IMP-8 (IMP-J) was launched by NASA on October 26, 1973 to measure the
magnetic fields, plasmas, and energetic charged particles (e.g.,
cosmic rays) of the Earth's magnetotail and magnetosheath and of the
near-Earth solar wind. IMP-8 continues to operate.
A hemispherical electrostatic analyzer measured the directional ... intensity of positive ions and electrons in the solar wind,
magnetosheath, and magnetotail. Ions as heavy as oxygen were resolved
when the solar wind temperature was low. Energy analysis was
accomplished by charging the plates to known voltage levels and
allowing them to discharge with known RC time constants. In the solar
wind, positive ions from 200 eV to 5 keV (15% spacing, 3% resolution)
and electrons from 5 eV to 1 keV (30% spacing, 15% resolution) were
studied. In the magnetosheath, positive ions from 200 eV to 5 keV (15%
spacing, 3% resolution) and from 200 eV to 20 keV (30% spacing, 15%
resolution) and electrons from 5 eV to 1 keV (30% spacing, 15%
resolution) were studied. In the magnetotail, positive ions from 200
eV to 20 keV (30% spacing, 15% resolution) and electrons from 5 eV to
1 keV (30% spacing, 15% resolution) and from 100 eV to 20 keV (15%
resolution) were studied.
Data consists of 12-sec magnetotail data; solar wind flow parameters,
based on proton and alpha particle measurements, given at
approximately 2-min resolution; and, hourly data obtained by averaging
2-min resolution solar wind data provided over the years by LANL.
Magnetosheath data were excluded from the 2-min data by LANL.
Data is available through anonymous ftp at NSSDC, the NSSDC ftpBrowser
and some plots from the PI site at LANL.
Other data include:
- 1-Hour averaged Proton and Alpha Solar Wind Moments Data
- Merged IMP-H and -J Hourly Averaged Solar Wind Plasma Data
- High Resolution Plasma Data (PROMIS period)
- 5 Minute Field and Plasma Data from UCLA
- 2-Minute Proton and Alpha Solar Wind Moments Data
- Hourly Averaged Solar Wind Plasma Density Velocity, Proton
- Solar Wind Three Hour Averaged Plasma Parameters from IMP I, J, and
- Five-minute Plasma Parameters in the Magnetotail, Three-hour Plots