The suprathermal ion mass spectrometer (SMS) onboard the Akebono (EXOS-D) satellite
The suprathermal ion mass spectrometer (SMS) onboard the Akebono (EXOS-D) satellite
复制标题
Akebono (EXOS-D) 卫星上的超热离子质谱仪 (SMS)
DOI：
10.5636/jgg.42.511
复制
发表时间：
1990
期刊：
影响因子：
--
通讯作者：
E. Sagawa
中科院分区：
文献类型：
--
作者：
B. Whalen;J. Burrows;A. Yau;E. E. Budzinski;A. Pilon;I. Iwamoto;K. Marubashi;S. Watanabe;H. Mori;E. Sagawa
超热离子质谱仪（SMS）是为研究低空磁层中热离子（0- 25 eV）和超热离子（25 eV-几keV）分布而研制的。该仪器具有质量（1- 70 amu/e）和等离子体密度（10-3至105 cm-3）的动态范围，足以定期测量远地点（104 km）和近地点（10300 km）的主要和次要离子分布函数。该仪器是一种射频型质谱仪，具有可编程的质量分辨率（Δm/m从0.06到0.20），它与所选择的能量和质量无关。本文给出了远地点附近热离子质量组成的测量结果，表明热离子质量组成从以H ~+和O ~+为主的组成变化到以“次要”离子密度为主的组成（O++，He+，N+）的量与H+和O+的量相当或更大。我们还提出了高时间分辨率的质量/能量/角度观测顶侧电离层等离子体中或附近的尖点区域的大部分等离子体的快速加热和圆锥分布的形成是显而易见的。这些独特的观测结果将与航天器上的其他等离子体诊断进行比较，以增加我们对电离层离子产生、对流和损失过程以及低空离子流现象的了解。
The Suprathermal Ion Mass Spectrometer (SMS) was developed to study the thermal (0-25eV) and suprathermal (25eV-several keV) ion distributions in the low altitude magnetosphere. The instrument has a mass (1-70amu/e) and plasma density (10-3 to 105cm-3) dynamic range sufficient to measure, on a regular basis, the major and the minor ion distribution functions at apogee (≈104km) as well as at perigee (≈300km). The instrument is a radio frequency type mass spectrometer and has a programmable mass resolution (Δm/m from 0.06 to 0.20) which is independent of energy and mass selected.We present here measurements of the thermal ion mass composition near apogee which show that the composition varies from one dominated by H+ and O+ to one in which the density of “minor” ions (O++, He+, N+) is comparable to or greater than that of H+ and O+. We also present high time resolution mass/energy/angle observations in the topside ionospheric plasma in or near the cusp region where rapid heating of the bulk of the plasma and the formation of conic distributions is clearly evident. These unique observations will be compared with other plasma diagnostics on the spacecraft to increase our understanding of ionospheric ion production, convection and loss processes as well as low altitude ion energization phenomena.