Gerardo, Jordan, Camilla.
On Thursday we assembled VAC sealing part of the CHETA VPs, D1700340-type02. The thinnest part of the optics are at 12o'clock if the VP is oriented with the P/N of D1700338 writing also ~12o'clock.
D1700338-v2-001 with D1700339-v2-001 and D1700338-v2-003 with D1700339-v2-003. Both have optics D1100439-type02, which are DAR coated for 1064nm and 10.6um.
Next steps is VAC testing, then first contact the window surfaces and add secondary window.
(Jordan, Jake, Owen, Gerardo)
Today we pressure and leak tested the viewports for CHETA. Both of the assemblies passed their tests, no issues to report.
Both viewport assemblies were pressure tested by applying vacuum pressure on the vacuum side of the assembly <1X10-03 Torr with a leak detector, and positive pressure on the air side, 15.5 psig using nitrogen gas. The new test cap worked great.
Next step is to finish the assemblies and install them.
Since the assemblies do not have an assembly number I'll list them as 003 and 001 due to their components SNs. The background reported by the LD at startup was at <1X10-10 Torr*L/Sec. These are LIGO viewports and they have a viton O-ring, thus He will permeate thru the O-ring, also the testing jig has two more O-rings. The signal did not shot up to the recorded number, it slowly got there.
- Assembly 003, after spraying it with He for about 5 seconds on two places the LD reported a leak rate of 3.3X10-09 Torr*L/Sec.
- Assembly 001, same process as above, the LD reported a leak rate of 6.3X10-09 Torr*L/Sec.
