Cavities in NF-Linac

Morteza AslaninejadCristian BontoiuJuergen Pozimski

Fast acceleration

Linear Pre-accelerator (244 MeV to 900 MeV)

RLA I 4.5 pass, 0.6 GeV/pass, (0.9 GeV to 3.6 GeV )

RLA II 4.5 pass, 2 GeV/pass (3.6 GeV to 12.6 GeV )Non scaling FFAG - 8 revolutions (12.6 GeV to 25 GeV )

Linac components

• Number of solenoids: 6+8+11 = 25• Number of Cavities : 6+8*2+11*4 = 66• Target Frequency : 201.25 MHz• Bunch spacing : 5 ns• Number of Bunches :88

SC Linac - 244 to 909 MeV. 25 cavities: First 6* 0.744826 m cavities.

Second 8* 1.489652 m cavities. Third 11* 2* 1.489652 m cavities.

6 short cryos15 MV/m

8 medium cryos17 MV/m

11 long cryos17 MV/m

1460

Tue Feb 12 12:47:13 2008 OptiM - MAIN: - M:\casa\acc_phys\bogacz\IDS\PreLinac\Linac_sol.opt

100

50

BE

TA_X

&Y

[m]

DIS

P_X

&Y

[m]

BETA_X BETA_Y DISP_X DISP_Y

1.1 Tesla solenoid 1.4 Tesla solenoid 2.4 Tesla solenoid

8 one meter solenoids. ks=1 6,one meter

solenoids. ks=1.4

11 one meter solenoids. ks=0.83

24.03.2009, CERN M. Aslaninejad (J. Pasternak)

All cavities off. Different initial values. Different KS for matching solenoids

0.230m 0.744m

0.685m

Single Cavity Design-Comsol

Frequency Scan

Single cavity with two tails

Frequency Scan

Single cavity with two tailsPoisson-Superfish

f=201.24716 MHz

Ez

Cavity Pair without tails

Frequency scan

f=1.994573e8 f=2.013306e8

f=1.994573e8 f=2.013306e8

Pair cavities with two tails

Frequency scan

Pair cavities using Poisson-Superfish

f=200.34887 MHz

Ez

Outlook

• Cavities for the Linac with different geometries using Comsol-RF module have been simulated.

• Frequency scan , field map and characteristic parameters have been obtained.

• Field map for solenoids produced.• Particle tracking using GPT done(Cristian)• Issues like Beam loading are consider(Juergen)