Programme

P.65 -- Poster, VCTP-46

Date: Wednesday, 6 October 2021

Time: 08:30 - 10:00

Partial level scheme of $^{182}$Ta obtained from $^{181}$Ta(n,2$\gamma$) experiment: preliminary results

Nguyen Ngoc Anh (1), Nguyen Xuan Hai (1), Nguyen Quang Hung (2, 3), Le Tan Phuc (2, 3), Le Thi Quynh Huong (4), Đinh Thi Tuong Quy (4), Cao Minh Nhan (4)

(1) Dalat Nuclear Research Institute, Vietnam Atomic Energy Institute, 01 Nguyen Tu Luc, 670000, Dalat City, Vietnam; (2) Institute of Fundamental and Applied Sciences, Duy Tan University, 700000, Ho Chi Minh City, Vietnam; (3) Faculty of Natural Sciences, Duy Tan University, 550000, Danang City, Vietnam; (4) Department of Natural Science and Technology, Khanh Hoa University, 650000, Nha Trang City, Khanh Hoa Province, Vietnam

A sample of $^{181}$Ta has been irradiated with thermal neutron produced by the Dalat Nuclear Research Reactor in order to create $^{182}$Ta compound nuclei, whose excitation energy is approximately equal to the neutron binding energy. The $^{182}$Ta compound nuclei deexcite to the ground state by emitting gamma transitions. The latter have been measured by a $\gamma - \gamma$ coincidence spectrometer [1], which, in fact, only detect two-step gamma cascades. From the measured two-step gamma cascades, we have constructed a partial level scheme of $^{182}$Ta, which consists of two-step gamma cascades corresponding to 8 different final levels, namely 0.0 ($3^-$), 16.27 ($5^+$), 97.83 ($4^+$), 114.31 ($4^-$), 150.150 ($4^+$), 173.237 ($5^-$), 237.28 ($5^-$), 292.93 ($5^-$) keV ones. All the detected levels are in agreement with those presented in the Evaluated Nuclear Structure Data File (ENSDF) library [2]. It, thus, confirms the validity of many data that currently exist in the ENSDF library. In addition, a large number of gamma transitions emitted from these detected levels to well-known low-lying states, which do not currently exist in the ENSDF library, are found. The possibility of considering these transitions found as the new data is discussed in the present report. References [1] Khang et al, Nuclear Instruments and Method A 634 (2011) 47-51. [2] https://www.nndc.bnl.gov/ensdf/

Presenter: Nguyen Ngoc Anh