Reports until 17:57, Thursday 02 November 2017
LHO VE
chandra.romel@LIGO.ORG - posted 17:57, Thursday 02 November 2017 - last comment - 11:52, Tuesday 05 December 2017(39270)
in chamber cleaning

Rakesh and I cleaned the ~ 30-50 contamination spots on XBM interior wall, a few feet away from cryo baffle, ranging in size from 1 mm diam. to 1" diam. We scraped the surface of these spots with small flat head screw drivers and a tool with a pointed edge, and collected the brown/black flakes, to be analyzed via FTIR. We wiped with IPA wipes and also tried acetone and methanol (wiped away same as IPA). The spots leave a stain on the SS wall. We are not able to remove 100% of this material with our cleaning technique. The beam tube wall is rough, so wiping is limited without creating other issues with wipe shedding. The location of these spots is two tube welds in from cryo baffle.

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chandra.romel@LIGO.ORG - 11:52, Tuesday 05 December 2017 (39637)

JPL results here:  https://dcc.ligo.org/E1700405

  • Particles showed a reddish / brown, flakey appearance when viewed at magnification.
  • Analysis by x-ray fluorescent microscope showed the particles to consist mainly of Iron. The results are shown in the table below.
  • Iron oxide was detected by Raman Spectroscopy.