Article

Robust design of NMR magnet through worst case analysis

Authors:
  • Università degli studi della Campania "Luigi Vanvitelli"
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Abstract

Magnets for Nuclear Magnetic Resonance applications are designed to provide high level of magnetic flux density in a testing volume with the greatest level of field homogeneity. Anyway, the manufacturing and assembly tolerances cause unavoidable uniformity degradation, that is usually counteracted by correction coils. The measurement of the magnetic field is the final verification of the complex design and fabrication process of a magnetic system, aimed also at defining currents in correction coils to improve uniformity. Anyway, when seeking high accuracy, it is necessary to assess the effect on final uniformity of uncertainties in the measurement technique. In this paper, an approach is presented to assess impact of measurement error bars on final device performance, based on Worst Case Analysis, guaranteeing quick computational time.

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... The design of the optimal shape of a magnet is among the most critical issues in many industrial and 14 scientific applications, including electro-magnetic devices, superconducting coils in high field accelera-15 tors (LHC, LHIC, HERA etc.) [1] in Nuclear Magnetic Resonance device [2], in Magnetic Resonance 16 Imaging device [3,4] and in Thermonuclear Fusion Device (Stellarators, Tokamaks, RFP etc.) [5]. In al-17 most all these applications the computational time is critical (e.g. in industrial application computational 18 time affects the time-to-market of a product). ...
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... The characteristics of the field profile (e.g., the homogeneity) in the target region, and possible constraints due to coil technology (e.g., the current density limit, as a function of the flux density, to prevent the quench in superconductor materials) can be included in the mathematical formulation of the problem. Typical examples are the coil systems used for the shimming of Magnetic Resonance Imaging apparatus (MRI) [1][2][3][4], or the magnets used for beam accelerators [5] or Thermonuclear Fusion Devices [6], while other examples are in [7][8][9]. ...
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