IPAC2017 - List of Authors (Jain, A.K.)

Paper	Title	Page
THPIK007	Production of Low Cost, High Field Quality Halbach Magnets	4118
	S.J. Brooks, J. Cintorino, A.K. Jain, G.J. Mahler BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. A shimming method has been developed at BNL that can improve the integrated field linearity of Halbach magnets to roughly 1 unit (1 part in 10⁴) at r=10mm. Two sets of magnets have been produced: six quadrupoles of strength 23.62T/m and six combined-function (asymmetrical) Halbach magnets of 19.12T/m with a central field of 0.377T. These were assembled using a 3D printed plastic mould inside an aluminium tube for strength. A shim holder, which is also 3D printed, is fitted within the magnet bore and holds iron wires of particular masses that cancel the multipole errors measured using a rotating coil on the unshimmed magnet. A single iteration of shimming reduces error multipoles by a factor of 4 on average. This assembly and shimming method results in a high field quality magnet at low cost, without stringent tolerance requirements or machining work. Applications of these magnets include compact FFAG beamlines such as FFAG proton therapy gantries, or any bending channel requiring a ~4x momentum acceptance. The design and shimming method can also be generalised to produce custom nonlinear fields, such as those for scaling FFAGs.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPIK007
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Production of Low Cost, High Field Quality Halbach Magnets

4118

S.J. Brooks, J. Cintorino, A.K. Jain, G.J. Mahler
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A shimming method has been developed at BNL that can improve the integrated field linearity of Halbach magnets to roughly 1 unit (1 part in 10⁴) at r=10mm. Two sets of magnets have been produced: six quadrupoles of strength 23.62T/m and six combined-function (asymmetrical) Halbach magnets of 19.12T/m with a central field of 0.377T. These were assembled using a 3D printed plastic mould inside an aluminium tube for strength. A shim holder, which is also 3D printed, is fitted within the magnet bore and holds iron wires of particular masses that cancel the multipole errors measured using a rotating coil on the unshimmed magnet. A single iteration of shimming reduces error multipoles by a factor of 4 on average. This assembly and shimming method results in a high field quality magnet at low cost, without stringent tolerance requirements or machining work. Applications of these magnets include compact FFAG beamlines such as FFAG proton therapy gantries, or any bending channel requiring a ~4x momentum acceptance. The design and shimming method can also be generalised to produce custom nonlinear fields, such as those for scaling FFAGs.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPIK007

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)