STIS Cycle-26 Calibration Phase-1 Last Revised: 05/21/18 Proposal ID: TBD Title: STIS/MAMA Fold Distribution PI: T. Wheeler Co-I(s): A. Welty --------------------------------------------------------------------------- # Orbit estimates are TOTAL for all of Cycle-26 Total Prime Orbits: 0 External Parallel Orbits: 0 Internals or no-impact orbits: 2 Comments on orbit estimate: 2 orbit per visit --------------------------------------------------------------------------- # This section should be written with a GO audience in mind -- use # Calibration plans in WFPC-2 handbook as a guide. Purpose: The performance of MAMA microchannel plates can be monitored using a MAMA fold analysis procedure that provides a measurement of the distribution of charge cloud sizes incident upon the anode giving some measure of change in the pulse-height distribution of the MCP and, therefore, MCP gain. Description: While globally illuminating the detector with a flat field, the valid event (VE) rate counter is monitored while various combinations of row and column folds are selected. The process is implemented using special commanding and is the same for the FUV and NUV MAMAs with the exception of the gratings/aperture/lamp combinations used for flat field illumination. This proposal executes the same steps as Cycle 25, Proposal 14976 and is described in STIS ISR 98-02R. Accuracy: 95% Comments on Accuracy: Position of the peak in the fold distribution can be measured to about 5% accuracy from this procedure. Products: Fold Analysis findings are reported to the STIS Science Team and S. Franka of Ball Aerospace after completion of analysis, typically one-two weeks after the execution of the test. --------------------------------------------------------------------------- # Link to Cycle 26 Science # Use the GO + GTO Phase 1 exposure listing and derived statistics # posted on WWW. Fraction of science programs supported by this calibration: 83.9% of STIS prime exposures use MAMAs, 100% of STIS SNAP exposures use MAMAs. List categories of science which can't be executed until after this proposal: None why: This is a health monitoring proposal and not an enabling or calibration proposal. List categories of science which are best performed contemporaneous with this proposal: None why: n/a --------------------------------------------------------------------------- # THE REST OF THIS FORM IS FOR INTERNAL USE --------------------------------------------------------------------------- Observation summary: Globally illuminate the detector with a flat field. Monitor the valid event (VE) rate counter while various combinations of row and column folds are selected. The process is the same for the FUV and NUV MAMAs with the exception of the gratings/aperture/lamp combinations used for flat field illumination. # Target information (copy for each target) Target Name. : n/a (internal) 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.) Table of exposures (copy for each exposure as appropriate/desired): ------------------------------------------------------------------------- **** This list of exposures needs to be repeated once every 6 months **** ------------------------------------------------------------------------- Note (1) Bright Object Protection Considerations (a) This proposal uses aperture/mirror/lamp combinations which are designed to produce count rates of ~100,000-200,000 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 150,000 counts (130,000 counts are used due to ground system restrictions) in a 1.0 second interval, from its nominal value of 77,000 counts in a 0.1 second interval. (c) For the reasons discussed in (b) and to prevent light from entering the hub area, this test should only be run with the STIS external shutter closed. Visit 1, Exposure 1: FUV Fold Test Setup Target or lamp : Dark Type of Acquisition : n/a Detector for observation : FUV MAMA (M1) Operating mode : Data Spectral Element : n/a Aperture : n/a Central Wavelength : n/a Exposure Time : 240s 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 1-3 NON-INT Set SGM Threshold = 15000, Integration Period = 0.1 s Configure Mechanisms Turn on HITM2 lamp at 10mA current Special commanding: Instruction = EOFOLDSET1 Visit 1, Exposure 2: FUV Fold Test Accum Target or lamp : Dark Type of Acquisition : n/a Detector for observation : FUV MAMA (M1) Operating mode : Accum Spectral Element : MIRROR Aperture : F25ND3 Central Wavelength : n/a Exposure Time : 300s 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: This image is a flat field exposure with the HITM2 using special commanding so that the lamp remains on after the exposure. Visit 1, Exposure 3: FUV Fold Test Target or lamp : Dark Type of Acquisition : n/a Detector for observation : FUV MAMA (M1) Operating mode : Data Spectral Element : MIRROR Aperture : F25ND3 Central Wavelength : n/a 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 : Special Commanding Comments: Special commanding: Instruction = EOFOLDTST1 Ð See below for details. Set SGM Threshold = 130000, Integration period = 1.0 secs (a) Collect counter samples during flat field illumination Collect 5 samples X events Collect 5 samples Y events Collect 5 samples Z events Collect 5 samples W events Collect 5 samples VE events Collect 5 samples EV events Collect 5 samples OR events (b) Disable MAMA Folds: C2, C3, C4, C5, C6, R2, R3, R4, R5, R6 (c) Conduct fold analysis Collect 5 samples VE for following 19 combinations of MAMA folds: (1) Enabled: C2, R2; Disabled: C3, C4, C5, C6, R3, R4, R5, R6 (2) Enabled: C2, R3; Disabled: C3, C4, C5, C6, R2, R4, R5, R6 (3) Enabled: C3, R2; Disabled: C2, C4, C5, C6, R3, R4, R5, R6 (4) Enabled: C2, R4; Disabled: C3, C4, C5, C6, R2, R3, R5, R6 (5) Enabled: C3, R3; Disabled: C2, C4, C5, C6, R2, R4, R5, R6 (6) Enabled: C4, R2; Disabled: C2, C3, C5, C6, R3, R4, R5, R6 (7) Enabled: C3, R4; Disabled: C2, C4, C5, C6, R2, R3, R5, R6 (8) Enabled: C4, R3; Disabled: C2, C3, C5, C6, R2, R4, R5, R6 (9) Enabled: C3, R5; Disabled: C2, C4, C5, C6, R2, R3, R4, R6 (10) Enabled: C4, R4; Disabled: C2, C3, C5, C6, R2, R3, R5, R6 (11) Enabled: C5, R3; Disabled: C2, C3, C4, C6, R2, R4, R5, R6 (12) Enabled: C4, R5; Disabled: C2, C3, C5, C6, R2, R3, R4, R6 (13) Enabled: C5, R4; Disabled: C2, C3, C4, C6, R2, R3, R5, R6 (14) Enabled: C4, R6; Disabled: C2, C3, C5, C6, R2, R3, R4, R5 (15) Enabled: C5, R5; Disabled: C2, C3, C4, C6, R2, R3, R4, R6 (16) Enabled: C6, R4; Disabled: C2, C3, C4, C5, R2, R3, R5, R6 (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 (d) Enable MAMA folds C2, C3, C4, C5, C6, R2, R3, R4, R5, R6 at completion of exposure. (e) Check lamp stability by checking EV and VE Collect 5 samples events (EV) to check lamp stability Collect 5 samples Valid Events (VE) to check lamp stability (f) Turn off HITM2 lamp (g) Collect event counter data for detector dark count rate Collect 5 samples X dark events Collect 5 samples Y dark events Collect 5 samples Z dark events Collect 5 samples W dark events Collect 5 samples VE dark events Collect 5 samples EV dark events Collect 5 samples OR dark events (h) At completion of procedure reset SGM to nominal operating level Visit 2, Exposure 1: NUV Fold Test - Fold Test Setup Target or lamp : Dark Type of Acquisition : n/a Detector for observation : NUV MAMA (M2) Operating mode : Data Spectral Element : n/a Aperture : n/a Central Wavelength : n/a Exposure Time : 240s 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 1-3 NON-INT Set SGM Threshold = 15000, Integration Period = 0.1 s Configure Mechanisms Turn on HITM1 lamp at 3.8mA current Special commanding: Instruction = EOFOLDSET2 Visit 2, Exposure 2: NUV Fold Test - Accum Target or lamp : Dark Type of Acquisition : n/a Detector for observation : NUV MAMA (M2) Operating mode : Accum Spectral Element : MIRROR Aperture : F25ND3 Central Wavelength : NONE Exposure Time : 120s 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: This image is a flat field exposure with the HITM1 using special commanding so that the lamp remains on after the exposure. Visit 2, Exposure 3: NUV Fold Test - Fold Test Target or lamp : Dark Type of Acquisition : n/a Detector for observation : NUV MAMA (M2) Operating mode : Data Spectral Element : MIRROR Aperture : F25ND3 Central Wavelength : n/a 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 : Special Commanding Comments: Special commanding: Instruction = EOFOLDTST2 Ð See below for details. Set SGM Threshold = 130000, Integration period = 1.0 secs (a) Collect counter samples during flat field illumination Collect 5 samples X events Collect 5 samples Y events Collect 5 samples Z events Collect 5 samples W events Collect 5 samples VE events Collect 5 samples EV events Collect 5 samples OR events (b) Disable MAMA Folds: C2, C3, C4, C5, C6, R2, R3, R4, R5, R6 (c) Conduct fold analysis Collect 5 samples VE for following 19 combinations of MAMA folds: (1) Enabled: C2, R2; Disabled: C3, C4, C5, C6, R3, R4, R5, R6 (2) Enabled: C2, R3; Disabled: C3, C4, C5, C6, R2, R4, R5, R6 (3) Enabled: C3, R2; Disabled: C2, C4, C5, C6, R3, R4, R5, R6 (4) Enabled: C2, R4; Disabled: C3, C4, C5, C6, R2, R3, R5, R6 (5) Enabled: C3, R3; Disabled: C2, C4, C5, C6, R2, R4, R5, R6 (6) Enabled: C4, R2; Disabled: C2, C3, C5, C6, R3, R4, R5, R6 (7) Enabled: C3, R4; Disabled: C2, C4, C5, C6, R2, R3, R5, R6 (8) Enabled: C4, R3; Disabled: C2, C3, C5, C6, R2, R4, R5, R6 (9) Enabled: C3, R5; Disabled: C2, C4, C5, C6, R2, R3, R4, R6 (10) Enabled: C4, R4; Disabled: C2, C3, C5, C6, R2, R3, R5, R6 (11) Enabled: C5, R3; Disabled: C2, C3, C4, C6, R2, R4, R5, R6 (12) Enabled: C4, R5; Disabled: C2, C3, C5, C6, R2, R3, R4, R6 (13) Enabled: C5, R4; Disabled: C2, C3, C4, C6, R2, R3, R5, R6 (14) Enabled: C4, R6; Disabled: C2, C3, C5, C6, R2, R3, R4, R5 (15) Enabled: C5, R5; Disabled: C2, C3, C4, C6, R2, R3, R4, R6 (16) Enabled: C6, R4; Disabled: C2, C3, C4, C5, R2, R3, R5, R6 (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 (d) Enable MAMA folds C2, C3, C4, C5, C6, R2, R3, R4, R5, R6 at completion of exposure. (e) Check lamp stability by checking EV and VE Collect 5 samples events (EV) to check lamp stability Collect 5 samples Valid Events (VE) to check lamp stability (f) Turn off HITM1 lamp (g) Collect event counter data for detector dark count rate Collect 5 samples X dark events Collect 5 samples Y dark events Collect 5 samples Z dark events Collect 5 samples W dark events Collect 5 samples VE dark events Collect 5 samples EV dark events Collect 5 samples OR dark events (h) At completion of procedure reset SGM to nominal operating level --------------------------------------------------------------------------- # Special needs of this proposal? Scheduling: This proposal should execute in the spring of every year. The exposures listed are for one execution only. Prerequisites : None PDB update? N On-board table update? N # Special Requirements: Real time? N Special commanding? Y Quick Data turnaround? N Special timing required? N Other? N Describe (& justify) special requirements: Special commanding is required to implement the requirement of this test. ------------------------------------------------------------------------- # Analysis Plan Expected FTE weeks for analysis: 0.2 Required turnaround on analysis (weeks): 2 Data volume (Mb needed for analysis): n/a Special software needed for analysis? (Describe): none Description of analysis Plans: (1-2 paragraphs): The analysis will be carried by the Engineering Team when the engineering data becomes available approximately two days after each visit. The time-tag images are examined for unusual spatial or temporal features. The fold test results are reported to the STIS Science Team and V. Argabright of Ball Aerospace.