CLIC MAIN LINAC DDS

1. CLIC MAIN LINAC DDS Vasim Khan

2. Summary of results ∆fmin = 65 MHz ∆tmax =15.38 ns ∆s = 4.61 m ∆fmin = 32.5 MHz ∆tmax =30.76 ns ∆s = 9.22 m 48cells 2-fold interleaving 24 cells No interleaving 48cells 2-fold interleaving 24 cells No interleaving

3. Summary of results ∆fmin = 8.12 MHz ∆tmax =123 ns ∆s = 36.92 m ∆fmin = 16.25 MHz ∆tmax = 61.52 ns ∆s = 18.46 m 96 cells 4-fold interleaving 192 cells 8-fold interleaving 192 cells 8-fold interleaving 96 cells 4-fold interleaving V. Khan LC-ABD 09, Cockcroft Institute 22.09.09 8/13

4. CLIC_G vs CLIC_DDS For CLIC_G structure <a>/λ=0.11, considering the beam dynamics constraint bunch population is 3.72 x 10^9 particles per bunch and the heavy damping can allow an inter bunch spacing as compact as ~0.5 ns. This leads to about 1 A beam current and rf –to-beam efficiency of ~28%. For CLIC_DDS structure (2.3 GHz) <a>/λ=0.126, and has an advantage of populating bunches up to 4.5x10^9 particles but a moderate Q~500 will require an inter bunch spacing of 8 cycles (~ 0.67 ns). Though the bunch spacing is increased in CLIC_DDS, the beam current is compensated by increasing the bunch population and hence the rf-to-beam efficiency of the structure is not affected alarmingly.

5. CLIC_G vs CLIC_DDS [1] A. Grudiev, CLIC-ACE, JAN 08 [2] H. Braun, CLIC Note 764, 2008 * Mean value of 8 structures

6. Single structure vs. Interleaved structure Interleaved structures Interleaved structures Single structure Single structure Mean of interleaved structures Mean of interleaved structures Single structure Single structure

7. Sumwake: 8-fold interleaved structure Mean deviation RMS sumwake

8. Random error RMS ∆f = 3.5 MHz

9. Random error RMS ∆f = 2.4 MHz

10. Single structure Eight fold Interleaving 1 9 17 185 2 10 18 186 3 11 19 187 4 12 20 188 5 13 21 189 6 14 22 190 7 15 23 191 8 16 24 192 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

11. Decoupling end cell from each structure

12. Decoupling 2 end cells from each structure

13. Decoupling both the end cells from each structure

14. Decoupling two end cells from either side from each structure

15. Decoupling first cell and two end cells from each structure + RMS 2.5 MHz Random error

16. Decoupling first cell and last cell from each structure + RMS 2.5 MHz Random error

17. A typical geometry : cell # 1 R b R t/2 h1 a1 Rc h a a r1 L a+a1

18. Structure GeometryCell parameters Iris radius Iris radius R amin, amax= 4.0, 2.13 Cavity radius Cavity radius b t/2 a1 Rc a bmin, bmax= 10.5, 9.53 a Fully Interleaved 8-structures a+a1 Sparse Sampled HPT (High Power Test) L

19. Structure GeometryCell parameters Iris thickness Iris thickness R tmin, tmax= 4.0, 0.35 Ellipticity Ellipticity b t/2 εmin, εmax= 1.0, 2.0 a1 Rc a a a+a1 Sparse Sampled HPT (High Power Test) Fully Interleaved 8-structures L

20. Structure GeometryManifold parameters Degree of manifold penetration Degree of manifold penetration Rcmin, Rcmax= 6.2, 7.5 R Manifold radius Manifold radius b t/2 a1 Rc a Rmin, Rmax= 3.25, 2.3 a Fully Interleaved 8-structures a+a1 Sparse Sampled HPT (High Power Test) L

21. Structure # 1 in an 8-fold interleaved design Structure # 8 in an 8-fold interleaved design

22. Structure # 1 in an 8-fold interleaved design Structure # 8 in an 8-fold interleaved design

23. Structure # 1 in an 8-fold interleaved design Structure # 8 in an 8-fold interleaved design

24. Sparse Sampled Structure Structure # 1 in an 8-fold interleaved design Structure # 8 in an 8-fold interleaved design

25. Sparse Sampled HPT (High Power Test) Kdn/df Kdn/df dn/df dn/df Fully Interleaved 8-structures dn/df dn/df Kdn/df Kdn/df

26. Sparse Sampled HPT (High Power Test)

27. Fully Interleaved 8-structures

28. Structure # 1 in an 8-fold interleaved design

29. Structure # 8 in an 8-fold interleaved design

30. SRMS: Random errors with 20 iterations ∆f = +/- 4.0 MHz RMS ∆f ~ 2.3 MHz