3-mm Receivers for the Australia Telescope Compact Array
Brief snapshot summaries of The Technology ,The
Science and The Benefits for Australia
of the 3-mm receiver upgrade project are presented here. Further details
for scientists and engineers are given in the Technical
And Scientific pages.
The technology:
Six new receivers will be built for installation on the newly surfaced anntennas
of the Australia Telescope Compact Array.
The new 3-mm receivers will be the first astronomy receivers to use cooled
Monolithic Microwave Integrated Circuit (MMIC) technology for low-noise
amplifiers and conversion components. Research into the design, fabrication
and application of indium phosphide (InP) MMIC's has been funded with $2.2M
awarded to the ATNF, in partnership with CSIRO Telecommunications and Industrial
Physics (CTIP), from the CSIRO Executive's Special Fund. As well as providing
advanced electronic devices for the MNRF work, the MMIC program will augment
greatly the range of high-frequency test equipment available to ATNF engineers
involved in the MNRF upgrades.
Prototype 3-mm receivers, cryogenically cooled to 20 degrees Kelvin and
covering a frequency range of roughly 85-115 GHz are already being designed
and built. The project involves;
- the design and construction of suitable feed horns - these will either
be corrugated on the inside or dielectrically loaded
- the design and testing of suitable Orthogonal Mode Transition components
and mixer systems
- the development of suitable low-noise amplifiers. Ultimately it is
hoped that MMICs using Indium Phosphide transistors will be used .
- the design and construction of receiver housing and mounting frames
etc.
The technical and
scientific pages contain more details on the design and construction
of the receivers.
The science:
By looking into space with receivers that can detect radio emission at wavelengths
as small as 3-mm it is possible to investigate chemical processes occurring
in space that cannot be detected at longer wavelengths.
Many interesting interstellar molecules will be observable with this system.
One example is the carbon sulfide (CS) molecule, which is commonly found
in the gas between stars in our own and other galaxies. Radiation from the
CS molecule is used to investigate the flow of matter onto protostars -
dense clouds that are collapsing to form new stars. Such radiation will
be able to be detected with the new system, which will enable astronomers
to probe regions of star formation that are otherwise inaccessible.
Radiation from molecules at mm-wavelengths can also indicate the presence
of cool molecular gas in other galaxies, which can be used to study the
processes that power active galaxies, and to probe the clouds of cool gas
at cosmological distances which are the progenitors of the galaxies we see
today.
The technical and
scientific pages contain more details on the science that can be done
with the new 3-mm receivers.
The benefits for Australia:
The design and production of the state-of-the-art amplifiers using MMIC
technology involves leading-edge electromagnetic and fabrication research.
Such research is strategic for other future applications of MMIC technology,
such as broadband mobile telecommunications. Australian expertise at the
CSIRO Division of Telecommunications and Industrial Physics is being exploited
here. The ATNF expects to utilise Australian industry to
produce these systems, and to provide prototypes and engineers able to transfer
to industry expertise in short-wavelength technology, a rapidly expanding
field in telecommunications. The Benefits
to Australia page contains more details on the benefits to Australia
of the MNRF AT Upgrade Project.
Go
to MNRF Projects Page
Go to MNRF Home Page
Go to ATNF Home Page
Last update by Michelle Storey. 18/3/99