| ID |
Date |
Author |
Type |
Category |
Subject |
Text |
 |
|
17274
|
Wed Nov 16 18:41:17 2022 |
yuta | Summary | BHD | Optical gain calibrations for BHD MICH | Optical gains of AS55 and BH55 are calibrated
for BHD MICH.
LO-ITM single bounce: |
|
|
17279
|
Thu Nov 17 14:12:58 2022 |
yuta | Summary | BHD | Optical gain calibrations for BHD MICH with lower UGF | [Paco, Yuta]
We found that MICH UGF was unexpectedly |
|
|
17282
|
Thu Nov 17 20:02:10 2022 |
yuta | Summary | BHD | MICH optical gain measurements with different LO phases | MICH
optical gain was measured with different
LO phases over ~90 degrees. |
|
|
17284
|
Fri Nov 18 13:05:00 2022 |
yuta | Summary | BHD | Gains adjusted for bandstop filters for BHD optics | [Paco, Yuta]
We realized that bandstop filters |
|
|
17285
|
Fri Nov 18 16:58:39 2022 |
yuta | Summary | BHD | Actuator calibrations for MICH BHD | As there is some confusion in actuator
calibration, we have done the measurement
again from scratch. |
7x |
|
17287
|
Fri Nov 18 22:46:02 2022 |
yuta | Summary | BHD | MICH optical gain measurements with different LO phases, with signs | MICH
optical gain with a sign was measured with
different LO phases over ~180 degrees, with |
|
|
17294
|
Mon Nov 21 17:44:00 2022 |
yuta | Summary | BHD | MICH BHD displacement sensitivity with AS55_Q and BHD_DIFF | [Paco, Yuta]
MICH displacement sensitivity was
compared under AS55_Q locking and BHD_DIFF |
|
|
17296
|
Mon Nov 21 18:43:46 2022 |
yuta | Update | BHD | c1hpc and c1lsc modified to send BHD_DIFF and BHD_SUM | [Anchal, Yuta]
To send BHD signals from c1hpc after |
|
|
17301
|
Wed Nov 23 11:06:08 2022 |
Anchal | Update | BHD | c1hpc and c1sus modified to add BS dither and demodulation option | c1hpc has option of dithering BS now (sending
excitation to BS LSC port to c1sus over IPC).
This is available for demodulating BHDC and |
|
|
17302
|
Wed Nov 23 12:58:33 2022 |
Yehonathan | Update | BHD | Some more calculations | Changed the BHD BS transmissivity to 0.56.
Demodulation Phases
As was noted before. The LO phase |
|
|
17303
|
Wed Nov 23 14:59:11 2022 |
Paco | Summary | BHD | BHD_DIFF sensitivity to BS dither with MICH Offset | [Yuta, Paco, Anchal]
We measured
(a) |
|
|
17308
|
Wed Nov 23 17:28:39 2022 |
Yehonathan | Update | BHD | Some more calculations | Fields at the BHD BS. More on this later. |
|
|
17309
|
Wed Nov 23 20:58:23 2022 |
yuta | Summary | BHD | BHD_DIFF sensitivity to BS dither with MICH Offset with different BH55 demodulation phases | [Anchal, Paco, Yuta]
Attachment #1 is the same plot as |
|
|
17317
|
Mon Nov 28 16:53:22 2022 |
Anchal | Summary | BHD | F2A filters on LO1 LO2 AS1 and AS4 | [Paco, Anchal]
I changed the script in /opt/rtcds/caltech/c1/Git/40m/scripts/SUS/outMatFilters/createF2Afilters.py |
|
|
17319
|
Mon Nov 28 18:21:50 2022 |
Paco | Summary | BHD | BH44 prep | I checked the LSC rack to evaluate what
we might need to generate 44 MHz rf in the
hypothetical case we go from BH55 to BH44 |
|
|
17322
|
Tue Nov 29 15:32:32 2022 |
Anchal | Update | BHD | c1hpc model updates to support double audio dither | Many changes have been done to c1hpc to
support dual demodulation at audio frequencies.
We moved away with ASS style of lockin setup |
|
|
17339
|
Tue Dec 6 13:09:44 2022 |
yuta | Update | BHD | c1cal model updates to support sensing matrix for BHD | [Anchal, Yuta]
We have modified c1cal model to support |
|
|
17343
|
Tue Dec 6 17:12:23 2022 |
yehonathan | Summary | BHD | LO phase control using audio (MICH and AS1) + RF | {Yuta, Yehonathan}
Today we lock LO phase using audio+RF
method in two variants: AS1+RF and MICH(BS)+RF. |
|
|
17345
|
Wed Dec 7 16:21:05 2022 |
yuta | Summary | BHD | Improved MICH BHD alignment | [Yehonathan, Yuta]
We found that moving AS1 in yaw improves |
|
|
17347
|
Thu Dec 8 17:52:39 2022 |
yuta | Summary | BHD | MICH BHD optical gain measurements at different LO phases, RF+audio dither | [Yehonathan, Yuta]
Sensing matrix measurements at
different LO phases were performed under |
|
|
17351
|
Fri Dec 9 13:18:57 2022 |
yuta | Summary | BHD | MICH BHD optical gain measurements at different LO phases, elliptic fit | [Yehonathan, Yuta]
Here's a plot using same dataset |
|
|
17398
|
Fri Jan 13 13:34:12 2023 |
Anchal | Summary | BHD | BH44 tuned and transimpedance measured | I've tuned one gold box RFPD to be
resonant at 44.26 MHz and I left the notch
to be near 66 MHz, however, it is only effective |
|
|
17401
|
Tue Jan 17 20:03:19 2023 |
yuta | Summary | BHD | BH44 installations: IQ demodulator is not orthogonal | [Anchal, Paco, JC, Yuta]
We have started hardware installations |
6x |
|
17402
|
Wed Jan 18 20:57:53 2023 |
Paco | Summary | BHD | IQ demod orthogonal | I tested a spare IQ demod board labeled
33.3 MHz (closer to 44 MHz than the 165 MHz
we had started using) and using the Moku |
|
|
17403
|
Thu Jan 19 12:12:09 2023 |
Anchal | Summary | BHD | IQ demod orthogonal | By sending two frequencies offset from
eachother to LO input and RF input, we measured
the remaining phase difference between I |
|
|
17404
|
Thu Jan 19 14:58:40 2023 |
rana | Summary | BHD | IQ demod orthogonal | the
problems with these circle plots: |
|
|
17405
|
Thu Jan 19 18:15:48 2023 |
yuta | Summary | BHD | BH44 RFPD optical path and LO/AS camera | [JC, Paco, Anchal, Yuta]
- We installed the new BH44 beam path |
|
|
17410
|
Mon Jan 23 11:20:44 2023 |
JC | Summary | BHD | BH44 RFPD optical path and LO/AS camera | Here's the beam path of BH44. |
|
|
17413
|
Mon Jan 23 22:51:17 2023 |
yuta | Summary | BHD | 60 Hz harmonics side lobe investigations | [Paco, Yehonathan, Yuta]
Since we have installed BH44, we
are seeing side lobes of 60 Hz + harmonics |
|
|
17414
|
Tue Jan 24 11:21:59 2023 |
yuta | Summary | BHD | FPMI displacement noise with 60 Hz harmonics side lobes | Just to show how bad 60 Hz noise is, I
compared FPMI displacement noise with pre-BH44
era (measured on Jan 13, 40m/17400). |
|
|
17415
|
Tue Jan 24 16:12:07 2023 |
rana | Summary | BHD | FPMI displacement noise with 60 Hz harmonics side lobes | 1) do a comparison with the whtiening before
the ADC on/off. This will tell us if it is
pickup before the whtiening filter or not. |
|
|
17417
|
Tue Jan 24 21:29:31 2023 |
yuta | Summary | BHD | Electronics diagram around BH44 and BH55 | 1) Turning the whitening filter before
the ADC on/off didn't changed the relative
height of 60 Hz peak compared with the |
|
|
17419
|
Wed Jan 25 11:35:20 2023 |
yuta | Summary | BHD | REFL55 visually inspected, BH44 Kapton taped | Following was done to investigate 60 Hz
noise issue, but no significant change in
the FPMI noise observed. |
|
|
17421
|
Wed Jan 25 14:33:07 2023 |
rana | Summary | BHD | REFL55 visually inspected, BH44 Kapton taped | Kapton tape is a good insulator, so its
a good block for 60 Hz. But it is mostly
useless for RF since the capacitance between |
|
|
17423
|
Wed Jan 25 18:01:21 2023 |
yuta | Summary | BHD | BH44 setup isolated, but 60 Hz noise stays the same | [Paco, Anchal, Yuta]
Isolating
BH44 setup from the rest didn't help |
|
|
17431
|
Fri Jan 27 19:35:31 2023 |
yuta | Summary | BHD | 60 Hz noise investigations around IMC | So far different measurements are consistent
with the hypothesis that the 60 Hz noise
is from PSL frequency noise (40m/17423). |
6x |
|
17432
|
Fri Jan 27 21:22:57 2023 |
yuta | Summary | BHD | V beam dump installed for BH44 RF PD | One of these V beam dumps was installed
for BH44 RF PD.
The rest is now stored in the box |
|
|
559
|
Tue Jun 24 22:31:10 2008 |
Masha | Update | Auxiliary locking | my first step in fiber stabilization | There is a new 1W INNOLIGHT NPRO laser at
the Symmetric Port.
|
|
|
564
|
Wed Jun 25 11:01:45 2008 |
Masha | Update | Auxiliary locking | fiber stabilization | For the first week, I have been learning about
fiber noise cancellation, auxiliary locking
techniques, and other relevant helpful topics |
|
|
620
|
Wed Jul 2 00:59:13 2008 |
Masha | Update | Auxiliary locking | balanced detection, noise plots, progress | Progress report submitted today(!). It is
on the 40m wiki page. Below is a figure of
some estimated noise sources.
|
|
|
647
|
Tue Jul 8 10:26:30 2008 |
Masha | Update | Auxiliary locking | setup updates | Yesterday I changed one of the beam splitters
in the Mach Zehnder to one with a more stable
mount as to reduce the system's coupling |
|
|
679
|
Wed Jul 16 11:00:15 2008 |
Masha | Update | Auxiliary locking | improving ADC input for the mach zehnder setup and completely unrelated happenings | For most of last week, the SURFs + Jenne were
helping Mike and Ken with "stray light control
for
|
|
|
685
|
Wed Jul 16 17:51:58 2008 |
Masha | Update | Auxiliary locking | long measurement | I'm taking a measurement on the SR785 spectrum
analyzer at low frequencies, so I'm going
to leave it by the symmetric port table for |
|
|
686
|
Wed Jul 16 22:29:05 2008 |
Masha | Update | Auxiliary locking | long measurement | [quote]I'm taking a measurement on the SR785
spectrum analyzer at low frequencies, so
I'm going to leave it by the symmetric port |
|
|
698
|
Fri Jul 18 19:30:20 2008 |
Masha | Update | Auxiliary locking | moving from 40m | I will be working in the basement of Bridge
probably starting next week; I moved the
NPRO laser and some of the optics from my |
|
|
734
|
Thu Jul 24 11:49:07 2008 |
Masha | Summary | Auxiliary locking | belated weekly summary | I designed a high pass filter to whiten the
spectrum from the Mach Zehnder to optimize
the
|
|
|
764
|
Wed Jul 30 12:03:44 2008 |
Masha | Summary | Auxiliary locking | weekly summary | I've been learning about mode matching/beam
propagation, so I can work on getting more
|
|
|
804
|
Wed Aug 6 13:57:44 2008 |
Masha | Summary | Auxiliary locking | weekly summary | Finished second progress report.
Working on improving the sensitivity of the |
|
|
1205
|
Mon Dec 29 18:01:07 2008 |
Aidan | Update | Auxiliary locking | Updated 40m Upgrade Document T080074-00-R |
Added a paragraph to the 40m Upgrade document
describing the fiber stabilization and frequency |
|
|
1490
|
Thu Apr 16 16:37:42 2009 |
Alberto | Update | Auxiliary locking | the zipper | It takes 18 months to double the computational
power of microprocessors but it took man
thousands of years to invent the zipper. |
|