1. Chromaticity correction in e-ring with TME cells and –I sextupole pairs in arcs
Y. Nosochkov
28 February 2017

2. E-ring with TME cells and SBCC (from Fanglei)
Study chromaticity correction using –I sextupole pairs in arcs for better compensation of sextupole non-linear geometric effects
24 TME cells per arc

3. TME cell sextupole options
Original 2-family sextupoles at center of the cell:
SXTarc01 (X) and SXTarc02 (y)
Also try SXTarc03 at beginning of the cell instead of SXTarc01
3 3 1 2

4. Sextupole configurations (per arc)
Cell 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 3a X Y 3b 3c 3d X1 X2 Y1 Y2 3e 3f
X and Y are for two horizontal or vertical sextupoles in a cell
X1 = X2/2, Y1 = Y2/2
Configurations 3a – 3f use SXTarc01 and SXTarc02 sextupoles
Configurations 4a, 4f are the same as 3a, 3f but use SXTarc03 and SXTarc02 sextupoles

5. Reference configuration: 2-family interleaved sextupoles in all cells
Energy range Dp/p > 0.005
Note: in all configurations, sextupoles are optimized for small tune shift and Db*, not for W-functions
Arc sext K2: 10.13, IP

6. Configuration 4
Same as config. 2, but with SXTarc03 instead of SXTarc01
Energy range Dp/p ~ 0.004
Arc sext K2: 30.53, -7.25 IP

7. Configuration 3a Energy range Dp/p ~ 0.002 Arc sext K2: 29.71, -48.56IP

8. Configuration 4a
Same as config. 3a, but with SXTarc03 instead of SXTarc01
Energy range Dp/p ~ 0.005
Arc sext K2: 89.75, IP

9. Configuration 3b Energy range Dp/p ~ 0.0025 Arc sext K2: 29.71, -48.56IP

10. Configuration 3d Energy range Dp/p ~ 0.002 Arc sext K2: 39.42, -64.53IP

11. Configuration 3e Energy range Dp/p ~ 0.0025 Arc sext K2: 19.89, -32.47IP

12. Configuration 4e
Same as config. 3e, but with SXTarc03 instead of SXTarc01
Energy range Dp/p ~
Arc sext K2: 60.08, IP

13. Configuration 3f Energy range Dp/p ~ 0.002 Arc sext K2: 19.89, -32.47IP