The ALMA Band-7 Cartridge

Abstract

The Atacama Large Millimeter/Sub-millimeter Array (ALMA) will be composed of at least 65 high-precision antennas. In this framework, IRAM is responsible for the design and production (component manufacturing and procurement, assembly and test) of 65 production and 8 spare state-of-the-art receivers, covering the 275-373 GHz frequency range, called the ALMA Band-7 cartridges. The core part of the receiver consists of dual polarization sideband separating (2SB) superconducting (SIS) mixers designed and fabricated at IRAM, and cascaded with 4-8 GHz cryogenic isolators and low noise amplifiers. The first production cartridge was delivered in Spring 2009. The last receiver (65th) has to be provided to the project before the end of September 2012. Currently, more than half of the production cartridges have been delivered and accepted by the project. Every cartridge has to be subjected to in depth preliminary acceptance tests to make sure that the specifications imposed by the project are met. In order to achieve such a level of quality with high de livery rate, some product (PA) and quality (QA) assurance processes had to be put in place and fully automated test setups had to be implemented. We will describe the cartridge design as well as PA/QA processes and present the test setups together with the performances of the production cartridges delivered so far.