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Below are the Minutes and Action Items of the Calibration Implementation Team Meetings. These minutes are taken from the OFFICIAL Minutes submitted to MSFC after each meeting. There is also a listing of the status of the Action Items from each CIT Meeting. If you would like to know the detailed status of any particular Action Item , or more importantly, if you are a delinquent Actionee and would like to submit a response to your Assigned Action, send an e-mail message to Scott.
(1/26/95)
The seventh Calibration Implementation Team (CIT) meeting was held on 08 November 1995 at MSFC.
Scott Texter opened the CIT meeting and reviewed the agenda. Scott pointed out that it is less than a year before the HRMA arrives at the XRCF, and less than six months before the start of intense integration of calibration GSE into the XRCF begins.
Next, Jack Hughes presented the latest HRMA XRCF performance predictions results from the X-ray Calibration Handbook. Jack showed results of raytraces including CAP vignetting, synchrotron optical constants, HRMA metrology data, and specific PH alignment errors. The results show that the HRMA at XRCF will have 68% encircled diameter of ~80 microns roughly independent of energy compared to about 33 microns for flight HRMA. The current MST plans do not include raytraces of flight performance for comparison to the XRCF predictions but some could be done informally.
Next, Mike Duncan presented the details of the ISIM LN2 cryoshroud. Mike pointed out that the shroud, as currently designed, can be operated in any of three modes. The current plan is to operate the shroud in a mode whereby 125 psi 80oK subcooled LN2 is input to the shroud at the bottom and exited from the top as subcooled LN2 at 95 psi for collection by the XRCF LN2 system. This mode insures that there will be no stagnant compartments of the shroud. The shroud must sink approximately 400 Watts from the ISIM and IC and keep the top panel, which is viewed by the ACIS radiator, below 88oK. Ball calculations have that a flow rate of 112 liters/hour are required to meet this requirement.
Dan Dewey next described progress that has been made in the development of a Objective Transmission Grating surrogate for use with the TMA during pre-calibration rehearsals. The HETG team will supply a grating with a TBD distribution of LETG, MEG, and HEG facets. One option is 5 LEG modules in a quadrant, and 8 HEG or MEG gratings in a quadrant. Exact quadrant populations require a little simulation to evaluate relative flux rates. SAO-MST is building a simple insertion/retraction mechanism which is supported by the TMA shutter frame. The combination of grating and mechanism is known as the TMA Objective Grating Assembly (TOGA). The TMA shutters are then used to select the facets when the grating is inserted.
Next, Steve O'dell showed that there will be no problem from stray x-ray radiation from the Flight Contamination Monitors (FCM's) impinging on the FPSI's.
Jon Arenberg then gave two related briefings on synchronization and countrate balancing between the BND detectors and the FPSI's, especially the ACIS. The issues of source variability (currently unmeasured), the synchronization of BND measurement times with ACIS measurements times, and the possibility that some measurements require more BND time than focal plane time for adequate counting statistics lead to lively discussions. The result appears to be that just as an aspect solution is derived, it may be important/possible to derive a source flux solution based on the ensemble of BND measurements. Ed Kellogg will provide (with input from several other key individuals) graphs showing the Effective Area of the BND-H and 500 detectors, as well as the various HRMA/SI combinations, as a function of x-ray energy, for reference.
Finally, John Nousek presented some general ACIS calibration planning issues. John pointed out that overhead time is needed for ACIS to calculate and readout bias maps during calibration. The ACIS team has agreed to supply more info on this, including general rules describing where bias measurements need to be made.
John also noted that "The Database" (i.e. Calibration Measurement DataBase (CMDB) aka the calibration Test List (CTL)) is a planning tool before execution and an archival index after XRCF but the definitive things are the commands to ACIS and the data returned from ACIS. The LuxelForbesPowell filters look very good.
Action items were then reviewed by Scott Texter and the plenary session of the CIT meeting ended. Meetings of the Logistics and CMDB Development CIT Subcommittees then commenced:
Logistics Subcommittee
The logistics logic-net/schedule was once again reviewed in detail. The calibration activities were modified to explicitly show 30 24-hour vacuum days for Phase I calibration (HRMA/OTG w/HXDS) and 60 24-hour vacuum days for Phase II calibration (HRMA/OTG w/FPSI). The 16 24-hour vacuum days allocated to HRMA Thermal Balance Testing remains unchanged. In addition, the pre-calibration rehearsal schedule was updated to reflect the shift in delivery of the ISIM from 01DEC96 to 01FEB97, and the planned vacuum check-out of the HRMA GSE. These changes resulted in the pre-calibration rehearsal now being divided into three vacuum rehearsal phases: (1) TMA/TOGA w/HXDS, (2) TMA/TOGA w/FAM/ISIM cryoshroud/SIM surrogate Z-drive/ACIS two-chip simulator, and (3) HRMA Support Structure (and related HRMA GSE) check-out w/HXDS. The logic-net has been updated to reflect these (and other) changes and a hard-copy will be sent to each team.
CMDB Development Subcommittee
A CTT splinter meeting was held on 11/8/95 at the XRCF following the morning's joint CIT/CTT meeting. The meeting was conducted by Jon Arenberg.
Currently, SAO has submitted to TRW portions of the Calibration Test List (CTL) for the HXDS, HRC, and LETG (with HXDS, HRC, and ACIS). The HETG and ACIS portions are still in process and are being brought up to date to work with the new Expander tool at SAO.
The following are summaries of the CTL thus far. Intermeasurement time has *not* been included; this is an orderdependant factor added by TRW. Intrameasurement times have been included by SAO. When studying the following numbers, consider that previous estimates of efficiency have put intermeasurement overhead at 20% to 50% of the total time, depending on the ordering method used.
HXDS alone measurements take 107.9 days. 43 of these measurements are "long," greater than 8 hours. In fact, these 43 measurements take 93 days. The two longest measurements take 16 days each. These numbers are, unfortunately, "real" and are due to lowflux sources. These measurements will not be given high priority and will be reviewed when better models and source characterizations are known.
HXDS with LETG measurements take 7.2 days. There are no "long" measurements.
HRC alone measurements take 43.3 days. There are 9 long measurements. These total 13 days. The longest two measurements each take 2.6 days.
LETG with HRC or ACIS totals 5.5 days. There are no long measurements.
The next topic discussed was the need for subprocedure names and definitions. Jon requested as an action that each team list the names of subprocedures they would be asking other teams to perform, and/or the subprocedures they were expecting to be asked to perform, as appropriate. Teams should also provide a simple explanation of each procedure.
This will assure that each team has prepared all the subprocedures that will be needed, and that these subprocedures are what is expected by the requestor. This list will also facilitate the test conductor's job of translating requests
between teams.
Finally, the nature of ACISspecific overhead was discussed. Depending on previous use, the ACIS may require data uploads or bias frame measurement before a given measurement. After the measurement, the ACIS may use a trickledownload procedure, which would intersperse previous (or bias) frame data with that of current frames. Since the PreACIS Measurement Overhead Time
(PAMOT) is order dependant, TRW must calculate it. Rules defining when PAMOT is needed were defined, but exact times involved are TBD. PostACIS Measurement Overhead Time (PAMOT) was also discussed, and further details, including worstcase times, are needed. John Nousek will work with his team to more
clearly define these times.
# Action Actionee Due Date
1 Determine optimal distribution of D. Dewey CLOSED
LETG, MEG, HEG facets on TOGA with
input from others
2 Generate graphs of EA of BND-500,H E. Kellogg
and HRMA/SI combinations
3 Provide representative bias J. Nousek CLOSED
implementation rules
4a Provide Listing of HXDS T. Norton/P. CLOSED
handling/integration/functional McKinnon
testing/verification XRCF
Subprocedures
4b Provide Listing of HRMA and HRMA GSE H. Morris CLOSED
handling/integration/functional
testing/verification XRCF
Subprocedures
5a Provide List of XSS Calibration J. Kolodziejczak CLOSED
Subprocedures
Provide List of SI Calibration All SI Teams 12/8/95
Subprocedures