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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 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.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 levels of signal count rate R29 (in mHz) required to resolve the 29.18 keV line as a doublet at 1% significance level for different values of the detector resolution  and the signal-to-noise ratio  at 106 s of measurement time. The red spot corresponds to the area of the branching ratio b and isomer transition energy  according to Ref. [2]. (For interpretation of the references to color in this figure caption, the reader is referred to the web version of this paper.)
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f0010: Curves of constant levels of signal count rate R29 (in mHz) required to resolve the 29.18 keV line as a doublet at 1% significance level for different values of the detector resolution and the signal-to-noise ratio at 106 s of measurement time. The red spot corresponds to the area of the branching ratio b and isomer transition energy according to Ref. [2]. (For interpretation of the references to color in this figure caption, the reader is referred to the web version of this paper.)


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 levels of signal count rate R29 (in mHz) required to resolve the 29.18 keV line as a doublet at 1% significance level for different values of the detector resolution  and the signal-to-noise ratio  at 106 s of measurement time. The red spot corresponds to the area of the branching ratio b and isomer transition energy  according to Ref. [2]. (For interpretation of the references to color in this figure caption, the reader is referred to the web version of this paper.)
© Copyright Policy
Related In: Results  -  Collection

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

f0010: Curves of constant levels of signal count rate R29 (in mHz) required to resolve the 29.18 keV line as a doublet at 1% significance level for different values of the detector resolution and the signal-to-noise ratio at 106 s of measurement time. The red spot corresponds to the area of the branching ratio b and isomer transition energy according to Ref. [2]. (For interpretation of the references to color in this figure caption, the reader is referred to the web version of this paper.)
Bottom Line: 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.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