LIGO-India
An Indo-US joint mega-project concept proposal
IndIGO Consortium
(Indian Initiative in Gravitational-wave Observations)
www.gw-indigo.org
Version: pII_v1 Jun 20, 2011 : TS
Detecting GW with Laser Interferometer
LIGO Optical Configuration
Power Recycled
Michelson
Interferometer
end test mass
Light bounces back and
forth along arms about
100 times
with Fabry-Perot Arm
Cavities
Light is “recycled”
about 50 times
input test mass
Laser
signal
beam splitter
Difference in distance of Paths  Interference of laser
light at the detector (Photodiode)
Courtesy: Stan Whitcomb
Initial LIGO Sensitivity Goal
• Strain sensitivity
<3x10-23 1/Hz1/2
at 200 Hz
l
Sensor Noise
» Photon Shot Noise
» Residual Gas
l
Displacement Noise
» Seismic motion
» Thermal Noise
» Radiation Pressure
3
LIGO and Virgo TODAY
Milestone: Decades-old plans to build and operate large interferometric GW detectors now
realized at several locations worldwide
Experimental prowess: LIGO, VIRGO operating at predicted sensitivity!!!!
Pre-dawn GW astronomy : Unprecedented sensitivity already allows
• Upper Limits on GW from a variety of Astrophysical sources. Refining theoretical
modelling
• Improve on Spin down of Crab, Vela pulsars,
• Exptally surpass Big Bang nucleosynthesis bound on Stochastic GW..
Laser Interferometer Gravitational-wave
Observatory (LIGO)
IndIGO - ACIGA meeting
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Advanced LIGO
•Take advantage of new technologies and on-going R&D
>> Active anti-seismic system operating to lower frequencies:
(Stanford, LIGO)
>> Lower thermal noise suspensions and optics :
(GEO )
>> Higher laser power 10 W  180 W
(Hannover group, Germany)
>> More sensitive and more flexible optical configuration:
Signal recycling
• Design: 1999 – 2010 : 10 years of high end R & D internationally.
• Construction: Start 2008; Installation 2011; Completion 2015
Schematic Optical Design of Advanced LIGO detectors
Reflects International cooperation
Basic nature of GW Astronomy
LASER
AEI, Hannover
Germany
Suspension
GEO, UK
“Quantum measurements”
to improve further via squeezed light:
• New ground for optical technologists in India
• High Potential to draw the best Indian UG
students typically interested in theoretical
physics into experimental science !!!
Advanced LIGO Laser
• Designed and contributed by Albert Einstein Institute<
Germany
• Higher power
– 10W -> 180W
• Better stability
– 10x improvement in intensity and frequency stability
Courtesy: Stan Whitcomb
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Advanced LIGO Mirrors
• Larger size
– 11 kg -> 40 kg
• Smaller figure error
– 0.7 nm -> 0.35 nm
• Lower absorption
– 2 ppm -> 0.5 ppm
• Lower coating thermal noise
•
•
•
All substrates delivered
Polishing underway
Reflective Coating process starting up
Courtesy: Stan Whitcomb
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Advanced LIGO Seismic Isolation
• Two-stage six-degree-of-freedom active isolation
– Low noise sensors, Low noise actuators
– Digital control system to blend outputs of multiple sensors,
tailor loop for maximum performance
– Low frequency cut-off: 40 Hz -> 10 Hz
Courtesy: Stan Whitcomb
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Advanced LIGO Suspensions
• UK designed and contributed
test mass suspensions
• Silicate bonds create quasimonolithic pendulums using
ultra-low loss fused silica fibres
to suspend interferometer optics
– Pendulum
Q ~105 -> ~108
four stages
Suppression at 10 Hz : ?
at 1 Hz : ?
40 kg silica test
mass
Courtesy: Stan Whitcomb
12
12
Scientific Payoffs
Advanced GW network sensitivity needed to observe
GW signals at monthly or even weekly rates.
• Direct detection of GW probes strong field regime of gravitation
 Information about systems in which strong-field and time dependent gravitation
dominates, an untested regime including non-linear self-interactions
• GW detectors will uncover NEW aspects of the physics
 Sources at extreme physical conditions (eg., super nuclear density physics), relativistic
motions, extreme high density, temperature and magnetic fields.
• GW signals propagate un-attenuated
weak but clean signal from cores of astrophysical event where EM signal is screened by
ionized matter.
• Wide range of frequencies  Sensitivity over a range of astrophysical scales
To capitalize one needs a global array of GW antennas separated by
continental distances to pinpoint sources in the sky and extract all the
source information encoded in the GW signals
LIGO-India: Why is it a good idea?
… for the World
• Strategic geographical relocation for GW astronomy
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Improved duty cycle
Detection confidence
Improved Sky Coverage
Improved Location of Sources required for multi-messenger astronomy
Determine the two polarizations of GW
• Potentially large science community in future
– Indian demographics: youth dominated – need challenges
– excellent UG education system already produces large number of trained
in India find frontline research opportunity at home.
• Large data analysis trained manpower and facilities exist (and
being created).
LIGO-India: Why is it a good idea? …for India
• Have a 20 year legacy and wide recognition in the Intl. GW community with
seminal contributions to Source modeling (RRI)& Data Analysis (IUCAA). High
precision measurements (TIFR), Participation in LHC (RRCAT)
Would not make it to the GWIC report, otherwise!
–
LIGO/ACIGA/EGO strong interest in fostering Indian community
– GWIC invitation to IndIGO join as member (July 2011)
• Provides an exciting challenge at an International forefront of experimental
science. Can tap and siphon back the extremely good UG students trained in
India. (Sole cause of `brain drain’).
– 1st yr summer intern 2010  MIT for PhD
– Indian experimental scientist  Postdoc at LIGO training for Adv. LIGO subsystem
• Indian experimental expertise related to GW observatories will thrive and attain
high levels due to LIGO-India.
– Sendhil Raja, RRCAT, Anil Prabhakar, EE, IIT Madras, Pradeep Kumar, EE, IITK Photonics
– Vacuum expertise with RRCAT (S.K. Shukla, A.S. Raja Rao) , IPR (S.K. Bhatt, Ajai Kumar)
• Jump start direct participation in GW observations/astronomy
going beyond analysis methodology & theoretical prediction --- to full fledged participation in
experiment, data acquisition, analysis and astronomy results.
• For once, perfect time to a launch into a promising field (GW astronomy)
with high end technological spinoffs, well before it has obviously blossomed.
“Once in a generation opportunity to host an Unique, path defining,
International Experiment in India .”
LIGO-India: Salient points of this megaproject
• On Indian Soil will draw and retain science & tech. manpower
• International Cooperation, not competition LIGO-India success critical to the success
of the global GW science effort. Complete Intl support
• Shared science risk with International community 
Shared historical, major science discovery credit !!!
• AdvLIGO setup & initial challenge/risks primarily rests with USA.
– AdvLIGO-USA precedes LIGO-India by > 2 years.
– India sign up for technically demonstrated/established part (>10 yr of operation in initial LIGO ) 
2/3 vacuum enclosure + 1/3 detector assembly split (US ‘costing’ : manpower and h/ware costs)
– However, allows Indian scientist to collaborate on highly interesting science & technical challenges
of Advanced LIGO-USA ( ***opportunity without primary responsibility***)
• Expenditure almost completely in Indian labs & Industry huge potential for
landmark technical upgrade in all related Indian Industry
• Well defined training plan
core Indian technical team thru Indian postdoc in related exptal areas
participation in advLIGO-USA installation and commissioning phase, cascade to training at Indian expt. centers
• Major data analysis centre for the entire LIGO network with huge potential
for widespread University sector engagement.
• US hardware contribution funded & ready advLIGO largest NSF project, LIGOIndia needs NSF approval but not additional funds
LIGO-India: unique once-in-a-generation opportunity
LIGO labs LIGO-India
• 180 W pre-stabilized Nd:YAG laser
• 10 interferometer core optics (test masses, folding mirrors, beam splitter, recycling mirrors)
• Input condition optics, including electro-optic modulators, Faraday isolators, a suspended mode-cleaner (12-m
long mode-defining cavity), and suspended mode-matching telescope optics.
• 5 "BSC chamber" seismic isolation systems (two stage, six degree of freedom, active isolation stages
capable of ~200 kg payloads)
• 6 "HAM Chamber" seismic isolation systems (one stage, six degree of freedom, active isolation stages
capable of ~200 kg payloads)
• 11 Hydraulic External Pre-Isolation systems
• Five quadruple stage large optics suspensions systems
• Triple stage suspensions for remaining suspended optics
• Baffles and beam dumps for controlling scattering and stray radiation
• Optical distortion monitors and thermal control/compensation system for large optics
• Photo-detectors, conditioning electronics, actuation electronics and conditioning
• Data conditioning and acquisition system, software for data acquisition
• Supervisory control and monitoring system, software for all control systems
• Installation tooling and fixturing
LIGO-India vs. Indian-IGO ?
Primary advantage: LIGO-India Provides cutting edge instrumentation &
technology to jump start GW detection and astronomy.
Would require at least a decade of focused & sustained technology developments
in Indian laboratories and industry
•
180 W Nd:YAG: 5 years;
– Operation and maintenance should benefit further development in narrow line width lasers.
– Applications in high resolution spectroscopy,
– precision interferometry and metrology.
• Input condition optics..Expensive..No Indian manufacturer with such specs
• Seismic isolation (BCE,HAM) .. Minimum 2 of years of expt and R&D.
– Experience in setting up and maintaining these systems  know how for
isolation in critical experiments such as in optical metrology,
AFM/Microscopy, gravity experiments etc.
• 10 interferometer core optics.. manufacturing optics of this quality and
develop required metrology facility : At least 5 to 7 years of
dedicated R&D work in optical polishing, figuring and metrology.
• Five quadruple stage large optics suspensions systems.. 3-4 years of
development.. Not trivial to implement.
– Benefit other physics experiments working at the quantum limit of noise.
LIGO-India: Expected Indian Contribution
• Indian contribution in infrastructure:
 Site (L-configuration: Each 50-100 m x 4.2 km)
 Vacuum system
 Related Controls
 Data centre
• Indian contribution in human resources:
 Trained manpower for installation and commissioning
 Trained manpower for LIGO-India operations for 10 years
 Simulation and Data Analysis teams
Science Payoffs
New Astronomy, New Astrophysics, New Cosmology, New Physics
” A New Window ushers a New Era of Exploration in Physics & Astronomy”
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Testing Einstein’s GR in strong and time-varying fields
Testing Black Hole phenomena
Understanding nuclear matter by Neutron star EOS
Neutron star coalescence events
Understanding most energetic cosmic events ..Supernovae, Gamma-ray bursts,
LMXB’s, Magnetars
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New cosmology..SMBHB’s as standard sirens..EOS of Dark Energy
Phase transition related to fundamental unification of forces
Multi-messenger astronomy
The Unexpected !!!!!
Technology Payoffs
• Lasers and optics..Purest laser light..Low phase noise, excellent
beam quality, high single frequency power
• Applications in precision metrology, medicine, micro-machining
• Coherent laser radar and strain sensors for earthquake prediction
and other precision metrology
• Surface accuracy of mirrors 100 times better than telescope
mirrors..Ultra-high reflective coatings : New technology for other fields
• Vibration Isolation and suspension..Applications for mineral prospecting
• Squeezing and challenging “quantum limits” in measurements.
• Ultra-high vacuum system 10^-9 tor (1picomHg). Beyond best in the
region
• Computation Challenges: Cloud computing, Grid computing, new
hardware and software tools for computational innovation.
Rewards and spinoffs
Detection of GW is the epitome of breakthrough science!!!
• LIGO-India  India could become a partner in international
science of Nobel Prize significance
• GW detection is an instrument technology intensive field pushing
frontiers simultaneously in a number of fields like lasers and
photonics. Impact allied areas and smart industries.
• The imperative need to work closely with industry and other end
users will lead to spinoffs as GW scientists further develop optical
sensor technology.
• Presence of LIGO-India will lead to pushing technologies and greater
innovation in the future.
• The largest UHV system will provide industry a challenge and
experience.
… rewards and spinoffs
• LIGO-India will raise public/citizen profile of science since it
will be making ongoing discoveries fascinating the young.
GR, BH, EU and Einstein have a special attraction and a pioneering facility in India
participating in important discoveries will provide science & technology role
models with high visibility and media interest.
• LIGO has a strong outreach tradition and LIGO-India will
provide a platform to increase it and synergetically benefit.
• Increase number of research groups performing at world
class levels and produce skilled researchers.
• Increase international collaborations in Indian research &
establishing Science Leadership in the Asia-Pacific region.
LIGO-India: … the challenges
Organizational
 National level DST-DAE Consortium Flagship Mega-project
 Identify a lead institution and agency
 Project leader
Construction: Substantial Engg project building Indian capability in large
vacuum system engg, welding techniques and technology
 Complex Project must be well-coordinated and effectively carried out
in time and meeting the almost zero-tolerance specs
Train manpower for installation & commissioning
 Generate & sustain manpower running for 10 years.
 Site
 short lead time
 International competition (LIGO-Argentina ??)
Technical
 vacuum system
 Related Controls
 Data centre
LIGO-India: … the challenges
Trained Manpower for installation & commissioning
LIGO-India Director
Project manager
Project engineering staff:
Civil engineer(s)
Vacuum engineer(s)
Systems engineer(s),
Mechanical engineers
Electronics engineers
Software engineers
Detector leader
Project system engineer
Detector subsystem leaders
10 talented scientists or research engineers
with interest and knowledge collectively spanning:
Lasers and optical devices, Optical metrology, handling and cleaning,
Precision mechanical structures, Low noise electronics, Digital control systems
and electro-mechanical servo design, Vacuum cleaning and handling)
Logistics and Preliminary Plan
• Assumption: Project taken up by DAE as a National Mega
Flagship Project.
All the persons mentioned who are currently working in their centers would be mainly in a
supervisory role of working on the project during the installation phase and training manpower
recruited under the project who would then transition into the operating staff.
• Instrument Engineering: No manpower required for design and
development activity. For installation and commissioning phase
and subsequent operation
• Laser ITF: Unnikrishnan, Sendhil Raja, Anil Prabhaker.
TIFR, RRCAT, IITM. 10 Post-doc/Ph.D students. Over 2-3 years.
Spend a year at Advanced LIGO. 6 full time engineers and
scientists. If project sanctioned, manpower sanctioned, LIGOIndia project hiring at RRCAT, TIFR, other insitututions/Labs.
Large scale ultra-high Vacuum enclosure
S.K. Shukla (RRCAT),A.S. Raja Rao (ex RRCAT),
S. Bhatt (IPR), Ajai Kumar (IPR)
•To be fabricated by IndIGO with designs from LIGO. A pumped volume of
10000m3 (10Mega-litres), evacuated to an ultra high vacuum of 10-9 torr
(pico-m Hg).
o Spiral welded beam tubes 1.2m in diameter and 20m length.
o Butt welding of 20m tubes together to 200m length.
o Butt welding of expansion bellows between 200m tubes.
o Gate valves of 1m aperture at the 4km tube ends and the middle.
o Optics tanks, to house the end mirrors and beam splitter/power and signal
recycling optics vacuum pumps.
o Gate valves and peripheral vacuum components.
o Baking and leak checking
Large scale ultra-high Vacuum enclosure
• 5 Engineers and 5 technicians
o Oversee the procurement & fabrication of the vacuum system
components and its installation.
o If the project is taken up by DAE then participation of RRCAT & IPR is more
intense
o All vacuum components such as flanges, gate-valves, pumps, residual gas
analyzers and leak detectors will be bought. Companies L&T, Fullinger,
HindHiVac, Godrej with support from RRCAT, IPR and LIGO Lab.
• Preliminary detailed discussions in Feb 2011 : companies like HHV,
Fullinger in consultation with Stan Whitcomb (LIGO), D. Blair (ACIGA) since this
was a major IndIGO deliverable to LIGO-Australia.
• Preliminary Costing for LIGO-India (vacuum component 400 cr)
Ultra-high Vacuum enclosure pictures
Logistics and Preliminary Plans
42 persons (10 PhD/postdocs, 22 scientists/engineers and 10 technicians)
• Mobile Clean rooms:
– Movable tent type clean rooms during welding of the beam tubes and assembly of the
system. Final building a clean room with AC and pressurization modules. SAC, ISRO. 1
engineer and 2 technicians to draw specs for the clean room equipments & installation.
• Vibration isolation system: 2 engineers (precision mechanical)
– install and maintain the system. Sourced from BARC. RED (Reactor Engineering
Division of BARC) has a group that works on vibration measurement, analysis and
control in reactors and turbo machinery.
• Electronic Control System: 4 Engineers
– install and maintain the electronics control and data acquisition system.
Electronics & Instrumentation Group at BARC (G. P. Shrivastava’s group) and
RRCAT.
– Preliminary training:six months at LIGO. Primary responsibility (installing and
running the electronics control and data acquisition system): RRCAT & BARC.
Additional activity for LIGO-India can be factored in XII plan if the approvals
come in early.
… Logistics and Preliminary Plans
Teams at Electronics & Instrumentation Groups at BARC may be interested
in large instrumentation projects in XII plan.
• Control software Interface: 2 Engineers
– install and maintain the computer software interface, distributed
networking and control system). RRCAT and BARC. Computer software
interface (part of the data acquisition system) and is the “Humanmachine-interface” for the interferometer. For seamless
implementation man power to be sourced from teams implementing
Electronic Control System.
• Site Selection & Civil Construction
– BARC Seismology Division Data reg. seismic noise at various DAE sites
to do initial selection of sites and shortlist based on other
considerations such as accessibility and remoteness from road traffic
etc. DAE: Directorate of Construction, services and Estate Management
(DCSEM): Co-ordinate design and construction of the required civil
structures required for the ITF. 2 engineers + 3 technicians (design &
supervision of constructions at site). Construction contracted to
private construction firm under supervision of DCSEM.
LIGO-India: … the challenges
Manpower generation for sustenance of the LIGO-India observatory : Preliminary
Plans & exploration
• Since Advanced LIGO will have a lead time, participants will be identified
who will be deputed to take part in the commissioning of Advanced LIGO and
later bring in the experience to LIGO-India
• Successful IndIGO Summer internships in International labs underway
o High UG applications 30/40 each year from IIT, IISER, NISERS,..
o 2 summers, 10 students, 1 starting PhD at LIGO-MIT
o Plan to extend to participating National labs to generate more experimenters
• IndIGO schools are planned annually to expose students to emerging opportunity in GW
science
o 1st IndIGO school in Dec 2010 in Delhi Univ. (thru IUCAA)
• Post graduate school specialization courses , or more
Jayant Narlikar: “Since sophisticated technology is involved IndIGO should like
ISRO or BARC training school set up a program where after successful
completion of the training, jobs are assured.”
Indian Site
LIGO-India: … the challenges
Requirements:
• Low seismicity
• Low human generated noise
• Air connectivity,
• Proximity to Academic institution, labs, industry
Preliminary exploration:
IISc new campus & adjoining campuses near Chitra Durga
• low seismicity
• 1hr from Intl airport
• Bangalore: science & tech hub
• National science facilities complex plans
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LIGO-India: Action points
If accepted as a National Flagship Mega Project under
the 12th plan then…
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Seed Money
Identification of 3-6 project leaders
Detailed Project Proposal
Site identification
1st Staffing Requirement meeting Aug 1-15
2nd Joint Staffing Meeting with LIGO-Lab
Vacuum Task related team and plans
Concluding remarks on LIGO India
• Home ground advantage !!! Once in a generation opportunity
• Threshold of discovery and launch of a new observational window
in human history!! Century after Einstein GR, 40 yrs of Herculean global effort
• Cooperative, not competitive science
• India at the forefront of GW science with 2nd generation of detectors:
Intl. shared science risks and credit
• Low project risk: commit to established tech. yet are able to take on
challenges of advLIGO (opportunity without primary responsibility)
“Every high
singletechnology
technology gains
they’refor
touching
pushing, and there’s
• Attain
Indian they’re
labs & industries
Thank you !!!
a lot of different technologies they’re touching.”
(Beverly Berger, National Science Foundation Program director for gravitational physics. )
• India pays true tribute to fulfilling Chandrasekhar’s legacy:
”Astronomy is the natural home of general relativity”
An unique once-in-a-generation opportunity for India. India could
play a key role in Intl. Science by hosting LIGO-India.
Deserves a National mega-science initiative
Detecting GW with Laser Interferometer
B
A
Path A
Path B
Difference in distance of Path A & B  Interference of laser light at
the detector (Photodiode)
Interferometry
Path difference of light  phase difference
Equal arms:
Dark fringe
The effects of gravitational
waves appear as a fluctuation in
the phase differences between
two orthogonal light paths of an
interferometer.
Unequal arm:
Signal in PD
Tailoring the frequency response
• Signal Recycling : New idea in interferometry
Additional cavity formed with
mirror at output
Can be made resonant,
or anti-resonant,
for gravitational wave frequencies
Allows redesigning the noise curve
to create optimal band sensitive to
specific astrophysical signatures