1. Describe helicity magnet (HM) system2. Con’s of PZT’s & Pro’s of HM–type system for BT measurements3. Other Possibilities, Comments from BT & Planning

Helicity Magnet Usage for Optics Measurements9/27/05 – Chao, Grames

Helicity Magnet System

Purpose - Produce helicity correlated beam orbit (position and/or angle) for the purpose of study or feedback.

Requirements1. Position and Angle -> 2 H and 2 V magnets2. Mimic Helicity Pattern -> Litz wire high bandwidth magnets

customized power supplies3. Suitable dyanmic range -> Exceed u, u’ at injector + suited @ 5

MeV4. Uncorrelated w/ charge asymmetry -> Downstream of apertures5. Zero cross-talk -> Electrically isolated system, fiber optic controls

History1. Idea scoffed at prior to 2003, but proposal considered during G0

prep.2. Working group formed (Areti, Cumbia, Dickson, Flood, Grames)3. Design + Review + Hurried Installation -> Not used by G0/HAPPEX

(2004)4. Improvements & functional system (Spring, ‘05)5. HAPPEX He testing (Summer ‘05) and preparation for HAPPEX-H

MHE0L01V

MHE0L03V,MHE0L03H

MHE0L02H

110 VACIsolation

TransformerGrounded cage containing

electrically isolated helicity magnet controls

(VME)

Tube protecting Litz magnet wire

Injector Helicity MagnetInstallation (0L01-0L03)

January 5-6, 2004

Closer look…

Con’s of PZT’s & Pro’s of HM–type system

Item Con’s PZT Pro’s HM

BPM Amplitude Small(100’s um)

Large(mm’s)

Position/Angle Coupled Uncoupled

Beam Mode Used CW for small amplitude

Tune OK w/ large amplitude

Physical Location Upstream of apertures

Downstream of apertures

Optics Location Before less understood reg.

After less understood reg.

Comparison with Parity Experiment

Different perturbation

(30 Hz vs. HEL)

Same perturbation (dual

purpose)

Possibilities, Comments & Planning

1. BT Studies – magnets can produce DC kicks (FOpt) or Large Amplitude 30 Hz orbit (C-S), may be helpful to improve Injector-Arc1 matching.

2. HAPPEX-He studies provide typ. performance summary (pending).

3. “As is” setup may be sufficient for Chao’s studies. Note: usefulness is downstream of cryo-unit, however, we may improve understanding upstream of cryo-unit as a result.

4. Requests to improve or evolve the system welcome -> gauge cost/benefit