(Alexa, Sheila)

We wanted to compare our senstitivty to angular motion between HIFOX and Y. I used Seigman (Lasers, Chap 19) equation for the beam displacement from the optical axis as a function of mirror displacements. In my calculation, I used the following values

• L = cavity length = 3994.472 (alog 9402)
• IMTX_ROC = 1939.52m     ETMX_ROC = 2241.54m
• TTMY_ROC = 2307m         ETMY_ROC = 2313m (from LIGO-T1300158)
• Assumed all mirror motion was .1urad.

I found the ratio of HIFO X to HIFOY for...

• motion of ETM resulting in displacement on ETM = 2.86
• motion of ETM resulting in displacement on ITM = 2.29
• motion of ITM resulting in displacement on ETM =1.97
• motion of ITM resulting in displacement on ITM = 2.46

11:50 - Bubba & Justin install parking beam beam dump cover on top of HAM2. Done 12:00 

11:09 - Justin on top of HAM2 checking parking beam beam dump mount. Done 11:16

10:00 - Betsy and Travis at End-Y working on monolithic install. 

09:25 - Mitch in LVEA West Bay working on ACB assembly. Done 12:10.
1:25 - Mitch in LVEA West Bay working on ACB assembly. Done 3:30. 

Sebastien, Hugh

We investigated a little more on BSC-ITMX comb issue that we noticed yesterday (see Jeff's log).

Our guess what that the position sensors are cross talking with each other between the chambers at the corner station. To verify that, we turned off the CPSs of BSC-BS, to see if it makes the comb disappear.

In the plots attached, the red curves are the reference curve (BSC-BS ON). We can see a comb on the rotational DOFs, starting at 0.45Hz. When the CPSs of the BS are OFF (blue curves), the comb goes away. At this point, I think we can clearly assest that we have a CPS issue.

PS: the huge spike at 0.5Hz on X and Y seems unrelated with the CPS effect. We're still investigating to understand where it comes from. For now, we just installed a narrow notch at this frequency in our blend filters as a temporary solution.

Hugh gave me instructions for recovering from a HEPI and ISI trip on ETMx, which should work for the ITM:

1) turn off any large inputs from lsc to hepi, set a large ramp time for reengaging it later. 

2) untrip watch dogs

3)isolate level 1

4) check RX +Ry (or all) current set points (in the bias screen) to see if they are the same as the target setpoints, if not set them to be the same. (this should only be a problem for the ETM)

ISI:

1)in watchdog screen set T240 limit to something large (only needed for ETM)

2) reset watch dogs if they are tripped

3) commands undamp (may not be necessary, especially if drives are small)

4) for ETM, make sure stage1 blends are all 750mHz

5) Isolate level 1

6) after that is done make sure that St 1 blend_x and blend_Y are T100mHz_N0.44 for the ETM.  For the ITM make sure that Sebastians Notch_narrow (for the 0.5Hz noise) is engaged. 

I think that is all!

The Apollo working on parking beam beam dump cover installation on HAM2 from 09:07 to 09:15.
 

h1dc0 data concentrator restarted to clear .ini mismatch on h1isiham5.

Both frame writers are now writing longer frames.  Testing is ongoing.

GPIB01-wifi IP: 10.22.10.20/20

GPIB01 IP: 10.22.10.30/20

...are at EX hooked up to the SR785

There is an exictation running on ITMX L2 Y, I would like to start locking the green arm, so I would like to stop this. 

With the reduced pitch motion in the green arm, I tried again to use the pure PZT dither scheme in pitch too. (I used it for yaw from the start).

That seemed to work just fine. So I disabled XPIT DOF1 and enabled XPIT DOF2.

I disabled the arm locking for the night to finish taking Y2Y transfer functions for L2 for ITMX and ETMX.

Another PtoP measurement on the M2 stage of PRM was launched at around 1:15 AM. It is running on opsws8 (which is Kissel's favorite workstation).

The diag file is in the official place:

/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/PRM/Common/Data/2014-01-25-H1SUSPRM_M2_PtoP_SweptSince_0p2to5Hz.xml

Kiwamu, Stefan

We increased the input power to 10Watt.

- We removed the lock from the rotational stage interlock.
- We rotated the Laser Power rotation stage from 56.1 to 30deg, raising the power by a factor of 10.
- The power levels IMC REFL and IMC WFSs were kept thge same by adjusting the lambda/2 rotation stage on IOT2L. We had and have 12mWatt on IMC REFL.
- We reduced the analog electronic gain on MC TRANS by a factor of 10.
- We verified that we now have 29.7mWatt on LSC-REFLAIR_A, and 30mWatt on on LSC-REFLAIR_B on ISCT1.


- We confirmed that the IMC UGF is still 54kHz.
- We updated the IMC Guardian to switch on all 3 stages, and increased the in-lock gain to 13dB. This left the phase margin at 26deg.