Deployment concept of the wide band sensitivity upgrade project in the ALMA Observatory

The Atacama Large Millimetre/submillimetre Array (ALMA) is the world's largest ground-based facility for observations at millimeter/submillimeter wavelengths. Inaugurated in March 2013, ALMA has already accomplished ten years of continued steady-state operations. It comprises 66 antennas located approximately 5000 meters at the Chajnantor Plateau in the Atacama Desert in Northern Chile. The ALMA partnership established the ALMA 2030 development program to improve ALMA's capability to avoid obsolescence for the next decade. The Wideband Sensitivity Upgrade (WSU) project, the first initiative of the ALMA 2030 development program, will replace the entire digital processing system, which includes the wideband digitizers, data transmission system, and data correlation system. A working group was charged to develop a WSU Deployment Concept based on a parallel deployment approach to minimize scientific downtime during the upgrade period, which could last up to five years. In this paper, the authors present the relevant aspects of this analysis and conclusions, which will pave the road to address the definition of the AIVC concept and the corresponding AIVC plan of the WSU project.