Conduction Cooled MgB&lt;sub&gt;2&lt;/sub&gt; Coil in Maximum Self Magnetic Flux Desity 2.3 Tesla Made with 300-Meter-long Multifilamentary MgB&lt;sub&gt;2 &lt;/sub&gt;Wire

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A wind-and-react MgB2 solenoid magnet for klystrons has been developed. While the current normal-conducting (Cu) magnet consumes 20 kW per magnet, this MgB2 magnet consumes less than 3 kW in refrigerator power. The conduction-cooled half coil of the magnet is 337 mm in inner diameter; the winding pack, 19.4 mm wide × 136.6 mm high, uses 2.7 km of 10 filament circular conductor, which is insulated with glass 0.83 mm in diameter, and is reacted after being wound onto a stainless steel bobbin. The coil has Cu plates of 0.2 mm in thickness between each coil layer and on the inner and outer sides. The magnet has two coils and produces 0.8 T in the center and its stored energy is 11.8 kJ. Together with the above-mentioned coil structure, these coils can consume stored energy in itself at quench without a special quench protection system. A performance test of the magnet was successful.

Section: Introductionmentioning

confidence: 93%

Development of Prototype MGB₂ Superconducting Solenoid Magnet for High-Efficiency Klystron Applications

Watanabe

Calatroni

Koga

et al. 2020

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“…8 shows the J e properties of several MgB 2 wires at 4.2 K. Here, FF means the filling factor of MgB 2 in the cross-section of each wire, and Pure or Dope means non-carbon doped or shown in a previous study [17]. The C-doped 1.5 mm wire was made by the in situ method and reported in our past study [4]. carbon-doped MgB 2 wire.…”

Section: Next Stepsmentioning

confidence: 99%

“…The wire for klystron magnets has higher J e compared to other typical wires in 6.5 T or lower magnetic field. In addition, C-doped 1.5 mm wire was made by Hitachi Ltd. [4] and it has the highest J e between 6 T to 7 T. It is expected that J e values of the C-doped 1.5 mm wire are higher than those of the wire for klystron applications in 3 T or lower magnetic field mainly due to the carbon additive.…”

Section: Next Stepsmentioning

confidence: 99%

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Performance of MgB₂ Superconductor Developed for High-Efficiency Klystron Applications

Tanaka

Suzuki

Kodama

et al. 2020

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An 8-km long MgB2 wire for a prototype klystron magnet was made and evaluated. The wire was made by a typical in situ method; it has 10 filaments and 0.67 mm in outer diameter. The homogeneity of Ic of this wire was evaluated by several methods. Deviation of Ic values in short sample wires was very small. In addition, the current sharing temperature of the MgB2 magnet (made of two reels of wire 2.9 km long each) agreed well with the estimated value of the Ic-B-T properties in short sample wires. Based on the obtained results, it can be said that the Ic properties of the entire wire length are quite uniform.

“…Multifilamentary MgB2 wire manufactured by Hitachi Ltd. using in-situ power in tube (PIT) method was investigated [15], [16]. Fig.…”

Section: A Mgb2 Sample Preparationmentioning

confidence: 99%

Experimental Test and Analysis of AC Losses in Multifilamentary MgB₂ Wire

Pei

Sheng

et al. 2019

Self Cite

AC losses in superconductors are essential for the design of cooling system for large scale power applications. Magnesium diboride (MgB2) superconducting wires have been investigated and manufactured over the last decade due to cheap raw materials and flexibility for coil design. In addition, multifilamentary MgB2 wires have been manufactured to reduce AC losses. In this paper, self-field AC losses of multifilamentary MgB2 wires with magnetic barrier were investigated using both experimental and numerical methods. A short straight wire sample and a coil sample were tested under various temperatures and frequencies between 16 Hz and 128 Hz. The test results show that the transportation loss is independent of the operating temperature. On basis of both theoretical and numerical study, it is found that hysteresis loss in superconductor accounts only for a small fraction of the transportation losses, ferromagnetic hysteresis loss in the magnetic barrier dominates when the transport current is low, whereas eddy current loss dominates when the transport current is close to the critical current.