A 2.3 GHz BANDWIDTH STRUCTURE FOR CLIC_DDS Vasim Khan 17.07.09

Spectral function 48cells 24 cells 2-fold interleaving No interleaving

∆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 ∆fmin = 16.25 MHz ∆tmax = 61.52 ns ∆s = 18.46 m ∆fmin = 8.12 MHz ∆tmax =123 ns ∆s = 36.92 m 96 cells 4-fold interleaving 192 cells 8-fold interleaving

Results based on only 3 cell simulations. Unloaded Unloaded Allowed limit = 260 MV/m Allowed limit = 56 K Corrected formula for effective pulse length [1] Results based on only 3 cell simulations. [1] A. Grudiev, CLIC-ACE, JAN 08

7 cell simulations.

232 47.3

(for corrected pulse length: Eff.=26.6%) Updated Parameters CLIC_G (Optimised) [1,2] CLIC_DDS (Non-optimised) Bunch space (rf cycles/ns) 6/0.5 8/0.67 Limit on wake (V/pC/mm/m) 7.1 5.6 Number of bunches 312 Bunch population (109) 3.72 4.5 Pulse length (ns) 240.8 273 Fill time (ns) 62.9 41.68 Pin (MW) 63.8 72 Esur max. (MV/m) 245 232 Pulse temperature rise (K) 53 47.3 RF-beam-eff. 27.7 24.1 (for corrected pulse length: Eff.=26.6%) [1] A. Grudiev, CLIC-ACE, JAN 08 [2] CLIC Note 764

Considering 8 fold interleaved structure Parameters Structure # 1 Structure # 8 f1, f24 (GHz) 15.5787, 17.9543 16.0329, 18.2153 ∆f (GHz) 2.0756 2.1824 a1, a24 (mm) 4, 2.5175 3.8968, 2.3 N (x109 particels/bunch) 5.41 4.6275

Structure # 1 Pin=76.5 MW 210 50.25

Structure # 8 73.5 MW

Sum RMS wake-field of an 8-fold interleaved structure Amplitude wake Sumwake wake

Random error in frequencies +/- 3.5 MHz Random error in f (MHz) Cell # f (GHz) Cell #

Random error in frequencies +/- 3.5 MHz 8 fold interleaved structure

Random error in frequencies +/- 3.5 MHz Amplitude wake Sumwake wake

Dipole simulations with fillet and high mesh Cell # 1 No fillet, solution is not converged (only 3 passes )and average mesh = 50 k Geometry with fillet, solution is converged and average mesh = 400 k Cell # 13 No fillet, solution is not converged (only 3 passes )and average mesh = 50 k Geometry with fillet, solution is converged and average mesh = 400 k No fillet, solution is not converged (only 3 passes )and average mesh = 40 k Cell # 24 Geometry with fillet, solution is converged and average mesh = 400 k