AEI-Potsdam: S. Mohanty, S. Mukherjee
     Caltech: Barish, Barton, Drever, Mours, Shawhan, Yamamoto, Zweizig
     Dublin: Ottewill
     Florida: Coldwell, Klimenko
     La. Tech: Greenwood
     LHO: Ito, Landry, Raab, Schofield, Sigg, Whitcomb
     Loyola: McHugh
     Michigan: Riles
     MIT: Sylvestre
     Oregon: Rakhola
     PSU: Sutton
     Syracuse: Penn, Saulson

Preparations for E4 Engineering Run (Investigations, Shift list)

• Update on IFO configuration - S. Whitcomb

The LLO 4K will plan to run in recombination mode, not recycled. If running in recombination proves untenable, single-arm running (as in E3) is a possible fallback. A final decision on configuration(s) will probably be made the day before the run begins. LHO will be running the regular PEM channels and hopes to run the 2K mode cleaner in lock.
• Run scheduling & plans - S. Marka

Pre-run site-site telecons will be held Thursday and Friday mornings at 10:00 CDT. Livingston participants are asked to verify the posted travel plans.
• Plans of investigation teams and new special requests - All

Investigation teams summarized plans for the run and post-run analysis:
• Seismic (D. Greenwood) - Will investigation 10 Hz peak seen at Livingston during E3
• Environmental correlations (A. Ottewill) - More DMT correlation software has been written to allow trend writing, triggers and pre-analysics windowing of data. The E4 investigation plan will follow that of E3.
• Inter-site correlations (M. Landry/R. Schofield) - No special requests. A special RDS will not be written. Instead, frames will be merged 1-2 weeks after the run and analyzed together.
• Environmental disturbances (R. Schofield) - Same approach as for E3. Two DMT transient monitors will be running.
• Calibration (M. Landry) - There will be a 4-hour pre-run calibration study Friday morning, and the last 4 hours on Monday morning will be devoted to calibration work. They hope for six injected frequency combs and will be writing a customized RDS.
• Tidal (F. Raab) -The E2 studies will be redone for E4. They are looking at how best to look at Livingston data from Hanford.
• Lock losses (KR) - Same plan as for E3. Keep eyes/ears open, look for coil saturations in particular. Will have lock transition monitor running and will look for correlation with triggers from transient monitors (e.g., Masahiro's glitchmon and John's pslmon).
• Timing precision (D. Sigg) - Same plan as for E3, but with a revised timing monitor and automated comparison
• Data integrity (J. Zweizig) - The usual two integrity monitors (bittest & slicemon) will be running, to look for stuck bits and repeated data. John will try to automate the comparison between the RDS and the CACR archive done for E3
• Data merging (P. Shawhan) - Top priority is ensuring data is available after the run via the archive. A detailed guide to accessing the data will be posted. In addition to the usual data trends, the DMT-generated trends will also be made available in the archive.

Line noise (S. Klimenko) - Same plan as for E3 with the addition of looking at inter-site line correlations. Will focus mainly on the dark-port channel. At the request of the calibration group, the injected calibration lines will be tracked and trend data recorded.

• LIne noise investigations:

 
• Intriguing line noise behavior in the magnetometer channel - S. Mukherjee

See report for details. In summary, magnetometer data from both sites were examined, and a number of lines seen. In addition to the expected 60 Hz and harmonics. other strong lines were seen at 56, 115 and 170 Hz. Scatterplots of different components show preferential orientation with oscillations, suggesting a radiating source, e.g., power line nearby. There is also an odd alternation of steady sinusoid with fluctuating sinusoids at a variety of frequencies with a 210 second time period. Stan suggested that compressors that cycle on and off with a comparable time period might be the source.
 
• Coherence of the LLO and LHO power mains - S. Klimenko

See report for details. In summary, the 60 Hz power monitor signals at LHO and LLO were studied for amplitude/phase variations and for coherence between the sites. Amplitudes were found in a 1-hour stretch to vary at the 0.2% level, while phase varied over the full 2pi range. Intersite coherence was measured with a 10-hour stretch. As was reported at an earlier telecon by Peter Fritschel for magnetometer channels, there is good coherence at 60 Hz for short time scales, as expected, but steady degradation at longer time scales. Here the coherence is measured by the cosine of the phase difference measured at the two sites, and a typical coherence time scale of 38 seconds measured. Surprisingly, a small but significant coherence is observed between the sites with a time lage of 340 and 560 seconds, an effect seen also in magnetometer channels. One interpretation is a common harmonic frequency in phase deviation from perfect 60 Hz at the two sites. A power spectrum of the phase difference between the sites shows peaks near 0.5, 0.9 and 2.0 mHz.

• General - J. Zweizig

The delaronde machine at LLO was hacked recently, along with other site computers. Szabi Marka and Tom Evans have been working to restore them. Szabi mentioned that delaronde users need to contact him to get new passwords. Memory leaks in the FrameCPP API have been found and fixed. The status of the trigger manager and triggers recently recorded are now more visible from the control room via new web pages. The DMT monitors run during E3 will be the default ones for E4 unless new versions are provided by the authors.

• Line noise:

 
• B. Allen, A. Ottewill (Adrian reporting)

Adrian is modifying his line monitors and correlation monitors to produce trends and triggers.
 
• E. Daw, S. Klimenko 
  Ed is helping Sergey add a DMT viewer interface to his line monitor. They plan to get together before and during the E4 run.

 
• A. Sintes (not present)

• Characterizing seismic noise:

• E. Daw 
  Ed is upgrading his rms-band-limited seismic monitor with a number of features that should be ready by E5.

 
• Inter-channel correlations:

• B. Allen, A. Ottewill (see above)

 
• Bilinear cross-couplings

 
• S. Penn

Steve will demonstrate his real-time bispectrum monitor to interested persons during E4. He is also working on a background monitor for non-Gaussianity.


• Operational state:

 
• D. Chin, K. Riles (KR reporting)

No changes to the osc infrastructure since E3. The lock loss monitor and servo instability monitor config files will be tuned shortly before E4 begins.

• Bandlimited RMS

 
• E. Daw  (see above)

 
• Time / Frequency plots

 
• S. Mohanty

Nothing new reported.
 
• J. Sylvestre 
  Working on new release of tid program. Release expected by the end of May.
  
  
• Non-Gaussian noise

 
• S. Penn (see above)

 
• S. Finn, G. Gonzalez, P. Sutton (Patrick reporting)
  An example  was shown of a monitor (currently foreground in root) that measures the Rayleigh nature of a data channel. It displays a plot of the band-limited standard deviation of power divided by the mean power vs frequency. A Gaussian channel should give a horizontal line at unity (within statistical fluctuations). Deviations from unity at a given frequency give a clue to underlying non-Gaussian sources of noise. Coherent lines tend to give low Rayleigh ratios, and segments of data with severe transients give mixed peaks and dips. Patrick is working to convert the foreground program into a background monitor compatible with the dmt viewer.

• Power spectral transients:

 
• S. Mohanty (see above)

 
• Servo instability:

 
• D. Chin, R. Gustafson, K. Riles (see above)

 
• Event catalog:

 
• J. Sylvestre, R. Weiss (see above)

• Impulse recognition:

 
• M. Ito

Filtering has been added to the glitch monitor to give cleaner transient detections. The filtering scheme is a Butterworth IIR that is configurable.


• Magnetic field and seismic transients

 
R. Frey, R. Rahkola (Rauha reporting)
Rauha is working with Szabi to understand magnetometer signals in the LVEA. Both Masahiro's and John's glitch monitors are being used.

A.O.B.

• Next detector characterization teleconference: Friday June 1 at 11:00 a.m. EDT (8:00 PDT).