nutsinee.kijbunchoo@LIGO.ORG - posted 17:52, Friday 17 July 2015 (19720)
Update to the complete violin mode study
A while ago I made a "complete" violin mode table here. Matt and Jeff was curious whether or not the frequencies belong to correct test mass. So, I went through the violin mode damping filters and see which one works and which doesn't. So far I was able to confirm that 24 out of 32 frequencies belong to the correct test masses. The filters were able to damp most of them. Three frequencies got rung up. The rest were still inconclusive (either the damping phases were off by 90 degrees or the test masses were wrong).
| Frequency | Test mass | Filter | Does the filter work? | Note |
| 500.054 | ITMX | MODE3 | yes | |
| 500.212 | MODE3 | yes | ||
| 501.092 | ITMX | MODE6 | yes | |
| 501.208 | MODE3 | yes | ||
| 501.254 | ITMX | MODE3 | yes | |
| 501.450 | MODE3 | yes | ||
| 502.621 | ITMX | MODE3 | NO | |
| 502.744 | MODE3 | yes | ||
| 503.007 | ITMY | MODE3 | yes | |
| 503.119 | MODE1 | yes | ||
| 504.803 | ITMY | MODE4 | NO | |
| 504.872 | MODE4 | yes | ||
| 501.606 | ITMY | MODE5 | NO | Rung up! |
| 501.682 | MODE5 | yes | ||
| 501.749 | ITMY | MODE6 | yes | |
| 501.811 | MODE6 | NO | ||
| 507.992 | ETMY | MODE5 | NO | |
| 508.146 | MODE5 | yes | ||
| 508.010 | ETMY | MODE5 | yes | |
| 508.206 | MODE5 | yes | ||
| 508.220 | ETMY | MODE5 | NO | |
| 508.289 | MODE5 | NO | ||
| 508.585 | ETMY | MODE5 | yes | |
| 508.661 | MODE5 | NO | ||
| 505.587 | ETMX | MODE6 | yes | |
| 505.707 | MODE6 | NO | ||
| 505.710 | ETMX | MODE4 | yes | |
| 505.805 | MODE4 | NO | Rung up! | |
| 506.922 | ETMX | MODE6 | yes | |
| 507.159 | MODE6 | yes | ||
| 507.194 | ETMX | MODE6 | NO | Rung up! |
| 507.391 | MODE6 | yes |
Below is the table of the violin mode damping filters used by Guardian and the frequencies they (supposed to) damp:
| w0 (Hz) | wc (Hz) | wc-w0 (Hz) | Filter (All FM1) | Test mass | Frequency covered |
| 506 | 513 | 7 | MODE5 | ETMY | All ETMY |
| 505.78 | 505.9 | 0.12 | MODE4 | ETMX | 505.710, 505.805 |
| 502 | 520 | 18 | MODE6 | ETMX | The rest of ETMX (cheater…) |
| 485.7 | 506.4 | 20.7 | MODE3 | ITMX | All ITMX |
| 501.05 | 501.11 | 0.06 | MODE6 | ITMX | 501.092 |
| 503.08 | 503.16 | 0.08 | MODE1 | ITMY | 503.119 |
| 502.96 | 503.06 | 0.1 | MODE3 | ITMY | 503.007 |
| 504.86 | 504.91 | 0.05 | MODE4 | ITMY | 504.803, 504.872 |
| 501.63 | 501.7 | 0.07 | MODE5 | ITMY | 501.606, 501.682 |
| 501.71 | 501.85 | 0.14 | MODE6 | ITMY | 501.749, 501.811 |
Both tables are included in the excel file attached below.
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