1. 1 ESS Warm End Linac Cooling Water 5-6 May 2014 John Jurns

2. Outline I. ESS cooling water system overview II. Warm end linac cooling requirements III. Cooling water interface with warm end linac cooling skids IV. Proposed CW system configuration V. Issues and questions

3. ESS cooling system characteristics Closed loop water-water heat exchanger and pump systems. Water system pressure nominally 10 bar Temperature control ± 1 degree C for most systems Three primary cooling loop supply temperatures – Low 5 deg C Medium 25 deg C High 50 deg C Primary cooling loops interface with: Individual cooling loads Substations located close to cooling loads (as required) Central Utility Building (CUB) – return cooling water interface with external District Heating system Water quality for primary system handled at CUB Secondary systems manage own water quality

4. ESS cooling water features - primary CW supply FEATURES OF PIPING SYSTEM: Material AISI 304 / 316 PN 16 Fittings Governing Code: PED / EN 13480 Design Temperature: -20° to 150° C Design Pressure: ~12 BARG Tests and inspections, NDT of welds, material certificates, welder qualification, design review, pressure tests

5. Ion Source/LEBT/MEBT/RFQ/DTL cooling

6. Proposed cooling water configuration for warm end linac Cooling water from CUB distributed to interface with warm end linac cooling skids at linac front end building Warm end linac cooling subsystems isolated due to unique cooling requirements Ion Source – Low conductivity water required for high voltage Ion Source LEBT/MEBT – Isolated cooling water loop due to risk of Tritium contamination RFQ/DTL – provide cooling water to high accuracy temperature secondary cooling systems provided by ESS partners MEBT/LEBT/ LWU/coupler s Ion source CUB RFQ cooling skid DTL cooling skids (5) RFQ DTL (5) CEA, INFN in-kind contribution scope Ion source Deionizer filter Magnet & coupler cooling skid

7. CouplersLWUs DTL MEBT RFQLEBT IS 25 C Return 25 C Supply DTL cooling skid RFQ cooling skid Magnet/coup ler cooling skid IS deionize filter Low Conductivity Water Front End Building Tunnel Notes DTL, RFQ cooling skids in-kind contribution Magnet/coupler cooling skid to isolate possible tritium contamination risk IS filter may not be required if primary LCW supply adequate Warm end linac cooling draft schematic

8. Warm end linac questions/issues ESS plans on providing 25 C supply temperature water to warm end linac cooling skids. Is this OK? What is expected ΔT at cooling skid? ESS would like to maximize cooling water return temperature with controls similar to sketch shown. Is this OK? We will need to coordinate instrument signals and control scheme to assure proper temperature control to equipment and high return temperature to ESS MEBT lists 100-200 μS/cm water quality as a requirement. Can MEBT tolerate low conductivity (< 0.5 μS/cm) water? How does INFN plan to monitor and manage their water quality? Is current physical layout of water skids in ESS front end building sufficient space to include provision for water treatment?

9. ESS/INFN interfaces Process interface – water, power and controls Physical interface – dimensions and layout for skids Water supply/treatment – INFN requirements from ESS ESS is developing standards for equipment – it would be good to coordinate ESS/INFN effort for common standards and equipment to improve maintainability of systems and components Warm end linac questions/issues (continued)

10. BACK-UP SLIDES

11. CW-L Buffer tank 150m 3 CW return <25⁰C CW supply 5⁰C PC HEAT PUMPS CW-M Buffer tank 150m 3 CW return 30-50⁰C CW supply 25⁰C PC CW return >50⁰C CW supply 50⁰C PC To Lund 80⁰C From Lund 45⁰C Central Utility Building Cooling Water Supply Heat exchanger

12. Optimization – CW return temp TC 25 C CWS from CUB CWR to CUB RFQ/ DTL TC Controls critical temperature in ”machine” Constant CW return temperature Constant inlet temperature to machine Stable temperature conditions at all heat loads Cooling loop for IS, LEBT, MEBT may be simpler as temperature control limits are not as strict Warm end linac cooling ESS We assume cooling system will look something like this for RFQ & DTLs: