June 21 AM: Compression Test with ACS On to Correlate Spot Motion

• Configuration:

  • ACS: Fully Assembled
  • Mounting: In TBF/Diamond
  • Cooling: Chillers
  • Optical Source: HRC Coronagraph Spot with Backlight
  • Starting Temp: Ambient at Start of Day
  • Add'l Sensors: LVDTs to Monitor Motion of Bench Relative to Enclosure & Theodolites to Monitor TBF and ACS Optical Cube Motion

• Figures:

  • Stability track: ( GIF, Postscript )
  • LVDT setup: ( HTML )
  • LVDT data: ( PDF )

• Results:

  • TBF B-Latch Used to Compress/Decompress Enclosure
    • Both Enclosure & Bench Move with Changing Load
    • Coronagraph Moves ~7 Pixels in Each Axis with Changing Load
      • Compression Effect is Repeatable; Decompression is Repeatable
      • Compression vs Decompression Motion Shows Hysteresis

• Conclusion:

  • Coronagraph Motion is Correlated with Enclosure/Bench Motion and is thus Caused (at least in part) by Stuck Y-Fitting