Understanding Electromagnetic Coupling is Important for Astronomers

Dr. Howard C. Reader from the University of Stellenbosch in South Africa visited NAOC on August 21, 2014 and gave a lecture. He started by posing a question to the audience. If current is flowing in a wire, how does it affect a nearby wire? The answer is via magnetic fields which lead to an electromagnetic coupling. He then talked about when he was working with ESA, he was presented with a task where circuit boards that had been designed and built by different companies worked properly when each board is separated from the other boards, but when these boards where installed in the housing of a satellite and were in close proximity to each other, they produced magnetic fields and electromagnetic couplings that lead to malfunctions. He continued his lecture by showing how combinations of electrical circuits can disrupt sensitive measurements and that it is important to properly shield instruments from effects of stray and unwanted currents. Such stray currents that arise from electromagnetic couplings can even damage equipment if not properly managed.

Dr. Reader continued by showing how his lab at the University of Stellenbosch specializes in computational predictions of currents and electromagnetic couplings, and how these techniques have been applied to the design and construction of the Square Kilometre Array (SKA). He emphasized the importance of maintaining a dialog between engineers who design and build the facility and scientists who will use it. In addition, he showed many cases where work by his group caught problems in the electrical design of the SKA that if not properly checked would decrease the sensitivity of the telescope and possibly cause damage. Such contribution by a specialist in this field is invaluable to building and operating the SKA so that is can enjoy optimal performance.