LER QDBM3L (PR02 LGPS 114)

LER PR02 LGPS 114 (QDBM3L) Paramters:
Magnet Unit(s) PR02 2052
Typical BDES -15.803 kG
Typical Current 60 A
Typical PS Voltage 20 V
Nominal Beta X 8.3 m
Nominal Eta X 0.26 m
Nominal Beta Y 17 m
Nominal Eta Y 0.009 m

Lattice Description

LER QDBM3L is one of a family of six quadrupole magnets (QDBM6L,QFBM5L, QDBM4L, QDBM3L,QDBM2L, and QFBM1L) near the end of straight 2 which match the optics from the exit of straight 2 into arc 1.

There is a set of these magnets at the entrance to IR2 (just after arc 3) and at the exit of IR2 (just before arc 1). These magnets live in the horizontal bending region close to the arcs.

The LER IR2 lattice is complicated tremendously by the need to simultaneously deflect the beam down vertically to overlap the HER vertically, bend the beam horizontally to accommodate the horizontal IP separation scheme, taylor the beta functions at local sextupoles to cancel IP focusing chromaticity, achieve skew quadrupole cancellations of the rotations caused by off axis trajectory in the BaBar solenoid, and implement the strong focusing necessary to achieve small IP beta functions.

These magnets set the beta and eta functions at the exit of the CCX/CCY section of LER IR2, just after the last vertical bend.