1. Project X Workshop - Cryogenics1 Project X CRYOGENICS Arkadiy Klebaner

2. Project X Workshop - Cryogenics2 OUTLINE Cryogenic Design Scope Design Concept Cryogenic Layout Heat Load Capacity Requirements Design Challenges Conclusions

3. Project X Workshop - Cryogenics3 CRYOGENIC DESIGN SCOPE Cryogenic Plant Cryogenic Distribution System Ancillary Systems

4. Project X Workshop - Cryogenics4 Design Concept Cryogenic plant –All major components of the Project X helium cryogenic plant have been used successfully in similar systems before –The special challenge of the Project X refrigeration system is to satisfy several demands of covering a wide range of heat loads. As operation at reduced capacity ( RF systems are turned off) can occur for extended time periods, it ’ s too expensive to compensate the heat load by electrical heating at 2 K

5. Project X Workshop - Cryogenics5 Design Concept (cont’d) Cryogenic Distribution System –Cryogenic string Up to 12 cryo modules –Two cryogenic units Upstream unit at 4.5K (?) – One cryo string Downstream unit at 2K – Four cryo strings Ancillary Systems –Industrially available components

6. Project X Workshop - Cryogenics6 Cryogenic Plant Warm Compressors 4K Cold Box 2K Cold Box Cold Compressors Controls Installation contracts

7. Project X Workshop - Cryogenics7 Model Plant Hybrid Plant Eq. Capacity 8 kW at 4.5K Multiple shield flows Three pressure cycle Two (2) first stage compressors Two (2)second stage compressors Sub-atmospheric warm stage Four (4) Cold Compressors Eight (8) turbo expanders Nitrogen exchanger for fast cooldown Good partial load (up to 60%) efficiency

8. Project X Workshop - Cryogenics8 Cryogenic Distribution System Low pressure cryogenic transfer line High pressure cryogenic transfer line Bayonet cans and expansion boxes String connecting boxes Upstream string feed box and end caps Downstream string feed box and end caps Gas helium header

9. Project X Workshop - Cryogenics9 Ancillary Systems Cooling towers Gas storage Liquid Storage Helium Purifier Recovery compressors Miscellaneous ( arc cells, hydrometers, instrument air, etc)

10. Project X Workshop - Cryogenics10 CRYOGENIC LAYOUT

11. Project X Workshop - Cryogenics11 String #5

12. Project X Workshop - Cryogenics12 Cryogenic Components 19 warm RF section solenoids 36 spoke CM solenoids 117 spoke resonators 305 elliptical cavities 112 quadrupoles Cryogenic distribution system

13. Project X Workshop - Cryogenics13 HEAT LOAD Estimated total heat load: 0.2 kW (static) + 0.4 kW (dynamic) = 0.6 kW @ 2K 0.9 kW (static) + 0.2 kW (dynamic) = 1.1 kW @ 4K 0.6 kW (static) + 0.3 kW (dynamic) = 0.9 kW @ 5-8K 5.4 kW (static) + 5.6 kW (dynamic) = 11.0 kW @ 40- 80K Static to the total heat load at 2K is 30% Heat load uncertainty factor is 30% Over capacity is 50%

14. Project X Workshop - Cryogenics14 CAPACITY REQUIREMENTS Plant installed capacity: – 1.1 kW @ 2K – 2.1 kW @ 4K – 1.7 kW @ 5-8K – 21 kW @ 40-80K Plant installed power - 2 MW COP’s –750 W/W @ 2K –258 W/W @ 4.5K –168 W/W @ 5-8K – 17 W/W @ 40-80K Good partial load efficiency Equivalent to 8 kW @4.5 K

15. Project X Workshop - Cryogenics15 DESIGN CHALLENGES Refine system design parameters –Heat loads –Components (cryomodules, etc) operating parameters and constraints Pressures envelop Temperatures envelop P affect on cavity tune, etc. Subatmospheric operation of the Low Energy linac

16. Project X Workshop - Cryogenics16 DESIGN CHALLENGES (cont’d) Pressure safety issues –Components MAWP ( Cryomodule pressure safety analysis) –Emergency venting –Code compliance

17. Project X Workshop - Cryogenics17 DESIGN CHALLENGES (cont’d) Operational and performance issues –Components cooldown/warm-up rates (dT/d , dT/dL) –System purification –System cooldown –System warm-up –Two-phase flow –Liquid control of long strings of cryogenic modules

18. Project X Workshop - Cryogenics18 DESIGN CHALLENGES (cont’d) Specialty components –Low pressure heat exchangers –String connecting boxes Mitigation of oxygen deficiency hazards Efficient cryogenic plant partial load operation

19. Project X Workshop - Cryogenics19 CONCLUSIONS We are seeking contributions from other laboratories to help address Project X design challenges Project X cryogenic system operating temperatures and pressure levels are largely determined by the choice of the ILC style cryomodules Most of the design challenges are similar to those that ILC and XFEL are faced with. Addressing these design challenges will benefit projects that utilize long strings of the ILC cryomodules Project X cryogenic system is technically feasible