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351.
C.J. Hailey T. Aramaki S.E. Boggs P.v. Doetinchem H. Fuke F. Gahbauer J.E. Koglin N. Madden S.A.I. Mognet R. Ong T. Yoshida T. Zhang J.A. Zweerink 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
The General Antiparticle Spectrometer (GAPS) is a new approach to the indirect detection of dark matter. It relies on searching for primary antideuterons produced in the annihilation of dark matter in the galactic halo. Low energy antideuterons produced through Standard Model processes, such as collisions of cosmic-rays with interstellar baryons, are greatly suppressed compared to primary antideuterons. Thus a low energy antideuteron search provides a clean signature of dark matter. In GAPS antiparticles are slowed down and captured in target atoms. The resultant exotic atom deexcites with the emission of X-rays and annihilation pions, protons and other particles. A tracking geometry allows for the detection of the X-rays and particles, providing a unique signature to identify the mass of the antiparticle. A prototype detector was successfully tested at the KEK accelerator in 2005, and a prototype GAPS balloon flight is scheduled for 2011. This will be followed by a full scale experiment on a long duration balloon from Antarctica in 2014. We discuss the status and future plans for GAPS. 相似文献
352.
A regulated peak-power tracking (RPPT) system for space power application is proposed. Large-signal stability analysis is provided to understand the main four different modes of operations of the system, as well as the mode transitions. A simple and effective control scheme for the system is also proposed. Small-signal analysis is performed thereafter to provide design optimization, and the predictions are verified by computer simulations 相似文献
353.
The Mars Global Surveyor mission has revealed that localized crustal paleomagnetic anomalies are a common feature of the Southern Hemisphere of Mars. The magnetometer measured small-scale magnetic fields associated with many individual magnetic anomalies have magnitudes ranging from hundreds to thousands nT at altitude above 120 km. That makes Mars globally different from both Venus and Earth. The data collected by Lunar Prospector near the Moon were interpreted as evidence that above regions of inferred strong surface magnetic fields on the Moon the SW flow is deflected, and a small-scale mini-magnetosphere exists under some circumstances. With a factor of 100 stronger magnetic fields at Mars and a lower SW dynamic pressure, those conditions offer the opportunity for a larger size of small `magnetospheres' which can be formed by the crustal magnetic fields. Outside the regions of the magnetic anomalies, the SW/Mars interaction is Venus-like. Thus, at Mars the distinguishing feature of the magnetic field pile-up boundary most likely varies from Venus-like to Earth-like above the crustal magnetic field regions. The observational data regarding the IMF pile-up regions near Venus and the Earth are initially reviewed. As long as the SW/Mars interaction remains like that at Venus, the IMF penetrates deep into the Martian ionosphere under the `overpressure' conditions. Results of numerical simulations and theoretical expectations regarding the temporal evolution of the IMF inside the Venus ionosphere and appearance of superthermal electrons are also reviewed and assessed. 相似文献
354.
The results of a preliminary analysis of microperturbations on the International Space Station during physical exercises of the crew are presented. The goal of this paper is to identify the parameters of perturbations
when physical exercises are performed. The results of measurements by sensors of microaccelerations of both Russian and American
segments during physical exercises in the service module of the Russian segment are analyzed. 相似文献
355.
A method is substantiated to ensure energy security for the satellite communication systems (SCS) at a close position of the
radio interception receiver. This is done by lowering the carrier frequency down to f
0 = 60…80 MHz and by applying spaced measurements with n ≥ 4 receiving antennas. 相似文献
356.
A. V. Tavrov O. I. Korablev A. V. Rodin I. I. Vinogradov A. Yu. Trokhimovsky A. Yu. Ivanov L. V. Ksanfomaliti D. A. Orlov 《Cosmic Research》2011,49(2):99-109
In order to observe exoplanets we propose a space-based achromatic stellar coronagraph combined with a 0.8–1.5 m telescope.
We develop an achromatic common path interferometer for observing an exoplanet (a faint off-axis source) on the background
of a hoste star (bright axial source). An image of the star and its copy acquire an achromatic phase shift by 180° and interfere
in antiphase. The achromatic phase shift is caused by geometric phase in the scheme of a three-dimensional interferometer.
The interference process divides spatially the dark and light fields of the star image redirecting them to the opposite sides
of a beam splitter. The interference process does not weaken the image of a planet, with equal intensities it is redirected
to both sides of a beam splitter. The suggested scheme of common path interferometer ensures mechanical stability. The background
signal is experimentally demonstrated to be reduced by six orders of magnitude. 相似文献
357.
I. A. Galiullin 《Cosmic Research》2011,49(2):175-178
The constraints imposed on parameters of a force field and of a symmetrical gyrostat in it are determined, at which regular
precession of this gyrostat demonstrate Lyapunov stability (or, respectively, instability). 相似文献
358.
Selected micro- and nano-systems developed recently at the Physical Electronics Laboratory of ETH Zurich are reviewed: (i) a fluxgate microsystem for detection of the Earth's magnetic field; (ii) a capacitive chemical sensor microsystem for detection of volatile organic compounds in air; and (iii) a parallel scanning AFM chip. The micro- and nano-systems combine sensor structures and readout circuitry on a single chip and are fabricated using industrial CMOS technology in combination with post-processing micromachining and film deposition 相似文献
359.
Possible consequences of collisions of natural cosmic bodies with the Earth’s atmosphere and surface are described. The methodological
basis of classification of consequences is the solution of meteor physics equations characterizing the trajectory of a body
in the atmosphere, namely, the dependence of the body’s velocity and mass on the flight altitude. The solution depends on
two dimensionless parameters characterizing the drag altitude and the role of mass loss by a meteoroid during its motion in
the atmosphere. Depending on values of these parameters, the degree of effect on the planetary surface considerably changes.
In particular, the conditions of cratering and meteorite fall on the planetary surface are obtained. The results are presented
in a simple analytical form. They quite match to the real events considered in the paper. Recommendations are given on further
investigations into the important problem of interaction of cosmic bodies with planetary atmospheres. 相似文献
360.
B. A. Antuf’ev 《Russian Aeronautics (Iz VUZ)》2008,51(3):227-231
A problem on low vibrations of a thin spherical shell is considered. A solid of finite dimensions is discretely attached to the shell by means of an elastic rod system. The calculation examples are presented. 相似文献