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Dynamics Explorer-1 had an instrument which could bias an external aperture plane. The
work basically redid an old Elden
Whipple paper, but with the new instrument. One of a number of papers I
did for/with Rick Chappell in Huntsville.
Aperture
Plane Potential Control for Thermal Plasma Measurements. (copies of
the 'original' spectrograms are on the
Day 287 page).
This work includes the October 1981 data described below for the Polar Wind.
Everybody was pretty happy about how well the aperture bias worked, and on the
basis of 20-minutes of data, we decided to use an 8-V negative bias for a large
fraction of the measurements thereafter. When the pitiful NASA data system
finally gave us a significant amount of data (much, much later), we found to our
horror that the channeltrons were being saturated, and we pretty much killed off
the radial low-mass channel, the one that measured hydrogen (and gave pitch
angle distributions). This was at least partly due to the short in the RPA
grids, which also eluded us for months.
One of the big things everybody
wanted to see with DE-1 was the Polar Wind. There was a fair amount of
furor early on - Chris Gurgiolo used some of the HAPI electrostatic analyzer
data (Jim Burch, SwRI), to stake a claim. Meanwhile, in Huntsville, we had
focused much of our attention on the aperture bias data set from day
287.
Jan Sojka at Utah State did a paper
with this data set, as well (Sojka et al, Characteristics of
thermal and suprathermal ions associated with the dayside plasma trough as
measured by the Dynamics Explorer retarding ion mass spectrometer, J. Geophys.
Res., 88, 7895-7911, 1983.)
From Huntsville, Tsgunobu Nagai did a GRL article, where I was a co-author:
First
Measurements Of Supersonic Polar Wind In The Magnetosphere, GRL, pages
669-672, 1984
There is a longer technical report
with many of the nitty-gritty details of the RIMS behavior, including an
annoying feature involving channeltron saturation. Charging Characteristics Of Dynamics Explorer
1. There was also a conference publication version given at the
ESA symposium. A Potential Control Method For Thermal Plasma Measurements on the DE-1
Spacecraft
| Day 287
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I made hundreds, if not thousands, of data plots for Day
287, the data found in the above papers. Here is an archive, of
sorts, of what we observed on that special day. |
Passive
Charging (geosynchronous orbit)
Active
Charge Control (including Polar)
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