Lifetime measurements of yrast states in $$^{\mathbf {178}}$$Pt using the charge plunger method with a recoil separator



Heery, J ORCID: 0000-0002-3023-9907, Barber, L, Vilhena, J, Singh, BS Nara, Herzberg, R-D ORCID: 0000-0001-9876-1518, Cullen, DM, Müller-Gatermann, C, Beeton, G, Bowry, M, Dewald, A
et al (show 22 more authors) (2021) Lifetime measurements of yrast states in $$^{\mathbf {178}}$$Pt using the charge plunger method with a recoil separator. The European Physical Journal A, 57 (4).

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Abstract

<jats:title>Abstract</jats:title><jats:p>Lifetime measurements in <jats:inline-formula><jats:alternatives><jats:tex-math>$$^{178}$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow /> <mml:mn>178</mml:mn> </mml:msup> </mml:math></jats:alternatives></jats:inline-formula>Pt with excited states de-exciting through <jats:inline-formula><jats:alternatives><jats:tex-math>$$\gamma $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>γ</mml:mi> </mml:math></jats:alternatives></jats:inline-formula>-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 <jats:inline-formula><jats:alternatives><jats:tex-math>$$4_1^+\rightarrow 2_1^+$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msubsup> <mml:mn>4</mml:mn> <mml:mn>1</mml:mn> <mml:mo>+</mml:mo> </mml:msubsup> <mml:mo>→</mml:mo> <mml:msubsup> <mml:mn>2</mml:mn> <mml:mn>1</mml:mn> <mml:mo>+</mml:mo> </mml:msubsup> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula><jats:inline-formula><jats:alternatives><jats:tex-math>$$257\,$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>257</mml:mn> <mml:mspace /> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula>keV <jats:inline-formula><jats:alternatives><jats:tex-math>$$\gamma $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>γ</mml:mi> </mml:math></jats:alternatives></jats:inline-formula>-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 <jats:inline-formula><jats:alternatives><jats:tex-math>$$2_1^+$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mn>2</mml:mn> <mml:mn>1</mml:mn> <mml:mo>+</mml:mo> </mml:msubsup> </mml:math></jats:alternatives></jats:inline-formula> 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 <jats:inline-formula><jats:alternatives><jats:tex-math>$$^{178}$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow /> <mml:mn>178</mml:mn> </mml:msup> </mml:math></jats:alternatives></jats:inline-formula>Pt alpha decay (<jats:inline-formula><jats:alternatives><jats:tex-math>$$E_{\mathrm {alpha}} = 5.458(5)$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>E</mml:mi> <mml:mi>alpha</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:mn>5.458</mml:mn> <mml:mrow> <mml:mo>(</mml:mo> <mml:mn>5</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> </mml:mrow> </mml:math></jats:alternatives></jats:inline-formula> 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 <jats:inline-formula><jats:alternatives><jats:tex-math>$$2_1^+$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mn>2</mml:mn> <mml:mn>1</mml:mn> <mml:mo>+</mml:mo> </mml:msubsup> </mml:math></jats:alternatives></jats:inline-formula> state, and 54(6) ps for the <jats:inline-formula><jats:alternatives><jats:tex-math>$$4_1^+$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mn>4</mml:mn> <mml:mn>1</mml:mn> <mml:mo>+</mml:mo> </mml:msubsup> </mml:math></jats:alternatives></jats:inline-formula> 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 <jats:inline-formula><jats:alternatives><jats:tex-math>$$\gamma $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>γ</mml:mi> </mml:math></jats:alternatives></jats:inline-formula> rays and recoils is not feasible.</jats:p>

Item Type: Article
Divisions: Faculty of Science and Engineering > School of Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 22 Apr 2021 10:16
Last Modified: 20 Jan 2022 14:10
DOI: 10.1140/epja/s10050-021-00425-8
Open Access URL: https://doi.org/10.1140/epja/s10050-021-00425-8
URI: https://livrepository.liverpool.ac.uk/id/eprint/3120168