Kataoka, Ohishi, Kokeyama
We tried to shine the end station, but did not succeed tonight. Our plan was to shake PR3 mirror both in pit and yaw while watching DC PD on EXA to hit a lucky spot.
First I had to add an oscillator on k1pr3 model. I added LCKINs on IM stage. New model was checked in on svn. Screens were also adapted.
So we shook PR3 both in pit and yaw at 0.03 Hz and 0.07Hz (LOCKING EXC MON attahced). Amplitude was 100. No light on EXA PDA1 was seen. A lot of 60Hz lines were observed instead (See, the second and third attachements). Probably the PD has the ground loop and it should be hunt. Also PR3 oplev pit yaw channels were not working well likely becaues of some software or data sender problems.
More fixing is necessary before finding the beam after all! I couldn't try further after a lot of the other works.
Maybe you got depressed a bit, but this data might be one of the proofs of good design of all baffles in the arm!
Anyway, it would be better to put a CCD camera (with max integration time) in the EXA chmaber instead of the PD...
By the way, the output in K1:VIS-EXA_PDA1_DC_OUTPUT in the Fig.1 shows some "signals", doesn't it? Are these just occasional noises?
By the way, the output in K1:VIS-EXA_PDA1_DC_OUTPUT in the Fig.1 shows some "signals", doesn't it? Are these just occasional noises?
We also thought they are some signals, but they were there even if IMC is unlocked. I think that's 60 Hz power line noise, which can be seen in the second attachment. The first attachment is from the StripTool, which has less sampling frequency. It looks like it has some signals because of the aliasing.
I think we can solve this by adding digital 60 Hz comb filter in the EXA_PDA1_DC filter bank.
And maybe we need to increase the power. I think I had brought some beam dumps usable in air into Kamioka...