| ID |
Date |
Author |
Type |
Category |
Subject |
Text |
 |
|
407
|
Tue Aug 15 00:09:01 2017 |
Zach | Electronics | Modeling | ESD Improvements | 2017-08-14
I did my
best to increase the excitation in the higher
order modes. By making the ESD narrower (a |
10x |
|
409
|
Tue Aug 15 16:43:58 2017 |
Zach | Electronics | Modeling | Unchanged Mode Insight | 2017-08-15
It appears
to me that the major factor limiting the
improvement of the modes that either remain |
|
|
411
|
Wed Aug 16 10:04:24 2017 |
Zach | Electronics | Modeling | ESD along edge | 2017-08-16
I placed
created a very narrow ESD placed along the
edge of the sample. The thought behind this |
|
|
412
|
Wed Aug 16 11:36:13 2017 |
Zach | Electronics | Modeling | Middle ESD | 2017-08-16
I created
a model with a drive offset in the middle.
It improved one of the modes by a factor |
|
|
414
|
Wed Aug 16 16:05:09 2017 |
Zach | Electronics | Modeling | Two ESD First test | 2017-08-16
I created
a model with two ESD's, essentially a
combination of my previous two attempts with |
|
|
415
|
Thu Aug 17 14:19:04 2017 |
Zach | Electronics | Modeling | Two ESD Optimization | 2017-08-17
I ran a
sweep of the position of the middle ESD to
determine the optimal arrangement. From the |
17x |
|
416
|
Thu Aug 17 23:34:51 2017 |
Zach | Electronics | Modeling | Optimized ESD Drawing | 2017-08-17
I made a
drawing of the Optimal ESD design. The bottom
combs (right hand in the rotated image) are |
|
|
417
|
Fri Aug 18 10:50:53 2017 |
Zach | Electronics | Modeling | ESD's with positive voltage | 2017-08-18
With both
electrodes driven at a positive voltage,
the results are still an improvement over |
|
|
419
|
Fri Aug 18 14:15:47 2017 |
Zach | Electronics | Modeling | Same Voltage ESD Sweep | 2017-08-18
I ran a
sweep of the central position in the two
ESD setup with both set at the same voltage. |
|
|
420
|
Fri Aug 18 15:10:23 2017 |
Zach, Gabriele | Electronics | Modeling | ESD prototype | 2017-08-18
We created
a prototype of PCB for the ESD design. Unfortunately
the orientation of the two combs was flipped, |
|
|
170
|
Wed Nov 9 15:32:11 2016 |
Gabriele | General | Noise hunting | Noise below 2 kHz is not due to the roughing pump, but to the clean air filters | The two spectra below show basically no
difference (blue roughing pump on, red, roughing
pump off) |
|
|
176
|
Thu Nov 10 17:04:05 2016 |
Gabriele | General | Noise hunting | Temporary second QPD | This morning I installed temporarily a
second QPD to monitor the input beam. The
goal was to understand where the vibrations |
|
|
181
|
Sun Nov 13 10:11:19 2016 |
Gabriele | General | Noise hunting | Noise due to air | The plot below compares the QPD signal
spectra in different configurations (roughing
pump on/off, air on/off). |
|
|
209
|
Wed Nov 23 08:55:41 2016 |
Gabriele | General | Noise hunting | "Advanced" vibration isolation | In normal conditions the RMS of the QPD
signals is dominated by the 58 Hz line generated
by the roughing pump. Also, when the modes |
|
|
216
|
Tue Nov 29 17:02:06 2016 |
Gabriele | Facility | Noise hunting | Suspending the roughing pump | I suspended the roughing pump with four
springs. The reduction of the 58 Hz peak
is similar to what I got when the pump was |
|
|
287
|
Wed Feb 1 15:23:42 2017 |
Gabriele | Optics | Noise hunting | Wandering line is due to the laser | The wandering line I mentioned in my previous
elog, which is spoiling most of the sensitivity,
turns out to be power noise of the laser. |
|
|
326
|
Thu Mar 2 11:27:47 2017 |
Gabriele | General | Noise hunting | Turbo pump of CR0 pollutes CR1 | The turbo pump of the CR0 chamber runs
at 833 Hz. It causes vibrations that pollute
the measurements in the CR1-4 chamber. In |
|
|
128
|
Tue Sep 27 08:53:46 2016 |
Gabriele | General | Vacuum | Etched disk installed | Installed the etched disk: using manually
the centering ring allowed me to get the
beam on the QPD. A couple of taps to the |
|
|
133
|
Mon Oct 17 10:50:50 2016 |
Gabriele | General | Vacuum | No sign of problems in the electrostatic drive | I opened the chamber and took the etched
disk out. Inspection of the electrostatic
drive does not show any sign of burn or damage. |
|
|
142
|
Fri Oct 21 14:03:17 2016 |
Gabriele | General | Vacuum | Roughing pump moved | I moved the roughing pump out of the clean
room, adding an extension hose.
|
|
|
165
|
Mon Nov 7 11:27:16 2016 |
Gabriele | General | Vacuum | Turbo pump excites some resonance at 58 Hz | I looked into a couple of turbo pump switch
on periods, and in both cases when the pump
speed hits 58 Hz, a resonance is excited. |
|
|
186
|
Mon Nov 14 11:28:33 2016 |
Gabriele | General | Vacuum | Viton pads | I added three 1"x1" viton pads
below the base plate, and realigned the entire
optical system to the horizontal reference |
|
|
195
|
Thu Nov 17 12:06:39 2016 |
Gabriele | General | Vacuum | Switching on the IGM moves the disk | Here's a trend of the QPD signals when
the IGM was turned on:
|
|
|
264
|
Thu Jan 19 07:32:33 2017 |
Alena | General | Vacuum | New chamber first pimp down | The new chamber was build. The first attempt
to pump down was unsuccessful because of
dislocated lid. After the lit was placed |
|
|
265
|
Thu Jan 19 12:49:17 2017 |
Gabriele | Facility | Vacuum | Skyhook installed | The SkyHook has been put in place and bolted
down to the floor.
|
|
|
267
|
Thu Jan 19 14:27:02 2017 |
Alena | General | Vacuum | First vacuum test new chamber | Turbo pump controller (new chamber) was
configured. Need to reduce the frequency
or setup a standby mode. First pump down: |
|
|
285
|
Tue Jan 31 16:50:55 2017 |
Gabriele, Alena | General | Vacuum | First pump-down with setup | This afternoon we started the pump-down
with all the system installed into the chamber.
Unfortunately the IGM vacuum gauge isn't |
|
|
498
|
Tue Mar 27 16:37:22 2018 |
Gabriele | General | Vacuum | Turbo pump for test chamber CR0 set point | I changed the set point of the test chamber
turbo pump to 666 Hz. This was done
by setting the "standby rotation speed" |
|
|
517
|
Thu Apr 12 10:33:06 2018 |
Gabriele | General | Vacuum | Read-out of vacuum gauges | I failed to interface in a reliable way
the datalogger with Linux. So i hooked up
the four analog outputs of the vacuum gauge |
|
|
703
|
Tue May 28 15:48:42 2019 |
Alena | General | Vacuum | Low pressure gauge exchange | After venting the vacum chamber (CR14)
a few times, checking for leaks and trying
to tune settings to the gauges controller, |
|