TTL1 Transfer Line: Preliminary Design

C. Hessler, M. Meddahi, B. Goddard,

PS2 meeting 12.03.2009

Thanks to: W. Bartmann, M. Benedikt, M. Eshraqi, F. Gerigk

PS2 meeting 12.03.2009 - TE/ABT/BTP 2

Driving Parameters

LP-SPL LP-SPL-5G HP-SPL

Kinetic energy [GeV] 4 5 5

Beam power [MW] 0.192 0.24 4

Max. fract. loss [m-1](due to Lorentz stripping)

assuming max. Ploss =0.1 W/m

5.2 e-7 4.17 e-7 2.5e-8

Max. dipole field [T] 0.115 0.0950 0.0858

Min. rho [m] 141 206 228

Expression fractional loss from A.J. Jason et al, IEEE Trans.Nucl.Sci. NS-28, 1981http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=4331890&isnumber=4331887

PS2 meeting 12.03.2009 - TE/ABT/BTP 3

TTL1 Beam Line Geometry

vertical bending magnets

horizontal bending magnets injectionchicanemagnet

SPL end point

100 m

V1 V2

H1 H2

magnetsub-magnets)

magnet length [m]

[mrad] per sub magnet

B [T] for 4 GeV

B [T] for5 GeV

V1 (4) 4 15.4 0.062 0.075

H1 (4) 6 -18.8 0.051 0.061

H2 (8) 6 21.0 0.056 0.068

V2 (4) 4 -19.0 0.077 0.093

limit LP-SPL: 0.115 0.095

limit HP-SPL: 0.0858

point C

beam

PS2 meeting 12.03.2009 - TE/ABT/BTP 4

TTL1 Beam Line Geometry

vertical bending magnets

horizontal bending magnets injectionchicanemagnet

SPL end point

100 m

V1 V2

H1 H2

magnetsub-magnets)

magnet length [m]

[mrad] per sub magnet

B [T] for 4 GeV

B [T] for5 GeV

V1 (4) 4 15.4 0.062 0.075

H1 (4) 6 -18.8 0.051 0.061

H2 (8) 6 21.0 0.056 0.068

V2 (4) 4 -19.0 0.077 0.093

limit LP-SPL: 0.115 0.095

limit HP-SPL: 0.0858

point C

beam

→ Design compatible with LP-SPL and HP-SPL

→ Maximum slope of 7.7%

PS2 meeting 12.03.2009 - TE/ABT/BTP 5

900 1000 1100 1200 1300 1400 1500

2100

2200

2300

2400

2500

2600

2700

2800

TTL1 Beam Line Geometry

TT11 transfer line

TI 2

TT10

TTL1 transfer line

PS2

SPS

x (m)

y (m

)

point C

PS2 meeting 12.03.2009 - TE/ABT/BTP 6

Beam and Twiss Parameters

x plane y plane

norm. 1 emittance [µm] 0.351 0.350

beta [m] 106.5 117.3

alpha [1] -0.055 -1.352

dispersion [m] 0 0

dispersion derivative [1] 0 0

SPL end point (Source: M. Eshraqi):

x plane y plane

beta [m] 15 15

alpha [1] 0 0

dispersion [m] -0.4 0

dispersion derivative [1] 0 0

Injection point (Source: W. Bartmann):

PS2 meeting 12.03.2009 - TE/ABT/BTP 7

Optics Simulation

Fodo lattice

→ 25 m cell length→ 90° phase advance per cell

2 matching sections

PS2 meeting 12.03.2009 - TE/ABT/BTP 8

Optics Simulation

PS2 meeting 12.03.2009 - TE/ABT/BTP 9

Optics Simulation

PS2 meeting 12.03.2009 - TE/ABT/BTP 10

Quadrupole Families

quadrupole family # of magnets

length [m]

max. strength |k1| [m-2]

# of power convertors

start matching section 4 2 6.5e-02 4

regular arc focusing quadrupoles

11 2 6.0e-02 1

regular arc defocusing quadrupoles

11 2 6.0e-02 1

end matching section 8 2 7.0e-02 8

PS2 meeting 12.03.2009 - TE/ABT/BTP 11

Aperture Calculation

s (m)

beam

env

elop

e (m

)

max

1.11.16,

cop

pDyx phys

x y

PS2 meeting 12.03.2009 - TE/ABT/BTP 12

Trajectory Correction Scheme (on-going)

Quadrupole displacement errors: Gaussian distribution in x/y with = 0.2 mm, cut at 3

Dipole field errors: Gaussian distribution of deflection with = 10 µrad, cut at 2 (→ relative field error of 5e-4)

Dipole tilt errors: Gaussian distribution with = 0.2 mrad, cut at 4 Monitor errors: Flat random distribution of ±0.5 mm in both planes

quadrupoles

correctors

BPMs

bending magnet

Assumed errors:

PS2 meeting 12.03.2009 - TE/ABT/BTP 13

Trajectory Correction: Results

uncorrected:

x: 1.4 mm rms

y: 2.8 mm rms

corrected:

x: 0.013 mm rms

y: 0.029 mm rms

max. corrector

strength:

x: 5.7e-02 mrad

y: 4.9e-02 mrad

PS2 meeting 12.03.2009 - TE/ABT/BTP 14

Next Steps

More detailed study of the trajectory correction scheme BI specifications Magnet specifications Momentum collimation Space charge effects with ABP colleagues Rebunching / phase rotation Beam loss estimates/maps Optimisation investigations (e.g. compacting bends?)