A5012235357- Superconducting and THz Device Technology
- Radio Astronomy Observations and Technology
- Physics of Superconductivity and Magnetism
- Dark Matter and Cosmic Phenomena
- Radio Frequency Integrated Circuit Design
- Cosmology and Gravitation Theories
- Atomic and Subatomic Physics Research
- Astronomy and Astrophysical Research
- Spacecraft Design and Technology
- Adaptive optics and wavefront sensing
- Random lasers and scattering media
- Galaxies: Formation, Evolution, Phenomena
- Quantum and electron transport phenomena
- Pulsars and Gravitational Waves Research
- Precipitation Measurement and Analysis
- Particle physics theoretical and experimental studies
- Superconductivity in MgB2 and Alloys
- Cold Atom Physics and Bose-Einstein Condensates
- Inertial Sensor and Navigation
- Scientific Research and Discoveries
- Geophysics and Gravity Measurements
Kyoto University
2020-2024
University of Tsukuba
2023
We search for the dark photon matter (DPDM) using a cryogenic millimeter-wave receiver. DPDM has kinetic coupling with electromagnetic fields constant of χ and is converted into ordinary photons at surface metal plate. signal this conversion in frequency range 18-26.5 GHz, which corresponds to mass 74-110 μeV/c^{2}. observed no significant excess, allowing us set an upper bound χ<(0.3-2.0)×10^{-10} 95% confidence level. This most stringent constraint date tighter than cosmological...
We present a transfer function-based method to estimate angular power spectra from filtered maps for cosmic microwave background (CMB) surveys. This is especially relevant experiments targeting the faint primordial gravitational wave signatures in CMB polarisation at large scales, such as Simons Observatory (SO) small aperture telescopes. While timestreams can be mitigate contamination low-frequency noise, usual methods that calculate mode coupling individual multipoles challenging covering...
Abstract Understanding telescope pointing (i.e. line of sight) is important for observing the cosmic microwave background (CMB) and astronomical objects. The Moon a candidate source calibration. Although visible size (30′) larger than that planets, we can frequently observe once month with high signal-to-noise ratio. We developed method performing calibration using observational data from Moon. considered tilts axes as well encoder collimation offsets In addition, evaluated effects...
Dark photons have been considered potential candidates for dark matter. The photon matter (DPDM) has a mass and interacts with electromagnetic fields via kinetic mixing coupling constant of $\ensuremath{\chi}$. Thus, DPDMs are converted into ordinary at metal surfaces. Using millimeter-wave receiver set in radioshielding box, we performed experiments to detect the conversion from DPDM frequency range 10--18 GHz, which corresponds $41--74\text{ }\text{ }\mathrm{\ensuremath{\mu}}\mathrm{eV}$....
Abstract We compute the expected sensitivity on measurements of optical depth to reionization for a ground-based experiment at Teide Observatory. simulate polarized partial sky maps GroundBIRD frequencies 145 and 220 GHz. perform fits simulated with our pixel-based likelihood extract reionization. The noise levels polarization are estimated as 110 <?CDATA $\mu {\rm{K}}\,\mathrm{arcmin}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>μ</mml:mi> <mml:mi...
A microwave kinetic inductance detector (MKID) is a cutting-edge superconducting detector. It comprises resonator circuit constructed with film on dielectric substrate. To expand its field of application, it important to establish method suppress the two-level system (TLS) noise that caused by electric fluctuations between two energy states at surface The density can be decreased expanding strip width (S) and gap from ground plane (W) in MKID circuit, allowing suppression TLS noise. However,...
GroundBIRD is a millimeter-wave telescope to observe the polarization patterns of cosmic microwave background (CMB). The target science topics are primordial gravitational waves from inflation and reionization optical depth. Therefore, this designed achieve highest sensitivity at large angular scales, ℓ = 6 - 300. For wide sky observations (~40% full-sky), scanning high rotation speed (120°/s) important remove atmospheric fluctuations. Microwave kinetic inductance detector (MKID) utilized...
The cutting-edge superconducting detector, Microwave Kinetic Inductance Detector（MKID） has been popular in the field of astronomical radio observations such as Cosmic Background（CMB）, star-forming regions, and galaxy surveying. MKID is a resonator-based detector which scalability to exceed O（1,000） pixels one readout line. photon-noise-limited sensitivity can be achieved with hybrid-type consists two materials. arrays are utilized “GroundBIRD” “Tsukuba-KID camera” projects led by Japanese...
GroundBIRD is a ground-based cosmic microwave background (CMB) experiment for observing the polarization pattern imprinted on large angular scales (ℓ > 6 ) from Teide Observatory in Tenerife, Spain. Our primary scientific objective precise measurement of optical depth τ (σ(τ ∼ 0.01) to reionization epoch Universe cross-check systematic effects measurements made by previous experiments. observes wide sky area Northern Hemisphere (∼ 40% full sky) while continuously rotating telescope at high...
Dark photons have been considered potential candidates for dark matter. The photon matter (DPDM) has a mass and interacts with electromagnetic fields via kinetic mixing coupling constant of $\chi$. Thus, DPDMs are converted into ordinary at metal surfaces. Using millimeter-wave receiver set in radioshielding box, we performed experiments to detect the conversion from DPDM frequency range 10--18 GHz, which corresponds 41--74 $\mu\mathrm{eV}$. We found no signal this upper limits $\chi <...
A microwave kinetic inductance detector (MKID) is a cutting-edge superconducting detector, and its principle based on resonator circuit. The transition temperature (Tc) of the MKID an important parameter because various characterization parameters depend it. In this paper, we propose method to measure Tc by changing applied power readout microwaves. small fraction deposited MKID, number quasiparticles in increases with power. Furthermore, quasiparticle lifetime decreases quasiparticles....
Understanding telescope pointing (i.e., line of sight) is important for observing the cosmic microwave background (CMB) and astronomical objects. The Moon a candidate source calibration. Although visible size ($\ang{;30}$) larger than that planets, we can frequently observe once month with high signal-to-noise ratio. We developed method performing calibration using observational data from Moon. considered tilts axes as well encoder collimation offsets In addition, evaluated effects...
A microwave kinetic inductance detector (MKID) is a cutting-edge superconducting detector, and its principle based on resonator circuit. The transition temperature (Tc) of the MKID an important parameter because various characterization parameters depend it. In this paper, we propose method to measure Tc by changing applied power readout microwaves. small fraction deposited in MKID, number quasiparticles increases with power. Furthermore, quasiparticle lifetime decreases quasiparticles....
We search for the dark photon matter (DPDM) using a cryogenic millimeter-wave receiver. DPDM has kinetic coupling with electromagnetic fields constant of $χ$, and is converted into ordinary photons at surface metal plate. signal this conversion in frequency range $18\text{--}26.5\,\mathrm{GHz}$, which corresponds to mass $74\text{--}110\,mu\mathrm{eV}/c^2$. observed no significant excess, allowing us set an upper bound $χ< (0.3\text{--}2.0)\times 10^{-10}$ 95\% confidence level. This most...