Energy response of X-rays under high flux conditions using a thin APD for the energy range of 6–33 keV

Masuda, Takahiko; Hiraki, T.; Kaino, Hiroyuki; Kishimoto, Shunji; Miyamoto, Yuki; Okai, K.; Okubo, Sho; Ozaki, R.; Sasao, N.; Suzuki, Kenta; Uetake, Satoshi; Yoshimi, A.; Yoshimura, K.

doi:10.1016/j.nima.2018.10.029

Cited by 5 publications

(4 citation statements)

References 31 publications

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“…The conceptual diagram of the signal processing is shown in Fig 6 . Each Si-APD output is amplified by a fast amplifier (Mini-circuits, RAM-8A+) located directly behind the Si-APDs. The amplified output is processed in several ways to obtain event characteristics 19,20 . First of all, it is converted to a logic signal by a lab-built constant fraction discriminator (CFD); this yields an event occurrence time.…”

Section: Appendices a Detector System A1 Apd Detector And Readout Systemmentioning

confidence: 99%

“…The values in the parentheses are those normalized to the sum, which is shown in the bottom row. The energy dependence of ε apd , together with the APD response function, is studied by a separate experiment at KEK-PF 19 ; it is expressed by ε apd (E) 1 − exp[−σ Si (E)ρ Si L Si ], where σ Si (E) is the photoelectric absorption cross section 26 of Si at the energy E, ρ Si the density and L Si an effective thickness of the Si sensor. Some uncertainties exit in determining L Si , but their effect is negligible for the ratio calculation.…”

Section: B22mentioning

confidence: 99%

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X-ray pumping of the 229Th nuclear clock isomer

Masuda

Yoshimi

Fujieda

et al. 2019

Nature

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Thorium-229 is a unique case in nuclear physics: it presents a metastable first excited state 229m Th, just a few electronvolts above the nuclear ground state. This so-called isomer is accessible by VUV lasers, which allows transferring the amazing precision of atomic laser spectroscopy to nuclear physics. Being able to manipulate the 229 Th nuclear states at will opens up a multitude of prospects, from studies of the fundamental interactions in physics to applications as a compact and robust nuclear clock. However, direct optical excitation of the isomer or its radiative decay back to the ground state has not yet been observed, and a series of key nuclear structure parameters such as the exact energies and half-lives of the low-lying nuclear levels of 229 Th are yet unknown. Here we present the first active optical pumping into 229m Th. Our scheme employs narrow-band 29 keV synchrotron radiation to resonantly excite the second excited state, which then predominantly decays into the isomer. We determine the resonance energy with 0.07 eV accuracy, measure a half-life of 82.2 ps, an excitation linewidth of 1.70 neV, and extract the branching ratio of the second excited state into the ground and isomeric state respectively. These measurements allow us to re-evaluate gamma spectroscopy data that have been collected over 40 years.

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Section: Appendices a Detector System A1 Apd Detector And Readout Systemmentioning

confidence: 99%

Section: B22mentioning

confidence: 99%

X-ray pumping of the 229Th nuclear clock isomer

Masuda

Yoshimi

Fujieda

et al. 2019

Nature

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“…The pellet was covered with two 20 Â 20 mm MgF 2 substrates, one on either side. The scattered X-ray photons were detected by a dedicated energy-sensitive X-ray detector (Masuda et al, 2017(Masuda et al, , 2019a.…”

Section: Nrs Measurementmentioning

confidence: 99%

Absolute X-ray energy measurement using a high-accuracy angle encoder

Masuda

Watanabe

Beeks

et al. 2021

J Synchrotron Radiat

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This paper presents an absolute X-ray photon energy measurement method that uses a Bond diffractometer. The proposed system enables the prompt and rapid in situ measurement of photon energies over a wide energy range. The diffractometer uses a reference silicon single-crystal plate and a highly accurate angle encoder called SelfA. The performance of the system is evaluated by repeatedly measuring the energy of the first excited state of the potassium-40 nuclide. The excitation energy is determined as 29829.39 (6) eV, and this is one order of magnitude more accurate than the previous measurement. The estimated uncertainty of the photon energy measurement was 0.7 p.p.m. as a standard deviation and the maximum observed deviation was 2 p.p.m.

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“…The pellet was covered with two 20 × 20 mm 2 MgF 2 substrates. The scattered X-ray photons were detected by a dedicated energy-sensitive X-ray detector [25,26].…”

Section: Nrs Measurementmentioning

confidence: 99%

Absolute X-ray energy measurement using a high-accuracy angle encoder

Masuda,

Watanabe,

Beeks

et al. 2020

Preprint

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This paper presents an absolute X-ray photon energy measurement method that uses a Bond diffractometer. The proposed system enables the prompt and rapid in-situ measurement of photon energies in a wide energy range. The diffractometer uses a reference silicon single crystal plate and a highly accurate angle encoder called SelfA. We evaluate the performance of the system by repeatedly measuring the energy of the first excited state of the potassium-40 nuclide. The excitation energy is determined as 29 829.39(6) eV. It is one order of magnitude more precise than the previous measurement. The estimated uncertainty of the photon energy measurement was 0.7 ppm as a standard deviation and the maximum observed deviation was 2 ppm.

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Energy response of X-rays under high flux conditions using a thin APD for the energy range of 6–33 keV

Cited by 5 publications

References 31 publications

X-ray pumping of the 229Th nuclear clock isomer

X-ray pumping of the 229Th nuclear clock isomer

Absolute X-ray energy measurement using a high-accuracy angle encoder

Absolute X-ray energy measurement using a high-accuracy angle encoder

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