12723( 3) - 27-Jun-2012 13:48:01 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 12723 Version: 3 Check-in Time: 27-Jun-2012 13:48:01 STScI Edit Number: 2 Title COS NUV MAMA Fold Distribution ------------------------------------------------------------------------------------ Type Cycle CAL/COS 19 ------------------------------------------------------------------------------------ Investigators Contact? PI: Mr. Thomas Wheeler Space Telescope Science Institute Y CoI: Dr. Alan D. Welty Space Telescope Science Institute N ------------------------------------------------------------------------------------ Abstract The performance of the MAMA microchannel plate can be monitored using a MAMA fold analysis procedure. The fold analysis provides a measurement of the distribution of charge cloud sizes incident upon the anode giving some measure of changes in the pulse-height distribution of the MCP and, therefore, MCP gain. This proposal executes the same steps as the COS MAMA Fold Analysis (12419) during Cycle 18. ------------------------------------------------------------------------------------ Observations 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 procedure is implemented using special commanding. The procedure is described below and in COS TIR 2010-01. The proposal nomenclature for the various anode fold configurations is: C2 = Column 2, R2 = Row 2, C3 = Column 3, R3 = Row 3, C4 = Column 4, R4 = Row 4, C5 = Column 5, R5 = Row 5, C6 = Column 6, and R6 = Row 6. The fold analysis is initiated by selecting the grating/lamp combination appropriate for the test. The following steps are then executed: Select the count rate monitor and collect 60 seconds of data; Repeat this for each of the count rate monitors W, X, Y, Z, OR, EV, VE; Disable all of the selectable folds (C2, C3, C4, C5, C6, R2, R3, R4, R5, R6); Collect 60 seconds of VE with folds C2, R2 enabled, other folds disabled; Collect 60 seconds of VE with folds C2, R3 enabled, other folds disabled; Collect 60 seconds of VE with folds C3, R2 enabled, other folds disabled; Collect 60 seconds of VE with folds C2, R4 enabled, other folds disabled; Collect 60 seconds of VE with folds C3, R3 enabled, other folds disabled; Collect 60 seconds of VE with folds C4, R2 enabled, other folds disabled; Collect 60 seconds of VE with folds C3, R4 enabled, other folds disabled; Collect 60 seconds of VE with folds C4, R3 enabled, other folds disabled; Collect 60 seconds of VE with folds C3, R5 enabled, other folds disabled; Collect 60 seconds of VE with folds C4, R4 enabled, other folds disabled; Collect 60 seconds of VE with folds C5, R3 enabled, other folds disabled; Collect 60 seconds of VE with folds C4, R5 enabled, other folds disabled; Collect 60 seconds of VE with folds C5, R4 enabled, other folds disabled; Collect 60 seconds of VE with folds C4, R6 enabled, other folds disabled; Collect 60 seconds of VE with folds C5, R5 enabled, other folds disabled; Collect 60 seconds of VE with folds C6, R4 enabled, other folds disabled; 12723( 3) - 27-Jun-2012 13:48:01 - [ 2] Collect 60 seconds of VE with folds C5, R6 enabled, other folds disabled; Collect 60 seconds of VE with folds C6, R5 enabled, other folds disabled; Collect 60 seconds of VE with folds C6, R6 enabled, other folds disabled; Enable all selectable folds (C2, C3, C4, C5, C6, R2, R3, R4, R5, R6); Collect 60 seconds of EV and 5 samples of VE counts to measure any lamp drift; Turn off the lamp; Select the W count rate monitor and collect 60 seconds of data for the dark rate; Repeat this for each of the other count rate monitors (X, Y, Z, OR, EV, and EV); Restore the global monitor to its normal value. Analysis of the data is performed by creating a histogram binned by the sums of the fold numbers for columns and rows: C2R2 = 4 folds C2R3 + C3R2 = 5 folds C2R4 + C3R3 + C4R2 = 6 folds C3R4 + C4R3 = 7 folds C3R5 + C4R4 + C5R3 = 8 folds C4R5 + C5R4 = 9 folds C4R6 + C5R5 + C6R4 = 10 folds C5R6 + C6R5 = 11 folds C6R6 = 12 folds The sum of the 4 to 12 folds is equal to VE. The total number of events >= 4 folds is EV. The number of events greater than 12 folds is EV-VE. Generate a plot of 4 fold/EV, 5 fold/EV through 12 fold/EV, with (EV-VE)/EV on the abscissa and with the ordinate labeled 4 fold, 5 fold.......... 12 fold. Results are sent to the COS Science Team and Vic Argabright of Ball Aerospace. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- Bright Object Protection Considerations. 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 100, 000 counts in a 1.0 second interval, from its nominal value of 20, 000 counts in a 0.1 second interval. This test should only be run with the COS extenal shutter closed. Special Commanding is used in this proposal. ------------------------------------------------------------------------------------ 12723( 3) - 27-Jun-2012 13:48:01 - [ 3] Visit: 01 Visit Requirements: GYRO MODE 3GOBAD; BETWEEN 01-MAY-2012:00:00:00 AND 01-JUN-2012:00:00:00; ON HOLD ; PARALLEL On Hold Comments: V01 should not be scheduled at all and should be placed on hold. The test only needs to be executed annually and it was executed as part of Proposal 12724, visit 04, COS NUV Detector Recovery after Anomalous Shutdown. 6/27/12 Additional Comments: Schedule one NUV MAMA fold analysis visit per year Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DARK S/C DATA NONE 1 475.0 S SAA CONTOUR 32; SPEC COM INSTR ELFOLDSET; SAME ALIGNMENT 1-2 Comments: Special setup for NUV Fold Analysis Test. Set the Software Global Monitor to 150, 000 ORCOUNTS per sec (sufficient to allow for spike at lamp turn-on). ------------------------------------------------------------------------------------------------------------------------------------ 12723( 3) - 27-Jun-2012 13:48:01 - [ 4] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 2 DEUTERIUM COS/NUV TIME-TA FCA G185M 1850 CURRENT=MEDIUM, 1 2300.0 S SPEC COM INSTR G BUFFER-TIME=2700 ELFOLDTST; QESIPARM TARGTYPE FOLD Comments: The NUV Fold Analysis will be conducted during a deuterium lamp time-tag exposure. The exposure specification will ensure that the FCA aperture will be used, that the OSMs will be positioned at NCM1FLAT and G185M/1850, and that the lamp current is set to MEDIUM. Qesiparm TARGTYPE must be specified as FOLD so that the instructions will command the proper lamp. Note that the commanding will turn the lamp off during the exposure, and the exposure commanding will issue a redundant lamp off command after the exposure. Set Software Global monitor SGM Threshold = 100, 000, SGM Integration period = 1 sec. The following steps are then executed: Select the W count rate monitor and collect 60 seconds of data for the dark rate; Repeat this for each of the other count rate monitors (X, Y, Z, OR, EV, and EV); Disable all of the selectable folds (C2, C3, C4, C5, C6, R2, R3, R4, R5, R6); Collect 60 seconds of VE with folds C2, R2 enabled, other folds disabled; Collect 60 seconds of VE with folds C2, R3 enabled, other folds disabled; Collect 60 seconds of VE with folds C3, R2 enabled, other folds disabled; Collect 60 seconds of VE with folds C2, R4 enabled, other folds disabled; Collect 60 seconds of VE with folds C3, R3 enabled, other folds disabled; Collect 60 seconds of VE with folds C4, R2 enabled, other folds disabled; Collect 60 seconds of VE with folds C3, R4 enabled, other folds disabled; Collect 60 seconds of VE with folds C4, R3 enabled, other folds disabled; Collect 60 seconds of VE with folds C3, R5 enabled, other folds disabled; Collect 60 seconds of VE with folds C4, R4 enabled, other folds disabled; Collect 60 seconds of VE with folds C5, R3 enabled, other folds disabled; Collect 60 seconds of VE with folds C4, R5 enabled, other folds disabled; Collect 60 seconds of VE with folds C5, R4 enabled, other folds disabled; Collect 60 seconds of VE with folds C4, R6 enabled, other folds disabled; Collect 60 seconds of VE with folds C5, R5 enabled, other folds disabled; Collect 60 seconds of VE with folds C6, R4 enabled, other folds disabled; Collect 60 seconds of VE with folds C5, R6 enabled, other folds disabled; Collect 60 seconds of VE with folds C6, R5 enabled, other folds disabled; Collect 60 seconds of VE with folds C6, R6 enabled, other folds disabled; Enable all selectable folds (C2, C3, C4, C5, C6, R2, R3, R4, R5, R6); Collect 60 seconds of EV and 5 samples of VE counts to measure any lamp drift; Turn off the lamp; Select the W count rate monitor and collect 60 seconds of data for the dark rate; Repeat this for each of the other count rate monitors (X, Y, Z, OR, EV, and EV); Restore the global monitor to its normal value. 12723( 3) - 27-Jun-2012 13:48:01 - [ 5] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ DARK 1 S/C DATA NONE none none none none 1 N/A DEUTERIUM 2 COS/NUV TIME-TA FCA G185M 1850 none none none none 1 N/A G 12723( 3) - 27-Jun-2012 13:48:01 - [ 6] Summary Form for Proposal 12723 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures FCA, NONE ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/NUV, S/C ------------------------------------------------------------------------------------------------------------------------------------ Opmodes DATA, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=2700, CURRENT=MEDIUM ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BETWEEN 01-MAY-2012:00:00:00 AND 01-JUN-2012:00:00:00, GYRO MODE 3GOBAD, ON HOLD , PARALLEL, QESIPARM TARGTYPE FOLD, SAA CONTOUR 32, SAME ALIGNMENT 1-2, SPEC COM INSTR ELFOLDSET, SPEC COM INSTR ELFOLDTST ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G185M ------------------------------------------------------------------------------------------------------------------------------------ Target Names DARK, DEUTERIUM ------------------------------------------------------------------------------------------------------------------------------------