List of Issues for Beam runing in ATF EXT and ATF2

1.Optics and layout

1.1 Finalization geometry

Confirmation of common Q strength with DR and finalization

of layout and optics ( Alignment group requires final version )

1.2 Optimization of SX strength and skew position in EXT

EXT tuning

2. EXT tuning

2.1 Dispersion correction

2.2 Coupling correction need new skew?

3. FF tuning

3.1 BBA

3.2 Beam size tuning

Traditional method, R-matrix method,….

Pole Face Modification of Q

ΔF =i 2NS WN 2m+1( ) e−i N 2m+1( )ψ

m=0

∞

∑

=i 2NS zN 2m+1( ) L2m+1m=0

∞

∑

Where a=h z

ΔV =hB =N h/ cosNφ( )1−1/ N

S=ΔV Δψ /π =ΔV Δzdψdz

/π

=12aN cosh π /2( )tanNφ{ }[ ]

−1cosNφ[ ]

2/ N−2

2 S/(a N)

N

N=2

2 S/(a N) has its max of 1 at N =0,and monotonically decreasing with larger N .

L3 =π4

⎛ ⎝

⎞ ⎠

3

e−i3Nψ +13e−i3ψ⎛

⎝ ⎞ ⎠

N=2ReL3

ImL3C6 =4SL3 <4a

ScalingC6

real=C6C2real r0

2 r0-6, B6 (5)=6!C6

real, B6= B6 (5) r 5/5!B6/B2= B6 (5) r 5/5!/(2C2

real r)= 3 C6real r 4/C2

real

= 3 C6C2realr0

-4 r 4/C2real = 3 C6 (r/r0)4

<12 a (r/r0)4 =12 (areal/ r02 ) (r/r0)4 =12 areal r 4 / r0

6

(a is also scaled )If r=10mm, bore radius r0 =25mm and we need B6/B2<1e-4,then areal <2e-7m2 . When the area is square, the dip height and width must be less than 4.5e-4 m. ??