11 T liquid helium-free superconducting magnet

Watanabe, Kazuo; Awaji, Satoshi; Sakuraba, J.; Watazawa, K.; Hasebe, T.; Jikihara, Kazunori; Yamada, Yutaka; Ishihara, Mamoru

doi:10.1016/s0011-2275(96)00091-4

Cited by 57 publications

(14 citation statements)

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“…The isothermal annealing treatments were carried out in a furnace installed in a cryocooler-cooled superconducting magnet capable of generating a high magnetic field of 11 T. [10] For comparison, the specimens were heated to the peak temperatures selected, ranging from 650 to 850 C at a heating rate of 50 C/min in an argon-flow atmosphere and cooled in the furnace after 25 min of holding time, respectively with and without applying a 10 T magnetic field. In both cases, the specimens were placed in the center of the magnetic bore with their rolling direction (RD) parallel to the magnetic field direction (MD).…”

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confidence: 99%

Effects of a High Magnetic Field on Microstructure and Texture Evolution in a Cold‐rolled Interstitial‐Free (IF) Steel Sheet during Annealing

Zhang

Zhao

et al. 2003

Adv Eng Mater

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In the past few decades, the effects of magnetic field on metallurgical phenomena have received great interest in relation with the modification of microstructure and the development of high-performance magnetic materials. [1±3] However, only limited studies have focused on recrystallization and recrystallization texture development in magnetic materials during magnetic field annealing. It was found that the application of a magnetic field could (i) produce some changes in the recrystallization texture in the case of a cold-rolled Fe-Co alloy, [4,5] (ii) introduce the <111> and <112> texture components with a swaged iron wire, [6] (iii) retard recrystallization and increase the {100} recrystallization texture component in the case of a cold-rolled Armco iron, [7] (iv) increase the frequency of low-angle boundaries in an Fe-Co alloy [8] and Fe3%Si alloy [9] and enhance the selectivity of the <001> axis alignment in an Fe-3%Si alloy. [9] With the current development of the cryocooling technique, high magnetic fields of over 10 T have become available at a reasonable in-lab cost. In this paper, we present a comparative study on the impact of a high magnetic field on the microstructure and texture evolution in a cold-rolled IF steel sheet during annealing.The material used in this study was a 76 % cold-rolled IF steel sheet of 1 mm thickness, with a chemical composition of (wt.%): 0.0023 C, 0.056 Ti, 0.014 Si, 0.16 Mn, 0.011 P, 0.0064 S, 0.052 Al, 0.0018 N. Specimens were taken from the sheet in a longitudinal direction parallel to the rolling direction. The isothermal annealing treatments were carried out in a furnace installed in a cryocooler-cooled superconducting magnet capable of generating a high magnetic field of 11 T. [10] For comparison, the specimens were heated to the peak temperatures selected, ranging from 650 to 850 C at a heating rate of 50 C/min in an argon-flow atmosphere and cooled in the furnace after 25 min of holding time, respectively with and without applying a 10 T magnetic field. In both cases, the specimens were placed in the center of the magnetic bore with their rolling direction (RD) parallel to the magnetic field direction (MD). The experimental setup is schematically shown in Fig. 1.The X-ray texture measurements were performed for the cold and annealed specimens at their one-quarter thickness by measuring three incomplete {110}, {200} and {211} pole figures up to a maximal polar angle of 70 with the Schulz back-reflection method. [11] The corresponding ODFs were calculated with the two-step method [12] and the results were presented in constant j-sections (Roe's notation). The microstructure of the longitudinal section of the specimens was examined with an optical microscope. For the specimens annealed at 700 C, the local orientations on the RD-ND plane close to the specimen center were measured using a SEM-EBSD system. The scan was carried out over a grid size of 192 x 120 with 2 lm spacing. The average indexed fractions of the two specimens was above 90 %. The microhardness tests ...

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confidence: 99%

Effects of a High Magnetic Field on Microstructure and Texture Evolution in a Cold‐rolled Interstitial‐Free (IF) Steel Sheet during Annealing

Zhang

Zhao

et al. 2003

Adv Eng Mater

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“…The development work on these systems was carried out during 1990s and during the last decade at several research groups [1][2][3][4][5]. In CFMS, the superconducting magnets are cooled to the desired operating temperature by conduction using the refrigeration capacity of a cryocooler (CCR).…”

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Experimental studies on thermal behavior of 6 Tesla cryogen-free superconducting magnet system

Kar¹,

Konduru²,

Kumar³

et al. 2012

AIP Conference Proceedings

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Peformance test and thermal analysis of conduction-cooled optimized current leads at nonoptimum operation AIP Conference Proceedings 1434, 597 (2012) Inter University Accelerator Centre Aruna Asaf Ali Marg, New Delhi, 110067, India ABSTRACT A 6 T cryogen-free superconducting magnet system (CFMS) with warm bore has been designed, built and tested for carrying out physical property measurements at high magnetic field. The CFMS has a vertical Φ 50 mm clear room temperature working bore. A two-stage GM-cryocooler of 35 W at 50 K and 1.5 W at 4 K cooling capacity has been used to cool the thermal radiation shield, hybrid current leads and the NbTi magnet. The magnet was charged to 102 A, which produced a field of 6 T, in less than 20 minutes. The outer surface temperature of magnet rose from 3.3 K at zero current to 3.9 K at 102 A current. The thermal link between cold head and magnet greatly influences the excitation rate and the stability of the magnet. Based upon our thermal analysis on the magnet system, an experimental study has been carried out on the thermal behavior of the magnet during its operation. A novel technique has been used for connecting the high temperature superconducting current leads to the magnet so as to reduce both electrical and thermal contact resistance at the 2 nd stage of the cryocooler. This paper briefly describes the design, development and results of experimental studies of thermal behavior of the system.

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“…After the first demonstration of hybrid current leads for conduction-cooled magnet system in 1993 [2], many conduction-cooled superconducting magnet systems have been developed and commercialized [3][4][5]. The heat conducted through the metal part of the lead and the Joule heat generated within it is transferred to the 1 st stage of the CCR.…”

Section: Introductionmentioning

confidence: 99%

Peformance test and thermal analysis of conduction-cooled optimized current leads at non-optimum operation

Kar¹,

Konduru²,

Kumar³

et al. 2012

AIP Conference Proceedings

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Current leads are the key components which make an electrical connection between room temperature power supply and superconducting magnets at 4.2 K. In any cryogenfree magnet system, major heat input comes from the copper current leads of the magnet. The dimensional optimization of the copper part of the hybrid current leads is done for a particular operating current between room temperature to the operating temperature of the 1 st stage of cryocooler (CCR). The conduction-cooled magnet may not necessarily be operated at the optimized current all the time. Hence for non-optimum current, the heat input per unit current will be increased both at under-current and over-current operation. The stabilized temperature, of the 1 st stage of CCR corresponding to each operating current, would mainly be governed by the dynamic heat input by the current lead. A pair of copper current leads working between the temperatures 300 K to 33 K has been optimized for 85 A optimum current. A simple analytical technique has been used for estimation of dynamic heat load at non-optimum operation. This paper describes the optimization procedure, estimation of dynamic heat input, measurement and detailed thermal analysis of conduction-cooled current leads at non-optimum operation.

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11 T liquid helium-free superconducting magnet

Cited by 57 publications

References 10 publications

Effects of a High Magnetic Field on Microstructure and Texture Evolution in a Cold‐rolled Interstitial‐Free (IF) Steel Sheet during Annealing

Effects of a High Magnetic Field on Microstructure and Texture Evolution in a Cold‐rolled Interstitial‐Free (IF) Steel Sheet during Annealing

Experimental studies on thermal behavior of 6 Tesla cryogen-free superconducting magnet system

Peformance test and thermal analysis of conduction-cooled optimized current leads at non-optimum operation

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