LCLS-II Magnetic Structure Design Review

LCLS-II Magnetic Structure Design Review

Steve Marks7/6/11

1

AgendaIntroduction S. Marks

Summary of relevant physics requirements, design elements affecting magnet blocks

S. Marks

Conceptual mechanical design A. Black

Magnetic structure assembly concept A. Black

Analysis of one vs. two blocks per pole D. Arbelaez

End Design – Theory R. Schlueter

Baseline magnetic design S. Marks

Magnetic analysis, resultsQuarter period model, resultsEnd design

J.-Y. Jung

Procurement strategy, magnet specification D. Munson

Conclusions, recommendations S. Marks

Slide 2Undulator Alternatives- 5m 6-15-11

Review Context and Objective

• Prepare for procurement of first prototype A total of four HXU* Magnet Modules, two each from two

vendors• Two operational magnet test units (top and bottom module pairs)• End modules included

Objective:• Qualify two magnet material vendors, and establish firm cost• Qualify the periodic magnet design• Test and qualify the end design• Test tuning + other tests

Slide 3Magnetic Structure Conceptual Design Review 7/6/11

*We want to compare blocks of the same variety from two different vendors.HXU is chosen because of the more demanding requirements.

Review Context and Objective

• Magnetic material procurement drives the schedule, so want to accelerate this procurement

• The overall magnetic design will be presented at a conceptual design level, but want to concentrate on those aspects that directly affect magnet blocks

• Desired outcome from review: approval to proceed with block procurement, or identification of modifications necessary before procurement

• Procurement of remaining magnet module components and assembly will follow by approximately two months

• Conceptual design review for overall system early August


Relevant Physics Requirements Related Design Elements

• Peak Beff: 1.93 T (SXU), 1.26 T (HXU) Choice of magnet material (Br, Hcj) Height of pole, overhang of magnet material

• Horizontal field roll off: |K/K| = 1.5×10-4 (SXU), 5.4×10-5 (HXU) at ±0.4mm Pole and block width

• |Bydz| < 40 Tm, |Bydz2| < 50 Tm2

With even number of poles, systematic Bydz = 0 Systematic Bydz2 related to end design (size of last three blocks), gap variation

• Offset• Entrance (and exit) kick have to be less than 14.7 Tm

• Tolerance on trajectory (non-systematic part of Bydz2), phase errors/shake Result of block non-uniformity, pole placement errors Number of blocks per pole, sorting Tuning mechanism(s), variation over gap range


Conceptual Mechanical Design

• Alan Black


One vs. Two Blocks

• Diego Arbalaez


Magnetic End Design – Theory

• R. Schlueter


Baseline Magnetic Design

• Magnetic material: Br = 1.32 T, Hcj = 21 kOe Examples: VACODYM 854TP,

NEOMAX 44AH, Shin Etsu N42SH• SXU

Peak Beff = 1.91 T (1.93 T) B/B|0.4mm = 2.3×10-5 (1.5×10-4)

• HXU Peak Beff = 1.28 T (1.26 T) B/B|0.4mm = 2.4×10-5 (5.4×10-5)

Slide 9

HXU Pole/Block

SXU Pole/Block

Magnetic Structure Conceptual Design Review 7/6/11

Magnetic Analysis

• J.-Y. Jung


Magnetic Material Procurement

• Dawn Munson


Conclusions and Recommendations

• The baseline design meets requirements• A modest savings (probably less than $1M) could be realized if

peak field requirement is relaxed for SXU by ~3% – Not recommended

• The use of two blocks per pole offers a significant advantage if coupled with appropriate sorting algorithm, will reduce the effort and risk during tuning – Recommended

• Solicit bids for both HXU and SXU blocks – Initial procurement of HXU blocks

• HXU end design meets requirements over most of gap range, will verify with prototype, initial SXU design scaled from HXU, but need to tweak – Better control will require active control (coil around end pole); will test with prototypes


LCLS-II Magnetic Structure Design Review

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