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Prospects for measuring the (229)Th isomer energy using a metallic magnetic microcalorimeter.

Kazakov GA, Schauer V, Schwestka J, Stellmer SP, Sterba JH, Fleischmann A, Gastaldo L, Pabinger A, Enss C, Schumm T - Nucl Instrum Methods Phys Res A (2014)

Bottom Line: The Thorium-229 isotope features a nuclear isomer state with an extremely low energy.In particular, resolving the 29.18 keV doublet in the γ-spectrum following the α-decay of Uranium-233, corresponding to the decay into the ground and isomer state, allows to measure the isomer transition energy without additional theoretical input parameters, and increase the energy accuracy.We study the possibility of resolving the 29.18 keV line as a doublet and the dependence of the attainable precision of the energy measurement on the signal and background count rates and the instrumental resolution.

View Article: PubMed Central - PubMed

Affiliation: Wolfgang Pauli Institute, Univ. Wien - UZA 4 Nordbergstrasse 15, A, 1090 Vienna, Austria ; Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Stadionallee 2, 1020 Vienna, Austria.

ABSTRACT

The Thorium-229 isotope features a nuclear isomer state with an extremely low energy. The currently most accepted energy value, 7.8±0.5 eV, was obtained from an indirect measurement using a NASA x-ray microcalorimeter with an instrumental resolution 26 eV. We study, how state-of-the-art magnetic metallic microcalorimeters with an energy resolution down to a few eV can be used to measure the isomer energy. In particular, resolving the 29.18 keV doublet in the γ-spectrum following the α-decay of Uranium-233, corresponding to the decay into the ground and isomer state, allows to measure the isomer transition energy without additional theoretical input parameters, and increase the energy accuracy. We study the possibility of resolving the 29.18 keV line as a doublet and the dependence of the attainable precision of the energy measurement on the signal and background count rates and the instrumental resolution.

No MeSH data available.


Related in: MedlinePlus

Curves of constant  labeled in eV in the  plane for different values of  and 106 s of total measurement time.
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f0030: Curves of constant labeled in eV in the plane for different values of and 106 s of total measurement time.

Mentions: In Fig. 5 we present curves of constant level of in the plane (, ) obtained from the Monte-Carlo simulation. Finally, in Fig. 6 we present the curves of constant in the plane for fixed ratios . One can see that improving the instrumental resolution by 1 eV increases the precision on the determination of by the same amount as doubling the 29.18 keV signal count rate, or doubling the measurement time t.


Prospects for measuring the (229)Th isomer energy using a metallic magnetic microcalorimeter.

Kazakov GA, Schauer V, Schwestka J, Stellmer SP, Sterba JH, Fleischmann A, Gastaldo L, Pabinger A, Enss C, Schumm T - Nucl Instrum Methods Phys Res A (2014)

Curves of constant  labeled in eV in the  plane for different values of  and 106 s of total measurement time.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4376067&req=5

f0030: Curves of constant labeled in eV in the plane for different values of and 106 s of total measurement time.
Mentions: In Fig. 5 we present curves of constant level of in the plane (, ) obtained from the Monte-Carlo simulation. Finally, in Fig. 6 we present the curves of constant in the plane for fixed ratios . One can see that improving the instrumental resolution by 1 eV increases the precision on the determination of by the same amount as doubling the 29.18 keV signal count rate, or doubling the measurement time t.

Bottom Line: The Thorium-229 isotope features a nuclear isomer state with an extremely low energy.In particular, resolving the 29.18 keV doublet in the γ-spectrum following the α-decay of Uranium-233, corresponding to the decay into the ground and isomer state, allows to measure the isomer transition energy without additional theoretical input parameters, and increase the energy accuracy.We study the possibility of resolving the 29.18 keV line as a doublet and the dependence of the attainable precision of the energy measurement on the signal and background count rates and the instrumental resolution.

View Article: PubMed Central - PubMed

Affiliation: Wolfgang Pauli Institute, Univ. Wien - UZA 4 Nordbergstrasse 15, A, 1090 Vienna, Austria ; Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Stadionallee 2, 1020 Vienna, Austria.

ABSTRACT

The Thorium-229 isotope features a nuclear isomer state with an extremely low energy. The currently most accepted energy value, 7.8±0.5 eV, was obtained from an indirect measurement using a NASA x-ray microcalorimeter with an instrumental resolution 26 eV. We study, how state-of-the-art magnetic metallic microcalorimeters with an energy resolution down to a few eV can be used to measure the isomer energy. In particular, resolving the 29.18 keV doublet in the γ-spectrum following the α-decay of Uranium-233, corresponding to the decay into the ground and isomer state, allows to measure the isomer transition energy without additional theoretical input parameters, and increase the energy accuracy. We study the possibility of resolving the 29.18 keV line as a doublet and the dependence of the attainable precision of the energy measurement on the signal and background count rates and the instrumental resolution.

No MeSH data available.


Related in: MedlinePlus