Study on the high brilliance operation mode of HLS

1. Study on the high brilliance operation mode of HLS Student: He Zhang Major: Nuclear technology and application Supervisor: Duohui He, Professor Lin Wang, Associate Professor

2. Introduction of HLS and the principles of high brilliance mode lattice design • Design of HLS high brilliance mode • The effects of ID in high brilliance mode

3. Introduction of HLS and the principles of high brilliance mode lattice design

4. Introduction of HLS

5. General Purpose Light Source（GPLS）Lattice Quadruple strength coefficient K： Q1 : K1= 1.5692 Q2 : K1=-0.9557 Q3 : K1=-2.2671 Q4 : K1= 3.0708 Q5 : K1= 3.0708 Q6 : K1= -2.2671 Q7 : K1= -0.9557 Q8 : K1= 1.5692 Tunes： νx = 3.58 νy = 2.58 Emittance： Emit ＝ 166 nm·rad

6. The old High Brilliance Light Scource (HBLS) Quadruple strength coefficient K： Q1 : K1= 2.494447 Q2 : K1=-2.526518 Q3 : K1= 3.820103 Q4 : K1=-0.747670 Q5 : K1=-3.107723 Q6 : K1= 4.821645 Q7 : K1= 4.633252 Q8 : K1=-2.765640 Tunes： νx = 5.8213 νy = 2.3254 Emittance： Emit ＝ 26.87 nm·rad

7. Tunes on the super periodic structure resonance graph • Change of βfunction VS. change of K

8. 1 2 High βy in straight section, ID can’t work。 Too strong quadruple strength. 2 4 3 4 3 1 Low βy in straight section, ID can work。 Under the current condition, no new elements needed. The same or lower emittance Under the current condition, no new elements needed. Weaker quadruple strength, K<4.3。 Low emittance，27 nm rad。 Characters of HBLS and the design purpose of new lattices • HBLS • New Lattices

9. HLS new high brilliance lattice design

10. 1 2 3 4 Between A and F，η and η ‘ are zero。 At point M， β ‘ and η’ is zero。 At point A, βy is small。 At point A, βx is about 20m。 Searching for 4-folded lattices with achromatic straight sections • Limits of 4 folded lattices with achromatic straight sections

11. K of Q3 VS. K of Q4 • Emittance ε VS. K of Q3

12. βx changes between [15m,35m], βy changes between [3m,9m] ，distribution of Ks of Q3 in all periodic solutions

13. 1 2 3 We can control the emittance by controlling the η. Difficult to find high brilliance 4 folded lattice with achromatic straight section. We should look for other lattices to achieve low emittance. • conclutions

14. New 2-folded lattice design • 2 folded Lattice L2 Qudruple strength coefficient K： Q1 : K1= 2.5808 Q2 : K1=-2.2038 Q3 : K1= 3.9596 Q4 : K1=-2.1481 Q5 : K1= 2.7563 Q6 : K1= 0 Q7 : K1=-2.7457 Q8 : K1= 2.3722 Tunes: νx = 4.449 νy = 2.425 Emittance： Emit ＝ 55.94 nm·rad

15. Tunes of L2 • Super periodic structure resonance graph • Change of βVS. Change of K

16. Change of tunes VS. momentum dispersion • Change of tunes VS. initial horizontal position • Change of tunes VS. initial vertical position

17. Dynamic aperture of L2

18. FMA

19. Position of correctors and BPMs

20. Error amplifier of L2

21. Simulation results of close orbit distortion correction of L2

22. Simulation results of close orbit distortion correction of L2

23. Simulation results of close orbit distortion correction of L2

24. An example of close orbit distortion correction of L2 • An example of close orbit distortion correction of L2

25. An example of close orbit distortion correction of L2

26. Dynamic aperture of L2 with errors • Brilliance at the midpoints of dipoles

27. New 4-folded lattice design with chromatic straight sections • New 4-folded lattice design with chromatic straight sections

28. 1 2 3 One cell optics of L1 One cell optics of L2 One cell optics of L3 • β function and η function of new 4-folded lattice

29. Tunes

30. 1 2 3 L1 L2 L3 • Super periodic structure resonance graph

31. 1 2 3 L1 L2 L3 • Change of βVS. Change of K

32. Change of tunes VS. change of momentum dispersion (L4-3) -0.18 < dp/p < 0.22

33. L4-3 Change of tunes VS. initial position

34. Dynamic aperture of L4-3

35. FMA

36. Error amplifier of L4-3

37. Simulation of close orbit distortion correction of L4-3

38. Simulation of close orbit distortion correction of L4-3

39. Simulation of close orbit distortion correction of L4-3

40. An example of close orbit distortion correction of L4-3

41. An example of close orbit distortion correction of L4-3

42. Dynamic aperture with errors of L4-3 • Brilliance at the midpoint of dipoles (L4-3)

43. Commissioning (2005.10.1-2005.10.7) • Lattice of commissioning • βfunction Maximal injection beam curent is 13.3mA, after ramping 7.4mA remains。

44. 1 3 2 We don’t know the exact relations between quadruple strength and its current when machine works in 200 MeV. Beam current is too low to correct the close orbit distortion. Injection acceptance is decreased by errors. Injection system is sensitive to errors。 Appropriate DC bump needed. • Possible reasons why beam current can’t accumulate in injection progress

45. 3 4 1 2 It is possible to increase the brilliance of HLS. We have to overcome some difficulties in commissioning. L4-3 has the lowest emittance and highest brilliance. L2 has better beam dynamics performance. • Conclusions

46. 1 Quantum lifetime • Beam lifetime of L4-3

47. 2 Elastic gas scattering lifetime • Beam lifetime of L4-3 Physical acceptance：Hx=22.2mm-mrad, Hy=44.3mm-mrad

48. 2 Elastic gas scattering lifetime • 关于L4-3寿命的计算 Lifetime VS. physical acceptance Lifetime VS. gas pressure

49. 2 Inelastic gas scattering lifetime • Beam lifetime of L4-3 Lifetime VS. momentum acceptance Lifetime VS. gas pressure

50. 2 Gas scattering lifetime • Beam lifetime of L4-3 Lifetime VS. gas pressure