SKA Update

Sean Dougherty and Russ Taylor

HIA Breaks the Mold: High Performance
New-Technology Antenna rolls off the press.

In the last e-cassi we announced the beginning of the PrepSKA program; a four-year coordinate program among the 19 countries in the international SKA consortium that will lead to a fully-costed design and implementation plan for phase I of the SKA and a deployment plan for the full SKA.   The latest SKA newsletter has a comprehensive update on international activities, including an article by the new international project engineer, Professor Peter Dewdney (http://www.skatelescope.org/PDF/news/SKA_NEWSLETTER_VOLUME_14.pdf).

Since that newsletter there has been a major breakthrough on the Canadian technology development, with the successful completion of the Mark 2 version of the CART (Composite Applications to Radio Telescopes) reflector and its deployment on our test mount. Laser ranging measurements reveal a superb surface, with a 0.51 mm rms from a best-fit parabola – good for efficient 30-GHz operation.  The Mk2 reflector shows none of the large-scale deviations present in the Mk1 prototype as a result of changes in the manufacturing process.

Figure 1. Measurement results for CART Mk2 composite reflector.

On September 12^th, the Mk1 reflector was replaced on the test mount by the Mk2, complete with feed structure designed to house the Phased Array Demonstrator (PHAD) prototype receiver array that is also part of the SKA development work (Figure 2).

Figure 2. CART Mk2 Reflector being lifted into place September 12^th. The housing for the PHAD array is visible at the focus.

Work is now progressing apace on both holography and surface measurements of the reflector, in addition to commissioning the PHAD array for on-the-sky testing. The Mk2 is a great success, with significant advancements in design and production of high-performance cost-effective composite radio reflectors and represents a significant aspect of Canada’s PrepSKA contribution.