High-spin states of $^{38}\mathrm{K}$ above the $31.67\phantom{\rule{4pt}{0ex}}\ensuremath{\mu}\mathrm{s}$ (${\ensuremath{\tau}}_{m}$) isomer, populated through the $^{12}\mathrm{C}(^{28}\mathrm{Si},\phantom{\rule{0.16em}{0ex}}np)^{38}\mathrm{K}$ reaction with a 110 MeV $^{28}\mathrm{Si}$ beam, have been studied by using the Indian National Gamma Array (INGA) facility. Two new levels and four new transitions have been added to the existing level scheme. The spins and parities of most of the levels above the isomer have been assigned, modified, and confirmed from ${R}_{\mathrm{DCO}}$, ${R}_{\mathrm{ADO}}$, and linear polarization measurements. The multipole mixing ratios ($\ensuremath{\delta}$) for a few transitions have been measured. Large-basis shell-model calculations have been performed to understand the microscopic origin of these levels. In our calculations, different particle restrictions in $sd$- and $pf$-shell orbitals were used to reproduce the experimental level energies. Two-nucleon transfer spectroscopic factors have also been calculated for the levels above the isomer to support the new spin and parity assignments. Prediction of collective excitation at high excitation energy in $^{38}\mathrm{K}$ is also discussed.

High spin states of $^{37}\mathrm{Ar}$, populated through the $^{27}\mathrm{Al}(^{12}\mathrm{C},np)^{37}\mathrm{Ar}$ reaction with a 40 MeV $^{12}\mathrm{C}$ beam, were studied using the Indian National Gamma Array (INGA) facility. The existing level scheme has been extended up to 10.5 MeV by adding some new levels and transitions. The spins and parities of the new levels were assigned from ${R}_{\mathrm{DCO}}$, ${R}_{\mathrm{ADO}}$, and linear polarization measurements. The spins and parities of the existing levels also were modified or confirmed in the present experiment. The multipole mixing ratios ($\ensuremath{\delta}$) for most of the transitions were measured and compared with the earlier measurements wherever available. Large basis shell model calculations with different particle restrictions in $sd$ and $pf$ orbitals were performed to understand the microscopic origin of these levels. A simple two-level mixing calculation was also performed to extract the amount of multiparticle multihole configuration mixing for a few levels.

The target development laboratory at Inter-University Accelerator Centre (IUAC) is one of the main facilities for the fabrication of nuclear physics targets in India. Vacuum evaporation and cold rolling technique are mainly used for the production of isotopically pure targets at IUAC. Targets of Gd, Pt, W, Mo, Ta, Ni, Ag and Sn have been developed in the form of self-supporting targets and with thin carbon backing. Recent progress in target development laboratory at IUAC will be discussed in the report.

Lifetime measurements have been carried out using the Doppler shift attenuation method (DSAM) for the negative- and positive-parity bands built on pi h(11/2) circle times nu(d(5/2)g(7/2)) and pi h(11/2) circle times nu h(11/2) configurations, respectively, in Cs-124. The reduced transition probabilities have been obtained for both the bands and are compared with the available theoretical calculations. The enhanced B(E1) rates for the linking transitions between the bands with the above configurations suggest the existence of octupole correlations in Cs-124. The observed electromagnetic properties for the positive-parity bands in Cs-124 agree well with the characteristics pattern required for chiral symmetry breaking.

High spin states of Cl-34 populated through Al-27(C-12,alpha n)Cl-34 reaction at E(C-12) = 40 MeV, have been studied using the Indian National Gamma Array facility. The level scheme has been extended up to 10.6 MeV utilizing the results of intensity, directional correlation, and linear polarization measurements. Lifetimes of a few excited states have been estimated for the first time using the Doppler shift attenuation method. Large-basis shell-model calculations within the sd-pf space have been done to understand the microscopic origin of the excited states. Involvement of pf orbitals have been found to be essential to reproduce the negative-parity as well as high spin positive-parity states. Onset of collectivity manifested through short half-lives and large B(E2) values have been reproduced well in the calculations.

High spin states of S-33 populated through Al-27(C-12, alpha pn)S-33 reaction at E(C-12) = 40 MeV have been studied using the Indian National Gamma Array (INGA) facility. The level scheme was extended and modified utilizing data from the gamma-gamma coincidence, directional correlation, and linear polarization measurements. Three levels of the negative parity yrast sequence were found to be connected by strong E2 transitions. The lifetimes of these states determined by the Doppler shift attenuation method have been utilized to study the evolution of collectivity with spin. Large basis shell model calculations have been performed to understand the microscopic origin of these levels.

A superdeformed (SD) band has been identified in a non-$\ensuremath{\alpha}$-conjugate nucleus ${}^{35}\text{Cl}$. It crosses the negative-parity ground band above $11/{2}^{\ensuremath{-}}$ and becomes the yrast at $15/{2}^{\ensuremath{-}}$. Lifetimes of all relevant states have been measured to follow the evolution of collectivity. Enhanced $B(E2)$, $B(E1)$ values as well as energetics provide evidence for superdeformation and existence of parity doublet cluster structure in an odd-$A$ nucleus in the $A\ensuremath{\simeq}40$ region. Large-scale shell-model calculations assign ${(sd)}^{16}{(pf)}^{3}$ as the origin of these states. Calculated spectroscopic factors correlate the SD states in ${}^{35}\text{Cl}$ to those in ${}^{36}\text{Ar}$.

A superdeformed (SD) band has been identified in a non - alpha - conjugate nucleus 35Cl. It crosses the negative parity ground band above 11/2- and becomes the yrast at 15/2-. Lifetimes of all relevant states have been measured to follow the evolution of collectivity. Enhanced B(E2), B(E1) values as well as energetics provide evidences for superdeformation and existence of parity doublet cluster structure in an odd-A nucleus for the first time in A = 40 region. Large scale shell model calculations assign (sd)16(pf)3 as the origin of these states. Calculated spectroscopic factors correlate the SD states in 35Cl to those in 36Ar.

Lifetime measurements have been carried out for high spin states in Cs-123 and Ba-124 using the Doppler shift attenuation method. The transition quadrupole moments Q(t) measured in the present work show a loss of collectivity after the alignment of neutron h(11/2) orbitals. The experimental results are compared with the existing theoretical calculations within the framework of the cranked shell model. The results are consistent with the evolution of triaxial shape due to the alignment of nu h(11/2) orbitals. However, larger deformation parameters beta(2) have been measured compared with the values predicted by the model calculations in both the nuclei.

Medium-spin states in 122Te have been populated using the reaction 116Cd (11B, p4n)122Te at a beam energy of 65MeV and \( \gamma\) -\( \gamma\) coincidences were measured using the INGA spectrometer. The previously known level scheme has been extended to spin \( \sim 23\hbar\) with the observation of the maximally aligned state at spin 22+. The experimental results are compared with the shell model calculations. The configurations of the energy levels and terminating states are discussed.

High-spin states in I-122 have been investigated using the Cd-116(B-11,5n)I-122 reaction at a beam energy of 65 MeV and gamma-ray coincidence events were recorded with the INGA spectrometer. The level scheme of I-122 has been extended up to spin I = 30. Experimental features, such as band-crossing frequencies, aligned angular momenta, signature splitting, and B(M1)/B(E2) ratios have been used for configuration assignments to low-energy band structures. Maximally aligned states involving all eight particles outside the Sn-114 core and states with one particle antialigned have been identified. Cranked Nilsson-Strutinsky calculations have been used to interpret high-spin structures.

Somnath Nag, Purnima Singh, K. Selvakumar, A. K. Singh, Abhijit Bisoi, A. Goswami, S. Bhattacharya, Surender Kumar, Kuljeet Singh, Jasmine Sethi, Sudipta Saha, T. Trivedi, S. K. Jadav, R. Donthi, B. S. Naidu, and R. Palit Department of Physics & Meteorology, I. I. T. Kharagpur, IN-721302, India Nuclear Physics Division, S. I. N. P., Kolkata 700064, India Applied Nuclear Physics Division, S. I. N. P., Kolkata 700064, India Dept. of Physics, Punjab University, Chandigarh 160014, India and Department of Nuclear and Atomic Physics, T. I. F. R., Mumbai 400005, India

Purnima Singh, Somnath Nag, K. Selvakumar, A. K. Singh, Abhijit Bisoi, A. Goswami, S. Bhattacharya, Surender Kumar, Kuljeet Singh, Jasmine Sethi, Sudipta Saha, T. Trivedi, S. K. Jadav, R. Donthi, B. S. Naidu, and R. Palit Department of Physics & Meteorology, Indian Institute of Technology Kharagpur, IN-721302, India Nuclear Physics Division, S. I. N. P., Kolkata 700064, India Applied Nuclear Physics Division, S. I. N. P., Kolkata 700064, India Dept. of Physics, Punjab University, Chandigarh 160014, India and Deptartment of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai 400005, India

K. Selvakumar1,∗ Subhashri Das A. K. Singh Purnima Singh, A.Gowsami R. Raut A. Mukherjee U. Datta Praminik, P.Dutta, S. Roy, G. Gangopadhyay, S. Bhowal, S. Muralithar Rakesh Kumar R. P. Singh, and M. Kumar Raju Thomas Reddy Department of Physics, IIT Kharagpur, Kharagpur-721 302, India Nuclear and Atomic Physics Division, Saha Institute of Nuclear Physics, Kolkatta-700 064, India Ananda Mohan College, Kolkata700 009, India S.N.Bose National Centre for Basic Sciences, Kolkata-700 064, India Department of Physics, University of Calcutta, Kolkatta-700 073, India Surendranath College, Kolkata-700 009, India Inter University Accelerator Center, New Delhi-110 067, India and Department of Physics, Andhra University, Visakhapatnam-530 003, India

The very neutron-deficient nuclei in the mass 170 region are expected to be rather soft with respect to β and γ vibration and the polarizing effect of the last nucleon becomes very important. In recent years evidence for stable triaxial shape has been investigated and established in several odd-A Lu nuclei in the form of wobbling bands [1]. TSD bands have also been observed in Hf isotopes but wobbling nature has not been confirmed. So far no experimental evidence for such bands have been found in odd-odd nuclei. The rotational bands of a number of nuclei in this mass region exhibit various features like multiquasiparticle excitation based on both low and high K values, signature splitting, band inversion etc [2]. The present experiment has been performed to look for the connecting transitions, extend the already observed bands to higher spins and try to observe the wobbling motion if possible.