Mobile Pumping Units for Particle Free Beam Vacuum

Abstract

International audienceFor 10 years our Institute CEA Saclay Irfu has been involved in several in-kind collaboration contracts with ESS at Lund (Sweden) and one of these includes the test of numerous cryomodules in a dedicated test bench designed at Saclay. The cryomodules start to be assembled cavity per cavity in a clean room and must be low pressure pumped, without adding particles and always in a clean room. This is the purpose of the mobile pumping units for particle free beam vacuum. These units are also designed for vacuum automatic procedures, residual gas analysis and can provide conformity reports. Furthermore, a connectable industrial touch panel is added for a mobile operator interface. Only few buttons have to be panel touched by an operator to start automatic procedures in order to get a very high quality vacuum. The embedded control system is PLC based and manages many communications, especially with the spectrometer embedded in the unit. Only one CPU manages all the communications (Profinet, Profibus, TCP-IP ASCII and even Modbus) and sensors or actuators are controlled by four input-output cards. This small-scale control system is innovative because it is versatile, very convenient to use, deploy and maintain. Nine mobile pumping units are operational and continuously used, frequently moved to different locations, controlled locally or remotely and are still reliable. The paper describes the control architecture and functionalities of this small but full of possibilities device