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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

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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


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


Physics goals
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


Externally triggered bursts search
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


Past research
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


Past research continued
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


Proposed research 2003 2006
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


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


Oregon Proposal, Jim Brau,

PAC, December 5, 2002


Oregon Proposal, Jim Brau,

PAC, December 5, 2002


http://apex.ligo-wa.caltech.edu/~roberts/PEMfrequencies.pdf

G010395-00-Z

Oregon Proposal, Jim Brau,

PAC, December 5, 2002


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


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


Nuclear power plant fans 36 cooling fans
Nuclear Power Plant Fans(36 cooling fans)

G000396-00-D

Oregon Proposal, Jim Brau,

PAC, December 5, 2002


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


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


Ii study and reduce the false coincidence rates between the three interferometers
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


Lightning strikes
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


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


Reduced data sets
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


Reduced data sets1
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


Proposal to expand activities to livingston
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


Advanced ligo
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


Newtonian noise limit

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


Summary
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


Oregon Proposal, Jim Brau,

PAC, December 5, 2002


Cosmic ray detectors
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


Cosmic ray detectors1
Cosmic Ray Detectors

Oregon Proposal, Jim Brau,

PAC, December 5, 2002


Hete location for xrf in s1
HETE location for XRF in S1

Oregon Proposal, Jim Brau,

PAC, December 5, 2002


Tuning pipeline

  • 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


Data analysis pipeline

  • 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


S1 document nearly complete
S1 Document nearly complete…

Oregon Proposal, Jim Brau,

PAC, December 5, 2002


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