lcls-ii magnetic structure design review steve marks 7/6/11 1
TRANSCRIPT
LCLS-II Magnetic Structure Design Review
Steve Marks
7/6/11
1
Agenda
Introduction 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
Slide 4Magnetic Structure Conceptual Design Review 7/6/11
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
Slide 5Magnetic Structure Conceptual Design Review 7/6/11
Conceptual Mechanical Design
• Alan Black
Slide 6Magnetic Structure Conceptual Design Review 7/6/11
One vs. Two Blocks
• Diego Arbalaez
Slide 7Magnetic Structure Conceptual Design Review 7/6/11
Magnetic End Design – Theory
• R. Schlueter
Slide 8Undulator Alternatives- 5m 6-15-11
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
Slide 10Undulator Alternatives- 5m 6-15-11
Magnetic Material Procurement
• Dawn Munson
Slide 11Magnetic Structure Conceptual Design Review 7/6/11
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
Slide 12Undulator Alternatives- 5m 6-15-11