Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 1 Design, Manufacture, Transport and Integration on-site in Chile of ALMA Antennas REFLECTOR PANEL DELTA QUALIFICATION PM# February 2006 Dated November 18 h, 2005

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 2 Present Qualification Status According to document BD-TN-ML-010 (Reflector Panel Qualification Status, dated March 2003) a comprehensive qualification test campaign has successfully been passed by the present Panel design Testing on Sample Sealing Tests UV Resistance of the Sealant Thermal Cycling Test Thermo-Optical Measurements RF Reflectivity Measurements Accelerated Corrosion Test Electrical Conductivity Measurement Sandwich Peeling Test Impact Test Coating Corrosion Tests Coating Adhesion Test Testing on Prototype Panel Surface measurement Sun Exposure Test Thermal Cycling Test Modal Survey Test Static Load Test Vibration Test Fatigue Test

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 3 Open Points Documents ALMA B-SPE V.B (ALMA Environmental Spec) require: The system exposed equipment shall be compatible with windblown dust, ashes and grit This specific point is not covered yet by the qualification testing; besides the requirement need to be quantified in order to allow AEM to clearly verify it.

Reproduction interdite © ALMA EUROPEAN CONSORTIUM Reproduction forbidden Design, Manufacture, Transport and Integration in Chile of ALMA Antennas Page 4 Way Forward In order to complete the panel qualification performed within the prototype activities it is proposed: to perform a dedicated sand erosion test on a sample (at Media Lario); particle size, composition and velocity, as well as test duration, have to be defined by ESO and agreed with AEM to expose one of the prototype damaged panels to the real Chajnantor weather environment and periodically (e.g. 3 every months up to PPDR) verify its status and in particular the rhodium coating and the sealant