H. Ishino

Radiation-hardness of VA1 with sub-micron process technology

We have studied the radiation hardness of the VA1, a Viking-architecture preamplifier VLSI chip. Large-scale integrated (LSI) samples are fabricated in 0.8 and 0.35 /spl mu/m process technologies to improve the radiation hardness of the LSI for the Belle silicon vertex detector upgrade. We have observed significant improvement of the radiation hardness with 0.8-/spl mu/m technology compared to 1.2-/spl mu/m technology. Little degradation of noise and gain is observed up to a total dose of 20 Mrd for the VA1 fabricated in the 0.35-/spl mu/m technology. We find that the radiation hardness improves with a scaling of better than t/sub ox//sup -6/ (t/sub ox/: oxide thickness). Basic parameters of MOSFETs are also studied to understand the mechanism of radiation damage in the VA1.

Millimeter-wave broadband antireflection coatings using laser ablation of subwavelength structures

We report on the first use of laser ablation to make submillimeter, broadband, antireflection coatings (ARCs) based on subwavelength structures (SWSs) on alumina and sapphire. We used a 515 nm laser to produce pyramid-shaped structures with a pitch of about 320 μm and a total height of near 800 μm. Transmission measurements between 70 and 140 GHz are in agreement with simulations using electromagnetic propagation software. The simulations indicate that SWS-ARCs with the fabricated shape should have a fractional bandwidth response of Δν/νcenter=0.55 centered on 235 GHz for which reflections are below 3%. Extension of the bandwidth to both lower and higher frequencies, between a few tens of gigahertz and a few terahertz, should be straightforward with appropriate adjustment of laser ablation parameters.

Bandpass mismatch error for satellite CMB experiments I: estimating the spurious signal

Future Cosmic Microwave Background (CMB) satellite missions aim to use the

Improvement of radiation hardness of double-sided silicon strip detector for Belle SVD upgrade

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Development of front-end electronics for Belle SVD Upgrades

mode polarization to measure the tensor-to-scalar ratio

Prototype design and evaluation of the nine-layer achromatic half-wave plate for the LiteBIRD low frequency telescope

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Frequency-Domain Multiplexing Readout with a Self-Trigger System for Pulse Signals from Kinetic Inductance Detectors

with a sensitivity of about

Development of Lumped Element Kinetic Inductance Detectors for phonon and photon detections

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Development of Microwave Kinetic Inductance Detectors for phonon and photon detections

. Achieving this goal will not only require sufficient detector array sensitivity but also unprecedented control of all systematic errors inherent to CMB polarization measurements. Since polarization measurements derive from differences between observations at different times and from different sensors, detector response mismatches introduce leakages from intensity to polarization and thus lead to a spurious

Latest Results from Super-Kamiokande

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