DocumentCode :
1755521
Title :
A Solid Nitrogen Cooled Linear Levitating System Based on 
Bulks
Author :
Fabbri, Massimo ; Morandi, Antonio ; Perini, Elena ; Giunchi, Giovanni
Author_Institution :
DEI-Guglielmo Marconi Dept. of Electr., Electron. & Inf. Eng., Univ. of Bologna, Bologna, Italy
Volume :
25
Issue :
3
fYear :
2015
fDate :
42156
Firstpage :
1
Lastpage :
5
Abstract :
An innovative linear levitating system based on MgB2 bulks produced by the reactive liquid infiltration method is designed and built. Details of the system are presented. The levitation performance is also evaluated by means of previous experimental data. The linear levitating system consists of four MgB2 arc-shaped tiles lodged inside a double-shell Dewar sliding on a guide made of Nd-Fe-B permanent magnets. The magnets on the guide are properly arranged in a flux shaper configuration in order to produce maximum stiffness. Each MgB2 bulk has a curvature radius of 165 mm (arc length of 200 mm), thickness of 10 mm, and width of 70 mm. The system is cooled by means of a solid nitrogen heat sink. Helium gas supply to a heat exchanger is used in order to cool down the MgB2 slabs and the nitrogen at a temperature in the range of 20-30 K. When the flow of helium gas is interrupted, the temperature of the solid nitrogen remains below 39 K for half an hour. During this time interval, levitation measurements can be performed. Experimental verification of the cooling concept has been carried out successfully.
Keywords :
boron alloys; cooling; heat sinks; iron alloys; magnesium compounds; magnetic bearings; magnetic levitation; neodymium alloys; nitrogen; permanent magnets; superconducting magnets; MgB2; N; Nd-Fe-B; arc-shaped tiles; double-shell Dewar; flux shaper configuration; heat exchanger; helium gas; levitation measurements; permanent magnets; radius 165 mm; reactive liquid infiltration method; size 10 mm; size 200 mm; size 70 mm; solid nitrogen cooled linear levitating system; solid nitrogen heat sink; superconducting magnetic bearings; temperature 20 K to 30 K; Helium; Magnetic flux; Magnetic levitation; Magnetic resonance imaging; Nitrogen; Solids; Superconducting magnets; $hbox{MgB}_{2}$; Magnetic levitation; MgB2; Solid Nitrogen cooling; Superconducting magnetic bearings; solid nitrogen cooling; superconducting magnetic bearings;
fLanguage :
English
Journal_Title :
Applied Superconductivity, IEEE Transactions on
Publisher :
ieee
ISSN :
1051-8223
Type :
jour
DOI :
10.1109/TASC.2014.2360755
Filename :
6912988
Link To Document :
