ESS – RF checks up to cavity operation readiness in tunnel Cecilia G. Maiano www.europeanspallationsource.se

Technical Commissioning of Systems After the handover from In-Kind Contributors, the testing at TS and tunnel installation the technical commissioning phase will start at ESS In this presentation an overview of the “checkpoints” for the monitoring of the cavity frequencies during their lifetime (i.e. has something happened during transport?) “reference values” to asses whether the cavities in cryomodules are fitting the operation frequency goal within the normal tuner action. 2017-11-07

Cavities Flow (MB) High Q Configuration FPC Configuration INFN Ref f at warm Out CEA ESS TS2 Out In In CM Measurements In DESY Out Assess ESS Linac Ref f at cold VT Measurements Oper f 2017-11-07

Frequency checks (MB) – Before String Outgoing control from INFN (or Vendor) to DESY. INFN Warm spectrum and transmissions (+HOM) First set of reference f data Define & agree on reference condition for acceptance at warm Incoming control at DESY. INFN Warm spectrum and transmissions (+HOM) Data acquired during tests at DESY. INFN Cold spectrum and transmissions (+HOM) Reference condition for acceptance at cold Cold measurement results Outgoing control from DESY to CEA. INFN Incoming control at CEA. CEA Warm spectrum and transmissions (+HOM) (No Tuner) 2017-11-07

Frequency Checks (MB) – After String Outgoing control from CEA. CEA Warm spectrum and transmissions (+HOM) (Tuner installed) Doorknob not installed! Tool Incoming inspection at TS2. ESS Before and after Doorknob Let’s stop here, but then there is a huge ESS workflow for testing and send to tunnel. (Discussion in next SRF Collaboration meetings) 2017-11-07

Transmission measurements Agree on “standard” measurement sequence All fundamental passband modes Each mode acquired with a SPAN of ~200 kHz If possible, calibrated transmission values (at least for the accelerating mode, better if all) No specific format enforced (.txt, .xls… etc. => HDF5) Consolidation in HDF DB at ESS But data need to exchanged with the cavity, to allow incoming/outgoing assessments 2017-11-07

Frequency preparation strategy 2017-11-07

Mbeta SRF “manual” 2017-11-07