HER QD&QF_RF (PR08 LGPS 5161)

HER PR08 LGPS 5161 (QD&QF_RF) Paramters:
Magnet Unit(s)

7042,7052,7062

8062,8072,8082

in both of

PR08&PR12

Typical BDES 45.381 kG
Typical Current 110 A
Typical PS Voltage 200 V
Nominal Beta X varies
Nominal Eta X 0.0 m
Nominal Beta Y varies
Nominal Eta Y 0.0 m

Lattice Description

QD&QF_RF is part of the magnet scheme which comprises the lattice for the RF straights 8 and 12. QD&QF_RF magnets are the more outboard from the straight midpoint magnets on either side (three on each side) of straights 8 and 12.

The two HER RF straights have a complicated interleaving of quadrupoles. This interleaving is symetric about the straight's midpoint, and comprises magnets with designations QFRFC, QDRFC, QFRF, QDRF, QDRF4, QDRF8, and QFRF9. The first two of these magnet types have a single power supply (both types QFRFC QDRFC both straights 8 and 12) called "QD&RFC". The second two also have a single power supply (both types QFRF QDRF both straights 8 and 12) called "QD&QFRF". The QDRF4 type has one power supply for both straights. The last two types (QDRF8 and QFRF9) have seperate power supplies each for each straight.

The interleaving scheme is as follows: Start at the straight midpoint with a QD magnet of type QDRFC. The progression away from this point is symetric each direction and progresses as QFRFC, QDRFC, QFRFC, QDRF4, QFRF, QDRF, QFRF, then QDRF8 and QFRF9.

The purpose of this complicated interleaving is to provide the capabilty of making a lattice which provides a "squeezing" of the beta functions in the middle of the straight to make beta peaks at the locations of (proposed but not to date realized) a family of octupole magnets. The beta "squeeze" scheme is popular since it allows greater betax/betay ratio as well as increasing the beta function at the target octupole location; allowing for less octupole magnet strength. The octupole family would be used to cancel amplitude dependant (i.e. nonlinear) tune shift.