QW Wien quadrupoles (200 kV upgrade)
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New Wien quadrupoles have been designed to operate at higher 200 kV energy but also with improved magnetic and mechanical design.
What to consider in a new design?
- Larger ID air-core quad that could fit over 2-3/4" flange
- Longer quad to provide more field strength (required values under study; appears we need at least 33% increase over existing QW @ 3A)
- Quads have to be bakeable to 250C; as they're still captured when vacuum assembly made-up before beam line bake out
- Operate w/ <10 A idea, so can use existing trim cards (like those presently used)
- Darmstadt triplet
- B. Steiner et al., Recent Simulation Results of the Polarized Electron injector (SPIN) of the S-DALINAC  (media:200204_Triplet.pdf)
- J. Benesch, Modeling the Darmstadt quad triplet JLAB-TN-19-025
- Design studies
- Lakshmi's slides for Sep 17, 2020 Weekly meeting media:QW Magnet design-V03-Lakshmi-20200913.pdf
- Lakshmi's slides from Aug 31, 2020 design meeting media:QW Magnet design-V02-Lakshmi-20200831.pdf
- Lakshmi's slides from Aug 20, 2020 design meeting media:QW Magnet design-V01-Lakshmi-20200819.pdf
- Final design report
- EM design media:EM design-QW-V01-210520.docx
- Measurement vs. Design media:MEG0002021-R004-MQW magnetic mapping-V01-210521.docx
- These quads are used to compensate the dipole focusing of the Wien filters.
- There is one installed on the 6-way cross upstream/downstream of each Wien filter.
- They were designed to fit on top of existing 6-way viewer cross (1.5" pipe w/ 2-3/4" flanges).
- In order to maximize the field strength they were designed w/ as small an ID as possible 2-3/4". However, this means they're captured by the flanges which are welded on after the coils are assembled. We'd love to eliminate this, to have a quad coil that would pass over the 2-3/4" flange.
- Their length is about 4.9", the length of the 6-way cross. They could be longer, however, the 6-way cross abuts an 8" zero-reducer flange on the Wien filter, so a longer coil could not be perfectly symmetric on the 6-way cross. But, that's OK. A great way to recover field strength, I guess.
- Engineering Drawings
- Assembly drawing media:ACC2004000-1035 - QW QUAD-CROSS ASSEMBLY.pdf
- Coil drawing media:QW_magnet.pdf
- QW info
- Present operating limit is 3A
- Field measurements may exist, need to look
- Jay should have a model of the quads, a good starting place, here's info from him:
On 3/5/2020 2:42 PM, Jay Benesch wrote: > IR of QW model 1.375". Cross section 0.3" radial by 0.22" azimuthal. > 4.92" overall length. 35 AT in my 1A model, not 36 T. 0.55 G-cm > dipole, 22.57 G, both evaluated at 1 cm radius. With 1 A and 36 T, > 23.21 G quadrupole at 1 cm radius.