Speaker
Description
In-beam $\gamma$-ray measurement of Pb-184
Joonas Ojala
University of Jyväskylä
joonas.k.ojala@jyu.fi
The excited states in Pb-184 were first observed at Accelerator Laboratory of the University of Jyväskylä in in-beam gamma-ray experiment using the recoil-decay tagging technique by Cocks et al. [1]. They assigned transitions belonging to a cascade of E2 transitions and forming a rotational band associated with prolate shape. In order to further probe the structure of the beyond mid-shell nucleus Pb-184, we have conducted a new in-beam study using the JUROGAMII+RITU+GREAT+TDR [2-4] instrumentation employing reaction 104Pd(83Kr,3n)184Pb with beam energy 354MeV. The improved experimental set-up allowed us to record ~130 times higher statistics compared to work by Cocks et al. In this presentation, we will show preliminary data that suggest the extension of the yrast band up to spin 14+ and provides evidence for transitions associated with non-yrast structures. Identification of the non-yrast states can provide stringent test for theoretical models in this region and probe the shape coexistence in neutron-deficient Pb isotopes beyond the N=104 mid-shell.
References
[1] Cocks, J., et al. EPJ A, 3(1):17–20, 1998. ISSN 1434-601X.
[2] Leino, M., et al. Nucl Instrum Methods Phys Res B, 99(1):653 – 656, 1995. ISSN
0168-583X.
[3] Page, R., et al. Nucl Instrum Methods Phys Res B, 204:634 – 637, 2003. ISSN
0168-583X.
[4] Lazarus, I., et al. IEEE Trans. Nucl. Sci., 48(3):567–569, 2001. ISSN 0018-9499.
