1. A. Perin, CERN, TE-CRG, 13 June 2012 1 ICL, 13 June 2012 Consolidation of the DFBX CL control system

2. A. Perin, CERN, TE-CRG, 13 June 2012 2 Outline The current control system has limitations on the current ramp rates and accelerations. For the 120 A the limitations are even more severe and do not allow the proper operation of these leads (cf LHC-DFBX-EC-0002 ) The thermometer used to control the gas flow was installed during the commissioning phase. It is not redundant and it is exposed to potential damage during the interventions on the DFBXs. The control method that is currently being used does not give any information on the actual real cooling of the leads and allows just a minimal level of control. Goals of the project: Improve robustness of control system Remove the limitations due to the current control system

3. A. Perin, CERN, TE-CRG, 13 June 2012 3 Outline On the 8 DFBX there are 112 resistive 600A leads 80 resistive 120 A leads : 40 control loops For each DFBX (14 x 600 A) + (5x 120A) gas flows

4. A. Perin, CERN, TE-CRG, 13 June 2012 4 Main points Main technical features Control in open loop: mass flow as a function of current in the leads Non radiation-hard flowmeters located in protected areas Gas flow to be routed to the flowmeters and back (max 100 m) (e.g. 0.1 g/s, diam. 15 mm tube, DP = 7 mbar) Get the information on electrical current and use it to regulate the mass flow

5. A. Perin, CERN, TE-CRG, 13 June 2012 5 Main points Main technical features Control in open loop: mass flow as a function of current in the leads Non radiation-hard flowmeters located in protected areas. (development of radtol flowmeters could not be done) Gas flow to be routed to the flowmeters and back (max 100 m) (e.g. 0.1 g/s, diam. 15 mm tube, DP = 7 mbar) Get the information on electrical current and use it to regulate the mass flow What do we need? -Install a rack (std. 19") with 19 flowmeters in a protected area for each DFBX -Signal connection to the cryo racks (approx. 40 wires) -Routing of 19 pipes diam. approx. 15 mm (inner diam) from DFBX to rack + routing of a 50 mm pipe back to the helium recovery line. -Get the electrical current information to cryo PLC.

6. A. Perin, CERN, TE-CRG, 13 June 2012 6 Main points What do we need? -Install a rack (std. 19") with 19 flowmeters in a protected area for each DFBX -Signal connection to the cryo racks (approx. 40 wires) -Routing of 19 pipes diam. approx. 15 mm (inner diam) from DFBX to rack + routing of a 50 mm pipe back to the helium recovery line. -Get the electrical current information to cryo PLC. Installation of racks -One standard rack / DFBX -Located next to cryo rack where possible (R2E)

7. A. Perin, CERN, TE-CRG, 13 June 2012 7 Main points Installation of racks -One standard rack / DFBX (could be different shape if needed) -Located next to cryo rack where possible (R2E) -First analysis for possible locations