Journal of The Japan Society of Microgravity Application
Print ISSN : 0915-3616
Volume 24 , Issue 1
Sixth Japan/China Workshop Microgravity Sciences
Showing 1-26 articles out of 26 articles from the selected issue
  • Nobuyuki Imaishi, Haruhiko Ohta
    2007 Volume 24 Issue 1 Pages 1-
    Published: January 31, 2007
    Released: January 21, 2021
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  • Hideki OKAMOTO, Kosuke NAGASHIO, Kazuhiko KURIBAYASHI, Itaru JIMBO
    2007 Volume 24 Issue 1 Pages 3-
    Published: January 31, 2007
    Released: January 21, 2021
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    The fragmentation of the faceted dendrite of B-doped Si solidified from the undercooled melt was investigated using an electromagnetic levitator. The <110> dendrites, which grew at Δ T< ~ 100 K, never fragmented because they were composed of {111} planes with a lowest interface energy. On the other hand, the <100> dendrites, which grew at Δ T>~ 100 K showing fourfold axial symmetry, broke up into small pieces at undercoolings of more than 200 K. It was suggested that the capillary force acts on the interface with a relatively high energy to break up the dendrite into small pieces, since the <100> dendrite is composed of {110} and {100} planes with interface energies larger than that of the {111} plane. Moreover, striations of concentric circles formed by the segregation of B revealed that the remaining melt solidifies from the surface toward the center to engulf the fragmented dendrites. This suggests that the <100> dendrites fragmented during and/or after the recalescence.
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  • Shumpei OZAWA, Kazuhiko KURIBAYASHI, Taketoshi HIBIYA
    2007 Volume 24 Issue 1 Pages 9-
    Published: January 31, 2007
    Released: January 21, 2021
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    Fe67(Nd33-xDyx), Fe67(Nd33-xTbx) (x= 0, 16.5, and 33) droplets were containerlessly solidified using a 26 m drop tube. This was a challenge to produce the Laves phase directly from the undercooled liquid, which have been theoretically predicted to exhibit the high magnetostrictive strain. In the Fe67Nd33 sample, the Nd2Fe17 and intergranular Nd phases were formed regardless of the sample diameter. On the other hand, in the Fe67Dy33 and Fe677Tb33 samples, the Laves phase was directly formed from the melt during its free fall. The amount of the Laves phase increased as the sample diameter decreased. As a result, the Fe67Dy33 sample with a diameter of 430 μm only consisted of the Laves phase. The Fe67(Nd16.5Dy16.5) and Fe67(Nd16.5Tb16.5) samples contained the Laves phase that was formed via a peritectic reaction between the Fe3RE and liquid phases. The Fe3RE phase was also directly formed from the undercooled melt, when the sample diameter was below 800 μm.
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  • Wanchun CHEN, Daodan LIU, Jiangtao DANG
    2007 Volume 24 Issue 1 Pages 15-
    Published: January 31, 2007
    Released: January 21, 2021
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    A new generation facility on crystal growth from low temperature (NGFCG) solution has been developed. The main objective for manufacturing the NGFCG is to develop the multi-function experimental facilities for fundamental study of crystal growth and to grow larger single crystal through long duration experiments under the earth and in space. NGFCG consists of the eight subsystems: the crystal growth cell; the solution heating; the solution transportation; the optical observation on in-situ and real time; the operation panel; the electric control; the temperature measurement and control; the data and image recording and processing subsystem. The breadboard model of NGFCG has been used to diagnose the fluid flow and the concentration fields near the solid/liquid interface during the crystal growth and dissolution processes of α-LiIO3, NaClO3, Ba(N0)2 and Sr(NO)2 crystals. This paper will report our experimental results. The topics are focused on the crystal growth and crystal morphology as well as interfacial phenomena. The research results indicated that (1) the solid/liquid boundary layer characteristic of crystallization is dependent on the crystal faces; (2) the solid/liquid boundary layer thickness during crystal growth and dissolution is much different; (3) the temperature turbulence in the supersaturated solution has strongly influenced on the solid/solution stability.
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  • Yan LIU, Fei AI, Yanfei ZHOU, Xiuhong PAN, Weiqing JIN
    2007 Volume 24 Issue 1 Pages 23-
    Published: January 31, 2007
    Released: January 21, 2021
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    A prototype of multi-zone materials processing facility for space applications has been developed for the future space materials science research in China. The prototype primarily consists of 4 parts, including a furnace, a sample unit, a driving mechanism system and a controller. The ten-zone furnace is specially designed for materials processing by both the Zone-melting and the Bridgman methods, with a maximum temperature of 1300℃ and a maximum axial temperature gradient of 40℃/cm. The sample unit consists of 12 magazines with 3 cartridges inside each magazine. Therefore, a total of 36 samples can be processed sequentially during once launch mission. The driving mechanism system consists of a sample rotating assembly, a sample linear exchange assembly and a sample translation assembly. The controller is a programmable microprocessor system of duel functions for system operation control and for data acquisition. By utilizing the prototype, BGO single crystal has been grown successfully on the earth.
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  • Shu USUBA, Yozo KAKUDATE, Tetsu MIENO
    2007 Volume 24 Issue 1 Pages 26-
    Published: January 31, 2007
    Released: January 21, 2021
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    The dependencies of the yields of C60 and C70 in the gas evaporation synthesis on the buffer gas pressure were experimentally observed under 1 G and 0 G. In both cases, the yields showed almost the same values until they reached the maximum at the helium pressure of 0.2-0.4 atm for C60 and 0.2-0.5 atm for C70. However in higher pressure region, the yields under 0 G decreased with pressure more rapidly than the yields under 1 G. The results were consistent with those predicted by the model based on a concept of annealing of an imperfect C60 cluster to a perfect C60 structure. According to this model, the higher yields of C60 and C70 under 1 G than those under 0 G at high buffer gas pressure were consistently explained in terms of the effect of natural convection in limiting the residence time of the imperfect C60 and C70 in high temperature state. These results suggested that the natural convection was expected to be a major obstacle in synthesizing any clusters having complex structures that required long residence times of their precursor clusters in high temperature state, such as endohedral metalloflluerenes and single-walled nanotubes.
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  • Jing LI, Zhangfu YUAN, Yifang PAN, Fumitaka TSUKIHASHI
    2007 Volume 24 Issue 1 Pages 33-
    Published: January 31, 2007
    Released: January 21, 2021
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    The relationships between surface tension of molten tin and its temperature coefficient with temperature and oxygen partial pressure were elucidated from the thermodynamic analysis. The emphasis is placed on the influence of the oxygen potential on the surface tension of molten tin. The surface tension of molten tin has been determined by a set of self-developed digital equipment with sessile drop method at oxygen partial pressure of 1.0 × 10-6 MPa under different temperatures, and the dependence of surface tension of molten tin on temperature has been also discussed. Based on the summarized relationships of surface tension of molten tin with temperature and oxygen partial pressure reported in literatures, the reasons of the difference in those reported data have been analyzed. Surface tensions of the same molten tin sample measured by using different equipments with sessile drop method have been compared also. Results of the comparison indicate that the measured results with sessile drop method under the approximate experimental conditions are coincident, and the self-developed digital equipment for surface tension measurement has higher stability and accuracy.
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  • Keiji MURAKAMI, Kenji MIKAMI, Yoshio HAYASHI
    2007 Volume 24 Issue 1 Pages 39-
    Published: January 31, 2007
    Released: January 21, 2021
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    Thermal property is very important for the microgravity experiment, to decide the experiment conditions and also to analysis the experiment results. Beside the flight hardware development for International Space Station, JAXA (Japanese Space Exploration Agency) is also developing the ground based experiment support systems to measure such thermal properties on ground. We will show the overview of the JAXA thermal property measurement system and some results using our system.
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  • Toshihide TOBITSUKA, Eiji MIYAZAKI, Masamitsu IMAI, Toyohiko YANO, Osa ...
    2007 Volume 24 Issue 1 Pages 43-
    Published: January 31, 2007
    Released: January 21, 2021
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    Five kinds of ceramic specimens, aluminum nitride, two kinds of silicon carbides fabricated by hot-pressing and reaction-sintering, and titanium nitrides ion-plated on aluminum and alumina plates space-exposed at the Service Module of the International Space Station were examined to evaluate property change. These specimens were fixed on the three sets of sample trays, which were set onto the external wall of the service module. The first set of specimens was retrieved after 315 days. After exposure in space, solar absorptance of all specimens increased. The roughness average of the surface became larger after space exposure for the case of aluminum nitride and silicon carbides specimens. The grain boundary phase of the reaction-sintered silicon carbide was obviously eroded, and many tiny particles were observed on the surface of grain boundary phase after the space exposure. The surface oxygen content of the space-exposed silicon carbide specimens where was not covered by a fixture jig increased markedly compared with those of blank, atomic oxygen-irradiated specimens and the covered part of the space-exposed specimens. After space exposure, oxygen was detected up to ~ 10 nm from the surface, which was deeper than the range calculated by SRIM-2003 code.
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  • L. DUAN, Q. KANG, W. R. HU
    2007 Volume 24 Issue 1 Pages 49-
    Published: 2007
    Released: January 21, 2021
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    Free surface deformation and surface oscillation of fluid are the most important physics phenomena in the field of fluid mechanics. In this paper, surface deformation and surface oscillation of the buoyant-thermo capillary convection in a rectangular cavity due to gravity and temperature gradient between the two sidewalls have been investigated. Temperature difference between the two side walls of the cavity is increased gradually, and the flow on the liquid layer will develop from stable convection to un-stable convection. An optical diagnostic system consisting of Michelson interferometer with image processor has been developed, it gives out the displacement of free surface. The present research results demonstrate that surface deformation and surface oscillation are related with temperature gradient and the thickness of liquid layer, it means that they are influenced by both of surface tension and buoyancy.
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  • Koichi NISHINO, Shaligram TIWARI
    2007 Volume 24 Issue 1 Pages 54-
    Published: January 31, 2007
    Released: January 21, 2021
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    The flow and heat transfer characteristics at the liquid-air interface of thermocapillary flow in liquid bridges of high Prandtl number fluids are investigated numerically. The conservation equations of mass, momentum and energy are solved in the coupled domain of the liquid bridge and the surrounding air with the help of available commercial CFD software. The thermocapillary effect has been incorporated as a body-force term in a very thin layer adjacent to the surface. All the computations are performed under steady state conditions. The upper and lower disk temperatures are varied in such a way so as to keep the mean temperature of the liquid to be same in all cases so that the assumption of constant property values for the liquid holds accurately. The computations are performed over a range of Marangoni numbers (Ma) for fixed ambient temperature conditions but most of the results presented here correspond to Ma= 13200. It has been shown with help of Biot number variation at the interface that the effect of microgravity on the behavior of surface heat loss can be closely mimicked by using a partition boundary (PB) in the air region. The presence of PB and microgravity modify the flow and temperature fields significantly as shown in clear and distinguishable plots for streamlines and temperature contours. The computed velocity and temperature profiles at the interface are validated against well established experimental results.
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  • Zhiwei SUN, Shenghua XU, Jie LIU
    2007 Volume 24 Issue 1 Pages 62-
    Published: January 31, 2007
    Released: January 21, 2021
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    A great deal of effort has been devoted to the influence of gravitational fields on the coagulation process. The Peclet number is commonly used for estimating the importance of the sedimentation influence on the aggregation in comparison to diffusion. González et al.1,2) chose a particle diameter as the characteristic length in their Peclet number evaluation and derived Pe=m0(1-p/p0)ga0/KBT, where m0 is mass of the particle, T is room temperature and KB is Boltzmann constant. They found that Pe is of the order of unity if the particles are 1 μrn in diameter, (1-p/p0) is less than but of the order of unity, see1,2). And then they concluded that ‘‘ 1 μm marks the transition between diffusive and drifting for individual particles’’. However, we testify that when dealing with the influence of sedimentation on coagulation, taking particle diameter as the characteristic length may be problematic. Our Brownian dynamics simulation shows that the degree of sedimentation influence on the coagulation decreases when the dispersion volume fraction increases. Therefore using a fixed length, such as the diameter of particle, as the characteristic length scale for Peclet number evaluation is not a good choice when dealing with the influence of sedimentation on coagulation. Our simulations demonstrated that several factors in the coagulation process, such as dispersion volume fraction and size distribution, should be taken into account for more reasonable evaluation of the sedimentation influence.
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  • J. F. ZHAO, N. YAN, G. LIU, S. X. WAN, W. R. HU
    2007 Volume 24 Issue 1 Pages 66-
    Published: January 31, 2007
    Released: January 21, 2021
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    In the present paper, a comprehensive literature review is presented focus on the scaling of CHF (critical heat flux) with gravity in pool boiling heat transfer from heated cylindrical surfaces, particularly in cases of electrically heated wires with small diameter. New data of CHF on thin wires utilizing a TCPB (Temperature-Controlled Pool Boiling) device in different gravity levels obtained from the recent space experiment aboard the 22nd Chinese recoverable satellite and the control experiments on the ground before and after the space flight are presented and discussed. The experiments are performed at 0.1 MPa and with a liquid subcooling of 26℃ nominally. It's found that the correlation of Lienhard & Dhir can predict the present data with good agreement, although the range of the dimensionless radius R ' is extended by three or more decades above the originally set limit. Based upon the different performances of CHF in constant and variable gravity conditions reported in the literature, it's conjecturable that there may exist some other parameters in addition to R' that play important roles in the CHF phenomenon with small Bond number.
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  • Yoichi SATO, Koichi INOUE, Haruhiko OHTA
    2007 Volume 24 Issue 1 Pages 71-
    Published: January 31, 2007
    Released: January 21, 2021
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    Transparent heating surface with multiple arrays of 88 thin film temperature sensors and mini-heaters is developed for the clarification of boiling heat transfer mechanisms under microgravity conditions, where the relation between local heat transfer coefficients and behaviors of liquid microlayer underneath attached vapor bubbles is investigated. Local surface temperature is controlled to keep constant by the feedback circuits, and a simple boundary condition on the heat transfer surface is realized. Preliminary boiling experiments on ground are conducted using FC72 as a test fluid at pressure P= 0.1 MPa, liquid subcoolingΔ Tsub = 10.8 K and a constant surface temperature 58.8℃. The local heat flux change characterized by the heat transfer enhancement due to the microlayer evaporation and the deterioration by the extending dry patches is detected corresponding to the observed liquid-vapor behaviors underneath a coalesced bubble.
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  • Yuji NAKAMURA
    2007 Volume 24 Issue 1 Pages 77-
    Published: January 31, 2007
    Released: January 21, 2021
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    A flame spread behavior under various partial gravity fields (from zero to normal gravity) in laboratory scale system has been investigated numerically to gain better understandings of fire behavior in Lunar or Martian environments. Two-dimensional, mass and heat transport with one-step finite rate reaction model are considered in the gas phase, whereas thermally-thin solid with two overall decomposition reactions are considered in the solid phase. Thermal interaction between the flame and surface leads continuous fuel supply into the gas phase and brings the flame spread behavior. Following four features are predicted depending on the imposed field gravity levels: 1) quasi-steady flame spread is observed under the condition considered, 2) flame spreads only one side (upstream) under extremely small gravity level, then additional downstream flame appears over certain gravity level, 3) flames start flicker over certain gravity level, 4) the spread rate shows maximum at certain gravity level where also shows maximum total heat release in the system. Gravity-induced flow correlation of spread rate follows a single curve, indicating that the instantaneous spread rate is essentially determined by the flow structure at the flame leading edge. It is suggested that severe fire retardant regulation and different fire safety strategy must be taken into account for the safety human activity on Lunar or Martian environments.
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  • Sheng-Guo GUAN, Liang-Cheng TU, Ze-Bing ZHOU, Jun LUO
    2007 Volume 24 Issue 1 Pages 86-
    Published: January 31, 2007
    Released: January 21, 2021
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    Motivated by extra dimensions theories that predict new effects, a proposal of experimental searching for the deviation from Newtonian gravitational Inverse-Square Law (ISL) in short-range is presented, which is based on an electrostatic space accelerometer to test ISL at the separation close to 10 μm. Several systematic uncertainties, including spurious force due to the Casimir force and electric force, and various sources of random uncertainty due to patch field and detector noise are discussed. Our analysis suggests that on microgravity, drag-free satellite, the proposed experiment will improve the current constraint on the possible new forces by 3 to 4 orders of magnitude.
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  • Hai-Bo TU, Shu-Chao WU, Yan-Zheng BAI, Shao-Bo QU, Jun LUO, Ze-Bing ZH ...
    2007 Volume 24 Issue 1 Pages 91-
    Published: January 31, 2007
    Released: January 21, 2021
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    An inertial sensor with aresolution of 10-12m s-2 Hz-1/2 from 0.1 mHz to 0.1 Hz for ASTROD I is designed. An electrostatic torsion pendulum facility is constructed to investigate the ground-based performance of the inertial sensor. The twist motion of the test mass of the torsion pendulum is monitored by a separated optical lever system and servo-controlled by electrostatic capacitance actuators. The preliminary result shows that the resolution of the electrostatic torsion pendulum comes to 10-11 Nm Hz-1/2 from 0.1 mHz to 0.5 Hz.
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  • Gang DENG, Liang-Cheng TU, Zhi-Long WAN, Cheng-Gang SHAO, Jun LUO
    2007 Volume 24 Issue 1 Pages 96-
    Published: January 31, 2007
    Released: January 21, 2021
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    A space proposal for precisely measuring Casimir force and its thermal effect is introduced, which is based on an electrostatic space accelerometer and a picogravity satellite. Two 4 x 4 cm2 parallel gold plates are used as test masses with a separation of 5 to 20 μm. The Casimir force and its thermal effect between the two plates are calculated and the feasibility of our new proposal is discussed. Our analyses indicate that the expected effects could be demonstrated with 0.1 ~ 1% accuracy in our proposal.
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  • Hiroshi TOMIDA, M. MATSUOKA, K. KAWASAKI, S. UENO, T. YOKOTA, N. KURAM ...
    2007 Volume 24 Issue 1 Pages 101-
    Published: January 31, 2007
    Released: January 21, 2021
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    The Monitor of All-sky X-ray Image (MAXI) is an X-ray all-sky monitor that will be attached to the Japanese Experiment Module (Kibo) of the International Space Station (ISS). MAXI will be transported by an H-II Transfer Vehicle (HTV) or the space shuttle in 2008. It employs X-ray slit cameras composed of slat collimators and a one-dimensional position-sensitive detector, with a field of view (FOV) of 1° x 160°. This narrow FOV sweeps almost the entire sky due to the orbital motion of the ISS without any pointing mechanism. The latitude of the source from the orbital plane is determined by a one-dimensional position-sensitive X-ray detector. The spatial resolution is 1.5 degrees in full width at half maximum (FWHM). MAXI employs two types of X-ray detectors, the CCD detector and the gas proportional counter. The CCD covers 0.5 to 12 keV with a moderate energy resolution of < 150 eV in FWHM at 5.9 keV, and the gas counter covers 2 to 30 keV with an effective area of 5350 cm2. This large area provides unprecedented sensitivity as an all-sky monitor, and enables us to systematically monitor faint sources such as extra-galactic objects for the first time. The data transferred to the ground station will be analyzed automatically to detect transient sources, such as X-ray novae. Observers will be informed of the position and flux of the sources as soon as possible via the Internet. All observed data will also be made public in an appropriate data format.
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  • Takashi SAKURAI, Masaoki HAGINO, Tetsuya YAMAMOTO
    2007 Volume 24 Issue 1 Pages 108-
    Published: January 31, 2007
    Released: January 21, 2021
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    We studied three active regions (NOAA 10030, 10069, 9661), which produced large flares. We analyzed the time evolution of the magnetic helicity injection Hin and force-free parameter &aipha; on flare days. We employed two kinds of data: One is the low cadence data (90 min) of longitudinal magnetograms of the full disk obtained from SOHO/MDI and vector magnetograms obtained by the Solar Flare Telescope (SFT) at National Astronomical Observatory of Japan. The other is the high cadence data (10 min) made from the interpolated SOHO/MDI magnetograms and the averaged SFT magnetograms. The results indicate that the temporal variation of the accumulated helicity injection roughly follows the time variation of force-free parameter α.
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  • Ken EBISAWA, T. TAMURA, K. MATSUZAKI, I. SHINOHARA, A. MIURA, H. MURAK ...
    2007 Volume 24 Issue 1 Pages 111-
    Published: January 31, 2007
    Released: January 21, 2021
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    DARTS (Data ARchive and Transmission System) is the scientific satellite database developed and maintained by Center of Planning and Information Systems (PLAIN center) at ISAS/JAXA. We introduce the structure and functionality of DARTS. All the current ISAS satellite data and most of the historical data are maintained at DARTS, and users can freely download the highly processed data and publish scientific results.
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  • Jun NISHIMURA
    2007 Volume 24 Issue 1 Pages 114-
    Published: January 31, 2007
    Released: January 21, 2021
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    Since the first visit of Japanese delegation of physicists in 1957, the communication of the scientists in both countries started. Then mutual visits and collaborative efforts of Cosmic-ray studies and Space sciences have been realized. One of the successful collaborative achievements is the study of the high-energy cosmic-ray phenomena at high mountain laboratories in Tibet, which has been operated since 1980. As for the space science, the collaborative scientific ballooning works, launching the balloons at Kagoshima Space Center, ISAS, fly over the East-China sea, recovering the payloads in the west of Shanghai, were successfully performed during 1986-88. The Institutions including Purple mountain observatory, Shanghai astronomical observatory Space Science and Technology Center in China, ISAS and the several Universities in Japan carried out the observations and analyses. Exchange program of the scientists are preceded, and it stimulates the studies of the respective fields. For the advance of the space science, it becomes possible to discuss the collaborative satellite observations. For this, I emphasize that it is most effective to promote together collaborative scientific ballooning works of long duration flights in China, not only for the scientific results of balloon observations but also for giving more experiences and chances of observations to the space scientists. It will help to increase the number of excellent young scientists, which is indispensable to develop the field of space science with future satellites and space probes.
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  • Shoji TORII, CALET Collaboration
    2007 Volume 24 Issue 1 Pages 120-
    Published: January 31, 2007
    Released: January 21, 2021
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    The CALorimetric Electron Telescope, CALET, mission is proposed for the Japanese Experiment Module Exposed Facility, JEM-EF, of the International Space Station. The mission goal is to reveal the high-energy phenomena in the universe by carrying out a precise measurement of the electrons in 1 GeV-10 TeV and the gamma-rays in 20 MeV-several TeV. The instrument will be composed of an imaging calorimeter of scintillating fibers and a total absorption calorimeter of BGO. The total thickness of absorber is 36 r.1 for electromagnetic particles and 1.6 m.f.p for protons. Total weight of the payload is nearly 2,500 kg, and the effective geometrical factor for the electrons could be larger than 0.5 ~ 1 m2 sr. The CALET has a unique capability to measure the electrons and the gamma-rays over 1 TeV since the hadron rejection power might be 10 6 and the energy resolution of electromagnetic particles better than a few % over 100 GeV. Therefore, it is promising to detect the change of energy spectra and the γ-ray line expected from candidates of the dark matter. We are expecting to launch the CALET around 2012 by the Japanese H-II Transfer Vehicle, HTV, and to observe for three years.
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  • Masakatsu ICHIMURA, CALET Collaboration
    2007 Volume 24 Issue 1 Pages 127-
    Published: January 31, 2007
    Released: January 21, 2021
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    The standard model of shock acceleration of cosmic ray nuclei around SNR (Supernova Remnants) suggests that the acceleration limits should be around Z x 10 14 eV for nuclei with atomic number Z. But no direct observations have shown the indication of this limit even for proton spectrum so far. On the other hand, we observe the energy spectra which are modified by the propagation in the Galaxy. So it is important to understand the propagation as well as the acceleration mechanisms. Observation of various components of cosmic ray nuclei up to 10 15 eV with higher statistical accuracy is essential to understand cosmic ray physics. In such situation, the CALET (CALorimetric Electron Telescope) mission is proposed for study of high energy cosmic rays. Although CALET is originally designed for detections of electrons and gamma rays, nuclear components of primary cosmic rays, from protons to iron nucleus and more, are also observable, because it has a calorimeter which is thick enough to detect nuclear interactions and to measure the energy by calorimetric method. The energy spectra for several nuclear components and the secondary/primary ratios which will be observed by CALET mission are roughly estimated with assuming three years operation. The CALET has capability to obtain the energy spectra for each nuclear species up to 10 15 eV, and to provide the unique data for secondary/primary ratios in unexplored energy region.
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  • [in Japanese]
    2007 Volume 24 Issue 1 Pages 131-
    Published: January 31, 2007
    Released: January 21, 2021
    JOURNALS OPEN ACCESS
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  • [in Japanese]
    2007 Volume 24 Issue 1 Pages 133-
    Published: January 31, 2007
    Released: January 21, 2021
    JOURNALS OPEN ACCESS
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