COS Cycle-21 Calibration Phase-1
Last Revised:
Proposal ID:
Title:
PI:
Co-I(s):
11/01/13
13533
COS NUV MAMA Recovery after Anomalous Shutdown
T. Wheeler
A. Welty
--------------------------------------------------------------------------# Orbit estimates are TOTAL for all of Cycle-21
Total Prime Orbits:
n/a
External Parallel Orbits:
n/a
Internals or no-impact orbits: n/a
Comments on orbit estimate:
This is a contingency proposal only.
--------------------------------------------------------------------------# This section should be written with a GO audience in mind -- use
# Calibration plans in WFPC-2 handbook as a guide.
Purpose: This proposal is designed to permit the safe and orderly recovery of
the COS/NUV MAMA detector after an anomalous shutdown. This is accomplished
by using slower-than-normal MCP and PC high-voltage ramp-ups and diagnostics.
Description: Anomalous shutdowns can occur because of bright object
violations, which trigger the Global Hardware Monitor or the Global Software
Monitor. Anomalous shutdowns can also occur because of MAMA hardware
anomalies or failures. The cause of the shutdown should be thoroughly
investigated and understood prior to recovery. Twenty-four hour wait
intervals are required after each test for MCP gas desorption and data
analysis. COS event flag 2 is used to prevent inadvertent MAMA usage.
The recovery procedure consists of three separate tests (i.e. visits) to
check the MAMA’s health after an anomalous shutdown. Each must be
successfully completed before proceeding onto the next. This proposal
executes the same steps as Cycle 20 proposal 13129.
(1) Signal processing electronics check. This reduces amplifier thresholds
to 0.28V and monitors the ORCOUNT rate. (MAMA HV is off during this
procedure)
(2) Slow, intermediate voltage HV ramp-up. The MCP and PC are slow-ramped
with plateaus to a MCP voltage 300V below nominal and a PC voltage of
-50V. A dark time-tag exposure is taken during this partial ramp. A
second time-tag dark exposure is taken where the event counter is cycled
through W, X, Y, Z, OR, EV and VE
(3) Slow, full voltage HV ramp-up. The MCP and PC are slow-ramped with
plateaus to the full MCP and PC operating voltages. As before, a dark
time-tag exposure is taken during the ramp. A second dark time-tag
exposure is taken where the event counter is cycled through W, X, Y, Z,
OR, EV and VE. This is followed by and fold analysis test (See COS MAMA
Fold Distribution for details).
Accuracy:
n/a
Comments on Accuracy:
n/a
Products:
n/a
--------------------------------------------------------------------------# Link to cycle 21 Science
# Use the GO + GTO Phase 1 exposure listing and derived statistics
# posted on WWW.
Fraction of science programs supported by this calibration: This is a
contingency procedure only.
List categories of science which can't be executed until after this proposal:
n/a
why:
n/a
List categories of science which are best performed contemporaneous with this
proposal:
n/a
why:
--------------------------------------------------------------------------# THE REST OF THIS FORM IS FOR INTERNAL USE
--------------------------------------------------------------------------Observation summary: The recovery from an anomalous shutdown consists of
three tests: a signal processing electronics check, high-voltage ramp-up to
an intermediate voltage and a high-voltage ramp-up to the full operating
voltage followed by a fold distribution test. During each of the two high
voltage ramp-ups, time-tag exposures are taken and diagnostics are performed.
Post-ramp dark time-tags with diagnostics are also taken. The final, full
ramp is followed by a fold distribution test.
# Target information (copy for each target)
Target Name.
: n/a
RA.
: n/a
Dec.
: n/a
Flux (and units).
: n/a
Visibility window (if known or relevant): n/a
Comment on choice of target
: n/a
#
#
#
#
#
#
Exposure list plan at the Phase I level. Be as complete as reasonable.
If possible information should be complete enough to allow easy
submission of a Phase 2 from this form. However, if you have to leave
some of the fields blank below, or want to provide the information
in another format, that is acceptable. (Make sure you do the BOP checking
though, as this is a phase-1 issue.)
------------------------------------------------------------------------**** This list of exposures should be executed ONLY in the event of ****
****
an anomalous COS/NUV MAMA shutdown
****
------------------------------------------------------------------------Note (1)
Bright Object Protection Considerations during the Visit 3 and Visit 6.
(a)
This proposal uses aperture/grating/lamp combinations which are
designed to produce count rates of ~1,000-2,000 count/sec. They should
not be changed without consultation with the P.I.
(b) During the execution of the fold analysis some anode folds are
disabled. Consequently, the OR counter does not provide a true
representation of the OR count and so the Software Global Monitor (SGM)
does not trigger until the enabled folds provide enough counts to the
OR counter to trigger the SGM's threshold. To compensate, while the
fold analysis is running the SGM threshold is reduced to 10,000 counts
in a 1.0 second interval, from its nominal value of 20,000 counts in a
0.1 second interval.
(c) For the reasons discussed in (b) and to prevent light from entering the
hub this test should only be run with the COS external shutter closed.
Note (2)
Voltage ramping terms and polarity terminology.
With the COS NUV MAMA detector, the term ramp-up means to make the MCP or PC
more negative in applied voltage. Ramping down means heading towards 0V.
Table of exposures (copy for each exposure as appropriate/desired):
Visit 1, Exposure 1: Signal Processing Electronics Checkout - LV On
Target or lamp
: Dark
Type of Acquisition
: n/a
Detector for observation
: COS/NUV
Operating mode
: Data
Spectral Element
: n/a
Aperture
: n/a
Central Wavelength
: n/a
Exposure Time
: 1005s
Number of Iterations
: 1
BOP Predicted Local Count Rate for MAMA : n/a, no detector HV
BOP Predicted Global Count Rate for MAMA: n/a, no detector HV
ETC PID IDs for Count Rates
: n/a
Special Requirements or options
: Special commanding
Comments:
Same alignment Sequence 1-3.
Switch on LV power supply.
Set SGM Threshold = 10000, Integration Period = 0.1 secs.
Set amplifier threshold to default (0.48V)- Collect a minimum of 30
telemetry points.
Set amplifier threshold to 0.28V- Collect a minimum of 30 telemetry
Points.
Special commanding: Instruction = ELHDTLVN_1.
Visit 1, Exposure 2: Signal Processing Electronics Checkout - LV Off
Target or lamp
: Dark
Type of Acquisition
: n/a
Detector for observation
: COS/NUV
Operating mode
: Data
Spectral Element
: n/a
Aperture
: n/a
Central Wavelength
: n/a
Exposure Time
: 30s
Number of Iterations
: 1
BOP Predicted Local Count Rate for MAMA : n/a, no detector HV
BOP Predicted Global Count Rate for MAMA: n/a, no detector HV
ETC PID IDs for Count Rates
: n/a
Special Requirements or options
: Special commanding
Comments:
Special commanding: Instruction = RLLVTHDN.
Visit 1, Exposure 3: Signal Processing Electronics Checkout - Set Flag 2
Target or lamp
: Dark
Type of Acquisition
: n/a
Detector for observation
: COS/NUV
Operating mode
: Data
Spectral Element
: n/a
Aperture
: n/a
Central Wavelength
: n/a
Exposure Time
: 1s
Number of Iterations
: 1
BOP Predicted Local Count Rate for MAMA : n/a, no detector HV
BOP Predicted Global Count Rate for MAMA: n/a, no detector HV
ETC PID IDs for Count Rates
: n/a
Special Requirements or options
: Special commanding
Comments:
Special commanding: Instruction = ELFLAG2.
Visit 2, Exposure 1: Intermediate HV Checkout - LV On
Target or lamp
: Dark
Type of Acquisition
: n/a
Detector for observation
: COS/NUV
Operating mode
: Data
Spectral Element
: n/a
Aperture
: n/a
Central Wavelength
: n/a
Exposure Time
: 60s
Number of Iterations
: 1
BOP Predicted Local Count Rate for MAMA : Special monitoring per ISR 98-03
BOP Predicted Global Count Rate for MAMA: Special monitoring per ISR 98-03
ETC PID IDs for Count Rates
: n/a
Special Requirements or options
: Special commanding
Comments:
Sequence 1-6 Non-Int.
Must clear event flag 2 for the commanding to execute.
Switch on LV power supply.
Special commanding: Instruction = ELHDTLVN_2.
Visit 2, Exposure 2: Intermediate HV Checkout - Ramp HV to -1750V/-50V
Target or lamp
: Dark
Type of Acquisition
: n/a
Detector for observation
: COS/NUV
Operating mode
: Time-Tag
Spectral Element
: Default
Aperture
: Default
Central Wavelength
: n/a
Exposure Time
: 1800s
Number of Iterations
: 1
BOP Predicted Local Count Rate for MAMA : Special monitoring per ISR 98-03
BOP Predicted Global Count Rate for MAMA: Special monitoring per ISR 98-03
ETC PID IDs for Count Rates
: n/a
Special Requirements or options
: Buffer Time = 2000
Special commanding
Comments:
The MCP and PC Voltage partial Ramp-ups will be performed in stages. The
ramp-up within a stage is by increments of -50V. The final MCP voltage
will be -1750V, 300V shy of the nominal value of -2050V. The final PC
Voltage will be -50V, rather than the nominal -800V setting. Use the
nominal yellow and red ramping limits. At the end of each stage, reset
the SGM to a Threshold = 100 and an Integration Period = 0.1 sec, and
collect telemetry samples of OR Counts for 4 minutes. The COS rate is 1
TLM sample/10 secs; ~24 samples will be obtained.
Stage 1 - MCP ramp-up (0 to -500V)
Stage 2 - MCP ramp-up (-500V to -1000V)
Stage 3 - MCP ramp-up (-1000V to -1500V)
Stage 4 - MCP ramp-up (-1500V to -1750V)
Stage 5 - PC Voltage ramp-up (+20 to -50V)
Special commanding: Instruction = ELHVPART2.
Visit 2, Exposure 3: Intermediate HV Checkout - Cycle SGM
Target or lamp
: Dark
Type of Acquisition
: n/a
Detector for observation
: COS/NUV
Operating mode
: Time-Tag
Spectral Element
: Default
Aperture
: Default
Central Wavelength
: n/a
Exposure Time
: 570s
Number of Iterations
: 1
BOP Predicted Local Count Rate for MAMA : Special monitoring per ISR 98-03
BOP Predicted Global Count Rate for MAMA: Special monitoring per ISR 98-03
ETC PID IDs for Count Rates
: n/a
Special Requirements or options
: Buffer Time = 720
Special commanding
Comments:
Set SGM Threshold = 200, Integration Period = 0.1 secs.
Collect minimum 5 samples W events.
Collect minimum 5 samples X events.
Collect minimum 5 samples Y events.
Collect minimum 5 samples Z events.
Collect minimum 5 samples OR events.
Collect minimum 5 samples EV events.
Collect minimum 5 samples VE events.
Special commanding: Instruction = ELHVDARK2.
Visit 2, Exposure 4: Intermediate HV Checkout - HV Off
Target or lamp
: Dark
Type of Acquisition
: n/a
Detector for observation
: COS/NUV
Operating mode
: Data
Spectral Element
: n/a
Aperture
: n/a
Central Wavelength
: n/a
Exposure Time
: 250s
Number of Iterations
: 1
BOP Predicted Local Count Rate for MAMA : Special monitoring per ISR 98-03
BOP Predicted Global Count Rate for MAMA: Special monitoring per ISR 98-03
ETC PID IDs for Count Rates
: n/a
Special Requirements or options
: Special commanding
Comments:
Ramp down detector.
Special commanding: Instruction = ELHVTLVN_2.
Visit 2, Exposure 5: Intermediate HV Checkout - LV Off
Target or lamp
: Dark
Type of Acquisition
: n/a
Detector for observation
: COS/NUV
Operating mode
: Data
Spectral Element
: n/a
Aperture
: n/a
Central Wavelength
: n/a
Exposure Time
: 30s
Number of Iterations
: 1
BOP Predicted Local Count Rate for MAMA : n/a
BOP Predicted Global Count Rate for MAMA: n/a
ETC PID IDs for Count Rates
: n/a
Special Requirements or options
: Special commanding
Comments:
Turn LV off.
Special commanding: Instruction = RLLVTHDN.
Visit 2, Exposure 6: Intermediate HV Checkout - Set Flag 2
Target or lamp
: Dark
Type of Acquisition
: n/a
Detector for observation
: COS/NUV
Operating mode
: Data
Spectral Element
: n/a
Aperture
: n/a
Central Wavelength
: n/a
Exposure Time
: 1s
Number of Iterations
: 1
BOP Predicted Local Count Rate for MAMA : n/a
BOP Predicted Global Count Rate for MAMA: n/a
ETC PID IDs for Count Rates
: n/a
Special Requirements or options
: Special commanding
Comments:
Set Flag 2.
Special commanding: Instruction = ELFLAG2.
Visit 3, Exposure 1: Full High Voltage Test - LV On
Target or lamp
: Dark
Type of Acquisition
: n/a
Detector for observation
: COS/NUV
Operating mode
: Data
Spectral Element
: n/a
Aperture
: n/a
Central Wavelength
: n/a
Exposure Time
: 60s
Number of Iterations
: 1
BOP Predicted Local Count Rate for MAMA : n/a
BOP Predicted Global Count Rate for MAMA: n/a
ETC PID IDs for Count Rates
: n/a
Special Requirements or options
: Special commanding
Comments:
Sequence 1-6 Non-Int.
Switch on LV power supply.
Must clear event flag 2 for the commanding to execute.
Special commanding: Instruction = ELHDTLVN_3.
Visit 3, Exposure 2: Full High Voltage Test - Ramp HV to -2050V/-800V
Target or lamp
: Dark
Type of Acquisition
: n/a
Detector for observation
: COS/NUV
Operating mode
: Time-Tag
Spectral Element
: Default
Aperture
:
Central Wavelength
:
Exposure Time
:
Number of Iterations
:
BOP Predicted Local Count Rate for MAMA :
BOP Predicted Global Count Rate for MAMA:
ETC PID IDs for Count Rates
:
Special Requirements or options
:
Default
n/a
3090s
1
Special monitoring per ISR 98-03
Special monitoring per ISR 98-03
n/a
Buffer_Time = 3300
Special commanding
Comments:
Special NUV HV turn on & slow full ramp up. The MCP and Field Voltage
Ramp-ups will be performed in stages. The ramp-up within a stage is by
increments of 50V. Use the nominal yellow and red limits for ramping. At
the end of each stage, reset the SGM to a Threshold = 100 and an
Integration Period = 0.1 sec, and collect telemetry samples of OR Counts
for 4 minutes. The COS rate is 1 TLM sample/10 secs; ~24 samples will be
obtained.
Stage 1 - MCP ramp-up (0 to -500V)
Stage 2 - MCP ramp-up (-500V to -1000V)
Stage 3 - MCP ramp-up (-1000V to -1500V)
Stage 4 - MCP ramp-up (-1500V to -1750V)
Stage 5 - PC Voltage ramp-up (+20 to -50V)
Stage 6 - MCP ramp-up (-1750V to -1850V)
Stage 7 - MCP ramp-up (-1850V to -1950V)
Stage 8 - Final MCP ramp-up (-1950V to-2050V)
Stage 9 - Final PC Voltage ramp-up (-50V to -800V)
Special commanding: Instruction = ELHVPART3.
Visit 3, Exposure 3: Full High Voltage Test - Cycle SGM
Target or lamp
: Dark
Type of Acquisition
: n/a
Detector for observation
: COS/NUV
Operating mode
: Time-Tag
Spectral Element
: Default
Aperture
: Default
Central Wavelength
: n/a
Exposure Time
: 450s
Number of Iterations
: 1
BOP Predicted Local Count Rate for MAMA : Special monitoring per ISR 98-03
BOP Predicted Global Count Rate for MAMA: Special monitoring per ISR 98-03
ETC PID IDs for Count Rates
: n/a
Special Requirements or options
: Buffer Time = 720
Special commanding
Comments:
Set SGM Threshold = 200, Integration Period = 0.1 secs
Collect 5 samples W dark events
Collect 5 samples X dark events
Collect 5 samples Y dark events
Collect 5 samples Z dark events
Collect 5 samples OR dark events
Collect 5 samples EV dark events
Collect 5 samples VE dark events
Special commanding: Instruction = ELHVDARK3.
Visit 3, Exposure 4: Intermediate HV Checkout - HV Off
Target or lamp
: Dark
Type of Acquisition
: n/a
Detector for observation
: COS/NUV
Operating mode
: Data
Spectral Element
: n/a
Aperture
: None
Central Wavelength
: n/a
Exposure Time
: 355s
Number of Iterations
: 1
BOP Predicted Local Count Rate for MAMA : Special monitoring per ISR 98-03
BOP Predicted Global Count Rate for MAMA: Special monitoring per ISR 98-03
ETC PID IDs for Count Rates
: n/a
Special Requirements or options
: Special commanding
Comments:
Ramp down detector, HV off.
Special commanding: Instruction = ELHVTLVN_3.
Visit 3, Exposure 5: Intermediate HV Checkout - LV Off
Target or lamp
: Dark
Type of Acquisition
: n/a
Detector for observation
: COS/NUV
Operating mode
: Data
Spectral Element
: n/a
Aperture
: n/a
Central Wavelength
: n/a
Exposure Time
: 30s
Number of Iterations
: 1
BOP Predicted Local Count Rate for MAMA : Special monitoring per ISR 98-03
BOP Predicted Global Count Rate for MAMA: Special monitoring per ISR 98-03
ETC PID IDs for Count Rates
: n/a
Special Requirements or options
: Special commanding
Comments:
Turn LV off.
Special commanding: Instruction = RLLVTHDN.
Visit 3, Exposure 6: Intermediate HV Checkout - Set Flag 2
Target or lamp
: Dark
Type of Acquisition
: n/a
Detector for observation
: COS/NUV
Operating mode
: Data
Spectral Element
: n/a
Aperture
: None
Central Wavelength
: n/a
Exposure Time
: 1s
Number of Iterations
: 1
BOP Predicted Local Count Rate for MAMA : n/a
BOP Predicted Global Count Rate for MAMA: n/a
ETC PID IDs for Count Rates
: n/a
Special Requirements or options
: Special commanding
Comments:
Set Flag 2.
Special commanding: Instruction = ELFLAG2.
Visit 4, Exposure 1: Full High Voltage Test - Fold Test Setup
Target or lamp
: Dark
Type of Acquisition
: n/a
Detector for observation
: COS/NUV
Operating mode
: Data
Spectral Element
: n/a
Aperture
: n/a
Central Wavelength
: n/a
Exposure Time
: 20s
Number of Iterations
: 1
BOP Predicted Local Count Rate for MAMA : Note (1)
BOP Predicted Global Count Rate for MAMA: Note (1)
ETC PID IDs for Count Rates
:
Special Requirements or options
: Special Commanding
Comments:
Sequence 1-2 Same-Alignment.
Set SGM Threshold = 15000, Integration Period = 0.1secs.
Special commanding: Instruction = ELFOLDSET.
Visit 4, Exposure 2: Full High Voltage Test - Fold Test
Target or lamp
: D2- Medium
Type of Acquisition
: n/a
Detector for observation
: COS/NUV
Operating mode
: Time-Tag
Spectral Element
: G185M
Aperture
: FCA
Central Wavelength
: 1850
Exposure Time
: 2300s
Number of Iterations
: 1
BOP Predicted Local Count Rate for MAMA : Note (1)
BOP Predicted Global Count Rate for MAMA: Note (1)
ETC PID IDs for Count Rates
:
Special Requirements or options
: Buffer Time = 2300
Special commanding
Comments:
Set SGM Threshold = 10,000, Integration Period = 1.0 secs
(a) Collect counter samples during flat field illumination
Collect 60 sec W events
Collect 60 sec X events
Collect 60 sec Y events
Collect 60 sec Z events
Collect 60 sec OR events
Collect 60 sec EV events
Collect 60 sec VE events
(b) Disable MAMA Folds: C2, C3, C4, C5, C6, R2, R3, R4, R5, R6
(c) Conduct fold analysis
Collect 60 sec VE for following 19 combinations of MAMA folds:
(1) Enabled: C2, R2; Disabled: C3, C4, C5, C6, R3, R4, R5,
(2) Enabled: C2, R3; Disabled: C3, C4, C5, C6, R2, R4, R5,
(3) Enabled: C3, R2; Disabled: C2, C4, C5, C6, R3, R4, R5,
(4) Enabled: C2, R4; Disabled: C3, C4, C5, C6, R2, R3, R5,
(5) Enabled: C3, R3; Disabled: C2, C4, C5, C6, R2, R4, R5,
(6) Enabled: C4, R2; Disabled: C2, C3, C5, C6, R3, R4, R5,
(7) Enabled: C3, R4; Disabled: C2, C4, C5, C6, R2, R3, R5,
(8) Enabled: C4, R3; Disabled: C2, C3, C5, C6, R2, R4, R5,
(9) Enabled: C3, R5; Disabled: C2, C4, C5, C6, R2, R3, R4,
(10) Enabled: C4, R4; Disabled: C2, C3, C5, C6, R2, R3, R5,
(11) Enabled: C5, R3; Disabled: C2, C3, C4, C6, R2, R4, R5,
(12) Enabled: C4, R5; Disabled: C2, C3, C5, C6, R2, R3, R4,
(13) Enabled: C5, R4; Disabled: C2, C3, C4, C6, R2, R3, R5,
(14) Enabled: C4, R6; Disabled: C2, C3, C5, C6, R2, R3, R4,
(15) Enabled: C5, R5; Disabled: C2, C3, C4, C6, R2, R3, R4,
(16) Enabled: C6, R4; Disabled: C2, C3, C4, C5, R2, R3, R5,
R6
R6
R6
R6
R6
R6
R6
R6
R6
R6
R6
R6
R6
R5
R6
R6
(d)
(e)
(f)
(g)
(h)
(17) Enabled: C5, R6; Disabled: C2, C3, C4, C6, R2, R3, R4, R5
(18) Enabled: C6, R5; Disabled: C2, C3, C4, C5, R2, R3, R4, R6
(19) Enabled: C6, R6; Disabled: C2, C3, C4, C5, R2, R3, R4, R5
Enable MAMA folds C2, C3, C4, C5, C6, R2, R3, R4, R5, R6
at completion of exposure.
Check lamp stability by checking EV and VE
Collect 60 sec events (EV) to check lamp stability
Collect 60 sec Valid Events (VE) to check lamp stability
Turn off D2 lamp
Collect event counter data for detector dark count rate
Collect 60 sec W dark events
Collect 60 sec X dark events
Collect 60 sec Y dark events
Collect 60 sec Z dark events
Collect 60 sec OR dark events
Collect 60 sec EV dark events
Collect 60 sec VE dark events
At completion of procedure reset SGM to nominal operating level
Special commanding: Instruction = ELFOLDTST
--------------------------------------------------------------------------# Special needs of this proposal?
This proposal is run to reactivate the COS MAMA following an anomalous
shutdown.
Scheduling: As needed
Prerequisites: (e.g., specific SMOV proposal; command development?)
PDB update?
On-board table update?
(Specify table name if known e.g. SIAF).
(Specify table name if known e.g. CCDBadPixelTable)
# Special Requirements:
Real time?
Y
Special commanding?
Y
Quick Data turnaround?
Y (time-tags and engineering telemetry)
Special timing required? N
Other?
N
Describe (& justify) special requirements: The engineering telemetry for each
step is required to evaluate the safety for proceeding.
------------------------------------------------------------------------# Analysis Plan per Anomalous Shutdown
Expected FTE weeks for analysis:
0.4
Required turnaround on analysis (weeks):
0.2 per test
Data volume (Mb needed for analysis):
n/a
Special software needed for analysis? (Describe):
The
Engineering Team possesses special COS software used for the fold analysis
Description of analysis Plans: (1-2 paragraphs)
Analysis is carried out by the Engineering Team within 24 hours of each test
in the checkout. The engineering telemetry data is examined (voltages,
currents, temperatures, relay position, status, and event counts) for
agreement with predicted values from previous ground and on-orbit tests or
model-predicted values.
The darks and time-tag images are examined for unusual spatial or temporal
features.