1. Vacuum tests of the accelerating structure mock-up The main outputs of the tests would be the following: Feasibility of the assembly of the vacuum manifold on a (brazed) accelerating structure estimation of the pump down time for a cavity, estimation of the thermal outgassing rate as a function of time influence of the number of the manifolds, sizes,… impact of SiC loads on vacuum pump down time, influence of air exposure on pump down time analysis of residual gas composition (Up to when is the vacuum dominated by water) feasibility of compact NEG pump + ion pump (+ impact of CH4) … Accelerating structure 4 removable vacuum manifolds with vacuum port Loads

2. Vacuum tests of the accelerating structure mock-up RGA Set up

3. TestPumpLoadsManifoldLink manifolds 11 turboNo1: 30*30No 21 turboYes1: 30*30No 3a1 turboYes1: 35*35?No 3b1 turboYes1: 25*25?No 3c1 turboYes1: …?No 41 turboYes1: 30*30 Yes: ~  25 5?4 turbo ? + diaphragmYes4: 30*30No 6 1 NEG (150 l/s) + ion pump Yes1: 30*30No 71 NEG (150 l/s)Yes1: 30*30No 8?1 NEG (100 l/s)Yes1: 30*30No 9 1 NEG (100 l/s) + (turbo+ diaphragm for CH4) Yes1: 30*30No … Vacuum tests of the accelerating structure mock-up Test sequence (to be refined) In parallel, a time-dependent vacuum model of each test configuration will be built and estimations compared to the measurements.