Jennie Siva Keita Mayank
Following our previous attempt here . We opened a new ISS PD array (S.N. 1202965).
This unit is in great condition. i.e.
1) No sign of contamination.
2) All the optics are intact (No chipping)
We tried interfacing the QPD-cable S1203257 with the QPD but it turned out that they are not compatible.
We will look for the updated version of the QPD cable.
More photos I took of the unboxed unit,
Keita holding part of QPD connector that connects to cable,
zoom in of part of prisms close to PD array to show they don't look damaged like the previous one we unboxed,
dcc and serial number of baseplate (this is different part for each observatory due to differing beam heights).
Keita explaining the QPD cable clamp to Shiva (right) and Mayank (left).
View of optics with periscope upper mirror on the left.
View of part of prisms close to periscope.
View of back of array and strain relief.
plus a picture of an packaged coptic that was sitting on top of this capsule while it was in the storage cupboard.
For future reference all the ISS arrays and there serial numbers are listed in the dcc entry for the assembly drawing LIGO-D1101059-v5.
[Matthew Mayank Siva Keita]
On Friday (2025-02-28) we moved the optics onto taller posts so that we did not have to pitch the beam up to much (in hind-sight, we probably would've been okay doing this) when we align the beam into the input port of the ISS array. We have not aligned the beam yet and most likely should re-profile it(may not need to) to ensure that the planned lens position is correct.
We also spent some time checking the electronics box for proper connections and polarity; then we tested the upper row of PDs (4 top ones) by plugging in each cathode/anode to the respective port. The output DSUB we used a breakout board and threw each channel onto an oscilloscope -- it seems that all four of the top row of PDs are functioning as anticipated.
Important Note:
Keita and I looked at the "blue glass" plates that serve as beam dumps, but just looking at the ISS array we do not know how to mount them properly. We think there may be some component missing that clamps them to the array. So we repackaged the blue-glass in its excessive lens paper.
