Description and Cost Benefit Analysis of Proposed Enhancements to ALMA

The Atacama Large Millimeter Array, or ALMA, is a conglomerate of 66 giant antennae located in the Atacama Desert of northern Chili. Through advanced computing, these antennae work together as a single telescope to pick up radio signals from stars, planets, or other galaxies. Since beginning operations in 2011, ALMA has played a major role in scientific discoveries propelling the field of astronomy. With ALMA’s extreme sensitivity and resolution, astronomers have been able to create 3-D mappings of molecular clouds, produce detailed images of protoplanetary formation, peer back over 13 billion years ago to the very first galaxies, and make many other astounding discoveries. Although it is stunningly cutting edge technology, ALMA could benefit from updates in order to ensure that it continues to provide the field with as many discoveries in the future. There are many proposed improvements to ALMA; this report focuses on four. The first, ALMA’s correlator chip, a vital part to any modern radio astronomy array is over 10 years old. In terms of computing power, it is orders of magnitude behind newer chips. Replacing the correlator chip could double ALMA’s bandwidth. The second, ALMA does not have a Band 2 receiver, which could be used to study the emission of high-redshift galaxies, deuterated molecules in cold gas, and a wide range of other applications . The third and fourth pertain to the Band 6 receiver, as well as the Band 3-8 receivers. These receivers produce undesirable noise temperature profiles and variations in gain. By altering the front-end configuration of the receiver and enhancing the amplifier system, these issues could be alleviated.