1 / 10

Update on a Proposed Bakeout CXC SOT & FOT, ACIS Instrument Team and MSFC Project Science

Update on a Proposed Bakeout CXC SOT & FOT, ACIS Instrument Team and MSFC Project Science. New Items since Last CUC Briefing (January 2005).

halen
Download Presentation

Update on a Proposed Bakeout CXC SOT & FOT, ACIS Instrument Team and MSFC Project Science

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Update on a Proposed Bakeout CXC SOT & FOT, ACIS Instrument Team and MSFC Project Science

  2. New Items since Last CUC Briefing (January 2005) • MIT/ACIS team conducted irradiation tests of flight spare CCDs at GSFC in May 2005. MIT/ACIS concluded that the CTI increase from another +30 C Bakeout would most likely be smaller than previously believed, ~5%. • MSFC Project Science continued to explore the sensitivity of the simulation results to the parameters (ie: temperatures of the relevant surfaces, volatility of the contaminant) • The ACIS contamination working group reviewed the new results in the summer and decided on July 15, 2005 against recommending a Bakeout. The team felt that the uncertainties were too large to be able to predict the outcome of the Bakeout with any confidence. • The Bakeout is therefore postponed indefinitely.

  3. 1 mo 1 wk 1 dy 5 yr 1 yr Docosane, nominal TOBF: Mass column O’Dell & Swartz (MSFC) e = 0.30 1: ACIS OBF 2: Camera top 3: ACIS snoot 4: ACIS collimator 5: SIM trans table 6: SIM focus struc 7: OBA stove pipe 8: Optical bench 9: OBA vent

  4. 1 mo 1 wk 1 dy 5 yr 1 yr Docosane, de-rated TOBF: Mass column O’Dell & Swartz (MSFC) e = 0.30 1: ACIS OBF 2: Camera top 3: ACIS snoot 4: ACIS collimator 5: SIM trans table 6: SIM focus struc 7: OBA stove pipe 8: Optical bench 9: OBA vent

  5. Limits on Vaporization Rates O’Dell & Swartz (MSFC) Min to vent 0.2 g in 1 orb:510-3mg cm-2 s-1 @ Tcoldest Min to clean OBF in 1 orb:210-3mg cm-2 s-1 @ TOBF-bake Upper limit at OBF center:110-7mg cm-2 s-1 @ TOBF-ops

  6. Monitoring the Contaminant:Transmission @ 700eV Grant (MIT)

  7. Monitoring the Contaminant: C-K Optical Depth Marshall (MIT)

  8. Summary of Bakeout Effort • There will not be a Bakeout anytime soon • We will continue to monitor the contaminant buildup and improve the characterization of the absorption of the contaminant • MIT/ACIS will analyze CTI measurements at temperatures between -90 C and -120 C to understand the temperature dependence of the CTI better • Calibration files for the time-dependent and spatial-dependent absorption of the contaminant are available in the CALDB & CIAO, we will continue to assess the accuracy of these corrections and update as necessary

  9. Bonus Material: ACIS FP Temperature Anomaly • ACIS DEA-A autonomously shutdown on 15 Sep 2005 • Two unintended consequences of the recovery from this anomaly FP temperature setpoint for -120 C was not loaded into the DEA-A The A/D converter which reports the DEA Housekeeping data initialized into a low resolution mode • The consequences of this were: 16 Sep 2005 - 05 Oct 2005 - the FP temperature was not regulating and was 1.3 degrees colder than reported in TLM 06 Oct 2005 - 15 Oct 2005 - the FP temperature WAS regulating but the reported temperature was 1.3 degrees warmer than the actual temperature (-118.4 C instead of -119.7 C) • The FP temperature regulation is back to nominal as of 15 Oct 2005

  10. FP Temperature Anomaly DePasquale (SAO)

More Related