Two more pre-production receivers were integrated into the array, bringing the total to five. These two receivers were installed with a new lens design that reduced receiver noise by up to 5K. The receiver integrations were conducted by two shifts of the Front End engineering team at the observatory, with on-site guidance of ESO to provide training and ensure procedures are ready for full receiver integration.

Both receivers' integration and lab testing went smoothly and the Front Ends were installed in two 12m antennas. In-antenna testing was carried out using an array of these two antennas (DV25 and PM03) plus a previously installed one with the original lens design (DA61) in a test environment running the Cycle-11 online software (which supports Band 2). The new lens design maintains good optical efficiencies and beam size on-sky, and the expected noise improvement was recovered in the system temperature.

The Band 2 project is now in full production, with 3 receivers per month being assembled and tested at NOVA in Groningen, the Netherlands. Integration of the production series receivers in ALMA Front Ends is expected to commence by November.

Band 2 is a collaboration of NOVA, GARD, INAF, NAOJ and ESO.

Contributed by Neil Phillips, Pavel Yagoubov and Gianni Marconi