Design of a 7 T Superconducting Magnet for Lanzhou Penning Trap

Author

Wu, W. ; He, Y. ; Ma, L.Z. ; Huang, W.X. ; Yao, Q.G. ; Wu, X. ; Guo, B.L. ; Zhang, B. ; Yuan, P. ; Xia, J.W.

Author_Institution

Grad. Univ. of Chinese Acad., Beijing, China

Volume

20

Issue

3

fYear

2010

fDate

6/1/2010 12:00:00 AM

Firstpage

989

Lastpage

992

Abstract

A penning trap system called LPT (LANZHOU PENNING TRAP) is now being developed for precise mass measurements in IMP (Institute of Modern Physics). The most key component of LPT is a superconducting magnet. A 156 mm warm bore and two cylinder good field regions with a distance of 220 mm are required for trapping ions and measurements. As the required homogeneity is better than 0.5 ppm, several complicated coaxial coils are used to produce such a magnetic field. The size and position of these coils are optimized by using a method combining linear program with multiobjective optimization. Superconducting shim coils and passive shim pieces are used to eliminate inevitable winding tolerances and environmental influence. The fringe field is decreased to 5 Gs at 2 m line from the center of the magnet by active shielding coils. The designs of the mechanical structure, the quench protection system are also introduced in this paper.

Keywords

optimisation; particle traps; superconducting magnets; Lanzhou penning trap; active shielding coils; coaxial coils; distance 220 mm; fringe field; mass measurement; mechanical structure; multiobjective optimization; quench protection system; superconducting magnet; superconducting shim coils; Homogeneous magnetic field; Penning trap; quench; superconducting magnet;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2010.2040957

Filename

5433310