Saebyeok Ahn - Academia.edu (original) (raw)

Papers by Saebyeok Ahn

arXiv (Cornell University), Feb 2, 2023

Proceedings of 41st International Conference on High Energy physics — PoS(ICHEP2022)

Axion, a hypothetical particle originally emerging from a proposed solution to the strong problem... more Axion, a hypothetical particle originally emerging from a proposed solution to the strong problem of particle physics, is one of the favored candidates addressing the dark matter puzzle. As part of the efforts within the Center for Axion and Precision Physics Research of the Institute for Basic Science, we are searching for axion dark matter using the haloscope method sensitive to masses around 24.5 µeV at Kim-Shifman-Vainshtein-Zakharov (KSVZ) sensitivity. A unique 8-cell cavity, used for the first time in search of KSVZ axions, is cooled down to 40 mK within a magnetic field of 8 T. The expected axion signal resonating with the TM 010-like mode of the cavity is picked up using an antenna and transferred to the readout chain. Implementing a flux-pumped Josephson parametric amplifier with 20 dB gain as the first stage of amplification, the system noise temperature was estimated to be 450 mK, corresponding to 1.6 photons. In this paper, we present results from data taken between December 2021 and June 2022, covering approximately 100 MHz.

arXiv (Cornell University), Oct 19, 2022

We report an axion dark matter search at Dine-Fischler-Srednicki-Zhitnitskii sensitivity with the... more We report an axion dark matter search at Dine-Fischler-Srednicki-Zhitnitskii sensitivity with the CAPP-12TB haloscope, assuming axions contribute 100% of the local dark matter density. The search excluded the axion-photon coupling gaγγ down to about 6.2 × 10 −16 GeV −1 over the axion mass range between 4.51 and 4.59 µeV at a 90% confidence level. The achieved experimental sensitivity can also exclude Kim-Shifman-Vainshtein-Zakharov axion dark matter that makes up just 13% of the local dark matter density. The CAPP-12TB haloscope will continue the search over a wide range of axion masses.

APS April Meeting Abstracts, 2019

Bozorgnia, 2017

A conventional axion search experiment utilizes microwave resonant cavities, where axions are con... more A conventional axion search experiment utilizes microwave resonant cavities, where axions are converted into photons under a strong magnetic field. Optimized cavity dimension is essential to enhance signal power from the axion-to-photon coupling, to broaden the frequency range, to minimize mode crossings, etc. An extensive study has been performed to optimize the dimension of a cavity and frequency tuning system using the COMSOL multiphysics simulation software. We introduce a figure of merit for this purpose, and present the results from the simulation study.

Bulletin of the American Physical Society, 2017

arXiv: Instrumentation and Detectors, 2017

In halo dark matter axion search experiments, cylindrical microwave cavities are typically employ... more In halo dark matter axion search experiments, cylindrical microwave cavities are typically employed to detect signals from the axion-photon conversion. To enhance the conversion power and reduce the noise level, cavities are placed in strong solenoid magnetic fields at sufficiently low temperatures. Exploring high mass regions in cavity-based axion search experiments requires high frequency microwave cavities and thus understanding cavity properties at high frequencies in extreme conditions is deemed necessary. We present a study of the magnetoresistance of copper using a cavity with a resonant frequency of 12.9 GHz in magnetic fields up to 15 T at the liquid helium temperature of 4.2 K. The observations are interpreted with the anomalous skin effect and size effect. For this study we utilize a second generation high temperature superconducting magnet designed with no-insulation and multi-width techniques. This measurement of magnetoresistance in high magnetic fields (> 10 T) is ...

Bulletin of the American Physical Society, 2018

Journal of Instrumentation, 2021

A real-time Data Acquisition (DAQ) system for the CULTASK axion haloscope experiment was construc... more A real-time Data Acquisition (DAQ) system for the CULTASK axion haloscope experiment was constructed and tested. The CULTASK is an experiment to search for cosmic axions using resonant cavities, to detect photons from axion conversion through the inverse Primakoff effect in a few GHz frequency range in a very high magnetic field and at an ultra low temperature. The constructed DAQ system utilizes a Field Programmable Gate Array (FPGA) for data processing and Fast Fourier Transformation. This design along with a custom Ethernet packet designed for real-time data transfer enables 100% DAQ efficiency, which is the key feature compared with a commercial spectrum analyzer. This DAQ system is optimally designed for RF signal detection in the axion experiment, with 100 Hz frequency resolution and 500 kHz analysis window. The noise level of the DAQ system averaged over 100,000 measurements is around -111.7 dBm. From a pseudo-data analysis, an improvement of the signal-to-noise ratio due to ...

Bulletin of the American Physical Society, 2017

Proceedings of 40th International Conference on High Energy physics — PoS(ICHEP2020), 2021

The axion is a hypothetical particle associated with the spontaneous symmetry breaking of the (1)... more The axion is a hypothetical particle associated with the spontaneous symmetry breaking of the (1) symmetry, proposed by Pecci and Quinn to resolve the Charge-Parity () problem in quantum chromodynamics. For invisible axions, cosmological and astrophysical observations impose the lower and upper limits on axion mass of eV and meV respectively. The axion in such a mass range could be a promising candidate for the cold dark matter. The CAPP-8TB experiment searches for the axion by detecting photons, produced by the axion-photon coupling, resonating in a microwave cavity. The experiment has recently obtained a result of axion search in the mass range of 6.62-6.82 eV. At the 90 % confidence level we probed the QCD axion down to a theoretical boundary, which is the most sensitive experimental result in the specific mass range to date. In this paper we will explain the detail of the experimental setup, parameters and analysis procedure. A plan for the next phase of the experiment for different mass ranges will also be discussed.

Proceedings of European Physical Society Conference on High Energy Physics — PoS(EPS-HEP2019), 2020

The axion is a hypothetical particle proposed to solve the strong CP problem, and also a candidat... more The axion is a hypothetical particle proposed to solve the strong CP problem, and also a candidate for dark matter. This non-relativistic particle in the galactic halo can be converted into a photon under a strong magnetic field and detected with a microwave resonant cavity. Relying on this detection method, many experiments have excluded some mass regions with certain sensitivities in terms of axion-photon coupling (g aγγ) for decades, but no axion dark matter has been discovered to date. CAPP-8TB is another axion haloscope experiment at IBS/CAPP designed to search for the axion in a mass range of 6.62 to 7.04 µeV. The experiment aims for the most sensitive axion dark matter search in this particular mass range with its first-phase sensitivity reaching the QCD axion band. In this presentation, we discuss the overview of the experiment, and present the first result. We also discuss an upgrade of the experiment to achieve higher sensitivity.

Journal of Instrumentation, 2017

In halo dark matter axion search experiments, cylindrical microwave cavities are typically employ... more In halo dark matter axion search experiments, cylindrical microwave cavities are typically employed to detect signals from the axion-photon conversion. To enhance the conversion power and reduce the noise level, cavities are placed in strong solenoid magnetic fields at sufficiently low temperatures. Exploring high mass regions in cavity-based axion search experiments requires high frequency microwave cavities and thus understanding cavity properties at high frequencies in extreme conditions is deemed necessary. We present a study of the magnetoresistance of copper using a cavity with a resonant frequency of 12.9 GHz at the liquid helium temperature in magnetic fields up to 15 T utilizing a second generation high temperature superconducting magnet. The observations are interpreted to be consistent with the anomalous skin effect and size effect. This is the first measurement of magnetoresistance at a high frequency (> 10 GHz) in high magnetic fields (> 10 T).

Proceedings of The 39th International Conference on High Energy Physics — PoS(ICHEP2018), 2019

Proceedings of The 39th International Conference on High Energy Physics — PoS(ICHEP2018), 2019

Astroparticle Physics, 2018

Conventional axion dark matter search experiments employ cylindrical microwave cavities immersed ... more Conventional axion dark matter search experiments employ cylindrical microwave cavities immersed in a solenoidal magnetic field. Exploring higher frequency regions requires smaller size cavities as the TM 010 resonant frequencies scale inversely with cavity radius. One intuitive way to make efficient use of a given magnet volume, and thereby to increase the experimental sensitivity, is to bundle multiple cavities together and combine their individual outputs ensuring phasematching of the coherent axion signal. We perform an extensive study for realistic design of a phase-matching mechanism for multiple-cavity systems and demonstrate its experimental feasibility using a double-cavity system.

arXiv (Cornell University), Oct 25, 2019

CONTENTS 3.3 Exploiting higher-order resonant modes 3.4 Study of magnetoresistance 3.5 R&D for hi... more CONTENTS 3.3 Exploiting higher-order resonant modes 3.4 Study of magnetoresistance 3.5 R&D for high Q cavity 3.6 Data acquisition 3.7 Experimental control system 4 Global Axion Research 4.1 Global Network of Optical Magnetometers for Exotic Physics (GNOME)113 4.2 Axion Resonant Interaction Detection Experiment (ARIADNE) 4.3 Dark Matter Axion Haloscope Search with the CAST Dipole Magnet at CERN (CAST-CAPP) REFERENCES 8. Start R&D on high quality cavity resonators that can tolerate large magnetic fields. Even though this project suffered from interference from outside CAPP forces, we currently have a small, but still promising program going on. IBS/CAPP Station operation: Local Station for GNOME has been in operation at CAPP since 2017 GNOME collaboration: CAPP has been actively involved in data analysis for GNOME Significance GNOME is the only experiment being able to investigate transient exotic spin coupling. GNOME is especially sensitive to transient events of axion or axion-like field with mass range below neV. None of experiment so far has attempted to look for axion or axion-like particles in this ultralight mass range. GNOME is capable to search for other terrestrial events such as Q-ball or axion clump that has been recently postulated in Astro-particle physics.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

Physics Letters B

In cavity-based axion dark matter search experiments exploring high mass regions, multiple-cavity... more In cavity-based axion dark matter search experiments exploring high mass regions, multiple-cavity design is under consideration as a method to increase the detection volume within a given magnet bore. We introduce a new idea, referred to as a multiple-cell cavity, which provides various benefits including a larger detection volume, simpler experimental setup, and easier phase-matching mechanism. We present the characteristics of this concept and demonstrate the experimental feasibility with an example of a double-cell cavity.

arXiv (Cornell University), Feb 2, 2023

Proceedings of 41st International Conference on High Energy physics — PoS(ICHEP2022)

Axion, a hypothetical particle originally emerging from a proposed solution to the strong problem... more Axion, a hypothetical particle originally emerging from a proposed solution to the strong problem of particle physics, is one of the favored candidates addressing the dark matter puzzle. As part of the efforts within the Center for Axion and Precision Physics Research of the Institute for Basic Science, we are searching for axion dark matter using the haloscope method sensitive to masses around 24.5 µeV at Kim-Shifman-Vainshtein-Zakharov (KSVZ) sensitivity. A unique 8-cell cavity, used for the first time in search of KSVZ axions, is cooled down to 40 mK within a magnetic field of 8 T. The expected axion signal resonating with the TM 010-like mode of the cavity is picked up using an antenna and transferred to the readout chain. Implementing a flux-pumped Josephson parametric amplifier with 20 dB gain as the first stage of amplification, the system noise temperature was estimated to be 450 mK, corresponding to 1.6 photons. In this paper, we present results from data taken between December 2021 and June 2022, covering approximately 100 MHz.

arXiv (Cornell University), Oct 19, 2022

We report an axion dark matter search at Dine-Fischler-Srednicki-Zhitnitskii sensitivity with the... more We report an axion dark matter search at Dine-Fischler-Srednicki-Zhitnitskii sensitivity with the CAPP-12TB haloscope, assuming axions contribute 100% of the local dark matter density. The search excluded the axion-photon coupling gaγγ down to about 6.2 × 10 −16 GeV −1 over the axion mass range between 4.51 and 4.59 µeV at a 90% confidence level. The achieved experimental sensitivity can also exclude Kim-Shifman-Vainshtein-Zakharov axion dark matter that makes up just 13% of the local dark matter density. The CAPP-12TB haloscope will continue the search over a wide range of axion masses.

APS April Meeting Abstracts, 2019

Bozorgnia, 2017

A conventional axion search experiment utilizes microwave resonant cavities, where axions are con... more A conventional axion search experiment utilizes microwave resonant cavities, where axions are converted into photons under a strong magnetic field. Optimized cavity dimension is essential to enhance signal power from the axion-to-photon coupling, to broaden the frequency range, to minimize mode crossings, etc. An extensive study has been performed to optimize the dimension of a cavity and frequency tuning system using the COMSOL multiphysics simulation software. We introduce a figure of merit for this purpose, and present the results from the simulation study.

Bulletin of the American Physical Society, 2017

arXiv: Instrumentation and Detectors, 2017

In halo dark matter axion search experiments, cylindrical microwave cavities are typically employ... more In halo dark matter axion search experiments, cylindrical microwave cavities are typically employed to detect signals from the axion-photon conversion. To enhance the conversion power and reduce the noise level, cavities are placed in strong solenoid magnetic fields at sufficiently low temperatures. Exploring high mass regions in cavity-based axion search experiments requires high frequency microwave cavities and thus understanding cavity properties at high frequencies in extreme conditions is deemed necessary. We present a study of the magnetoresistance of copper using a cavity with a resonant frequency of 12.9 GHz in magnetic fields up to 15 T at the liquid helium temperature of 4.2 K. The observations are interpreted with the anomalous skin effect and size effect. For this study we utilize a second generation high temperature superconducting magnet designed with no-insulation and multi-width techniques. This measurement of magnetoresistance in high magnetic fields (> 10 T) is ...

Bulletin of the American Physical Society, 2018

Journal of Instrumentation, 2021

A real-time Data Acquisition (DAQ) system for the CULTASK axion haloscope experiment was construc... more A real-time Data Acquisition (DAQ) system for the CULTASK axion haloscope experiment was constructed and tested. The CULTASK is an experiment to search for cosmic axions using resonant cavities, to detect photons from axion conversion through the inverse Primakoff effect in a few GHz frequency range in a very high magnetic field and at an ultra low temperature. The constructed DAQ system utilizes a Field Programmable Gate Array (FPGA) for data processing and Fast Fourier Transformation. This design along with a custom Ethernet packet designed for real-time data transfer enables 100% DAQ efficiency, which is the key feature compared with a commercial spectrum analyzer. This DAQ system is optimally designed for RF signal detection in the axion experiment, with 100 Hz frequency resolution and 500 kHz analysis window. The noise level of the DAQ system averaged over 100,000 measurements is around -111.7 dBm. From a pseudo-data analysis, an improvement of the signal-to-noise ratio due to ...

Bulletin of the American Physical Society, 2017

Proceedings of 40th International Conference on High Energy physics — PoS(ICHEP2020), 2021

The axion is a hypothetical particle associated with the spontaneous symmetry breaking of the (1)... more The axion is a hypothetical particle associated with the spontaneous symmetry breaking of the (1) symmetry, proposed by Pecci and Quinn to resolve the Charge-Parity () problem in quantum chromodynamics. For invisible axions, cosmological and astrophysical observations impose the lower and upper limits on axion mass of eV and meV respectively. The axion in such a mass range could be a promising candidate for the cold dark matter. The CAPP-8TB experiment searches for the axion by detecting photons, produced by the axion-photon coupling, resonating in a microwave cavity. The experiment has recently obtained a result of axion search in the mass range of 6.62-6.82 eV. At the 90 % confidence level we probed the QCD axion down to a theoretical boundary, which is the most sensitive experimental result in the specific mass range to date. In this paper we will explain the detail of the experimental setup, parameters and analysis procedure. A plan for the next phase of the experiment for different mass ranges will also be discussed.

Proceedings of European Physical Society Conference on High Energy Physics — PoS(EPS-HEP2019), 2020

The axion is a hypothetical particle proposed to solve the strong CP problem, and also a candidat... more The axion is a hypothetical particle proposed to solve the strong CP problem, and also a candidate for dark matter. This non-relativistic particle in the galactic halo can be converted into a photon under a strong magnetic field and detected with a microwave resonant cavity. Relying on this detection method, many experiments have excluded some mass regions with certain sensitivities in terms of axion-photon coupling (g aγγ) for decades, but no axion dark matter has been discovered to date. CAPP-8TB is another axion haloscope experiment at IBS/CAPP designed to search for the axion in a mass range of 6.62 to 7.04 µeV. The experiment aims for the most sensitive axion dark matter search in this particular mass range with its first-phase sensitivity reaching the QCD axion band. In this presentation, we discuss the overview of the experiment, and present the first result. We also discuss an upgrade of the experiment to achieve higher sensitivity.

Journal of Instrumentation, 2017

In halo dark matter axion search experiments, cylindrical microwave cavities are typically employ... more In halo dark matter axion search experiments, cylindrical microwave cavities are typically employed to detect signals from the axion-photon conversion. To enhance the conversion power and reduce the noise level, cavities are placed in strong solenoid magnetic fields at sufficiently low temperatures. Exploring high mass regions in cavity-based axion search experiments requires high frequency microwave cavities and thus understanding cavity properties at high frequencies in extreme conditions is deemed necessary. We present a study of the magnetoresistance of copper using a cavity with a resonant frequency of 12.9 GHz at the liquid helium temperature in magnetic fields up to 15 T utilizing a second generation high temperature superconducting magnet. The observations are interpreted to be consistent with the anomalous skin effect and size effect. This is the first measurement of magnetoresistance at a high frequency (> 10 GHz) in high magnetic fields (> 10 T).

Proceedings of The 39th International Conference on High Energy Physics — PoS(ICHEP2018), 2019

Proceedings of The 39th International Conference on High Energy Physics — PoS(ICHEP2018), 2019

Astroparticle Physics, 2018

Conventional axion dark matter search experiments employ cylindrical microwave cavities immersed ... more Conventional axion dark matter search experiments employ cylindrical microwave cavities immersed in a solenoidal magnetic field. Exploring higher frequency regions requires smaller size cavities as the TM 010 resonant frequencies scale inversely with cavity radius. One intuitive way to make efficient use of a given magnet volume, and thereby to increase the experimental sensitivity, is to bundle multiple cavities together and combine their individual outputs ensuring phasematching of the coherent axion signal. We perform an extensive study for realistic design of a phase-matching mechanism for multiple-cavity systems and demonstrate its experimental feasibility using a double-cavity system.

arXiv (Cornell University), Oct 25, 2019

CONTENTS 3.3 Exploiting higher-order resonant modes 3.4 Study of magnetoresistance 3.5 R&D for hi... more CONTENTS 3.3 Exploiting higher-order resonant modes 3.4 Study of magnetoresistance 3.5 R&D for high Q cavity 3.6 Data acquisition 3.7 Experimental control system 4 Global Axion Research 4.1 Global Network of Optical Magnetometers for Exotic Physics (GNOME)113 4.2 Axion Resonant Interaction Detection Experiment (ARIADNE) 4.3 Dark Matter Axion Haloscope Search with the CAST Dipole Magnet at CERN (CAST-CAPP) REFERENCES 8. Start R&D on high quality cavity resonators that can tolerate large magnetic fields. Even though this project suffered from interference from outside CAPP forces, we currently have a small, but still promising program going on. IBS/CAPP Station operation: Local Station for GNOME has been in operation at CAPP since 2017 GNOME collaboration: CAPP has been actively involved in data analysis for GNOME Significance GNOME is the only experiment being able to investigate transient exotic spin coupling. GNOME is especially sensitive to transient events of axion or axion-like field with mass range below neV. None of experiment so far has attempted to look for axion or axion-like particles in this ultralight mass range. GNOME is capable to search for other terrestrial events such as Q-ball or axion clump that has been recently postulated in Astro-particle physics.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

Physics Letters B

In cavity-based axion dark matter search experiments exploring high mass regions, multiple-cavity... more In cavity-based axion dark matter search experiments exploring high mass regions, multiple-cavity design is under consideration as a method to increase the detection volume within a given magnet bore. We introduce a new idea, referred to as a multiple-cell cavity, which provides various benefits including a larger detection volume, simpler experimental setup, and easier phase-matching mechanism. We present the characteristics of this concept and demonstrate the experimental feasibility with an example of a double-cell cavity.