1. Lifetime measurements of yrast states in ¹⁷⁸ Pt using the charge plunger method with a recoil separator
- Author
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Heery, J., Barber, L., Vilhena, J., Nara Singh, B. S., Herzberg, R.-D., Cullen, D. M., Müller-Gatermann, C., Beeton, G., Bowry, M., Dewald, A., Grahn, T., Greenlees, P. T., Illana, A., Julin, R., Juutinen, S., Keatings, J. M., Leino, M., Luoma, M., O’Donnell, D., Ojala, J., Pakarinen, J., Rahkila, P., Ruotsalainen, P., Sandzelius, M., Sarén, J., Sinclair, J., Smith, J. F., Sorri, J., Spagnoletti, P., Tann, H., Uusitalo, J., and Zimba, G.
- Subjects
platina ,ydinfysiikka - Abstract
Lifetime measurements in \(^{178}\)Pt with excited states de-exciting through \(\gamma\)-ray transitions and internal electron conversions have been performed. Ionic charges were selected by the in-flight mass separator MARA and measured at the focal plane in coincidence with the \(4^{+}_{1}→2^{+}_{1}\) 257 keV γ-ray transition detected using the JUROGAM 3 spectrometer. The resulting charge-state distributions were analysed using the differential decay curve method (DDCM) framework to obtain a lifetime value of 430(20) ps for the \(2^{+}_{1}\) state. This work builds on a method that combines the charge plunger technique with the DDCM analysis. As an alternative analysis, ions were selected in coincidence with the \(^{178}\)Pt alpha decay (\(E_{\mathrm {alpha}} = 5.458(5)\) MeV) at the focal plane. Lifetime information was obtained by fitting a two-state Bateman equation to the decay curve with the lifetime of individual states defined by a single quadrupole moment. This yielded a lifetime value of 430(50) ps for the \(2^{+}_{1}\) state, and 54(6) ps for the \(4^{+}_{1}\) state. An analysis method based around the Bateman equation will become especially important when using the charge plunger method for the cases where utilising coincidences between prompt \(\gamma\) rays and recoils is not feasible.
- Published
- 2021