1. FAIR MT/Cryogenics, Seong Yeub Shim Beam-Tube Eddy Loss S. Y. Shim

2. FAIR MT/Cryogenics, Seong Yeub Shim Table of contents Motivation Computation –Highlight data Summary

3. FAIR MT/Cryogenics, Seong Yeub Shim Motivation Early Studies –Simple analytical approach –2D analysis –3D analysis Analysis issues –Effect of cooling pipe & ribs –Temperature profile during magnet operation Improvements in this study –2D+3D analysis including cooling pipe and ribs –Extract eddy loss and temperature profile during the cycles up to 62 th –Check design criterion

4. FAIR MT/Cryogenics, Seong Yeub Shim Operation condition & Criterion Operation scenario –maximum : 1.9 T –minimum : 0.253 T –Ramping rate : 4 T/sec –High field flat top duration : 0.1 sec –Low field flat bottom duration : 0.8 sec Temperature Criterion given by UHV group –In order to keep UHV  Highest Temperature < 15 K Lowest Temperature < 6 K  t  0.412 sec

5. FAIR MT/Cryogenics, Seong Yeub Shim Length of the Chamber : 2976 mm Wall thickness : 0.3 mm Aperture : 128 mm  58 mm Rib thickness : 3 mm Rib pitch : 20 mm Cooling tube diameter : 5 mm Cooling tube thickness : 0.5 mm Dimension

6. FAIR MT/Cryogenics, Seong Yeub Shim FE model 1.VC with Cooling pipe 2.Coils 3.Air (Vacuum region) 4.Iron 5.Far field elements Material parameter 1.c(T) 2.k(T) 3.M(H) for iron 4.  = 5.0  10 -7  m 5.  r = 1 Eddy current, its loss and the temperature on Beam-Tube are calculated simultaneously. FE model

7. FAIR MT/Cryogenics, Seong Yeub Shim Magnet operation

8. FAIR MT/Cryogenics, Seong Yeub Shim Magnetic flux density during machine operation

9. FAIR MT/Cryogenics, Seong Yeub Shim Joule Heat Generation due to eddy current (position 1) The unit in this result is watt/m 3. The average power loss is 3.43 watt/m. The result without cooling pipe shows the loss of 2.37 watt/m.

10. FAIR MT/Cryogenics, Seong Yeub Shim Temperature profile with respect to the circumference of the VC

11. FAIR MT/Cryogenics, Seong Yeub Shim Temperature curve as a function of cycle (time)

12. FAIR MT/Cryogenics, Seong Yeub Shim Joule Heat Generation (position 2)

13. FAIR MT/Cryogenics, Seong Yeub Shim Change the cooling pipe position The cooling pipe is shifted to the side of the Beam-Tube, position 2. As we expected, the loss is increased ~ 22 % compared with original position, position 1.

14. FAIR MT/Cryogenics, Seong Yeub Shim Temperature profile

15. FAIR MT/Cryogenics, Seong Yeub Shim Criterion

16. FAIR MT/Cryogenics, Seong Yeub Shim Temperature profile

17. FAIR MT/Cryogenics, Seong Yeub Shim Joule Loss Distribution

18. FAIR MT/Cryogenics, Seong Yeub Shim Joule Loss Distribution

19. FAIR MT/Cryogenics, Seong Yeub Shim Summery of Eddy Loss Beam-Tube Cooling pipe Beam-Tube Cooling pipe ribs maximum loss14.37 watt24.12 watt25.95 watt average loss7.21 watt11.52 watt12.4 watt 72 % 60 % Number of SIS100 dipole : 108Total loss : 1340 watt It is 15 % of total dynamic heat load of the FAIR. In order to reduce the load, the electrical insulation between the cooling pipe and ribs/Beam-Tube is now considered and tested.