排序方式: 共有17条查询结果,搜索用时 15 毫秒
11.
Gold R.E. Krimigis S.M. Hawkins S.E. Haggerty D.K. Lohr D.A. Fiore E. Armstrong T.P. Holland G. Lanzerotti L.J. 《Space Science Reviews》1998,86(1-4):541-562
The Electron, Proton, and Alpha Monitor (EPAM) is designed to make measurements of ions and electrons over a broad range of
energy and intensity. Through five separate solid-state detector telescopes oriented so as to provide nearly full coverage
of the unit-sphere, EPAM can uniquely distinguish ions (Ei≳50 keV) and electrons (Ee≳40 keV) providing the context for the
measurements of the high sensitivity instruments on ACE. Using a ΔE×E telescope, the instrument can determine ion elemental
abundances (E≳0.5 MeV nucl−1). The large angular coverage and high time resolution will serve to alert the other instruments
on ACE of interesting anisotropic events. The experiment is controlled by a microprocessor-based data system, and the entire
instrument has been reconfigured from the HI-SCALE instrument on the Ulysses spacecraft. Inflight calibration is achieved
using a variety of radioactive sources mounted on the reclosable telescope covers. Besides the coarse (8 channel) ion and
(4 channel) electron energy spectra, the instrument is also capable of providing energy spectra with 32 logarithmically spaced
channels using a pulse-height-analyzer. The instrument, along with its mounting bracket and radiators weighs 11.8 kg and uses
about 4.0 W of power. To demonstrate some of the capabilities of the instrument, some initial performance data are included
from a solar energetic particle event in November 1997.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
12.
Lanzerotti L.J. Krimigis S.M. Decker R.B. Hawkins S.E. Gold R.E. Roelof E.C. Armstrong T.P. 《Space Science Reviews》2001,97(1-4):243-248
Charged particle instrumentation that will be flying on six spacecraft in the heliosphere between 1 and 90 AU during 2001–2004
will provide a global view of the interplanetary medium that has not heretofore been available. Comparative analyses of the
data that will be obtained will provide new understanding of the global evolution of heliospheric features such as traveling
shock waves, coronal mass ejections, solar activity-produced particle injections, and anomalous cosmic rays.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
13.
Prominent enhancements in Doppler scintillation lasting a fraction of a day (solar source several degrees wide) and overlying the neutral line represent the signature of the heliospheric current sheet and the apparent interplanetary manifestation of coronal streamers near the Sun. This first detection of coronal streamers in radio scintillation measurements provides the link betweenin situ measurements of the spatial wavenumber spectrum of electron density fluctuations beyond 0.3 AU and earlier measurements deduced from radio scintillation and scattering observations inside 0.3 AU. Significant differences between the density spectra of fast streams and slow solar wind associated with the heliospheric current sheet near the Sun reinforce the emerging picture that high- and low-speed flows are organized by the large-scale solar magnetic field, and that while the contrast between solar wind properties of the two flows is highest near the Sun, it undergoes substantial erosion in the ecliptic plane as the solar wind expands. 相似文献
14.
M. J. Reiner K. A. Anderson E. Roelof T. Armstrong G. B. Hospodarsky J. Fainberg R. G. Stone L. Lanzerotti D. A. Gurnett J. L. Phillips R. Forsyth 《Space Science Reviews》1995,72(1-2):261-266
Both the Ulysses and Galileo spacecraft detected energetic electrons and Langmuir waves that were associated with a type III radio burst on 10 December 1990. At the time of these observations, these spacecraft were in the ecliptic plane and separated by 0.4 AU, with Galileo near the Earth at 1 AU and Ulysses at 1.36 AU. From the measured electron arrival times, the propagation path lengths of the electrons to both Ulysses and Galileo were estimated to be significantly longer than the length of the Parker spiral. These long path lengths are interpreted as due to draping of the interplanetary magnetic field lines around a CME. The onset times of the Langmuir waves at Ulysses and Galileo coincided with the estimated arrival time of the 9 keV and 14 keV electrons, respectively. 相似文献
15.
Armstrong 《世界航空航天博览》2002,(20):44-48
美国陆军开始配发制式钢盔的历史可以追溯到第一次世界大战,当时远赴欧洲参战的美国军队还未列装制式钢盔,只得紧急采用了英制“平碟”式钢盔。英式钢盔在美军中一直服役到1942年中期,之后被著名的M1头盔所取代。M1头盔是美国自行研制的第一代制式头盔,外形为半球形,下部为波浪状曲线,增加防护面积,相当简练经典。M1头盔经历了二战、朝鲜战争、越南战争,成为美国大兵最重要的象征。 相似文献
16.
Investigations are carried out at JPL on radiofrequency interferences at very low levels (-130 to -180 dBm) in various bands, especially the 1-2 GHz band. Extrapolation of interferences in the years to come is attempted. 相似文献
17.
The theory and observations of energetic ion acceleration in interplanetary shock waves is reviewed. The shock acceleration of the solar wind plasma and particle transport effects are discussed. Suggestions are offered for future research in shock acceleration physics.An invited paper presented at STIP Workshop on Shock Waves in the Solar Corona and Interplanetary Space, 15–19 June, 1980, Smolenice, Czechoslovakia.NAS/NRC Research Associate. 相似文献