A 2.3 GHz BANDWIDTH A 2.3 GHz BANDWIDTH STRUCTURE FOR CLIC_DDSSTRUCTURE FOR CLIC_DDS

Vasim KhanVasim Khan

17.07.09

Spectral function

96 cells4-fold interleaving

192 cells8-fold interleaving

24 cellsNo interleaving

48cells2-fold interleaving

96 cells4-fold interleaving

192 cells8-fold interleaving

24 cellsNo interleaving

48cells2-fold interleaving

∆fmin = 65 MHz∆tmax =15.38 ns∆s = 4.61 m

∆fmin = 32.5 MHz∆tmax =30.76 ns∆s = 9.22 m

∆fmin = 16.25 MHz∆tmax = 61.52 ns∆s = 18.46 m

∆fmin = 8.12 MHz∆tmax =123 ns∆s = 36.92 m

A 31.1I @ 23.4%

tLEaccIη b

CLIC_DDS

fillrbin tttPypulseenerg

beamenergy

p

rfillrfillbp

τT

ns 2462

pp1t

2

pp1ttttτ

0.5637.77

21.12

P

Ppp

.5MW47P

ULout

Lout

in

te)(approxima ns 23t

ns 40t

ns 208.111.9942

3128t

r

fill

b

Corrected formula for effective pulse length [1]

UnloadedUnloaded

1.19AI @ 27.7%ηCLIC_G

[1] A. Grudiev, CLIC-ACE, JAN 08

Allowed limit = 260 MV/m

Allowed limit = 56 K

Results based on only 3 cell simulations. Results based on only 3 cell simulations.

7 cell simulations. 7 cell simulations.

232 47.3

correctedp

p

fillrbin

bCLIC_DDS

@ 26.6%

@ 24.2%

tttP

tLEaccI

energy pulse

energy beamη

0.5637.77

21.12

P

Ppp

MW 27P

ULout

Lout

in

te)(approxima ns 23t

ns 41.68t

ns 208.111.9942

3128t

r

fill

b

ns 247.3

2

pp1t

2

pp1ttttτ

ns 273.03tttτ

rfillrfillbcorrectedp

rfillbp

A 1.13

GHz 11.9942

8101.6104.75

I19-9

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 312 312

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

Updated

Considering 8 fold interleaved structureConsidering 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

<a>/λ 0.13

N (x109 particels/bunch) 5.41 4.6275

21050.25

Pin=76.5 MW

correctedp

p

fillrbin

bCLIC_DDS

@ 24.4%

@ 22.2%

tttP

tLEaccI

energy pulse

energy beamη

A 1.11

GHz 11.9942

8101.6104.6275

I19-9

Structure # 1Structure # 1

73.5 MW

Structure # 8Structure # 8

correctedp

p

fillrbin

bCLIC_DDS

@ 25.3%

@ 23.0%

tttP

tLEaccI

energy pulse

energy beamη

A 1.11

GHz 11.9942

8101.6104.6275

I19-9

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

Amplitude wake Sumwake wake

Cell #

Random error in f (MHz)

Cell #

f (GHz)

Random error in frequencies +/- 3.5 MHz

8 fold interleaved structure

Random error in frequencies +/- 3.5 MHz

Random error in frequencies +/- 3.5 MHz

Amplitude wake Sumwake wake

Dipole simulations with fillet and high mesh

Cell # 13

Cell # 24

Geometry with fillet, solution is converged and average mesh = 400 k

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 # 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

24 cell structure

Dashed curve : Unloaded conditionSolid curve : Beam loaded condition

∆T (K)

Pin (MW)

Eacc (MV/m)

Esur (MV/m)

Allowable limit on Esur

Avg. Eacc

Allowable limit on ∆T

8 – fold interleavingStructure # 1

Dashed curve : Unloaded conditionSolid curve : Beam loaded condition

∆T (K)

Pin (MW)

Eacc (MV/m)

Esur (MV/m)

Allowable limit on Esur

Avg. Eacc

Allowable limit on ∆T

8 – fold interleavingStructure # 8

Dashed curve : Unloaded conditionSolid curve : Beam loaded condition

∆T (K)

Pin (MW)

Eacc (MV/m)

Esur (MV/m)Allowable limit on Esur

Avg. Eacc

Allowable limit on ∆T