[Isocops] IBEX CEU SOH check for Orbits 148-151. * RED LIMITS on V and T *
Mark Tapley
mtapley at swri.edu
Thu Mar 22 16:42:36 EDT 2012
IBEX instrument teams,
Still working; commanded and expected RED LIMITS continue on
IBEX-Hi Negative Collimator Voltage. Note, system design should
accommodate -3100V, and maximum commanded voltage is -1600V, so limit
on plot does in fact need revision.
A different RED LIMIT occurs on IBEX-Lo TOF Temperature Arc
149b. This is almost certainly spurious; it's only a single reading,
no temperature ramp-up or -down.
--------------------
For Arc 148a: Serious spin problems, last 1/3 of arc. ACS
shows FractionValid going to near zero. As noted in previous report,
IBEX-Hi Negative Collimator Voltage is commanded to RED LIMIT of
1300V. IBEx-Lo PAC Current Monitor seems to exceed yellow high
current for one sample at ramp-up; this is a fairly normal
occurrence. Otherwise Nominal.
For Arc 148b: Serious spin problems, first day or so. ACS
shows FractionValid at near zero, returning slowly to 100%, then
dipping again near end of orbit. IBEX-Hi ESA Voltage shows several
excursions to zero near the end of the arc, consistent with a gain
scan. A descending staircase patter also appears in IBEX-Lo MCP
Current Monitor, in IBEX-Lo MCP Volt Monitor, IBEX-Lo TOF MCP Current
Monitor, IBEX-Lo TOF MCP Volt Monitor, and MCP Voltage Setting.
Otherwise Nominal.
For Arc 149a: Serious spin problems, first day or so. ACS
shows FractionValid near zero, recovering around day 1. As noted in
previous report, IBEX-Hi Negative Collimator Voltage is commanded to
-1400V which is beyond plot RED LIMIT of -1300V. IBEX-Hi CEM Current
shows a series of stair-steps consistent with a gain scan around Day
1.7, also reflected in IBEX-Hi CEM Voltage (with CEM 4 offset ~100V
above the others this time), IBEX-Hi ESA Voltage excursions to zero,
and IBEX-Hi TOF Box Voltage (set back to -5500V from -6000 during the
scan). Otherwise Nominal.
For Arc 149b: No obvious spin problems. IBEX-Lo MCP Volt
monitor shows 2 drop-outs, in the middle of the "fuzz suppression"
due to IBEX-Lo PMT Voltage set-back. *** IBEX-Lo TOF Temperature
shows a single (almost certainly spurious) reading above the RED
LIMIT about day 4.7. ***. Otherwise Nominal.
For Arc 150a: Spin rate looks good, but a phase offset is
corrected around Day 1. FractionValid, which had been around zero, is
returning to 100% around that time. As noted in previous report,
IBEX-Hi Negative Collimator Voltage is commanded to -1400V which is
beyond plot RED LIMIT of -1300V. Otherwise Nominal.
For Arc 150b: No obvious spin problems. IBEX-Hi ESA Voltage
goes to zero once near beginning and once near end of arc, consistent
with O-Mode operation as commanded. Otherwise Nominal.
For Arc 151a: Spin problems for first 1.5 days; FractionValid
goes to zero during most of that time, then recovers to 100%. As
noted in previous report, IBEX-Hi Negative Collimator Voltage is
commanded to -1400V which is beyond plot RED LIMIT of -1300V. IBEX-Hi
ESA Voltage goes to zero once near beginning and once near end of
arc, consistent with O-Mode operation as commanded. "Fuzz" as often
before, modulated by IBEX-Lo PMT Voltage. Otherwise Nominal.
For Arc 151b: Spin problems for last ~1 day of orbit;
FractionValid has been decaying all Arc, goes to ~10% for last day
and ACS indicates loss of spin lock. Noticeable IBEx-HI CEM Back
Counts day 8.7. IBEX-Hi ESA Voltage goes to zero once near beginning
and once near end of arc, consistent with O-Mode operation as
commanded. Otherwise Nominal.
--------------------
...based on data at http://ibex.unh.edu/ibexhome/id-leops/status/ in
appropriate directories.
--
- Mark 210-379-4635
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