| Item type |
学位論文 / Thesis or Dissertation(1) |
| 公開日 |
2010-06-09 |
| タイトル |
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タイトル |
Experimental study of superconducting wire motion on the base insulating material in magnetic field |
| タイトル |
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タイトル |
Experimental study of superconducting wire motion on the base insulating material in magnetic field |
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言語 |
en |
| 言語 |
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言語 |
eng |
| 資源タイプ |
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資源タイプ識別子 |
http://purl.org/coar/resource_type/c_46ec |
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資源タイプ |
thesis |
| 著者名 |
RUWALI, Kailash
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| フリガナ |
ルワリ, カイラシ
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| 著者 |
RUWALI, Kailash
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| 学位授与機関 |
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学位授与機関名 |
総合研究大学院大学 |
| 学位名 |
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学位名 |
博士（理学） |
| 学位記番号 |
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内容記述タイプ |
Other |
|
内容記述 |
総研大甲第1280号 |
| 研究科 |
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|
値 |
高エネルギー加速器科学研究科 |
| 専攻 |
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値 |
12 加速器科学専攻 |
| 学位授与年月日 |
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学位授与年月日 |
2009-09-30 |
| 学位授与年度 |
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値 |
2009 |
| 要旨 |
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内容記述タイプ |
Other |
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内容記述 |
One of the most prominent applications of superconductivity is high field<br />magnet. Mechanical disturbance such as abrupt conductor motion is one of the main<br />origin of premature quench (transition from superconducting state to the normal<br />resistive state) in high current density superconducting coils. The wire motion occurs<br />when electromagnetic force to conductor exceeds constrain force including frictional<br />force on the surface of conductor. Behavior of superconducting wire motion depends<br />on the electromagnetic force acting on it, frictional property of the insulating material<br />and thrust force applied to the superconducting wire.<br /> The experiments for superconducting wire motion in magnetic field was<br />carried out using small coil wound on stainless steel (SUS) bobbin using Polyimide<br />film as an insulating material and high strength polyethylene fiber (Dyneema: DF)<br />reinforced plastic (DFRP) bobbin [1]. The Dyneema fiber has negative thermal<br />expansion [2] and low coefficient of friction [3]. It was found that voltage spikes<br />generated due to sudden wire motion in case of DFRP bobbin are a few and small in<br />amplitude. The speculations are; the negative thermal expansion of the DFRP bobbin<br />restrains the wire motion and low coefficient of friction between superconducting<br />wire and DFRP bobbin reduces sudden motion.<br /> In order to study the effect of frictional coefficient of insulating material on<br />superconducting wire motion under the influence of electromagnetic force, a special<br />experimental setup was designed and fabricated. The main distinctiveness of the<br />experimental setup is that the tension of the superconducting wire can be changed<br />during the experiments. The experimental set up consists of a cryostat,<br />superconducting solenoid magnet, sample holder, tensional unit to apply tension to<br />the superconducting wire, power supplies and pen recorder or a 16-bit data recorder<br />to measure the voltage tap signal. The sample holder consists of two parts, a semi-<br />circular head and a body part. Experiments were conducted at 4.2 K by varying the<br />experimental conditions such as the tension to the superconducting wire,<br />superconducting wire current ramp rate and different insulating materials at the<br />interface of the superconducting wire and semi-circular head. <br /><br /> Voltage taps to measure the signal generated due to the superconducting wire<br />motion are connected at the end of the semi-circular head. To reduce the voltage tap<br />loop area, a groove was incorporated in the semi-circular head and the voltage tap<br />wire was passed through it. The voltage tap signal is measured by a pen recorder or a<br />16-bit data recorder with a sampling rate of 1 MS/s. Sudden wire motion was<br />indicated by observing the voltage spikes. <br /> In order to examine the effect of the current ramp rate on the superconducting<br />wire motion, ramp rate was changed from 0.4 A/s to 1.69 A/s. The superconducting<br />wire tension was varied from 7.1 N to 35.8 N to study the effect of tension on the<br />superconducting wire motion. During all experiments, a constant magnetic field of 6<br />T was applied by superconducting solenoid magnet. <br /> In the thesis work, different types of insulating material were used to study<br />superconducting wire motion under electromagnetic force. They are Polyimide film,<br />cloth / sheet material fabricated using Dyneema fiber, Zylon fiber and Teflon. The<br />Dyneema / Zylon fiber has negative thermal expansion and a low coefficient of<br />friction.<br /> We have verified the effectiveness of this system. We could measure the<br />pattern of voltage spikes. The time duration of voltage spikes are of the same order<br />for all the samples. The peak voltage tap signal amplitude, velocity of wire motion,<br />distance moved by wire and energy dissipated due to wire motion in case of<br />Polyimide film is more than 2 order of magnitude larger than Dyneema based<br />insulating materials and Zylon cloth. Hence use of Dyneema / Zylon based materials<br />as an interface material between layers of superconducting wire may reduce the<br />frictional heat generated due to wire motion and could make superconducting magnet<br />performance more reliable. |
| 所蔵 |
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値 |
有 |
| フォーマット |
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内容記述タイプ |
Other |
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内容記述 |
application/pdf |
要旨・審査要旨 (174.3 kB)
