Advanced LIGO project status: getting ready to listen to the universe Giacomo Ciani for the LIGO Scientific Collaboration LIGO- G1401371

Advanced LIGO project status:getting ready to listen to the universe

Giacomo Cianifor the

LIGO Scientific Collaboration

LIGO- G1401371

2Giacomo Ciani for the LSC LIGO-G1401371

• GW and laser interferometers

• Building and commissioning Advanced LIGO

• Near and far future in LIGO

• The GW detectors network

• Summary

Dec 19th, 2014 – CGC Conference in Fort Lauderdale

Overview


• Who says GWs exist?– Predicted by General Relativity– Hulse-Taylor: indirect evidence by binary pulsar

spin-down (Nobel Prize 1993)

• What are gravitational waves?– Ripple in space-time travelling at the speed of light

• Who creates GWs?– Mass distributions changing in a non-spherically

symmetric way (e.g. binary systems)

• What is their effect?– Relative change in lengths orthogonal to

propagation direction– The effect is VERY small: typical size


FAQs on gravitational waves

ΔL/L ~ 10-21

Giacomo Ciani for the LSC LIGO-G1401371 4

A whole orchestra on the stage


10-9 Hz 10-4 Hz 100 Hz 103 Hz

Relic radiationCosmic Strings

Supermassive BH Binaries

BH and NS Binaries

Binaries coalescences

Extreme Mass RatioInspirals

Supernovae

Spinning NS

??

???

?

10-16 Hz


And a microphone for everyone


10-9 Hz 10-4 Hz 100 Hz 103 Hz



BH and NS Binaries



Supernovae

Spinning NS

??

???

?

10-16 HzInflation Probe Pulsar timing Space detectors Ground interferometers


And a microphone for everyone


10-9 Hz 10-4 Hz 100 Hz 103 Hz



BH and NS Binaries



Supernovae

Spinning NS

??

???

?

10-16 HzInflation Probe Pulsar timing Space detectors Ground interferometers

See Laleh Sadeghian talk right after this

See Guido Mueller talk on Sunday


DL

P PD

• Inherently differential• Broad band• Long baseline


Laser interferometers and GWs

Laser

“+” polarized GW propagating

orthogonal to the screen

Simulated action!Not a real

gravitational wave

Phase: f = 4p (Lx – Ly) /l ~ DLPower: PPD = PBS sin2f


Caltech

MIT


Enhanced LIGO

Laser

4 km4 km

Laser:30W - 1064nm

Output mode cleaner:Reject junk light to clean signal on photodetector

DC Homodyne Readout

30kW30kW

Power Recycling Mirror:

Enhances effective input power

Input Mode Cleaner:Cleans the laser mode

and stabilize the frequency

Arm cavities:increase the number of photons probing

the GW strain

2 Locations3 interferometers

9Giacomo Ciani for the LSC LIGO-G1401371Dec 19th, 2014 – CGC Conference in Fort Lauderdale

Enhanced LIGO performance

Laser

4 km4 km

Laser:30W - 1064nm


DC Homodyne Readout

30kW30kW

Power Recycling Cavity:

enhances effective input power




the GW strain

102

103

10-23

10-22

Frequency [Hz]

h(f)

[H

z-1/2

]

NS-NS range: 15->20 Mpc

S5 – Initial LIGO best c

urve

S6 – Enhanced LIGO best curve


Enhanced LIGO

Laser

4 km4 km

Laser:30W - 1064nm


DC Homodyne Readout

30kW30kW

Power Recycling Cavity:

enhances effective input power




the GW strain

102

103

10-23

10-22

Frequency [Hz]

h(f)

[H

z-1/2

]

Factor 2-3 improvement

at high frequencies.NS-NS range: 15->20 Mpc

S5 – Initial LIGO best c

urve

S6 – Enhanced LIGO best curve

SHUT DOWN Q4/2010

What have we been doing since?


Data analysis and publications

• S5/S6 data have produced more than 30 papers in the last 3 years:– See http://www.ligo.org/science/outreach.php

• Several papers use joint data runs from LIGO and VIRGO

• Many of these papers involve other astronomy experiments/collaborations (multimessenger astronomy):– SWIFT– InterPlanetary Network– ANTARES– NINJA– Ground based optical, X-ray and radio telescopes– …

• S5 data has gone public: you can start you own search now! losc.ligo.org

http://www.ligo.org/science/outreach.php

http://www.ligo.org/science/outreach.php


Advanced LIGO designInput Laser Mirrors Topology Readout SensitivitySuspensions

iLIGO 10W(10 kW arm) 10 kg Power-Recycled

Fabry-PerotRF

etherodyne 3 10-23 Hz-1/2Single pendulum(LF cutoff ~40 Hz)

aLIGO 180W(>700 kW arm) 40 kg Dual-Recycled

Fabry-PerotDC

homodyne5 10-24 Hz-1/2

(tunable)Quadruple pendulum

(LF cutoff ~10 Hz)

Seismic isolation

Passive

Active

Routine detection not certain, but plausible!

• Design limited by fundamental noise: quantum, thermal• Improvement at low frequency (from 40 to 10 Hz)• 10x strain sensitivity 1000x observable volume (=rates)


• The plan: staggered installation– LLO/LHO to build and

commission different subsystem in parallel


Building Advanced LIGONow!




• Installation now complete:– Livingston: May 2014– Hanford: August 2014




Test mass coating pattern



• Installation now complete:– Livingston: May 2014– Hanford: August 2014

• Not without difficulties!– Cleanliness– Optical coatings– Vacuum system– …



LHO ETMsin 532 nm and

1064 nm laser light


• Commissioning work much faster than iLIGO:– Building on the experience of iLIGO– Better subsystems modeling and testing


The progress toward a science run



• First full IFO lock at Livingston: May 27th, 2014• Milestone 2+ hours full IFO lock May 29th, 2014






– Rapid improvement in the instrument noise (measured by NS-NS range)






– Rapid improvement in the instrument noise (measured by NS-NS range)

• LHO first full lock on December 3rd, 2014



Advanced LIGO broadband

CALIBRATION IS PRELIMINARY


• DAC major transition glitch

• TM cleanliness issues at LHO

• TM Charging:– Fluctuating charge on Test Masses– Developing discharge system based on

ionizer– But, charge comes back… ion pumps?

Green light?

• Suspected parametric instability observed at LLO:– Interaction between laser field higher

order modes and optics acoustic modes

– Can induce resonances high enough to break IFO lock

• What’s coming next?Dec 19th, 2014 – CGC Conference in Fort Lauderdale

Many challenges ahead


• Engineering run (ER6) ongoing at LLO• Working towards 2 hours full lock at Hanford• Ongoing commissioning• First coincident Engineering Run: early 2015?

• First coincident Observation Run: late 2015?


The near future

Currently investigating loss (cleanliness?) issues

We could be listening to the universe!


• Will need to find a balance between commissioning and observation time• A possible scenario:


Balancing times

2015: > 3 month run, 40 - 80 MpcPossible Detection

2016-17: > 6 month run, 80 - 120 MpcLikely Detection

2017-18: > 9 month run, 120 - 170 MpcMulitple Detections

Initial LIGO, 15 Mpc


…and beyond

• R&D for (minor) upgrades to aLIGO (before 2020?):– Advanced (crystalline) optical

coatings– squeezed light, filter cavities– longer suspensions

• Consolidating ideas and designs for major upgrades (using current facilities):– Cryogenics– silicon optics– 1550 nm lasers– Seismometers array for Newtonian

noise subtraction– Straw man design study

• Brainstorming about next generation (new facilities needed)

Photon Statistics SNR ~ √PLaser

Photon Statistics SNR ~ 1/√PLaser

DissipativeDynamics


In the meanwhile around the world…


aLIGO Hanford~2015

aLIGO Livingston~2015




aLIGO Hanford~2015


LIGO India2022?

?


• Proposal: move one of the two Hanford detectors to India

– LIGO to provide detector components, assistance for installation and commissioning

– India to provide infrastructures, personnel and operations

• Advantages:– Improved sky localization– Reduced downtime

• Status:– Site selection reduced to 3 (final

recommendation expected by spring 2015)

– National Science Board cleared NSF to approve the project

– Installment of new government in India halted approval process (could resume before the end of the year)

• If everything goes well, LIGO India could come online in 2022Dec 19th, 2014 – CGC Conference in Fort Lauderdale

LIGO India




aLIGO Hanford~2015


AdVIRGO~2016

LIGO India2022?

?


• Located in Italy• Operated by European

Consortium• 3 km arm length• Similar design to aLIGO:

– unique SuperAttenuator suspensions


Advanced VIRGO

28

• Subsystems commissioning under way:

• Laser delivering 45W• IMC locked June 2014

• Construction end: fall 2015• Could be ready for science

run in 2016




aLIGO Hanford~2015


AdVIRGO~2016

KAGRA2020

LIGO India2022?

?


• Located in Kamioka mines, Japan

• 3 km arm length• Pioneering in next

generation technologies:– Underground – Cryogenics– Alternative materials


Other detectors: KAGRA

• Facilities almost completed

• Three stages plan• iKAGRA (~4 Mpc)

by 2016• Intermediate (~20

Mpc) by 2018• Final bKAGRA (140

Mpc) by 2020




aLIGO Hanford~2015


AdVIRGO~2016

GEO600Now!

KAGRA2020

LIGO India2022?

?


• Locate in Hannover, Germany• Part of the LIGO collaboration• 600 m baseline

– Limited sensitivity at low frequencies• Very high duty cycle• Pioneers advanced techniques:

– Squeezing– Signal recycling– Thermal compensation– Automation– More…

• The only listener until 2015!


Other detectors: GEO HF




aLIGO Hanford~2015


AdVIRGO~2016

GEO600Now!

KAGRA2020

Increased detection confidence (coincidence runs)

Reduced downtime

Enhanced sky coverage Better and faster source localization

More reliable source parameters estimation

LIGO India2022?

?


• The initial generation of GW interferometer has been a success (despite no detection)

• Advanced LIGO is progressing fast towards goal sensitivity:– Could be listening to the GW sky in less than a year!

• Other advanced GW detectors around the world to join 1-2 years after

• We expect/hope to be doing full fledged GW astronomy by the end of the decade!


Summary


Additional slides


Who’s making noise?


Laser

Amplitude and frequency noise

Residual gas

Seismic noise

Shot noise

Radiation pressure


iLIGO strain sensitivity


Size of anH nucleus!

NowInauguration First Lock Full Lock all IFO

4K strain noise

@150 Hz [Hz-1/2]

3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4

1999 2000 2001 2002 2003 2004 2005 2006

1 2 3 4

2007

1 2 3 4

2008

1 2 3 4

2009

1 2 3 4

2010

1 2 3 4

2011

Design Sensitivity

10-17 10-18 10-20 10-21 10-22 3x10-23

Enhanced LIGO

Seismic noise (displacement): mechanical vibration of the ground transmitted to the mirror through the pendulum chain

Suspension thermal (displacement): thermal agitation induce noise in mirror motion

Shot noise (detection): random arrival of photons creates noise at high frequencies

Documents

Advanced LIGO project status: getting ready to listen to the universe Giacomo Ciani for the LIGO Scientific Collaboration LIGO- G1401371