| Magnet Unit(s) | PR04 1032,1072 |
|---|---|
| Typical BDES | -169.35 kG/m |
| Typical Current | 110 A |
| Typical PS Voltage | 20 V |
| Nominal Beta X | 4.7 m |
| Nominal Eta X | 0.3 m |
| Nominal Beta Y | 24 m |
| Nominal Eta Y | 0.0 m |
LER SCY4R03 powers two of the four SD sextupole magnets in arc 3.
Each of the 6 LER arcs has eight sextupole magnets.
Arcs 1 and 3 have SF/SD magnets powered locally with two families of SF (SCX4 and SCX3) and two families of SD (SCY4 and SCY3) laid out symetrically for the two arcs about the collision point. Each of these four families has one "pair" of sextupoles per arc, with "pair" members having 180 degrees betatron phase difference between, and the two families (in each plane) having 90 degrees phase difference.
The SCY3 magnet pairs have their vertical beta function enhanced (to make their effect stronger) and have the same betatron phase as the IP QD1 magnets. In this way the local chromaticity generated by the IP beta squeeze is cancelled as near to the source (locally) as feasible. For the vertical chromaticity this cancellation is done out in the arcs.
The horizontal IP chromaticity is cancelled inboard of the arcs inside IR2 by the SCX1/SCX2 sextupole pair (one pair on each side of the IP).