The evaporative cooling system for the ATLAS inner detector

This paper describes the evaporativesystem used to cool the silicon detectorstructures of the inner detectorsub- detectorsof the ATLAS experimentat the CERN Large Hadron Collider. The motivation for an evaporativesystem, its design and construction are discussed. In detail the particular requirements of the ATLAS inner detector, technical choices and the qualification and manufacture of final components are addressed. Finally results of initial operational tests are reported. Although the entire system described, the paper focuses on the on- detectoraspects. Details of the evaporativecooling plant will be discussed elsewhere.