LINAC4 Vacuum Control System Review J. De la Gama, Vacuum Controls, 2014-09-19

Vacuum Control System Overview LINAC 4 Description LINAC 4 Vacuum Control System Gas Injection Interlocks and Alarms rules Interlocks logic References J. De la Gama, Vacuum Controls, 2014-09-19 <#>/14

LINAC4 Description Linac4, the new 160 MeV CERN H- injector, is presently being constructed at CERN Building 400 with the goal of improving the LHC injection chain with a new higher energy linac. A dynamic pressure in the low 10-7 mbar is therefore requested all along the machine, starting from the RFQ. LINAC4 Vacuum Requirement The Linac4 vacuum system has to respond to the three criteria of reliability, robustness and minimal downtime in case of failure during operation. Together with these criteria, ultimate pressure is the essential technical parameter for the vacuum system. Specification values vary along the longitudinal coordinate, where the most constraining requirement is the large pressure drop between the LEBT and the RFQ (<5.10-7mbar). Pressure in the LEBT, up to 1.10-5mbar, is regulated by gas injection, to optimize space charge compensation. Accelerating structures and TL: < 1.10-7mbar. G.Vandoni. J. De la Gama, Vacuum Controls, 2014-09-19 <#>/14

Total: 13 VRGPT (TPG300) 52 signals 44 VRPI 88 signals Linac4 Vacuum Controls Hardware Spec: 6 Vacuum Sectors SOURCE – 3x VRGPT (TPG300) RFQ – 2x VRGPT (TPG300) & 9x VRPI CHOPPER – 2x VRGPT (TPG300) & 4x VRPI DTL – 2x VRGPT (TPG300) & 5x VRPI CCDTL – 2x VRGPT (TPG300) & 14x VRPI PIMS – 2x VRGPT (TPG300) & 12x VRPI DONE!! DONE!! DONE!! DONE!! Total: 13 VRGPT (TPG300) 44 VRPI 52 signals 88 signals J. De la Gama, Vacuum Controls, 2014-09-19 <#>/14

Gas Injection Fixed turbomolecular pumping groups with backing dry scroll pumps are used to evacuate the heavy gas load from source and LEBT gas injection, where pressure and gas species is not compatible with ion pumps. A Residual Gas Analyzer (RGA)is separately pumped. LEBT, Its function is to transport the beam from the ion source and match it to the RFQ input parameters, gas injection is ensured by a regulated gas dosing valve, one smaller scroll pump evacuates the differential gas on the line. <#>/20 J. De la Gama, Vacuum Controls, 2014-09-19

Interlocks and Alarms rules Chopper Valve RF Valve Penning gauge Ion Pump Condition: IF (Penning gauge signal OK) THEN (Ion Pumps can operate ) 1 SIG>RF VRP Lev1B VRP Lev1A VRP Lev1A VRP Lev1A VRP Lev1A REL2/4 J. De la Gama, Vacuum Controls, 2014-09-19

Interlocks logic Alarms for RF Each VVS is controlled by 4 devices that can give the interlock signal. A sector valve can be opened if ALL devices are ready. A sector valve is closed when there is an interlock trigger of 3 of the 4 devices The VVS-1 and VVS+1 will be closed. In this way two sectors are isolated . In LINAC4 it is used the same configuration and logic than in LHC. J. De la Gama, Vacuum Controls, 2014-09-19

Next Steps… Cabling, installation and commissioning for Half-sector Test Installation and commissioning for CDDTL, CDTL & PIMPS VRPI Calibration (32 devices) Documentation Update J. De la Gama, Vacuum Controls, 2014-09-19

References Presentation Interlock LHC (Gael Girardot) Hardware Configuration. (S. Blanchard & K.Radwan) Racks Layout Technical Description of the LINAC 4 Vacuum System (G. Vandoni) Thanks to J. Yanez, F. Aragon, K. Radwan, Gia, Helder, Fabien, Philippe, A. Gutierrez and S. Blanchard for your help and support. J. De la Gama, Vacuum Controls, 2014-09-19