1. Towards an NMC Ring: Dispersion suppressor & long straight section
PS2 meeting
Towards an NMC Ring: Dispersion suppressor & long straight section
Y. Papaphilippou
October 24th, 2007

2. PS2 Meeting, Y. Papaphilippou
Outline
The short NMC module
Dispersion suppressor
Arc
Straight section
Summary
24/10/07
PS2 Meeting, Y. Papaphilippou

3. PS2 Meeting, Y. Papaphilippou
The “short” NMC module
1 asymmetric FODO cell with bends and a low-beta doublet
Phase advances of 272o,260o per module
γt of 10i
Five families of quads, with max. strength of 0.1m-2
Max. beta of around 60m in both planes
Min. dispersion of -2.3m and maximum of 4.6m
Chromaticities of -1.1,-1.7
Total length of 71.72m
Slightly shorter (~1.1m) than last time to accommodate dispersion suppressor
24/10/07
PS2 Meeting, Y. Papaphilippou

4. Dispersion suppressor cell
Similar half module as for the NMC with 2+5 dipoles (instead of 2+4)
Using 4 families of quads to suppress dispersion, while keeping beta functions “small”
Maximum beta of 70m
Total length of 77.31m

5. PS2 Meeting, Y. Papaphilippou
5 NMC modules + 2 dispersion suppressor cells
Phase advances of (10.4π,10.2π) – not matched
γt of 11.6i
9 families of quads, with max. strength of 0.1m-2
Max. beta of around 73m in horizontal and 64m on the vertical plane
Dispersion of -2.3m and maximum of 4.6m
Chromaticities of -7.5,
Total length of m
Slightly longer than FODO arc (2.6m)
The NMC arc
24/10/07
PS2 Meeting, Y. Papaphilippou

6. PS2 Meeting, Y. Papaphilippou
5 NMC modules + 2 dispersion suppressor cells
Phase advances of (10.4π,10.2π) – not matched
γt of 11.6i
9 families of quads, with max. strength of 0.1m-2
Max. beta of around 73m in horizontal and 64m on the vertical plane
Dispersion of -2.3m and maximum of 4.6m
Chromaticities of -7.5,
Total length of m
Slightly longer than FODO arc (2.6m)
The straight section
24/10/07
PS2 Meeting, Y. Papaphilippou

7. PS2 Meeting, Y. Papaphilippou
Summary
Short NMC cell with dispersion suppressor leaving almost the same space as the FODO cell
Low imaginary transition energy
“Reasonable” optics functions
In progress
Dispersion suppressor refinement
Matching to the straight section
Module length optimisation
Minimise quadrupole families number
Systematic phase advance scanning
Working point matching
Chromaticity correction
Dynamic aperture evaluation
done
done
done
Less important
24/10/07
PS2 Meeting, Y. Papaphilippou