Robert, Anamaria
Yesterday during the commissioning period I was running some tests at low frequency from the control room and Robert went in to look into a HAM5 viewport (for OFI issues). During my tests I noticed several times that the 82ish peak in DARM went very high, possibly excited by viewport activites. I attach here a spectrogram that shows the 82Hz and the closest HAM5 accelerometer. We lost lock a minute or two after this time. Some of the ring-ups line up with some of the accelerometer disturbances, but not all. Perhaps if we go through several of the chamber accelerometers, we could find one that lines up with all of them and better triangulate where the 82 Hz is coming from.
Fri May 03 10:12:05 2024 INFO: Fill completed in 12min 1secs
Famis 26489
Output of Check_T240_Centering.py :
Averaging Mass Centering channels for 10 [sec] ...
2024-05-03 08:16:49.261630
There are 13 T240 proof masses out of range ( > 0.3 [V] )!
ETMX T240 2 DOF X/U = -0.343 [V]
ITMX T240 1 DOF X/U = -1.206 [V]
ITMX T240 1 DOF Y/V = 0.358 [V]
ITMX T240 1 DOF Z/W = 0.461 [V]
ITMX T240 3 DOF X/U = -1.244 [V]
ITMY T240 3 DOF X/U = -0.572 [V]
ITMY T240 3 DOF Z/W = -1.611 [V]
BS T240 1 DOF Y/V = -0.379 [V]
BS T240 3 DOF Y/V = -0.334 [V]
BS T240 3 DOF Z/W = -0.476 [V]
HAM8 1 DOF X/U = -0.35 [V]
HAM8 1 DOF Y/V = -0.396 [V]
HAM8 1 DOF Z/W = -0.671 [V]
All other proof masses are within range ( < 0.3 [V] ):
ETMX T240 1 DOF X/U = -0.077 [V]
ETMX T240 1 DOF Y/V = -0.04 [V]
ETMX T240 1 DOF Z/W = -0.073 [V]
ETMX T240 2 DOF Y/V = -0.269 [V]
ETMX T240 2 DOF Z/W = -0.275 [V]
ETMX T240 3 DOF X/U = -0.023 [V]
ETMX T240 3 DOF Y/V = -0.155 [V]
ETMX T240 3 DOF Z/W = -0.024 [V]
ETMY T240 1 DOF X/U = 0.09 [V]
ETMY T240 1 DOF Y/V = 0.12 [V]
ETMY T240 1 DOF Z/W = 0.18 [V]
ETMY T240 2 DOF X/U = -0.071 [V]
ETMY T240 2 DOF Y/V = 0.172 [V]
ETMY T240 2 DOF Z/W = 0.094 [V]
ETMY T240 3 DOF X/U = 0.193 [V]
ETMY T240 3 DOF Y/V = 0.115 [V]
ETMY T240 3 DOF Z/W = 0.125 [V]
ITMX T240 2 DOF X/U = 0.164 [V]
ITMX T240 2 DOF Y/V = 0.264 [V]
ITMX T240 2 DOF Z/W = 0.259 [V]
ITMX T240 3 DOF Y/V = 0.157 [V]
ITMX T240 3 DOF Z/W = 0.146 [V]
ITMY T240 1 DOF X/U = 0.099 [V]
ITMY T240 1 DOF Y/V = 0.088 [V]
ITMY T240 1 DOF Z/W = 0.002 [V]
ITMY T240 2 DOF X/U = 0.061 [V]
ITMY T240 2 DOF Y/V = 0.233 [V]
ITMY T240 2 DOF Z/W = 0.103 [V]
ITMY T240 3 DOF Y/V = 0.076 [V]
BS T240 1 DOF X/U = -0.193 [V]
BS T240 1 DOF Z/W = 0.104 [V]
BS T240 2 DOF X/U = -0.087 [V]
BS T240 2 DOF Y/V = 0.025 [V]
BS T240 2 DOF Z/W = -0.149 [V]
BS T240 3 DOF X/U = -0.184 [V]
Assessment complete.
-------------------------------------------------
Output of check_sts_centering.py
Averaging Mass Centering channels for 10 [sec] ...
2024-05-03 08:22:21.261255
There are 2 STS proof masses out of range ( > 2.0 [V] )!
STS EY DOF X/U = -4.063 [V]
STS EY DOF Z/W = 2.831 [V]
All other proof masses are within range ( < 2.0 [V] ):
STS A DOF X/U = -0.495 [V]
STS A DOF Y/V = -0.773 [V]
STS A DOF Z/W = -0.624 [V]
STS B DOF X/U = 0.396 [V]
STS B DOF Y/V = 0.958 [V]
STS B DOF Z/W = -0.457 [V]
STS C DOF X/U = -0.711 [V]
STS C DOF Y/V = 0.876 [V]
STS C DOF Z/W = 0.425 [V]
STS EX DOF X/U = -0.04 [V]
STS EX DOF Y/V = 0.053 [V]
STS EX DOF Z/W = 0.085 [V]
STS EY DOF Y/V = 0.04 [V]
STS FC DOF X/U = 0.245 [V]
STS FC DOF Y/V = -1.019 [V]
STS FC DOF Z/W = 0.679 [V]
Assessment complete.
TITLE: 05/03 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 160Mpc
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 3mph Gusts, 1mph 5min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.09 μm/s
QUICK SUMMARY:
H1 has been locked for 10 hours and surviveded a 5.7 earthquake out of the Philippines.
Everything looks great!
TITLE: 05/03 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Observing at 153Mpc
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY: We've now been Locked for 2:40 and are Observing. Two locklosses(1, 2) during my shift, but relocking was easy and we didn't have any locklosses during PRMI/DRMI like we have been having lately.
LOG:
23:00 Relocking, at MOVE_SPOTS
23:19 NOMINAL_LOW_NOISE
23:24 Observing
00:54 Lockloss
02:00 NOMINAL_LOW_NOISE
02:03 Observing
03:05 Earthquake mode activated due to local earthquake just off the coast of Washington&Canada
03:09 Lockloss from earthquake
03:15 Started an Initial Alignment
03:25 Back to CALM
03:39 Initial Alignment complete, relocking
04:20 NOMINAL_LOW_NOISE
04:23 Observing
Start Time | System | Name | Location | Lazer_Haz | Task | Time End |
---|---|---|---|---|---|---|
20:23 | SQZ | Terry | Optics lab | LOCAL | SQZ work | 23:55 |
20:47 | SQZ | Kar Meng | Optics lab | LOCAL | SQZ work | 23:21 |
21:15 | SQZ | Camilla | Optics lab | LOCAL | Join SQZ crew | 23:05 |
22:02 | CAL | Tony, Francisco, Rick | PCAL lab | LOCAL | PCAL work | 01:45 |
22:43 | VAC | Gerardo | MidY | N | CP check | 23:27 |
Closes FAMIS#28351, last checked 76900
Attached are the results for the In-Lock SUS Charge Measurements from this past Tuesday + last six months. Similar to last time it was posted in the alog (77059), the excitations still have not automatically run for the ITMs since March 13th, something which we are still troubleshooting. So I have only attached the plots for ETMX and ETMY since any of the previous runs with ITM excitations have been previously alogged.
Lockloss 05/03 03:09UTC due to sudden local earthquake
Multiple SRM saturations in the minute leading up to LL, which I thought was interesting
04:20 NOMINAL_LOW_NOISE
04:23 Observing
02:03 Observing
PCAL Main optics Table was disconnected & rotated 90 degrees, leveled to match the hieght of the other optics table in the lab.
PCAL Rack was shut down and moved and reconnected.
PCAL Pneumatics were unplugged moved and reconnected.
Aloging so we have a record of exactly when this change happened.
Today I repeated a few damping loop injections that we had done at LLO. I did all 6 BOSEMs on the BS and 3 on ITMX. I injected circa 100 above ambient. I did not see anything for the BS injections, and saw a small coupling on the ITMX. It remains to be seen if the other suspensions slowly add up to a significant contribution to DARM. Sheila recommended that Josh, the new fellow, take this on in consultation with Jeff so we sat down and I passed on the methods.
The dtt's are to be found in: /ligo/home/anamaria.effler/dtt/damping/ and each test is saved separately. The first attachment shows an example injection on the BS, with the references being the background. The second attachment shows the injection awggui. I did a uniform noise with an 8th order butterworth bandpass 10 to 100 Hz. The gain was 600 for all BOSEMs tested, BS and ITMX. For DARM projection it's best to inject directly at the OSEM basis such that the noises are easy to add up incoherently.
I copied over a coupling calculation code to be found in: /ligo/home/anamaria.effler/scripts/
The three python files there, as well as the darmcalGDS_meters.txt should be copied to be used. The coupling_utils.py is kinda all that's needed, but an example usage is in test_coupling_utils.py. In this script, at the bottom, one can choose the channel injected, add the times for the background and injection, duration and the frequency range to be used, filename to save the data, etc. It will show and save a plot of the derived estimated ambient contribution to DARM from that injection. See example plot for ITMX F2 in the third attachment. It also saves a text file of the coupling function to be used for noise budgets, but only of the measured blue points (which are determined by the darm threshold chosen - for this data I chose 2). I set the default DARM to be GDS CLEAN but it can be changed in the call of the coupling function or in the base code.
TITLE: 05/02 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 13mph Gusts, 8mph 5min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.09 μm/s
QUICK SUMMARY:
Currently at ADS_TO_CAMERAS. wind low, around 15mph
TITLE: 05/02 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 159Mpc
INCOMING OPERATOR: Oli
SHIFT SUMMARY: Robert replaced all the view-ports, so the LVEA is ready to be transitioned back to SAFE whenever. We broke back into the 160s today, we briefly hit 161.8 Mpcs. Johnson Controls finished and headed out around 21:10UTC.
Lock#1
17:52UTC Lost lock right before 11.5 hours, possibly from a jack being used in the optics/pcal lab
Lock#2
No good flashes, went through CHECK_MICH. PRMI then locked pretty low but ASC was able to fix it
18:18 UTC VPW major dust alarm, 0 to 80k in a few seconds. It came down after 10-15 minutes
18:21UTC Lost lock after turning on BS_STAGE2 too early, from the alignment not being that great? The next attempt I held us in engage_drmi_asc for a few minutes before continuing.
4 SDF diffs I accepted, relating to SCRL FF and Y2LI accepted SDF diffs for Sheilas SCRL FF gain and Y2L measurements
Lock#3
We struggled to get past ENGAGE_DRMI_ASC, the BS was getting kicked (glitches?) mostly seen by the ST1 L4Cs and T240s
Relocking at MAX_POWER right now
LOG:
Start Time | System | Name | Location | Lazer_Haz | Task | Time End |
---|---|---|---|---|---|---|
15:11 | SAF | LASER HAZARD | LVEA | YES | LVEA is LASER HAZARD | 19:03 |
16:00 | pem | Robert | EndY | N | Turn on an amplifier | 16:13 |
16:01 | LSC | Sheila | CR | N | SRCL FF, Y2L | 17:21 |
16:22 | VAC | Jordan | MidY | N | CP3 pump | 16:56 |
16:23 | FAC | Kim | H2 | N | Tech clean | 16:33 |
17:00 | CAL | Rick, Francisco | PCAL lab | LOCAL | PCAL work | 21:07 |
16:39 | SQZ | Terry | Optics lab | Local | SQZ work | 18:14 |
16:40 | PEM | Robert | EndY then X | N | Move amplifier | 17:29 |
16:43 | CAL | Rick | LVEA | Y | Parts search | 16:59 |
17:03 | SQZ | Kar Meng | Optics lab | N | SQZ work | 18:14 |
17:20 | CAL | Tony | CER, PCAL lab | N/local | Grab a laptop then PCAL work | 21:07 |
17:48 | Betsy | LVEA | Y | Checks | 18:03 | |
18:05 | PEM | Robert | LVEA | Y | Put viewports back on | 18:25 |
20:23 | SQZ | Terry | Optics lab | LOCAL | SQZ work | 22:51 |
20:47 | SQZ | Kar Meng | Optics lab | LOCAL | SQZ work | 23:21 |
21:15 | SQZ | Camilla | Optics lab | LOCAL | Join SQZ crew | 23:05 |
22:02 | CAL | Tony, Francisco | PCAL lab | LOCAL | PCAL work | 23:02 |
22:06 | CAL | Rick | PCAL lab | LOCAL | PCAL work | 23:06 |
We had several locklosses from DRMI in the last hour. PRCL was oscillating at just above 100 Hz, because it's gain was too high. I reduced the PRCL1 gain from 8 to 4. I then remeasured once DRMI was transitioned to 3F, the gain was now too low by a factor of 2, so I set it back to 8.
I won't make this change in the guardian, because I don't know if this is consistent or not.
My notes on this PRCL motion before locklosses:
I have found multiple other times where PRCL has had rapid motion like seen in the above alog. Screen shots included below.
This is just in ISC state 101 so far.
But it does seem like this started on the 23rd, as I have not been able to find a time when this happened before April 23rd.
List of Locklosses that have happened in ISC state 101
ID GPS UTC guardian state state duration tags analysis status
0 1398722295 1398722295.375 2024-05-02 21:57:57.375000 UTC 101 fail
1 1398342613 1398342613.1875 2024-04-28 12:29:55.187500 UTC 101 INITIAL_ALIGNMENT fail
2 1397959320 1397959320.25 2024-04-24 02:01:42.250000 UTC 101 0:00:52 MAINTENANCE EARTHQUAKE INITIAL_ALIGNMENT analyzed [0.29.1]
3 1397958844 1397958844.0 2024-04-24 01:53:46.000000 UTC 101 MAINTENANCE EARTHQUAKE fail
*4 1397918529 1397918529.375 2024-04-23 14:41:51.375000 UTC 101 analyzing -----------Good Example
*5 1397915450 1397915450.0 2024-04-23 13:50:32.000000 UTC 101 analyzing -----------Good Example
6 1397490602 1397490602.0625 2024-04-18 15:49:44.062500 UTC 101 0:00:12 analyzed [0.29.1]
7 1397351257 1397351257.566406 2024-04-17 01:07:19.566406 UTC 101 WINDY OMC_DCPD REFINED fail
8 1397349619 1397349619.261719 2024-04-17 00:40:01.261719 UTC 101 REFINED WINDY INITIAL_ALIGNMENT OMC_DCPD fail
9 1397333742 1397333742.512695 2024-04-16 20:15:24.512695 UTC 101 0:00:33 WINDY REFINED analyzed [0.29.1]
10 1397226213 1397226213.3125 2024-04-15 14:23:15.312500 UTC 101 INITIAL_ALIGNMENT fail
11 1396929654 1396929654.377441 2024-04-12 04:00:36.377441 UTC 101 REFINED INITIAL_ALIGNMENT fail
12 1396880628 1396880627.856934 2024-04-11 14:23:29.856934 UTC 101 0:00:11 REFINED analyzed [0.29.1]
13 1396751608 1396751608.208984 2024-04-10 02:33:10.208984 UTC 101 REFINED analyzing
14 1396370541 1396370540.857422 2024-04-05 16:42:02.857422 UTC 101 REFINED fail
15 1396368947 1396368941.705078 2024-04-05 16:15:23.705078 UTC 101 REFINED OMC_DCPD fail
16 1396363292 1396363292.875 2024-04-05 14:41:14.875000 UTC 101 FSS_OSCILLATION BOARD_SAT EARTHQUAKE INITIAL_ALIGNMENT fail
17 1396184286 1396184286.200195 2024-04-03 12:57:48.200195 UTC 101
Make Histogram of the following data after excluding DAQ restarts:
['H1:GRD-ISC_LOCK_STATE_N.mean,m-trend']
<H1:GRD-ISC_LOCK_STATE_N.mean (0.0166667Hz, MTREND, FLOAT64)>
lines read from servers: 47066
Number of time values where Query state H1:GRD-ISC_LOCK_STATE_N == state 101 is true: 277
Number of Unique times the channel was in such a state: 149
Length of SCstart: 149 Length of SCstop: 149 length of duration 149
0 1396042620 1396042620 0
1 1396042920 1396042920 300
2 1396095060 1396095060 52140
3 1396098000 1396098000 2940
4 1396133820 1396133820 35820
5 1396165320 1396165320 31500
6 1396184700 1396184700 19380
7 1396200540 1396200600 60
8 1396214760 1396214760 14220
9 1396218300 1396218300 3540
10 1396246980 1396246980 28680
11 1396358340 1396358340 111360
12 1396359600 1396360260 660
13 1396361700 1396361700 2100
14 1396362120 1396363200 1080
15 1396367940 1396367940 5820
16 1396368180 1396368180 240
17 1396368420 1396368840 420
18 1396370160 1396370160 1740
19 1396370460 1396370460 300
20 1396385340 1396385340 14880
21 1396451220 1396451220 65880
22 1396494480 1396494480 43260
23 1396548420 1396548600 180
24 1396549140 1396549320 180
25 1396686480 1396686480 137340
26 1396686780 1396686780 300
27 1396728060 1396728060 41280
28 1396746360 1396746360 18300
29 1396747140 1396747140 780
30 1396749420 1396749420 2280
31 1396752120 1396752120 2700
32 1396769520 1396769520 17400
33 1396773900 1396773900 4380
34 1396774140 1396774140 240
35 1396790760 1396790760 16620
36 1396794540 1396794540 3780
37 1396814460 1396814460 19920
38 1396814760 1396814820 60
39 1396930080 1396930140 60
40 1396930380 1396930440 60
41 1396998480 1396998480 68100
42 1397047080 1397047260 180
43 1397047500 1397047680 180
44 1397144280 1397144280 96780
45 1397146080 1397146080 1800
46 1397146620 1397146740 120
47 1397173920 1397173920 27300
48 1397187300 1397187300 13380
49 1397190360 1397190600 240
50 1397225160 1397225160 34800
51 1397226120 1397226120 960
52 1397229900 1397229900 3780
53 1397292240 1397292300 60
54 1397292600 1397292600 360
55 1397335440 1397335560 120
56 1397346900 1397346900 11460
57 1397354820 1397354820 7920
58 1397357220 1397357220 2400
59 1397370960 1397370960 13740
60 1397458140 1397458140 87180
61 1397458440 1397458620 180
62 1397466240 1397466240 7800
63 1397471460 1397471460 5220
64 1397471760 1397471760 300
65 1397494320 1397494320 22560
66 1397524440 1397524440 30120
67 1397524740 1397524800 60
68 1397526420 1397526420 1680
69 1397538420 1397538600 180
70 1397538900 1397538900 480
71 1397599800 1397599800 60900
72 1397600520 1397600700 180
73 1397601000 1397601060 60
74 1397646900 1397646900 45900
75 1397647140 1397647200 60
76 1397647740 1397647800 60
77 1397662560 1397662560 14820
78 1397663220 1397663220 660
79 1397690400 1397690400 27180
80 1397715900 1397715900 25500
81 1397716260 1397716260 360
82 1397716740 1397716860 120
83 1397718120 1397718120 1380
84 1397720280 1397720280 2160
85 1397720520 1397720520 240
86 1397726160 1397726160 5640
87 1397727180 1397727180 1020
88 1397763780 1397763780 36600
89 1397766480 1397766540 60
90 1397848140 1397848140 81660
91 1397848440 1397848500 60
92 1397852880 1397852880 4440
93 1397853660 1397853660 780
94 1397867760 1397867760 14100
95 1397868720 1397868780 60
96 1397912580 1397912580 43860
97 1397915820 1397915820 3240
98 1397916060 1397916060 240
99 1397918940 1397919000 60
100 1397937540 1397937540 18600
101 1397952300 1397952480 180
102 1397952960 1397952960 660
103 1397956860 1397957040 180
104 1397957280 1397957280 420
105 1397957880 1397957880 600
106 1397958600 1397958780 180
107 1397959680 1397959860 180
108 1397960220 1397960220 540
109 1397976900 1397976900 16680
110 1397977140 1397977140 240
111 1398037920 1398037980 60
112 1398038280 1398038280 360
113 1398081000 1398081000 42720
114 1398194400 1398194400 113400
115 1398195300 1398195300 900
116 1398219480 1398219480 24180
117 1398219780 1398219900 120
118 1398252540 1398252540 32760
119 1398275280 1398275280 22740
120 1398276660 1398276660 1380
121 1398341760 1398341760 65100
122 1398359160 1398359340 180
123 1398360060 1398360240 180
124 1398361020 1398361020 960
125 1398381240 1398381420 180
126 1398382260 1398382440 180
127 1398553560 1398553560 171300
128 1398554100 1398554100 540
129 1398574020 1398574080 60
130 1398574560 1398574740 180
131 1398574980 1398574980 420
132 1398607740 1398607740 32760
133 1398619380 1398619380 11640
134 1398619680 1398619800 120
135 1398620340 1398620460 120
136 1398629940 1398630120 180
137 1398630360 1398630360 420
138 1398661560 1398661740 180
139 1398662160 1398662160 600
140 1398664260 1398664320 60
141 1398708420 1398708420 44160
142 1398709140 1398709140 720
143 1398722220 1398722220 13080
144 1398723240 1398723240 1020
145 1398724620 1398724620 1380
146 1398733740 1398733800 60
147 1398734040 1398734220 180
148 1398734580 1398734700 120
Looking for times where PRCL is above 1000:
['H1:LSC-PRCL_IN1_DQ.mean,m-trend']
<H1:LSC-PRCL_IN1_DQ.mean (0.0166667Hz, MTREND, FLOAT64)>
lines read from servers: 47066
Number of time values where Query state H1:LSC-PRCL_IN1_DQ > state 1000 is true: 11
Number of Unique times the channel was in such a state: 3
Length of SCstart: 3 Length of SCstop: 4 length of duration 4
1396110540 1396110660 120 120
1396117620 1396117800 180 180
1397322360 1397919840 597480
Counting states completed
Times ISC_Lock was in Aquire_DRMI_1F [101]
Start: Stop: Duration: Min: Max:
0 1396110540 1396110660 120
1 1396117620 1396117800 180
2 1397322360 1397322480 120
Maybe be use this channel H1:LSC-PRCL_TRIG_MON to check filter out times.
DCPD sat then LL
23:24 Observing
Had to accept sdf for SUS-ETMY_L3_LOCK_BIAS_OFFSET to get into Observing
I tuned the Y2L gains in the same way as in 77539.
I've added two templates to userapps/asc/h1/templates/manually_tune_P2L.xml and manually_tune_A2L.xml
These templates have excitations for LOCK P (or Y) for each suspension at 30 Hz. In all the quads, we have bandstops for 30 Hz in ISCINF_P and Y (FM7). To do this I turned all 8 of those filters on, then one at a time inject 30 Hz into Lock for each DOF, checking for the height of the peak in DARM, coherence with the injection, and the transfer function of the excitation to DARM. I changed the gain to improve the transfer function until the phase flips.
If this has to be done frequently we should make a script that will do this, as it seems that the script that calculates based on the ratio of transfer functions doesn't work well.
The attachment shows that the improvement in DARM from today's commissoning time mostly comes from SRCL feedforward (and maybe the ESD bias tuning), but that the CHARD Y coherence hasn't changed much.
Robert, Anamaria
Yesterday we opened the viewports of the oplevs for both ITMX and ITMY to find the alignment of the CP's.
The procedure relies on the fact that the optics are not coated for red so we can see all four surfaces. The separation between the beams at this distance (~34m) is about 10cm due to the wedges (in the table below from the galaxy page). The test mass has a vertical wedge, thick down, so the AR beam will show up directly below. The CP is supposed to be perfectly parallel to the back surface so the closest surface of the CP (CP1) would land essentially right on top of the ITM AR beam. Then the CP has a similar size wedge, but horizontal, so the second CP surface would hit at the same level as CP1 and ITM AR but to the left or right, depending which ITM.
The first plot attached shows the nominal view of these beams as seen at the oplev viewport on the white page. The yellow pages were attached to the lexand covering the viewport and the beams were marked. The full view of all the beams no longer fits through the viewport due to the addition of nozzle baffles so we had to walk the oplev sender to find all the beams. For the ITMX we lucked out and the ITM AR beam was visible at the top gap of the baffle at the same time as the second AR reflection and the CP beam were visible in the aperture. As such we are able to scale the misalignments to the wedge value. We verified the CP beams by moving the CPs, and we scanned to find the second CP surface (CP2) horizontally at about the right distance from CP1.
wedge ITM/CP | misalignment | |
CP-X | 0.07/0.07 deg | 1.7 mrad down |
CP-Y | 0.08/0.07 deg | 0.55 mrad down |
By down I mean they are further pitched down towards the arm.
One would think that we have +/- 440 urad range in pitch on the R0, but it seems its range is much less than advertised. Even stranger, this was also found to be the case at L1, on both ITM R0. When we moved CPY, with respect to this calibration it only moves ~230 urad. So we cannot make it back to the nominal position of overlapping the ITM AR beam. For yaw we did a smaller step so more error on it, but it's about 60% of slider value. More on this later.
(CPY is the one that Robert found to modulate the noise from the MC tube baffle.) Speaking of the L1 experience, we even had to vent back in 2016 to fix one of these CP misalignments, which was too close to HR actually. The interesting thing to me, looking back, is that L1 still has a similar misalignment for CPX to the H1 CPY and we don't see as high noise coupling at the IMC tube.
CPX is very misaligned by comparison, but not linked to the MC tube scatter. Alena has agreed to help us track where these ghost beams land at P/SR3 and the scraper baffles, now that we know their exact orientation.
+Peter, Jeff
Regarding the reduced range of CPY R0, we checked what the BOSEMs and the coil current monitors had to say about the range during our optical measurement. Jeff kindly calibrated the RMSMONs so we could see what the current really is. The data is in the attached screenshot. We did not check the CPX but, as I mention above, we found this to be the case at LLO as well. For pitch I show F1, which gets the largest drive, for yaw I show one of F2/F3 which get identical drives. In terms of range, I define it as how far from 0 we can go, so half range technically, but it's max DAC output and current. If we want more range we have to decide if we can afford more than ~45mA on the BOSEMs.
CPY | Slider [urad] | range [%] | OSEM readback [urad] | Oplev meas [urad] | Coil current [mA] |
PIT | 440 | 100 | 1130 | 230 | 45 |
YAW | 200 | 33 | 160 | 120 | 16 |
Minhyo, Sheila
Changed the gain values of the RANGE BLRMS's filters (RLP_1 ~ 7) at 17:48:44 (UTC).
I referenced the accumulated BNS range in Apr.-11 and Apr.-17, to reverse calculated the additional factors for the filter gains (1/BNS = scope * factor).
The New gain values are defined as (Prev. gain) * (Avg. Factor).
Attached three screenshots are; 1) Accumulated BNS range plot, 2) Factor calculation, 3) H1OAF.diff after made all changes.