IF and KL measurements with 4D interferometer. Runa Briguglio, OAA. Rationale. New experimental set-up (4D+BCU39), that permits the reduction of convection and vibration noise. Acquisition of Influence Functions. Determination of KL modes and testing. Table of contents.
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Runa Briguglio, OAA
New experimental set-up (4D+BCU39),
that permits the reduction of convection
and vibration noise.
Acquisition of Influence Functions
Determination of KL modes
Capture .raw 28 Hz
Process .cal 9 Hz
Reduce .h5 1.2 Hz
Sampling -- Processing
Frequency and n° of frames…
No faults found at f<15Hz
Ok for IF acquisition, at max freq.
No delay, 200 us pulses
Optic Fiber, 40MHz bus
(25 ns pulses)
TTL & Opto-coupled
Start of Frame
0 20 40 ms
Start of frame 12ms Start of frame
Slopes to AdSec Slopes to AdSec
Oversampling period (5 ms)
8 ms Image acquisition 8 ms Image acquisition
Before the mode application
The transient is not seen!
We command a trefoil and 4 zero-shapes
as starting point reference
1 +modeSampling procedure
0. connect & set-up
2 +modeSampling procedure
0. Commands applied by AdSec
Images ‘production’ (process+reduction:.dat .h5)
Data analisys w/template: [1,-1,1]
Analisys of electrical data