A5084492015- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Particle Detector Development and Performance
- Quantum Chromodynamics and Particle Interactions
- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Neutrino Physics Research
- Superconducting and THz Device Technology
- Computational Physics and Python Applications
- Astrophysics and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Radio Astronomy Observations and Technology
- Semiconductor materials and devices
- Radiation Detection and Scintillator Technologies
- GaN-based semiconductor devices and materials
- Silicon Carbide Semiconductor Technologies
- Distributed and Parallel Computing Systems
- Astronomy and Astrophysical Research
- Geophysics and Gravity Measurements
- Nuclear reactor physics and engineering
- Astronomical Observations and Instrumentation
- Medical Imaging Techniques and Applications
- Particle accelerators and beam dynamics
- Physics of Superconductivity and Magnetism
- Muon and positron interactions and applications
The University of Tokyo
2012-2023
University of Tsukuba
2012-2022
Fujitsu (Japan)
2019-2020
Kyoto University
2020
RIKEN
2018-2019
AGH University of Krakow
2012-2018
Nippon Soken (Japan)
2018
The University of Adelaide
2013-2017
Institute of Physics
2017
Jagiellonian University
2017
We report an innovative embedded device wafer level packaging technology based on a "molded reconfigured 200 mm wafer". Silicon dice are tested, grinded, and diced. For the set-up of "reconfigured wafer" these bare silicon placed faces down onto carrier system. The core process this is encapsulation dice. demonstrate that compression molding promising approach with respect to robust processing, topology, adhesion, reliability properties. base apply thin-film interconnects similar back-end...
In this paper, we demonstrate 600 V highly reliable GaN high electron mobility transistors (HEMTs) on Si substrates. technologies are most important for the mass-production at Si-LSI manufacturing facility. High breakdown voltage over 1500 was confirmed with stable dynamic on-resistance (R<inf>ON</inf>) using cascode configuration package. These HEMT based packages have passed qualification standards of Joint Electron Devices Engineering Council (JEDEC) (1–5) first time. acceleration...
For cosmic microwave background (CMB) polarization observations, calibration of detector angles is essential. We have developed a fully remote controlled system with sparse wire grid that reflects linearly polarized light along the direction. The new feature remote-controlled for regular calibration, which has not been possible in calibrators past experiments. control can be achieved by two electric linear actuators load or unload into position centered on optical axis telescope between time...
A surface potential measuring system was developed by utilizing Pockels sensor for the distribution on stress grading (SG) of form wound motor coils. Bi <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> Ge xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> O xmlns:xlink="http://www.w3.org/1999/xlink">12</inf> (BGO) crystal is put close to a object and capacitively-induced voltage end BGO measured using effect itself. The spatial resolution...
Manufacturing readiness of the world's first highly reliable 650V GaN HEMT is demonstrated with high process capability (CpK>1.6) for leakage and on resistance. This technology was developed in a Si-CMOS compatible 6-inch foundry has been over one thousand wafers worth data spread two generations nodes covering multiple products packages collected during ramp up post qualification. Silicon manufacturing processes are employed including gold-free that avoid use evaporation/liftoff typical to...
Abstract We present the development of a Superconducting Tunnel Junction (STJ) detector using Hafnium (Hf) as photon which was designed to search for radiative decay cosmic background neutrinos. The energy spectrum from neutrino has sharp edge at high end. To detect this edge, we need micro-calorimeter infrared photons with resolution. have optimized condition producing Hf-STJ and observed that had Josephson currents disappeared by applying magnetic field.
We established a production method of millimeter-wave absorber by using 3D-printed mold. The mold has periodic pyramid shape, and an absorptive material is filled into the This shape reduces surface reflection. made from transparent in range. Therefore, unmolding not necessary. A significant benefit this easy prototyping with various shapes materials. produced test model used two-component epoxy encapsulant as material. achieved low reflectance: ∼1% at 100 GHz. sometimes maintained...
A novel epitaxial growth technique–chloride multisource growth–for ternary compounds is described. Beams of the source vapors, CuCl, Ga and S (Se), are supplied into a high-purity nitrogen or hydrogen atmosphere 10 -4 Torr. The c -axis growths CuGaS 2 CuGaSe attained on GaAs (100) substrates at 600–620°C. effects CuCl/Ga supply ratio layer examined. layers strained compressively along by thermal expansion mismatch between grown substrate.
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...
Abstract We report the development of a large-diameter superconducting magnetic bearing (SMB) used in continuously rotating cryogenic half-wave plate (HWP) polarization modulator for cosmic microwave background (CMB) experiments. A precise measurement CMB will place tighter constrains on inflation, describing rapid expansion early universe. The is critical instrument suppressing 1/f contamination, which mainly caused by atmospheric noise, and mitigating systematic uncertainties that arise...
The Simons Observatory (SO) is a cosmic microwave background (CMB) survey experiment that includes small-aperture telescopes (SATs) observing from an altitude of 5,200 m in the Atacama Desert Chile. SO SATs will cover six spectral bands between 27 and 280 GHz to search for primordial B-modes sensitivity $\sigma(r)=0.002$, with quantified systematic errors well below this value. Each SAT self-contained cryogenic telescope 35$^\circ$ field view, 42 cm diameter optical aperture, 40 K half-wave...
Polarized patterns in the cosmic microwave background (CMB) radiation contains rich knowledge for early stage of universe. In particular their odd-parity at large angular scale (> 1°), primordial B-modes, are smoking-gun evidence inflation. The GroundBIRD experiment aims to detect these B-modes with a ground-based apparatus that includes several novel devices: high-speed rotational scan system, cold optics, and kinetic inductance detectors (MKIDs). We plan start observations Canary Islands...
We present the development of Superconducting Tunnel Junction (STJ) detectors as a far-infrared single photon spectrometer, which is motivated for an application to search radiative decay cosmic neutrino background (CνB). The energy spectrum from decays CνB expected have sharp edge at high end in region ranging 14 meV 25 (from 50 μm 90 wavelength) infrared and overwhelming foreground zodiacal emission. Thus, detector required photon-by-photon detection with sufficiently resolution, order...
This manuscript proves maturity of GaN-on-Si technology for the world's first highly reliable 650V GaN HEMT [2],[3],[4],[5],[6],[7],[8] by demonstrating three years manufacturing data since ramp. was initially developed in a pilot line Transphorm Goleta, CA and then later ported into Si-CMOS compatible 6-inch foundry at AFSW(Aizu Fujitsu Semiconductor Wafers Solution Ltd). Data set generated from over thousand wafers worth spread generations nodes covering multiple products packages post...
Manufacturing readiness of the world's first highly reliable 650V GaN HEMT is demonstrated with high process capability (CpK >1.6) for leakage and on resistance. This manufacturing was developed in a Si-CMOS compatible 6-inch foundry has been over five thousand wafers worth data, spread four generations technology nodes. The analysis covers multiple device products packages collected during industrialization JEDEC qualified year period. Silicon processes are employed including gold-free...
We proposed a new high resolution single photon infrared spectrometer for search radiative decay of cosmic neutrino background(C$\nu$B). The superconducting-tunnel-junctions(STJs) are used as photoncounting device. Each STJ consists Nb/Al/Al${}_{\mathrm{x}}$O${}_{\mathrm{y}}$/Al/Nb layers and their thicknesses optimized the operation temperature at 370 mK cooled by ${}^{3}$He sorption refrigerator. Our STJs achieved leak current 250 pA measured data implies that smaller area fulfills our...
Our understanding of physics at very early Universe, as 10 −35 s after the Big Bang, relies on scenario known inflationary cosmology. Inflation predicts a particular polarization pattern in cosmic microwave background, B -mode yet strength such is extremely weak. To search for we are constructing an off-axis rotating telescope to mitigate systematic effects well maximize sky coverage observation. We will discuss present status GroundBIRD telescope.
The cosmic microwave background (CMB) radiation is an afterglow of the Big Bang. It contains crucial keys to understand beginning universe. In particular, odd-parity patterns CMB polarization, B-modes, at more than degree-scale, are best probe detect primordial gravitational waves inflation. GroundBIRD experiment aims this large angular scale from ground. employs novel techniques; a high-speed rotational scanning system (20 revolution-per-minutes) with cold optics below 4K, and kinetic...
A new lifted diffused-layer (LID) MOSFET has been devised and fabricated, where the major portions of source/drain (S/ D) diffused layers are placed on top field insulator to reduce S/D parasitic capacitances. The primary feature this is that structure processing especially developed for submicrometer gate lengths. fabricated LID with a 0.5-µm length 10-nm oxide thickness showed good electrical characteristics, such as maximum transconductance 115 mS/mm an inverter delay time 59 ps/stage.
We present the status of development Superconducting Tunnel Junction (STJ) detector for COsmic BAckground Neutrino Decay search (COBAND) experiment. The signal cosmic background neutrino decay is identified as a sharp cutoff at high energy end in far-infrared region ranging from 15meV to 30meV spectrum photons space. COBAND experiment will be done rocket and satellite experiments order detect For photon experiment, we are developing STJ detectors. use combination diffraction grating array...