  The Atacama Large Millimeter/submillimeter Array (ALMA) is the premier
telescope for sensitive, high-resolution observations at millimeter and
submillimeter wavelengths. The array consists of fifty 12-m diameter antennas
that can be reconfigured to baselines as long as 16 km, twelve 7-m antennas
that sample the short visibility spacings, and four 12-m antennas that provide
total power capabilities for spectral line and continuum observations. Located
in the Atacama desert in northern Chile at an elevation of 5000 m on the
Chajnantour plateau, the ALMA site provides excellent observing conditions with
low precipitable water vapor. The large number of antennas, the high-altitude
site, and excellent receivers with low-noise performance provide an extremely
sensitive, flexible instrument for submillimeter imaging.
