The Atacama Compact Array (ACA) will supplement ALMA in order to provide the "missing spacings" in the uv-plane coverage, caused by the finite size of and the minimum distance between the elements of ALMA. ACA will consists of about a dozen small antennas of a diameter between 6 and 8 m. In this Memo I consider a number of aspects related to the antennas. After reviewing the basic requirements on the antennas, I look in some detail on the possibilities of using the ALMA antenna mounting for the ACA dishes. Minimizing the "collision radius" to enable close packing is important for the ACA. I suggest a straw man ACA antenna consisting of a 7 m diameter reflector with a short focal length (F/D = 0.3) on an ALMA mounting. A number of points for further study is listed.
View a PDF version of ALMA Memo #339.
Download a PS version of ALMA Memo #339.
Last modified: December 05, 2000
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