Reports until 11:15, Friday 24 June 2011
X1 SEI
vincent.lhuillier@LIGO.ORG - posted 11:15, Friday 24 June 2011 (976)
BSC-ISI Testing
Here is a glimpse of the testing done on the ISI BSC8:

Electronic, we changed:
-	1 coil driver
-	1 anti-image chassis
-	1 sensor electronic board (and the sensor that goes with  it)

Instruments:
-	We replaced on coarse CPS sensor (and the electronic board). We stole two sets from unit2. Spares will be shipped from M.I.T in the coming days.
-	We had to open a GS13 can to adjust the 3 main springs holding the moving mass. This mass was resting at the bottom. We should receive replacement GS13 from LLO in about 2 weeks
-	There is a gain of 2 between the front panel and the back panel of the CPS satellite box.

Software:
-	We had a couple of issues with watchdogs tripping when threshold were set up higher than the 2^15 bit (40K for instance). This problem might be coming from the decimation filters from the IOP to the model (64K to 4K). We will investigate later.
-	The Matlab transfer functions measurement program uses the decimate function (8 order Chebychev low pass filters at 0.8 x Nyquist frequency) to downsample the excitation signal.  The decimation filters used to record signals on the frame builder have a corner frequency at ~0.7 x Nyquist frequency (with an order lower than 8). The Transfer functions are strongly affected over 700Hz for the geophones and 300Hz for the CPS. It will be fixed in the coming days.
-	In attachment, you will find a list the (101) channels recorded on the DAQ with their datarate. This list is the minimum required for testing and commissioning. The Overall datarate is 1.4MB/s. The allowed datarate is 2MB/s. 

Main results:
-	Stage1 is closed to a final balance
-	First resonance is at 215Hz on stage 1 (blades resonance? Need to be investigated)
-	First resonance is over 150 Hz on stage 2 (poor quality measurements at high frequency)

I have attached few figures 
-	The ISI with the cabling
-	Powerspectra of the sensors
-	Linearity test
-	Transfer functions (L2L main coupling)
Images attached to this report
Non-image files attached to this report