1 / 32

Jim Brau Univ. of Oregon December 5, 2002

Oregon Proposal for LIGO Research. Jim Brau Univ. of Oregon December 5, 2002. LSC collaborator since formation of LSC in 1997 Research aimed at search for burst sources of gravity waves Recognize identification and amelioration of noise sources is prerequisite

lassie
Download Presentation

Jim Brau Univ. of Oregon December 5, 2002

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Oregon Proposal for LIGO Research Jim Brau Univ. of Oregon December 5, 2002 LSC collaborator since formation of LSC in 1997 Research aimed at search for burst sources of gravity waves Recognize identification and amelioration of noise sources is prerequisite (principal focus of Oregon effort) Future effort will build on our energetic engagement in LIGO “shake-down” Expand effort in data analysis most connected to our past involvements, and consistent with our astrophysical goals Oregon Proposal, Jim Brau, PAC, December 5, 2002

  2. Oregon LIGO Group Faculty: Jim Brau Ray Frey David Strom Research associates: Isabel Leonor Robert Schofield (1/2 time at LHO) Nikolai Sinev Graduate students: Masahiro Ito (full time at LHO) Rauha Rahkola (full time at LHO last yr, 1/2 time at LHO now) Brian Stubbs Oregon Proposal, Jim Brau, PAC, December 5, 2002

  3. PHYSICS GOALS • Gravitational Wave Bursts • externally triggered searches and untriggered searches • Gamma Ray Bursts are prototypical (although likely too distant) • we are looking • In order to develop our ability to find GW bursts in the data stream, we were drawn to the Physics Environment Monitoring, where many potential sources of burst backgrounds appear Oregon Proposal, Jim Brau, PAC, December 5, 2002

  4. Externally-triggered Bursts Search • R. Rahkoladeveloped ETG (aka DSO) which applies statistical method of Finn, Mohanty, and Romano: compare on-source and off-source distributions of cross-correlation statistic • Tested with E7 playground data • Applied to S1 • Only one event in S1 coincident with LLO*LHO • HETE X-Ray flare • Currently finalizing S1 search write-up for Bursts UL group • Preparing for S2 Oregon Proposal, Jim Brau, PAC, December 5, 2002

  5. Past Research • Assisted in setting up the Physics Environment Monitoring System (PEM) • Identified, studied, and helped reduce sources of environmental coupling to the interferometers • magnetic fields, seismic signals, acoustic, radio frequency, weather, developed cosmic ray detector • Investigated between-site environmental correlations • Developed data analysis, monitoring and distribution software • Produced veto monitors (continued) Oregon Proposal, Jim Brau, PAC, December 5, 2002

  6. Past Research(continued) • Contributed to Advanced LIGO • Performed numerous commissioning activities • Shift participation (manned about 1/5 of LHO) • S1 detector characterization investigations • 13 LSC investigations • 6 lead or co-lead by Oregon physicists • Glitches (rates, causes) M. Ito • Quantify correlated enviromental transients between sites R. Schofield, R. Frey • Identify & catalog environmental disturbances R. Schofield, R. Rahkola • Data quality R. Rahkola, R. Schofield • Data set reduction I. Leonor • Hardware astrophysical signal injection I. Leonor Oregon Proposal, Jim Brau, PAC, December 5, 2002

  7. Proposed Research(2003-2006) I. Improve Sensitivity and Decrease False Detection Rates at Individual Interferometers by Reducing Environmental Influences II. Study and Reduce the False Coincidence Rates Between the Three Interferometers III. Develop Astrophysical Analysis Methods, Data Quality Monitoring Tools, and Methods for Data Distribution • continuation of past investigations • expand activities to Livingston • contribute in many areas of our activity to development of Advanced LIGO Oregon Proposal, Jim Brau, PAC, December 5, 2002

  8. I. Improve Sensitivity and Decrease False Detection Rates at Individual Interferometers by Reducing Environmental Influences • Identify specific sources • internal sources • e.g. Periscope, office air handler, PSL table legs, test mass controller fans • external sources • e.g. Nuclear power plant fans, trucks • Reduce environmental coupling Oregon Proposal, Jim Brau, PAC, December 5, 2002

  9. Oregon Proposal, Jim Brau, PAC, December 5, 2002

  10. Oregon Proposal, Jim Brau, PAC, December 5, 2002

  11. http://apex.ligo-wa.caltech.edu/~roberts/PEMfrequencies.pdf G010395-00-Z Oregon Proposal, Jim Brau, PAC, December 5, 2002

  12. I. Improve Sensitivity and Decrease False Detection Rates at Individual Interferometers by Reducing Environmental Influences • Identify specific sources - internal sources • e.g. Periscope, office air handler, PSL table legs, test mass controller fans AS_Q G000396-00-D Oregon Proposal, Jim Brau, PAC, December 5, 2002

  13. I. Improve Sensitivity and Decrease False Detection Rates at Individual Interferometers by Reducing Environmental Influences • Identify specific sources - external sources • e.g. Nuclear power plant fans, trucks Peak at 2.295 Hz responsible for 20% of RMS is 4k mode cleaner control (MC_F) Effect reduced by resonant gain stage, but still responsible for several percent of RMS of HAM2 coils. What is the source? Mobile seismometer suggests cooling towers at ENW nuclear power plant G000396-00-D Oregon Proposal, Jim Brau, PAC, December 5, 2002

  14. Nuclear Power Plant Fans(36 cooling fans) G000396-00-D Oregon Proposal, Jim Brau, PAC, December 5, 2002

  15. I. Improve Sensitivity and Decrease False Detection Rates at Individual Interferometers by Reducing Environmental Influences • Identify specific sources - external sources • e.g. Nuclear power plant fans, trucks G000262-00-D Oregon Proposal, Jim Brau, PAC, December 5, 2002

  16. I. Improve Sensitivity and Decrease False Detection Rates at Individual Interferometers by Reducing Environmental Influences • Acoustic coupling (resulting from test bursts) • acoustic coupling at two different locations during S1, demonstrating the need for PEM vetoes H2:LSC-AS_Q H2:LSC-AS_Q H0:PEM-HAM10_MIC H0:PEM-PSL2_MIC elog-08/23/2002-16:26 Oregon Proposal, Jim Brau, PAC, December 5, 2002

  17. II. Study and Reduce the False Coincidence Rates Between the Three Interferometers • Monitor inter-site environmental correlations • e.g. Lightning strikes are potential sources • Characterize the false coincidence rate between the two Hanford interferometers • Many mechanisms reduce independence of Hanford interferometers Oregon Proposal, Jim Brau, PAC, December 5, 2002

  18. Lightning Strikes • Stand alone code developed to search for intersite events by locating coincidences in 15 ms window for aligned and misaligned time series • High rate of intersite bursts on coil magnetometer (probably lightning) • No detection on voltage monitors, seismometers, MC_F, fluxgate magnetometers • No evidence on other channels • studies are continuing G020253-00-Z Oregon Proposal, Jim Brau, PAC, December 5, 2002

  19. III. Develop Astrophysical Analysis Methods, Data Quality Monitoring Tools, and Methods for Data Distribution • Reduced Data Sets • Externally triggered burst search analysis code • Glitch detectors and other monitors • e.g. glitchMon, absGlitch • Event processing and coincidence analysis tools • e.g. EventTool Oregon Proposal, Jim Brau, PAC, December 5, 2002

  20. Reduced Data Sets Working closely with LDAS team to develop effective RDS http://darkwing.uoregon.edu/ ~ileonor/ligo/s1/rds/ s1rds.html • 5-fold reduction in total S1 data volume from channel selection and downsampling • 22-fold reduction in total number of channels • channel list will be refined for future science runs; goal is to reduce data volume by factor for ten or more • studies were done on the feasibility of performing resampling on frame data using a linear filter and correcting for the time delay before saving resampled data in frame format, so that unwanted filtering effects are transparent to the end user • (see http://darkwing.uoregon.edu/~ileonor/rds/ligords_0201.pdf) Oregon Proposal, Jim Brau, PAC, December 5, 2002

  21. Reduced Data Sets Gain in access time by RDS for 640 seconds of data and 1280 seconds of data Oregon Proposal, Jim Brau, PAC, December 5, 2002

  22. Proposal to Expand Activities to Livingston • New postdoctoral research associate at LLO working closely with R. Schofield at Hanford • Measure magnetic, acoustic, seismic, and RF coupling at all three Livingston stations • Work to reduce coupling • Work with local staff to expand environmental monitoring, as planned at Hanford • Other work outlined in proposal Oregon Proposal, Jim Brau, PAC, December 5, 2002

  23. Advanced LIGO • Many proposed activities contribute to Advanced LIGO, as have our past efforts: • Showed that Newtonian noise may limit the sensitivity of Advanced LIGO below 10 Hz (T010074-03-D). • Measured statistics of earthquake motion for planning of Advanced LIGO control system (G010017-00-1). • Contributed extensively to the environmental assessment for Advanced LIGO (T010074-03-D). • Measured ambient magnetic fields, transfer functions to vacuum chambers, and coupling to the interferometer (G990079-29-M). Oregon Proposal, Jim Brau, PAC, December 5, 2002

  24. Hughes & Thorne Schofield Newtonian Noise Limit • 3 - 10 Hz based on typical truck traffic excitation at Yend station, anisotropy ratio of 1, and an assumption of fund. Rayleigh and Love modes (propagation velocity of 450 m/sec) • 20 - 30 Hz based on measurements in the LVEA with minimum equipment operating (no 4k racks at that time), and assumed a Raleigh mode T010074-03-D Oregon Proposal, Jim Brau, PAC, December 5, 2002

  25. Summary Oregon Research aimed at search for burst sources of gravity waves I. Improve Sensitivity and Decrease False Detection Rates at Individual Interferometers by Reducing Environmental Influences II. Study and Reduce the False Coincidence Rates Between the Three Interferometers III. Develop Astrophysical Analysis Methods, Data Quality Monitoring Tools, and Methods for Data Distribution Expand effort to Livingston Build on our energetic engagement in LIGO “shake-down” I have shown a sampling of studies by the Oregon group Please refer to the proposal for a complete list Oregon Proposal, Jim Brau, PAC, December 5, 2002

  26. Extra transparencies follow Oregon Proposal, Jim Brau, PAC, December 5, 2002

  27. Cosmic Ray Detectors A very energetic cosmic ray shower incident on a test mass could, in principle, create a background to gravity wave searches. The two mechanisms usually considered are (1) the transfer of the particle momenta (impulse) to the test mass; (2) the loss of particle energy resulting in internal-mode excitations within the test mass. A. Marin, “Cosmic Muon Signature in LIGO,” 1998. Estimates place the effects of cosmic rays to be a few orders of magnitude below LIGO sensitivity. Still, it is important to have an independent monitor check estimates and confirm size for Advanced LIGO Oregon Proposal, Jim Brau, PAC, December 5, 2002

  28. Cosmic Ray Detectors Oregon Proposal, Jim Brau, PAC, December 5, 2002

  29. HETE location for XRF in S1 Oregon Proposal, Jim Brau, PAC, December 5, 2002

  30. Input: • sets of representative data excluding lock stretch containing astrophysical trigger • approximate calibration transfer function Validating Data Conditioning • Time-domain conditioning • Split Hanning Window • Approximate Calibration Filter Are the c.c. distributions stationary? List of frequency regions to be removed (start with 60Hz harmonics) • Input: • sets of data within lock stretch– but excluding surrounding ± 2 hours– containing astrophysical trigger • Fourier-domain conditioning • Frequency-region removal Baseline Data Conditioning • Time-domain conditioning • Split hanning window • Approximate calibration filter • 2nd Time-domain conditioning • Bandpass filter • Extract middle of data Tuning the Data Conditioning Add non-stationary frequency regions to list • Fourier-domain conditioning • Frequency-region removal Compare spectra of “best” and “worst” distributions • 2nd Time-domain conditioning • Bandpass filter • Extract middle of data No 1st Yes 2nd Yes Output: Final data conditioning routine for Data Analysis pipeline Create c.c. statistic distributions for all data sets Create c.c. statistic distributions for all data sets Tuning Pipeline Oregon Proposal, Jim Brau, PAC, December 5, 2002

  31. Input: • Astrophysical trigger time, source direction • Conditioned, approximately calibrated data within lock stretch containing astrophysical trigger (excluding data used in Tuning Pipeline) • Simulated bursts (white noise, 1ms Gaussian) of known strain, conditioned like data Upper Limit on hrms (Statistical Method) Account for data conditioning (missing frequencies) by proportionality factor Upper Limit on hrms (Method of Injections) Upper Limit on C.C. Statistic Choose a burst of known strain Create ‘off-source’ distribution of c.c. statistics - times not associated with trigger - close enough for data to be stationary Create ‘off-source’ distribution with injected bursts Is the distribution mean just outside the F-C upper limit? Calculate ‘on-source’ statistic - time associated with trigger - time delay calculated from trigger source direction, timestamp Modify injected burst’s amplitude appropriately No Yes Determine significance of ‘on-source’ c.c. statistic (upper limit) using Feldman-Cousins, table X Upper limit applies to simulated burst type only Data Analysis Pipeline Oregon Proposal, Jim Brau, PAC, December 5, 2002

  32. S1 Document nearly complete… Oregon Proposal, Jim Brau, PAC, December 5, 2002

More Related