The reactive liquid Mg infiltration of Boron powders preforms is an easy technique to obtain high density and large superconducting bulk MgB2 manufacts, in which the supercurrents can percolate without obstacles by grains boundaries. The microstructure of these manufacts, as well their superconducting characteristics, can be tailored according to the Boron powders used and the particular arrangements of the reactants in a stainless steel container. A discussion of the superconducting characteristics of prototype manufacts of various shape will be given. The practical application of these manufacts, as permanent magnets for bearings or as current leads, will be discussed with reference to other superconducting bulk options. The expected temperature range for the use of this material will be between 15K and 30K and that calls for the development of reliable and cheap cryogenic systems.
{"title":"The Superconducting Properties of High Density Bulk MgB2 Obtained by Reactive Liquid Mg Infiltration","authors":"G. Giunchi","doi":"10.1063/1.2192428","DOIUrl":"https://doi.org/10.1063/1.2192428","url":null,"abstract":"The reactive liquid Mg infiltration of Boron powders preforms is an easy technique to obtain high density and large superconducting bulk MgB2 manufacts, in which the supercurrents can percolate without obstacles by grains boundaries. The microstructure of these manufacts, as well their superconducting characteristics, can be tailored according to the Boron powders used and the particular arrangements of the reactants in a stainless steel container. A discussion of the superconducting characteristics of prototype manufacts of various shape will be given. The practical application of these manufacts, as permanent magnets for bearings or as current leads, will be discussed with reference to other superconducting bulk options. The expected temperature range for the use of this material will be between 15K and 30K and that calls for the development of reliable and cheap cryogenic systems.","PeriodicalId":80359,"journal":{"name":"Advances in cryogenic engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1063/1.2192428","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59399708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Since the introduction of the cable‐in‐conduit conductor (CICC) concept, a variety of alloys have been proposed for fabricating the jacket. The jacket provides primary containment of the liquid helium coolant and is typically also the primary structural component for the magnet coils. These functions create requirements for strength, toughness, fatigue crack resistance, and fabricability. When the CICC uses Nb3Sn superconductor, the conduit alloy must retain good mechanical properties after exposure to the superconductor’s reaction heat treatment. Here we present data from cryogenic fracture toughness and fatigue crack growth rate tests on 316LN and a Cr‐Mo‐Ni base super‐alloy (Haynes 242) at 4 K before and after the exposure to the heat treatment. These alloys are presently being considered as candidates for use in the next‐generation series connected hybrid magnet for the NHMFL. Both of the alloys are found to have adequate fatigue and fracture properties for the CICC application while the superalloy ha...
自引入电缆-导管导体(CICC)概念以来，已经提出了各种合金来制造护套。护套提供液氦冷却剂的主要容器，通常也是磁铁线圈的主要结构部件。这些功能产生了对强度、韧性、抗疲劳裂纹和可制造性的要求。采用Nb3Sn超导体时，管道合金经超导体反应热处理后，必须保持良好的力学性能。在这里，我们给出了316LN和Cr - Mo - Ni基超级合金(Haynes 242)在4 K热处理前后的低温断裂韧性和疲劳裂纹扩展速率测试数据。这些合金目前被认为是下一代串联混合磁体用于NHMFL的候选人。两种合金都具有足够的抗疲劳和断裂性能，而高温合金则具有较好的抗疲劳和断裂性能。
{"title":"Effect of an Aging Heat Treatment on the 4 K Fracture and Fatigue Properties of 316LN and Haynes 242","authors":"R. Walsh, V. Toplosky, Ke Han, J. Miller","doi":"10.1063/1.2192340","DOIUrl":"https://doi.org/10.1063/1.2192340","url":null,"abstract":"Since the introduction of the cable‐in‐conduit conductor (CICC) concept, a variety of alloys have been proposed for fabricating the jacket. The jacket provides primary containment of the liquid helium coolant and is typically also the primary structural component for the magnet coils. These functions create requirements for strength, toughness, fatigue crack resistance, and fabricability. When the CICC uses Nb3Sn superconductor, the conduit alloy must retain good mechanical properties after exposure to the superconductor’s reaction heat treatment. Here we present data from cryogenic fracture toughness and fatigue crack growth rate tests on 316LN and a Cr‐Mo‐Ni base super‐alloy (Haynes 242) at 4 K before and after the exposure to the heat treatment. These alloys are presently being considered as candidates for use in the next‐generation series connected hybrid magnet for the NHMFL. Both of the alloys are found to have adequate fatigue and fracture properties for the CICC application while the superalloy ha...","PeriodicalId":80359,"journal":{"name":"Advances in cryogenic engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1063/1.2192340","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59395982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Poly‐diCylopentadiene (poly‐DCPD) resins are widely used because of their excellent physical and mechanical properties and their compatibility with various molding techniques. Poly‐DCPD’s ability to be rotationally molded has generated the potential for this crosslinked thermoset polymer to be used for cryogenic tanks. In turn, this has generated the need for cryogenic materials property data on these resins. In a collaborative research agreement between the National High Magnetic Field Laboratory (NHMFL) and Cymetech LLC, five different variations of poly‐DCPD have been thermally and mechanically characterized. Specifically, the tensile, compressive, shear and flexural properties have been measured at 77 K, as well as thermal contraction to 77 and 4 K. There are subtle differences in the properties between each formulation and larger discrepancies when compared to cryogenic data for other polymers. The thermal contraction to 77 K and elastic modulus are typical compared to other epoxies and polyester while the 77 K strength and elongation to failure are superior. The high strengths and elongations are good indicators that poly‐DCPD also has good toughness — an important property in many low temperature applications. This initial cryogenic properties database for poly‐DCPD allows it to be considered as a neat polymer in cryogenic applications, as well as an excellent matrix material for fiber reinforced composites in cryogenic applications.Poly‐diCylopentadiene (poly‐DCPD) resins are widely used because of their excellent physical and mechanical properties and their compatibility with various molding techniques. Poly‐DCPD’s ability to be rotationally molded has generated the potential for this crosslinked thermoset polymer to be used for cryogenic tanks. In turn, this has generated the need for cryogenic materials property data on these resins. In a collaborative research agreement between the National High Magnetic Field Laboratory (NHMFL) and Cymetech LLC, five different variations of poly‐DCPD have been thermally and mechanically characterized. Specifically, the tensile, compressive, shear and flexural properties have been measured at 77 K, as well as thermal contraction to 77 and 4 K. There are subtle differences in the properties between each formulation and larger discrepancies when compared to cryogenic data for other polymers. The thermal contraction to 77 K and elastic modulus are typical compared to other epoxies and polyester whi...
{"title":"Thermal and Mechanical Properties of Poly‐Dicyclopentadiene (DCPD) at Cryogenic Temperatures","authors":"V. Toplosky, R. Walsh","doi":"10.1063/1.2192354","DOIUrl":"https://doi.org/10.1063/1.2192354","url":null,"abstract":"Poly‐diCylopentadiene (poly‐DCPD) resins are widely used because of their excellent physical and mechanical properties and their compatibility with various molding techniques. Poly‐DCPD’s ability to be rotationally molded has generated the potential for this crosslinked thermoset polymer to be used for cryogenic tanks. In turn, this has generated the need for cryogenic materials property data on these resins. In a collaborative research agreement between the National High Magnetic Field Laboratory (NHMFL) and Cymetech LLC, five different variations of poly‐DCPD have been thermally and mechanically characterized. Specifically, the tensile, compressive, shear and flexural properties have been measured at 77 K, as well as thermal contraction to 77 and 4 K. There are subtle differences in the properties between each formulation and larger discrepancies when compared to cryogenic data for other polymers. The thermal contraction to 77 K and elastic modulus are typical compared to other epoxies and polyester while the 77 K strength and elongation to failure are superior. The high strengths and elongations are good indicators that poly‐DCPD also has good toughness — an important property in many low temperature applications. This initial cryogenic properties database for poly‐DCPD allows it to be considered as a neat polymer in cryogenic applications, as well as an excellent matrix material for fiber reinforced composites in cryogenic applications.Poly‐diCylopentadiene (poly‐DCPD) resins are widely used because of their excellent physical and mechanical properties and their compatibility with various molding techniques. Poly‐DCPD’s ability to be rotationally molded has generated the potential for this crosslinked thermoset polymer to be used for cryogenic tanks. In turn, this has generated the need for cryogenic materials property data on these resins. In a collaborative research agreement between the National High Magnetic Field Laboratory (NHMFL) and Cymetech LLC, five different variations of poly‐DCPD have been thermally and mechanically characterized. Specifically, the tensile, compressive, shear and flexural properties have been measured at 77 K, as well as thermal contraction to 77 and 4 K. There are subtle differences in the properties between each formulation and larger discrepancies when compared to cryogenic data for other polymers. The thermal contraction to 77 K and elastic modulus are typical compared to other epoxies and polyester whi...","PeriodicalId":80359,"journal":{"name":"Advances in cryogenic engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1063/1.2192354","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59396195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
W. Tang, Xiuyan Li, Enhou Han, Yong-bo Xu, Yiyi Li
The influence of temperature on the deformation and failure behavior of AZ80 wrought Mg alloy has been examined from 77K to 298K. It is found that the yield strength (YS) and ultimate strength (UTS) are increasing with the temperature decreasing, while the elongation is decreasing especial between 213K and 143K. Based on the mechanical tests, observation of environmental scanning electron microscope (ESEM) and transmission electron microscope (TEM), it is proposed that the alloy deforms mainly by slips and twins, but undergoes different mechanism of cleavage in the range of testing temperature. At T>213K, the alloy ductility is higher because the dislocations could pass through twins but pile up at precipitate phase: Mg17Al12, which causes the crack nucleate. At T<143K, the alloy ductility is lower because the dislocation slip are suppressed greatly and dislocations pile up at twins, and cause crack nucleate and expand along twins quickly. At 143K
在77K ~ 298K范围内，研究了温度对AZ80变形镁合金变形和失效行为的影响。结果表明，随着温度的降低，合金的屈服强度(YS)和极限强度(UTS)逐渐升高，而伸长率则逐渐降低，在213K ~ 143K之间表现得尤为明显。通过力学试验、环境扫描电镜(ESEM)和透射电镜(TEM)观察，认为合金变形主要以滑移和孪晶变形为主，但在试验温度范围内发生不同的解理机制。在tbbb213k时，由于位错可以穿过孪晶，但在Mg17Al12析出相堆积，导致裂纹形核，合金的塑性较高。在T<143K时，由于位错滑移受到极大抑制，位错在孪晶处堆积，导致裂纹迅速形核并沿孪晶扩展，合金塑性较低。在143 k
{"title":"Deformation Behavior of AZ80 Wrought Magnesium Alloy at Cryogenic Temperatures","authors":"W. Tang, Xiuyan Li, Enhou Han, Yong-bo Xu, Yiyi Li","doi":"10.1063/1.2192349","DOIUrl":"https://doi.org/10.1063/1.2192349","url":null,"abstract":"The influence of temperature on the deformation and failure behavior of AZ80 wrought Mg alloy has been examined from 77K to 298K. It is found that the yield strength (YS) and ultimate strength (UTS) are increasing with the temperature decreasing, while the elongation is decreasing especial between 213K and 143K. Based on the mechanical tests, observation of environmental scanning electron microscope (ESEM) and transmission electron microscope (TEM), it is proposed that the alloy deforms mainly by slips and twins, but undergoes different mechanism of cleavage in the range of testing temperature. At T>213K, the alloy ductility is higher because the dislocations could pass through twins but pile up at precipitate phase: Mg17Al12, which causes the crack nucleate. At T<143K, the alloy ductility is lower because the dislocation slip are suppressed greatly and dislocations pile up at twins, and cause crack nucleate and expand along twins quickly. At 143K","PeriodicalId":80359,"journal":{"name":"Advances in cryogenic engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1063/1.2192349","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59396495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The jacket of the central solenoid (CS) for ITER is designed to support cyclic tension load generated by the electro‐magnetic hoop force during operation. Therefore, the CS jacket material requires high tensile strength, high ductility, and high resistance to fatigue. JK2LB was developed in Japan as a candidate material for CS jacket by using low carbon and boron additions in JK2. The preliminary data of mechanical property for JK2LB without cold work has shown improvement of ductility in comparison to JK2. As a routine multi‐party verification process, a series of new mechanical tests including tensile, fatigue crack growth and fracture toughness have been carried out at 4K in MIT for both the base metal and welds of JK2LB. The test materials provided by JAREI were subjected to various cold work and aging before testing. It is found that the cold work has significant impact on the properties. Large variation of the tensile properties is observed. It includes a few specimens with brittle‐like behavior. Th...
{"title":"Mechanical Properties of JK2LB at 4K","authors":"Jun Feng, J. Kim, R. Ballinger, J. Minervini","doi":"10.1063/1.2192351","DOIUrl":"https://doi.org/10.1063/1.2192351","url":null,"abstract":"The jacket of the central solenoid (CS) for ITER is designed to support cyclic tension load generated by the electro‐magnetic hoop force during operation. Therefore, the CS jacket material requires high tensile strength, high ductility, and high resistance to fatigue. JK2LB was developed in Japan as a candidate material for CS jacket by using low carbon and boron additions in JK2. The preliminary data of mechanical property for JK2LB without cold work has shown improvement of ductility in comparison to JK2. As a routine multi‐party verification process, a series of new mechanical tests including tensile, fatigue crack growth and fracture toughness have been carried out at 4K in MIT for both the base metal and welds of JK2LB. The test materials provided by JAREI were subjected to various cold work and aging before testing. It is found that the cold work has significant impact on the properties. Large variation of the tensile properties is observed. It includes a few specimens with brittle‐like behavior. Th...","PeriodicalId":80359,"journal":{"name":"Advances in cryogenic engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1063/1.2192351","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59396505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Humer, E. Seidl, H. Weber, P. Fabian, S. Feucht, N. Munshi
Glass‐fiber reinforced plastics (GFRPs) are used as insulation materials for the superconducting magnet coils of the International Thermonuclear Experimental Reactor (ITER). The radiation environment present at the magnet location will lead to gas production, swelling and weight loss of the laminate, which may result in a pressure rise combined with undefined stresses on the magnet coil casing. Consequently, these effects are important parameters for the engineering and design criteria of superconducting magnet coil structures. In this study, newly developed epoxy and cyanate‐ester (CE) based S2‐glass fiber reinforced insulation systems were irradiated at ambient temperature in the TRIGA‐Mark II reactor (Vienna) to a fast neutron fluence of 1 and 5×1021 m−2 (E>0.1 MeV) prior to measurements of gas evolution, swelling and weight loss. The CE based laminates show increased radiation resistance, i.e. less gas evolution. The highest radiation hardness up to the highest dose was observed in a pure CE system. I...
{"title":"Gas Evolution Measurements on Reactor Irradiated Advanced Fusion Magnet Insulation Systems","authors":"K. Humer, E. Seidl, H. Weber, P. Fabian, S. Feucht, N. Munshi","doi":"10.1063/1.2192369","DOIUrl":"https://doi.org/10.1063/1.2192369","url":null,"abstract":"Glass‐fiber reinforced plastics (GFRPs) are used as insulation materials for the superconducting magnet coils of the International Thermonuclear Experimental Reactor (ITER). The radiation environment present at the magnet location will lead to gas production, swelling and weight loss of the laminate, which may result in a pressure rise combined with undefined stresses on the magnet coil casing. Consequently, these effects are important parameters for the engineering and design criteria of superconducting magnet coil structures. In this study, newly developed epoxy and cyanate‐ester (CE) based S2‐glass fiber reinforced insulation systems were irradiated at ambient temperature in the TRIGA‐Mark II reactor (Vienna) to a fast neutron fluence of 1 and 5×1021 m−2 (E>0.1 MeV) prior to measurements of gas evolution, swelling and weight loss. The CE based laminates show increased radiation resistance, i.e. less gas evolution. The highest radiation hardness up to the highest dose was observed in a pure CE system. I...","PeriodicalId":80359,"journal":{"name":"Advances in cryogenic engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1063/1.2192369","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59396953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Hennessy, E. Mueller, O. Mueller, J. Park, R. R. Neal
Several cryogenic power converter modules were built and tested, including a low‐voltage, high‐power series based on Cryo‐MOSFETs and a high‐voltage, high‐power series based on Cryo‐IGBTs. Half‐bridge modules were manufactured and demonstrated in liquid nitrogen. The hardware is such that several half‐bridge modules can be interconnected to form a multiphase full bridge. Conduction losses in the MOSFET modules were reduced by more than an order of magnitude. Switching powers up to 340 kW were achieved in the MOSFET modules, and 720 kW was demonstrated in the IGBT series. These modules can be utilized in fully integrated, megawatt‐level cryogenic power systems.
{"title":"Cryogenic Power Converter Module Performance","authors":"M. Hennessy, E. Mueller, O. Mueller, J. Park, R. R. Neal","doi":"10.1063/1.2192373","DOIUrl":"https://doi.org/10.1063/1.2192373","url":null,"abstract":"Several cryogenic power converter modules were built and tested, including a low‐voltage, high‐power series based on Cryo‐MOSFETs and a high‐voltage, high‐power series based on Cryo‐IGBTs. Half‐bridge modules were manufactured and demonstrated in liquid nitrogen. The hardware is such that several half‐bridge modules can be interconnected to form a multiphase full bridge. Conduction losses in the MOSFET modules were reduced by more than an order of magnitude. Switching powers up to 340 kW were achieved in the MOSFET modules, and 720 kW was demonstrated in the IGBT series. These modules can be utilized in fully integrated, megawatt‐level cryogenic power systems.","PeriodicalId":80359,"journal":{"name":"Advances in cryogenic engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1063/1.2192373","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59397636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Different applications of superconductors require different material properties. In this paper a short account is given of the relevant properties of the main materials of interest, BSCCO, MgB2 and YBCO. While BSCCO tapes are well established, the low irreversibility field limits their use at 77K while at 30K where they can stand reasonably high magnetic fields, the cheapness and ease of manufacture of MgB2 makes this new material a serious competitor. Bulk YBCO is also well developed and can produce high fields, but coated YBCO conductors have more applications if the cost can be brought down. AC losses are central to many applications. Since the loss/vol is proportional to Jc, but the volume of material required for a given magnet is inversely proportional to Jc the loss is independent of the material used and depends only on the width of the conductor. However using fine filaments requires that they be decoupled, and is in conflict with the need to avoid high angle grain boundaries across the current p...
{"title":"Superconducting Materials for Practical Applications","authors":"A. Campbell","doi":"10.1063/1.2192376","DOIUrl":"https://doi.org/10.1063/1.2192376","url":null,"abstract":"Different applications of superconductors require different material properties. In this paper a short account is given of the relevant properties of the main materials of interest, BSCCO, MgB2 and YBCO. While BSCCO tapes are well established, the low irreversibility field limits their use at 77K while at 30K where they can stand reasonably high magnetic fields, the cheapness and ease of manufacture of MgB2 makes this new material a serious competitor. Bulk YBCO is also well developed and can produce high fields, but coated YBCO conductors have more applications if the cost can be brought down. AC losses are central to many applications. Since the loss/vol is proportional to Jc, but the volume of material required for a given magnet is inversely proportional to Jc the loss is independent of the material used and depends only on the width of the conductor. However using fine filaments requires that they be decoupled, and is in conflict with the need to avoid high angle grain boundaries across the current p...","PeriodicalId":80359,"journal":{"name":"Advances in cryogenic engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1063/1.2192376","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59397937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Zeitlin, E. Gregory, J. Marte, M. Benz, R. Scanlan, D. Dietderich
MEIT conductors fabricated with Nb‐1at%Zr filaments are evaluated as to the effect of the additions of Oxygen and Titanium introduced through the tin core. The effects as a function of time and temperature are evaluated through reaction area and grain size. Current density in the reaction layer is evaluated as a function of magnetic field and the reaction variables. In the temperature range of 850 °C to 900°C the addition of oxygen yielded the best results with layer current density of 1877 A/mm2 at 12 T. Fabrication experience with Nb‐1at%ZrOx filaments and solutions are also discussed.
{"title":"The Effect on the Superconducting Properties of the Addition of Oxygen and Titanium to (Nb‐1Zr)3Sn Mono Element Internal Tin (MEIT) Conductors","authors":"B. Zeitlin, E. Gregory, J. Marte, M. Benz, R. Scanlan, D. Dietderich","doi":"10.1063/1.2192389","DOIUrl":"https://doi.org/10.1063/1.2192389","url":null,"abstract":"MEIT conductors fabricated with Nb‐1at%Zr filaments are evaluated as to the effect of the additions of Oxygen and Titanium introduced through the tin core. The effects as a function of time and temperature are evaluated through reaction area and grain size. Current density in the reaction layer is evaluated as a function of magnetic field and the reaction variables. In the temperature range of 850 °C to 900°C the addition of oxygen yielded the best results with layer current density of 1877 A/mm2 at 12 T. Fabrication experience with Nb‐1at%ZrOx filaments and solutions are also discussed.","PeriodicalId":80359,"journal":{"name":"Advances in cryogenic engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1063/1.2192389","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59398212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Miyoshi, S. Awaji, H. Oguro, G. Nishijima, K. Watanabe
We found that critical current Ic, upper critical field Bc2 and critical temperature Tc are greatly enhanced by pre‐bending treatment for bronze route Nb3Sn superconductors, called the pre‐bending effect. The superconducting properties of Nb3Sn superconductor are sensitive to strain. However, a pre‐bending treatment of the Nb3Sn wire enhances the properties. This is because the treatment causes relaxation of the residual strain in the Nb3Sn layer in the wire.Interestingly, the pre‐bending effect also makes the Nb3Sn wire stronger against strain. By using this effect, the react‐and‐wind (R&W) method is expected to be applicable for the fabrication of the Nb3Sn superconducting coil. In this paper, the development of Nb3Sn coils made by the R&W method with the pre‐bending effect is described, and the efficiency of the cable assembled by the reacted Nb3Sn strands is discussed.
{"title":"Ic Enhancement Effect in Nb3Sn Coils Fabricated by the React‐and‐Wind Method","authors":"K. Miyoshi, S. Awaji, H. Oguro, G. Nishijima, K. Watanabe","doi":"10.1063/1.2192392","DOIUrl":"https://doi.org/10.1063/1.2192392","url":null,"abstract":"We found that critical current Ic, upper critical field Bc2 and critical temperature Tc are greatly enhanced by pre‐bending treatment for bronze route Nb3Sn superconductors, called the pre‐bending effect. The superconducting properties of Nb3Sn superconductor are sensitive to strain. However, a pre‐bending treatment of the Nb3Sn wire enhances the properties. This is because the treatment causes relaxation of the residual strain in the Nb3Sn layer in the wire.Interestingly, the pre‐bending effect also makes the Nb3Sn wire stronger against strain. By using this effect, the react‐and‐wind (R&W) method is expected to be applicable for the fabrication of the Nb3Sn superconducting coil. In this paper, the development of Nb3Sn coils made by the R&W method with the pre‐bending effect is described, and the efficiency of the cable assembled by the reacted Nb3Sn strands is discussed.","PeriodicalId":80359,"journal":{"name":"Advances in cryogenic engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1063/1.2192392","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59398272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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