Highlights from Detchar Sessions, including joint sessions with ASIS -------------------------------------------------------------------- (LSC meeting at LIGO Hanford Observatory - August 16-19, 2004) [ HIGHLIGHTS OF HIGHLIGHTS MARKED BY "--->" ] TUESDAY ------- 30' S2 & S3 calibration status (Gaby Gonzalez) Highlights: New S2 calibration report (60 pages) with detailed error estimates. Better understanding of fast fluctuations in L1 (microseism, stacks, bounce. Investigating low-gain excursions that give servo instabilities (data quality flag. ---> Final S3 calibration expected soon, using Xavi's faster-sampled, complex alphas, beta. Incorporates new hardware measurements at LHO. Errors on alpha/beta below 1%, but true variations through run at 4-15% ---> Have kicked off review process with external committee (Lazzarini, Shoemaker, Weiss) Expect S4 to benefit from new photon calibrator (recent progress at LHO) and from quieter LLO conditions with HEPI for DC calibration. 15' Time domain calibration (Xavi Siemens) Highlights: h(t) frames now available for S3 -- Please try them out! Web page: http://www.lsc-group.phys.uwm.edu/~siemens/ht.html Nice audio demo of inspiral chirp in raw AS_Q vs h(t) New h(t) frame spec to be used soon by GEO - will use for LIGO a bit later ---> --> Major milestone! -- Good example of valuable LSC service work and welcome addition to calibration working group 20' S3 Glitches (Laura Cadonati) ---> Highlights: Lessons from S2: Loud candidates are interesting! PEM vetoes DO matter! (sometimes) S3 strategies: Go after particular playground features for monitor tuning Focus on H1-H2 correlated glitches Use common glitch database for easy collaboration Many S3 investigations under way, using DMT monitors, burst and inspiral triggers. Some vetoes look promising - high efficiency and low deadtime. Preliminary evidence of PEM coupling to AS_Q. 10' S2/S3 Data Quality (John Zweizig) Highlights: Summarized S2 version 5 and S3 version 2 DQ segment releases ---> Can live with least-significant-byte corruption: - Rarely affected AS_Q and benign (10**-5 level) even when present S3 version 3 will have miscellaneous known problems flagged (photodiode saturations, front-end synchronization errors, dusty times) 15' AS_I/Q glitches from oscillator phase noise (Gaby Gonzalez) Highlights: Examined proliferation of correlated glitches in AS_Q and AS_I. Due to oscillator phase noise. ---> With judicious cut on AS_Q/AS_I ratio, can safely veto. But livetime calculation requires care. Periods of especially high glitch rates to be DQ-flagged. --------------------------------------------------------------------- WEDNESDAY ---------- 20' Status of BurstMon and non-stationary noise (Sergey Klimenko) Highlights: New DMT monitor very nearly ready - awaiting standardized calibration infrastructure Three figures of merit: 1) h_rss(at 50% efficiency) from injected waveforms 2) Non-stationarity measures 3) Glitch rates Non-stationarity in S3 H1 much worse than in S2 H1 --> affects burst search :( ---> Promising major addition to DMT figure-of-merit lineup for S4 10' Status of PulsMon (Giovanni Santostasi) Cancelled (presented status report at August 6 detchar telecon; making progress, but much work to do) 10' Status of StochMon (Marc Cenac) ---> Highlights: Much progress made this summer as SURF student (mentors: Brian O'Reilly, Ken Franzen) Will compare local IFO actual noise with reference spectra from other IFO's Calculations have been cross checked with MATLAB Refinements to be added during/after detector investigation camp 10' Hardware injections of stochastic waveforms - Results from S3 and plans for S4 (Sukanta Bose) Highlights: Circumvented goofup in original IFO injections by examining recorded excitation channel for IFO 1 and applying to IFO 2. ---> Can now see correlated signals. Will try correlated injections into Allegro too for S4. . 10' Report from the Detection Committee (Peter Saulson) ---> Highlights: Each search group has provided a "detection checklist" tailored to analysis ("event" checks vs signal character vs ...). Assembling single document to be circulated to collaboration soon. Will also provide a "procedures document" to follow. Note: 3 of 4 groups have already faced this issue at some level! --> not an idle exercise! 10' Planning for the S4 run (Keith Riles) (Addressed in slides to follow) 10' S3 timing issues (Szabi Marka) Highlights: S3 AS_Q timing document released long ago. Focussed here on timing of some auxiliary channels where 1-second shifts are seen for a handful of science segments during S3. Problem tracked down to faulty DAQ controller. ---> Working on more comprehensive monitoring for S4. 10' Modeling the input optics in the LIGO IFO's using E2E (Raghu Dodda) ---> Highlights: Attempting extensive end-to-end model simulation of input optics and coupling to rest of interferometer. Agreement better for pendulum motion than for angular wobble. Work is needed on transfer functions. Starting to address Mode Cleaner locking now. --------------------------------------------------------------------- THURSDAY -------- 20' S2/S3 interchannel correlations (Nelson Christensen) ---> Highlights: Responding to request from pulsar group, undergraduate Sarah Vigeland has produced web-based catalog of lines in AS_Q (S2/S3, H1/H2/L1) that are correlated with PEM channels. Have also followed up on particular requests by analysts to understand sources of lines observed in AS_Q. Now turning attention to correlations in H1/H2 AS_Q to chase down (both stationary and transient) Seeing evidence of seismic disturbances affecting LHO AS_Q channels 20' Environmental disturbances and intersite correlated transients (Robert Schofield) Highlights: Dust glitches: Post-run investigations confirm only dark port responsible. Acrylic sheet enclosure gives 50x decrease in glitch rates. HEPA filter with fan allows quick clearing of dust (commissioning!). ---> Has compiled list of times during S3 when dark port table visited, for inclusion in next data quality segment release. Acoustics: Ongoing work to isolate sources and reduce couplings, including one unintended new source (lousy beam dump, now replaced) ---> Magnetic couplings: Problem with pulsed heater coils being addressed: Sidebands on 60 Hz from pulsing being eliminated by removing pulsing and replacing with continuous heating moderated by cooling water. Continuous 60 Hz line being mitigated by reducing area of heating coils (reducing mutual inductance) - observe reduction by 3 times. Dewar glitches: Test insulation of one dewar tank ($25K!) seems to work well. Reduces diurnal temperature fluctuations by factor of 4. ---> Reduces detected dewar glitches by factor of 6 (low statistics!) Should help LHO lock lengths in S4 considerably. Seismic sensitivity: LHO end Y mass was unduly sensitive to seismic noise Tracked down to faulty optical lever interface board - Fixed ---> Inter-site bursts: Scanned over many PEM channels in special inter-site RDS files. Found no statistically significant excess of bursts Airplanes: Showed nifty "movie" of acoustic spectra from different stations as plane passed nearby -> clear visual signature 10' Status of SpecMon (Tim Bodiya) ---> Highlights: New interactive DMT GUI monitor for exploratory studies. Has background monitor engine to succeed ServoMon, for long-term studies. Should be useful as stand-alone tool or with DTT. 10' Status of SuspensionMon (Rauha Rahkola) Highlights: Rauha taking over from graduated student Brian Stubbs. ---> Will work to address most urgent remaining tasks in time for pre-engineering run testing. 20' Generation of realistically modelled detector noise - production and application (Soma Mukherjee) Highlights: Developed quite sophisticated noise modeling with separation of "floor", lines, and transients. Includes transient classification and ability to simulate noise. ---> Will work on adapting into DMT monitor. 15' Bilinear coupling monitoring (Steve Penn) ---> Highlights: Interactive DMT BicoViewer has nifty new features (e.g., easy channel selection, expected resolution for frequency / time parameter choices). Also outputs gif files for easy "movie" viewing later with a script. Working on new heterodyning feature to allow fast zooms on artifacts. Background BicoMon monitor allows selection of particular frequency bands of interest. Nifty online demo followed by plea for beta testers and volunteers to use these tools for investigations. 10' LineAmp studies (Mike Ashley) Highlights: In heterodyning calibration lines for studying data quality, has found that good windowing makes a big difference. With compiled MATLAB code, can run over all S3 data in 45 minutes with 70 nodes. ---> Will work with Gaby and Xavi to see this through to producing refined DQ flags. 15' Study of the Output Mode-Cleaner prototype using the Phase Camera (Joe Betzwieser) Highlights: Described work to understand behavior of output mode cleaner that was tried out recently on H1 (recall poor noise behavior shown by Peter Fritschel). ---> Fairly simple modelling (that agrees well with measurements) confirms that behavior of transmitted light is explained primarily by astigmatism in the small triangular cavity and by small misalignment. 15' Identification and removal of limiting noise sources of GEO600 (Josh Smith) Highlights: GEO is now attacking noise sources at lower frequencies in a systematic campaign to understand present sensitivity limitations. Noise sources examined include: low laser power (2W/10W), laser amplitude fluctuations, oscillator phase noise, laser frequency noise, acoustic and air current disturbances, and scattered light. ---> Using a "noise projection" technique and many investigations, they have accounted for 50-70% of noise seen in band.