ALMA’s Central Array on the Chajnantor plains
The Atacama Large Millimeter/submillimeter Array (ALMA) sits on the Chajnantor plains nearly 5,000 m above sea level and currently has 66 high precision antennas working together at millimeter and submillimeter wavelengths. There are three different types of antennas (European, North American, and Japanese antennas) found in ALMA that can be distinguished by the design of the wire on the main dish. The European antennas have simple wiring with no pattern underneath it. The wiring touches the edges of the dish and shaped like an X. On the other hand, the wiring of the Japanese antennas do not touch the edges of the dish, are shaped like lowercase-T and have a triangular-like pattern under the end of each wire. The wiring of the North American antennas also appears in the shape of a lowercase-T, however it is larger than the Japanese Antenna’s wiring since it touches the edge of the dish. There is also a triangular pattern found underneath the entire wire of the antenna.
