27 research outputs found
New Particle Identification Approach with Convolutional Neural Networks in GAPS
The General Antiparticle Spectrometer (GAPS) is a balloon-borne experiment
that aims to measure low-energy cosmic-ray antiparticles. GAPS has developed a
new antiparticle identification technique based on exotic atom formation caused
by incident particles, which is achieved by ten layers of Si(Li) detector
tracker in GAPS. The conventional analysis uses the physical quantities of the
reconstructed incident and secondary particles. In parallel with this, we have
developed a complementary approach based on deep neural networks. This paper
presents a new convolutional neural network (CNN) technique. A
three-dimensional CNN takes energy depositions as three-dimensional inputs and
learns to identify their positional/energy correlations. The combination of the
physical quantities and the CNN technique is also investigated. The findings
show that the new technique outperforms existing machine learning-based methods
in particle identification.Comment: 7 pages, 10 figure
Thermal Control System to Easily Cool the GAPS Balloon-borne Instrument on the Ground
This study developed a novel thermal control system to cool detectors of the
General AntiParticle Spectrometer (GAPS) before its flights. GAPS is a
balloon-borne cosmic-ray observation experiment. In its payload, GAPS contains
over 1000 silicon detectors that must be cooled below -40^{\circ}\mbox{C}.
All detectors are thermally coupled to a unique heat-pipe system (HPS) that
transfers heat from the detectors to a radiator. The radiator is designed to be
cooled below -50^{\circ}\mbox{C} during the flight by exposure to space. The
pre-flight state of the detectors is checked on the ground at 1 atm and ambient
room temperature, but the radiator cannot be similarly cooled. The authors have
developed a ground cooling system (GCS) to chill the detectors for ground
testing. The GCS consists of a cold plate, a chiller, and insulating foam. The
cold plate is designed to be attached to the radiator and cooled by a coolant
pumped by the chiller. The payload configuration, including the HPS, can be the
same as that of the flight. The GCS design was validated by thermal tests using
a scale model. The GCS design is simple and provides a practical guideline,
including a simple estimation of appropriate thermal insulation thickness,
which can be easily adapted to other applications.Comment: 8 pages, 14 figures, 3 table
Large-area Si(Li) Detectors for X-ray Spectrometry and Particle Tracking for the GAPS Experiment
Large-area lithium-drifted silicon (Si(Li)) detectors, operable 150{\deg}C
above liquid nitrogen temperature, have been developed for the General
Antiparticle Spectrometer (GAPS) balloon mission and will form the first such
system to operate in space. These 10 cm-diameter, 2.5 mm-thick multi-strip
detectors have been verified in the lab to provide <4 keV FWHM energy
resolution for X-rays as well as tracking capability for charged particles,
while operating in conditions (~-40{\deg}C and ~1 Pa) achievable on a
long-duration balloon mission with a large detector payload. These
characteristics enable the GAPS silicon tracker system to identify cosmic
antinuclei via a novel technique based on exotic atom formation, de-excitation,
and annihilation. Production and large-scale calibration of ~1000 detectors has
begun for the first GAPS flight, scheduled for late 2021. The detectors
developed for GAPS may also have other applications, for example in heavy
nuclei identification
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本論文では鳴門におけるワカメ養殖技術の開発・普及に関わった方々に対して聞き取り調査を行い,ワカメ養殖の経緯と先人の努力を記録として残すことを目的とする。 調査の結果,漁民の生活の向上のために努力した先人のワカメ養殖にかける熱意が明らかとなった。今後,このような地域に密着した教材を使うことにより,科学技術の発展が人間生活の向上に役立っていることを実感する学習の展開が可能である。The aim of interviewing anyone who had been involved in the technological development and dissemination of “ Wakame” seaweed aquaculture in Naruto, was to record for posterity our ancestor’s efforts and history of Wakame seaweed aquaculture. As the investigation went on, the surge of enthusiasm for our wakame seaweed farming ancestors, who were striving to improve the life of fishermen, became clear as the result.Next, we realized that using educational materials for development of science and technology in close contact with such areas, contributes to render improvement of human life possible
The Japanese space gravitational wave antenna; DECIGO
DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future
Japanese space gravitational wave antenna. DECIGO is expected to open a new window of
observation for gravitational wave astronomy especially between 0.1 Hz and 10 Hz, revealing
various mysteries of the universe such as dark energy, formation mechanism of supermassive
black holes, and inflation of the universe. The pre-conceptual design of DECIGO consists of
three drag-free spacecraft, whose relative displacements are measured by a differential Fabry–
Perot Michelson interferometer. We plan to launch two missions, DECIGO pathfinder and pre-
DECIGO first and finally DECIGO in 2024
DECIGO pathfinder
DECIGO pathfinder (DPF) is a milestone satellite mission for DECIGO (DECi-hertz Interferometer Gravitational wave Observatory) which is a future space gravitational wave antenna. DECIGO is expected to provide us fruitful insights into the universe, in particular about dark energy, a formation mechanism of supermassive black holes, and the inflation of the universe. Since DECIGO will be an extremely large mission which will formed by three drag-free spacecraft with 1000m separation, it is significant to gain the technical feasibility of DECIGO before its planned launch in 2024. Thus, we are planning to launch two milestone missions: DPF and pre-DECIGO. The conceptual design and current status of the first milestone mission, DPF, are reviewed in this article
The status of DECIGO
DECIGO (DECi-hertz Interferometer Gravitational wave Observatory) is the planned Japanese space gravitational wave antenna, aiming to detect gravitational waves from astrophysically and cosmologically significant sources mainly between 0.1 Hz and 10 Hz and thus to open a new window for gravitational wave astronomy and for the universe. DECIGO will consists of three drag-free spacecraft arranged in an equilateral triangle with 1000 km arm lengths whose relative displacements are measured by a differential Fabry-Perot interferometer, and four units of triangular Fabry-Perot interferometers are arranged on heliocentric orbit around the sun. DECIGO is vary ambitious mission, we plan to launch DECIGO in era of 2030s after precursor satellite mission, B-DECIGO. B-DECIGO is essentially smaller version of DECIGO: B-DECIGO consists of three spacecraft arranged in an triangle with 100 km arm lengths orbiting 2000 km above the surface of the earth. It is hoped that the launch date will be late 2020s for the present