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Yoshida, S.

Publications and source records attributed to Yoshida, S..

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Limits on the Low-energy Electron Antineutrino Flux from the Brightest Gamma-Ray Burst of All Time

The electron antineutrino flux limits are presented for the brightest gamma-ray burst (GRB) of all time, GRB221009A, over a range of 1.8–200 MeV using the Kamioka Liquid Scintillator Antineutrino Detector. Using multiple time windows ranging from minutes to days surrounding the event to search for electron antineutrinos coincident with the GRB, we set an upper limit on the flux under the assumption of several power-law neutrino source spectra, with power-law indices ranging from 1.5 to 3 in steps of 0.5. No excess was observed in any time windows ranging from seconds to days around the event trigger time T 0 . For a power-law index of 2 and a time window of T 0 ± 500 s, a flux upper limit of 2.34 × 10 9 cm −2 was calculated. The limits are compared to the results presented by IceCube.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2024

Measurements of the charge ratio and polarization of cosmic-ray muons with the Super-Kamiokande detector

We present the results of the charge ratio (𝑅) and polarization (𝑃$^{𝜇}_{0}$) measurements using decay electron events collected between September 2008 and June 2022 with the Super-Kamiokande detector. Because of its underground location and long operation, we are able to perform high-precision measurements by accumulating cosmic-ray muons. We measured the muon charge ratio to be 𝑅 = 1.32 ± 0.02⁢(stat +syst) at 𝐸 𝜇 ⁢cos⁡𝜃 Zenith = 0.7$^{+0.3}_{−0.2}$ TeV, where 𝐸 𝜇 is the muon energy and 𝜃 Zenith is the zenith angle of incoming cosmic-ray muons. This result is consistent with the Honda flux model while indicating a tension with the 𝜋⁢𝐾 model of 1.9⁢𝜎. We also measured the muon polarization at the production location to be 𝑃$^{𝜇}_{0}$ = 0.52 ± 0.02 (stat+syst) at the muon momentum of 0.9$^{+0.6}_{−0.1}$ TeV/𝑐 at the surface of the mountain; this also suggests a tension with the Honda flux model of 1.5⁢𝜎. This is the most precise measurement ever to experimentally determine the cosmic-ray muon polarization near 1 TeV/𝑐. These measurement results are useful to improve atmospheric neutrino simulations.

Atmospheric neutrino oscillations↗
NASA NTRS2016

The Design, Implementation, and Performance of the Astro-H SXS Aperture Assembly and Blocking Filters

The calorimeter array of the JAXA Astro-H (renamed Hitomi) Soft X-ray Spectrometer (SXS) was designed to provide unprecedented spectral resolution of spatially extended cosmic x-ray sources and of all cosmic x-ray sources in the Fe-K band around 6 keV. The properties that make the SXS a powerful x-ray spectrometer also make it sensitive to the entire electromagnetic band. If characterized as a bolometer, it would have a noise equivalent power (NEP) of < 4x10(exp -18) W/(Hz)0.5. Thus it was imperative to shield the detector from thermal radiation from the instrument and optical and UV photons from the sky. Additionally, it was necessary to shield the coldest stages of the instrument from the thermal radiation emanating from the warmer stages. These needs are addressed by a series of five thin-film radiation blocking filters that block long-wavelength radiation while minimizing x-ray attenuation. The SXS aperture assembly is a system of barriers, baffles, filter carriers, and filter mounts that supports the filters and inhibits their potential contamination. The three warmer filters also were equipped with thermometers and heaters for decontamination.

microcalorimeter↗
NASA NTRS2015

Measuring the Heat Load on the Flight ASTRO-H Soft Xray Spectrometer Dewar

The Soft Xray Spectrometer (SXS) instrument on-board the ASTRO-H X-ray mission is based on microcalorimeters operating at 50 mK. Low temperature is achieved by use of an adiabatic demagnetization refrigerator (ADR) cyclically operating up to a heat sink at either 1.2 K or 4.5 K. The 1.2 K heat sink is provided by a 40 liter superfluid helium dewar. The parasitic heat to the helium from supports, plumbing, wires, and radiation, and the cyclic heat dumped by the ADR operation determine the liquid helium lifetime. To measure this lifetime we have used various techniques to rapidly achieve thermal equilibrium and then measure the boil-off rate of the helium. We have measured a parasitic heat of 650 microwatts and a cyclic heat of 100 microwatts for a total of 750 microwatts. This closely matches the predicted heat load. Starting with a fill level at launch of more than 33 liters results in a lifetime of greater than 4 years for the liquid helium. The techniques and accuracy for this measurement will be explained in this paper.

cryogenic Equipment↗
NASA NTRS2014

Operation of an ADR Using Helium Exchange Gas as a Substitute for a Failed Heat Switch

The Soft X-ray Spectrometer (SXS) is one of four instruments on the Japanese Astro-H mission, which is currently planned for launch in late 2015. The SXS will perform imaging spectroscopy in the soft X-ray band (0.3-12 keV) using a 6 6 pixel array of microcalorimeters cooled to 50 mK. The detectors are cooled by a 3-stage adiabatic demagnetization refrigerator (ADR) that rejects heat to either a superfluid helium tank (at 1.2 K) or to a 4.5 K Joule-Thomson (JT) cryocooler. Four gas-gap heat switches are used in the assembly to manage heat flow between the ADR stages and the heat sinks. The engineering model (EM) ADR was assembled and performance tested at NASA/GSFC in November 2011, and subsequently installed in the EM dewar at Sumitomo Heavy Industries, Japan. During the first cooldown in July 2012, a failure of the heat switch that linked the two colder stages of the ADR to the helium tank was observed. Operation of the ADR requires some mechanism for thermally linking the salt pills to the heat sink, and then thermally isolating them. With the failed heat switch unable to perform this function, an alternate plan was devised which used carefully controlled amounts of exchange gas in the dewar's guard vacuum to facilitate heat exchange. The process was successfully demonstrated in November 2012, allowing the ADR to cool the detectors to 50 mK for hold times in excess of 10 h. This paper describes the exchange-gas-assisted recycling process, and the strategies used to avoid helium contamination of the detectors at low temperature.

Adiabatic demagnetization↗
NASA NTRS2014

Mineralogical Variation of Chelyabinsk with Depth from the Surface of the Parent Meteoroid

The Chelyabinsk meteorite, which passed over the Chelyabinsk Oblast, Russia on Feb. 15th, 2013, brought serious damage by the shock wave and airburst. The diameter of the parent meteoroid is estimated to be approximately 20 m in diameter [1]. It was reported that the impact by this meteorite shower was 4,000 times as large as the TNT explosive and this was the largest airburst on Earth since the asteroid impact in Tunguska, Russia in 1908. The mineralogy and geochemical study of the recovered samples shows that Chelyabinsk is an LL5 chondrite [1]. In this study we analyzed several fragments of Chelyabinsk whose noble gas compositions have been measured and depths from the surface of the parent meteoroid were estimated [2]. We examined how mineralogical characteristics change with depth from the surface. This kind of study has never been performed and thus may be able to offer significant information about the evolution of meteorite parent bodies.

Yoshida, S.↗
NASA NTRS1992

Effect of total parenteral nutrition, systemic sepsis, and glutamine on gut mucosa in rats

The effect of the combination of total parenteral nutrition (TPN) and systemic sepsis on mucosal morphology and protein synthesis was investigated. Rats were given a standard TPN mixture consisting of glucose (216 kcal.kg-1.day-1), lipid (24 kcal.kg-1.day-1), and amino acids (1.5 g N.kg-1.day-1) for 5 days. On the 5th day the rats (n = 37) were randomized into four groups according to diet as follows: 1) control nonseptic on standard TPN, 2) control nonseptic on TPN with glutamine, 3) septic on standard TPN, and 4) septic with the TPN supplemented with glutamine. Twenty hours after the injection of Escherichia coli, the rats were given a 4-h constant infusion of [U-14C]leucine to determine the mucosal fractional protein synthesis rates. The following results were obtained. 1) Histological examination showed that systemic sepsis caused tissue damage to the ileum and jejunum. 2) Glutamine supplementation attenuated these changes. 3) There were no visible changes to the colon either from glutamine supplementation or sepsis. 4) Sepsis was associated with an increase in mucosal protein synthesis and decreased muscle synthesis. 5) Addition of glutamine to the TPN mix further increased protein synthesis in the intestinal mucosa of septic rats.

Non-NASA Center↗
NASA NTRS1989

Survey observations of emission-line stars in the Orion region

Survey observations were conducted for H alpha-emission stars in the Orion region using the Kiso Schmidt telescope and partly the CTIO Curtis Schmidt telescope. In the area of about 25 square degrees, a total of 236 H alpha-emission objects, mostly supposed to be T Tau type stars, have been detected among which 155 are new ones including 6 non-stellar objects. Celestial coordinates and V-magnitude are measured for the detected objects. Eye estimation of the H alpha-emission intensity is also made at three epochs in a time span of about two years, where notable variation of H alpha intensity was found in 68 out of 236 objects. Besides a remarkable concentration along the northern dark cloud complex, a loose concentration is noticed near the Orion Belt region, fairly well coinciding with the distribution of the Orion OBIb association members. A comparison with the Av-map is also made to see the relationship between the distribution of emission-line objects and that of interstellar dust.

Wiramihardja, Suhardja D.↗
NASA NTRS1973

Variations of three-dimensional anisotropy of cosmic rays during Forbush decreases.

Variations of three-dimensional anisotropy of cosmic rays during Forbush decreases are examined by a spherical harmonic method and by constructing successive isointensity contour maps in the solar ecliptic coordinate system. The east-west and north-south anisotropies are studied statistically and for several individual events; the data are based on cosmic ray records from about 24 stations for the 3-year period from 1966 to 1968. For the individual events, the high anisotropies of about 4% are examined in terms of the convective, diffusive and density gradient components of the differential streaming as well as the interplanetary magnetic field and solar wind. In each case, vector gradients are derived that lead to the observed anisotropies, and the magnitude of these gradients is typically 10-20 times that of the quiet time interplanetary gradient.

Yoshida, S.↗
NASA NTRS1971

Cosmic-ray variations and the interplanetary sector structures.

Fifteen passages of interplanetary sector structures that occurred between December 1967 and June 1968 are examined. A spherical harmonic analysis of cosmic ray intensity is performed to obtain cosmic ray intensity variations as a function of asymptotic latitude, longitude, and universal time. A clear north-south asymmetry of cosmic ray intensity, which depends on the sign of the interplanetary sector magnetic fields, is revealed.

Yoshida, S.↗