Instrumentation is the foundation of OzGrav’s research. Under the direction of OzGrav Deputy Director Professor David McClelland, we are pursuing novel instrumentation research under the following programs:
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The OzGrav instrumentation theme will make major contributions towards implementing the international gravitational wave community's 30-year Roadmap. It proposes three major stages of audio-band instrumentation development: a) bringing the current generation of advanced detectors up to full sensitivity, multiplying the discovery volume of the Universe by ~15 times from current detectors; b) a range of modest-cost detector enhancements to increase the detection volume roughly another 6-fold by the mid-2020s; and c) Cosmic Explorer and Einstein Telescopes - third-generation detectors in new facilities that will see every compact binary system in the universe! These instruments will be much larger, use new materials and operate at cryogenic temperatures. OzGrav’s Space program will grow Australia's involvement in space detector development and the Pulsar Timing Program continues our leadership in pulsar processor development.
The programs are coordinated by the Instrumentation Theme Planning Committee chaired by the Deputy Director and consisting of program leaders.
The programs are coordinated by the Instrumentation Theme Planning Committee chaired by the Deputy Director and consisting of program leaders.
major programs
Quantum Program chairs: Dr Terry McRae (ANU) and Prof Peter Veitch (Adelaide)
Due to the quantum nature of light, a laser beam carries an uncertainty in its amplitude and phase that create quantum noise. Using a nonlinear process called "squeezing" at gravitational wave signal frequencies of 10 Hz - 10 kHz, one can modify quantum noise by e.g. reducing noise on the phase at the expense of more noise on the amplitude, or vice versa.
Our Quantum Program will involve building a squeezed light source at 2μm that produces a factor of 10 noise reduction. Our team also has extensive experience in developing high power lasers and we will develop and stabilise a continuous-wave 2μm high power (>200W) laser designed for use in the future third-generation LIGO detector, referred to as "LIGO Voyager". |
Low-frequency Newtonian noise mitigation Program chairs: Dr Bram Slagmolen (ANU) and Prof JU Li (UWA)
A low-frequency gravitational force sensor provides a novel approach for measuring gravitational forces using torsion systems. We will use new Australian techniques that will enable the ability to measure, and ultimately control, the seismic and atmospheric induced Newtonian Noise. To achieve this, numerous auxiliary sensors are integrated, such as tilt-sensors and seismic sensor arrays, to produce such a low-frequency sensors.
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Distortions and Instabilities Program chairs: Dr Carl Blair (UWA) and Prof David Ottaway (Adelaide)
This Program involves monitoring and controlling for parametric instabilities and thermal distortions. Optical losses throughout the LIGO interferometer, including those due to optical wavefront distortion, need to be minimised. Thus, critical wavefronts must be matched to an extremely high precision. We are developing and optimising Hartmann sensors, advanced phase cameras, and wavefront-control actuators that can eventually be used in LIGO Voyager to mitigate optical losses. We will also model, test and implement control schemes for parametric instability suitable for aLIGO and future generations of LIGO. They will be tested at the Gingin facility and subject to performance, will be implemented at aLIGO to help the observatory achieve full sensitivity.
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Commissioning Program chairs: Dr Daniel Brown (Adelaide) and Dr Bram Slagmolen (ANU)
The commissioning of Advanced LIGO will continue for most of the life of OzGrav as the detectors are continually improved. Our investigators, postdocs and students will have opportunities to spend time at the LIGO observatories to contribute directly to commissioning on-site. This ongoing involvement will ensure that Australian instrument scientists are well versed in the practical issues that confront these large scale interferometers, and that OzGrav R&D is relevant to these state of the art instruments. OzGrav members will play key roles in installing and commissioning at Advanced LIGO: squeezing instrumentation; automatic mode-matching in the interferometer output (signal) chain; upgrades to these interferometers; and control systems to mitigate sources of instabilities and distortions
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Space Instrumentation Program chair: Dr Andrew Wade (ANU)
The benefits and the challenges of measuring millihertz gravitational waves on Earth have long been recognised, and several decades ago the international community began planning a dedicated space-based gravitational wave detector. Led by the European Space Agency (ESA) in consortium with NASA, the Laser Interferometer Space Antenna (LISA) will be the first space mission to survey the entire Universe with gravitational waves. A detector in space has two primary advantages. First, the detector can be situated far away from sources of gravitational noise that pollute the gravitational spectrum on Earth. Second, the interferometer arms can be made very long, of order a million times longer than ground-based detectors, taking advantage of the natural vacuum of space and amplifying the effect of the gravitational waves. OzGrav brings together researchers with extensive experience with NASA Interferometer Instrumentation (CI: McKenzie and AI: Shaddock) and the European leader of the LISA project (PI: Danzmann) to investigate measurement techniques for future gravitational wave detectors in space.
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Pulsar Timing Program chair: Prof Matthew Bailes (Swinburne)
The search for gravitational waves using pulsar timing arrays requires instrumentation that eliminates unnecessary sources of systematic errors and removes the deleterious effects that the interstellar medium has on the otherwise sharp profiles of millisecond pulsars. In the 1970s astronomers realised that the optimal way to do this was by digitising the voltages present in a radio receiver at the Nyquist rate and processing the data on a supercomputer. Swinburne University of Technology has been a pioneer of supercomputing-based instrumentation for radio telescopes and was selected by the Square Kilometre Array consortium to design the pulsar processor for the Square Kilometre Array. This design work will be completed by mid-2016 but prototypes of the pulsar processor are being deployed at the Parkes 64m antenna and the South African MeerKAT pathfinder that will ultimately be extended into SKA Phase I mid, a 500M telescope perfect for pulsar timing array observations. OzGrav will help validate the pulsar processor prototypes developed at Swinburne for the Australian and South African radio telescopes to optimise their performance for pulsar timing array gravitational wave detection.
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Future Detector Planning Chairs: Prof Matthew Bailes (Swinburne) & Prof David McClelland (ANU)
OzGrav members are involved in future detector planning through engagement on a range of working groups and projects.
The OzGrav High Frequency (OzHF) working group brings together members from across our nodes, themes and programs. It is a highly collaborative and cross-disciplinary endeavour that is investigating the scientific drivers, technical requirements, and cost of a mid-scale detector that probes the high-frequency regime to better understand the physics of binary neutron stars. In addition, with support from the Australian Research Council, OzGrav members are closely engaged in the planning of a third generation (3G) detector that is being led by the Gravitational Wave International Committee (GWIC). |