HER QFS1E (PR08 LGPS 5150)

HER PR08 LGPS 5150 (QFS1E) Paramters:
Magnet Unit(s)

PR04:9022

PR06:6162,9022

PR08:6162,9022

PR10:6162,9022

PR12:6162

Typical BDES 44.761 kG
Typical Current 150 A
Typical PS Voltage 120 V
Nominal Beta X 24 m
Nominal Eta X 0.13 m
Nominal Beta Y 10 m
Nominal Eta Y 0.0 m

Lattice Description

QFS1E is one of seven string power supplies (QFS3E, QDS3E, QDS2E, QFS2E, QDS1E, QFS1E, and QDS0XE) used for "dispersion suppression" in arcs 5,7,9 and 11.

In general the HER arcs have QFs and QDs each powered in series for the whole ring except for the seven quadrupole magnets at the beginning and end of the arc. For a general HER arc, these first/last seven are used to cancel the dispersion going into the adjacent straights, and to generate a dispersion mismatch in the arc which controls (increases) the horizontal beam emittance. The HER arcs not adjacent to IR2 (generally) have these "dispersion suppressor" quads powered together by one power supply for each family member (eg QFS2 appears eight times in the four non-IR2 adjacent arcs such that eight QFS2 magnets share one power supply called QFS2E).

Arcs 1 and 3 (being adjacent to IR2) have this "dispersion suppressor" scheme done with individual power supplies for each magnet (except the QDS3 on the outward half arcs which are in series with the rest of the ring's QDs) to allow further tunability of the dispersion and beta functions adjacent to the collision straight at IR2.