Bilateral collaboration between Mexico and the United Kingdom for the construction of technical equipment (CHARM) for the Large Millimeter Telescope (LMT/GTM)

The Large Millimeter Telescope Alfonso Serrano (LMT), is the largest millimeter radio telescope in the world, and was founded in 2006. This radio telescope is the final product of a collaboration agreement between Mexico and the United States in the 1990s. It is located on top of an extinct volcano in Mexico at an altitude of 4600 meters above sea level. In 2018, the University of Manchester and the Rutherford Appleton Laboratory signed an agreement with the Instituto Nacional de Astrofisica Optica y Electronica (INAOE) to train Mexican astronomers in high-frequency radio receiver construction techniques by designing an innovative device called Collaborative Heterodyne Amplifier Receiver for Mexico (CHARM) designed to work at a frequency of 345 GHz. The research team, composed of British and Mexican technicians and scientists, installed CHARM at the LMT in 2019 and began testing the equipment until the COVID-19 pandemic shut it down in March 2020. This paper describes the collaboration process between Mexico and the United Kingdom, facilitated by a British institution dedicated to supporting scientific projects in developing countries, the Global Challenges Research Fund (GCRF).