable to be the Hoyle analogue state according to the theoretical prediction, remains inconclusive.

The new facility, Extreme Light Infrastructure – Nuclear Physics (ELI-NP), is a combined laser-gamma nuclear physics research facility currently undergoing its final implementation stages in Măgurele near Bucharest, Romania. It already hosts two fully-operational 10 PW laser arms and, by 2023, it will also house a γ-beam system based on laser Compton backscattering, capable of delivering a high-brilliance, low-energy beam at E γ ≲ 19.5 MeV. Owing to this unique laser-gamma instrumentation combination, several types of experiments will be possible at ELI-NP, including high precision nuclear resonance fluorescence (NRF) experiments. In this case, the main γ-beam detection system for performing NRF studies at ELI-NP is represented by the ELI Array of DEtectors (ELIADE), featuring eight high-purity germanium (HPGe) segmented clover detectors. The current work presents the characteristics of two of the ELIADE detectors, including their photopeak detection efficiency, energy resolution, and peak-to-total ratio measured using γ-ray sources, as well as the timing performance obtained via in-beam measurements. For these latter detector tests, 130La was populated via the fusion evaporation reaction 121Sb(12C,3n)130La using a beam energy of 53 MeV at the Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN-HH), also located in Măgurele. Herein, we report on the results of the ^130La linear polarization measurements taken using the ELIADE detectors as Compton polarimeters. The results obtained from the in-beam experiment were compared to several already published works and we present new information on the transition multipolarity in 130La.

The study of odd-odd nuclei around Z = 50 shell closure is interesting to study the collective as well as the single particle states. The odd-odd nuclei exhibit the combined features of odd proton and odd neutron. At low excitation energy, the nuclei around A~100 of this region, are expected to be dominated by the single particle excitations. It has been observed that the nuclei also exhibit collective structures that coexist with the single particle structures. With energy and angular momentum the collectivity develops, through the occupation of h11/2 high-j negative parity orbital and also through the promotion of a proton from g9/2 -upsloping orbital into the -downsloping g7/2 orbital and thereby, leads the system towards the prolate deformation. The Sb isotopes, near Z = 50 magic shell closure, can provide an ideal laboratory for exploring the single as well as the collective structures within a single nuclear system. So far the information available on the structure of 116 Sb [1-3] is not enough compared to its neighboring isotopes. The aim of present work is to look for the near yrast structures of 116 Sb populated via -beam and to look for the crossover E2 transitions for the previously predicted magnetic rotational band [3].

The emergence of a new era reaching beyond current state-of-the-art ultrashort and ultraintense laser technology has been enabled by the approval of around € 850 million worth of structural funds in 2011–2012 by the European Commission for the installation of Extreme Light Infrastructure (ELI). The ELI project consists of three pillars being built in the Czech Republic, Hungary, and Romania. This challenging proposal is based on recent technical progress allowing ultraintense laser fields in which intensities will soon be reaching as high as I0 ∼ 1023 W cm−2. This tremendous technological advance has been brought about by the invention of chirped pulse amplification by Mourou and Strickland. Romania is hosting the ELI for Nuclear Physics (ELI-NP) pillar in Măgurele near Bucharest. The new facility, currently under construction, is intended to serve the broad national, European, and international scientific community. Its mission covers scientific research at the frontier of knowledge involving two domains. The first is laser-driven experiments related to NP, strong-field quantum electrodynamics, and associated vacuum effects. The second research domain is based on the establishment of a Compton-backscattering-based, high-brilliance, and intense γ beam with Eγ ≲ 19.5 MeV, which represents a merger between laser and accelerator technology. This system will allow the investigation of the nuclear structure of selected isotopes and nuclear reactions of relevance, for example, to astrophysics with hitherto unprecedented resolution and accuracy. In addition to fundamental themes, a large number of applications with significant societal impact will be developed. The implementation of the project started in January 2013 and is spearheaded by the ELI-NP/Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH). Experiments will begin in early 2020.

The Extreme Light Infrastructure is a major European undertaking with the aim of constructing a set of facilities that can produce the worlds highest intensity laser beams as well as unique high-brilliance, narrow-bandwidth gamma-ray beams using laser-based inverse Compton scattering. The latter will be one of the unique features of the facility in Bucharest-Magurele, Romania, where the scientific focus will be towards nuclear physics and nuclear photonics both with high intensity lasers and gamma beams individually, as well as combined. One of the main instruments being constructed for the nuclear physics and applications with high-brilliance gamma-beams research activity is the ELIADE gamma-ray detector array. This array consists of eight segmented HPGe clover detectors as well as large-volume LaBr3 detectors. The nuclear physics topics are expected to cover a large range including, but not limited to, properties of pygmy resonance and collective scissors mode excitations, parity violation in nuclear excitations, and matrix elements for neutrinoless double-beta decay. However, the uniqueness of the environment in which ELIADE will operate presents several challenges in the design and construction of the array. Here, we discuss some of these challenges and how we plan to overcome them, as well as the current status of implementation.