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2009 MAGNET DEVELOPMENT AND INSTRUMENTATIONPulsed high-field coilsThe production of user coilsAlso in 2009 the copper-zylon coils remain the workhorseof the laboratory. The production of these coils has nowbecome standard; parts are parameterized and can be producedin 2 weeks on the computerized milling machine,the actual winding takes less than a week and testing a fewdays. Since most of the time parts are in stock and at least4 members of the team have the experience to wind a coil,a standard coil can be produced in 10 days. Moreover, thepolicy is to have at least one standard coil in stock, in orderto avoid as far as possible any delay for users after a(finally unavoidable) coil failure. A first glidcop zylon coilwas tested up to 72 T and is now available for users duringthe time the 1 MJ transportable generator is available.Given the success of this small-volume, short-pulse prototype,we have constructed a longer pulse (t max = 33 ms,t total = 200 ms ) 72 T coil which can be energized by the14 MJ generator. This magnet has been successfully testedand is now available to users on a permanent basis.Figure 168:XXL coilSpecial coilsIn 2009 a special coil for optical experiments (BMV) wasdeveloped and successfully tested in house and to the highestfield at our colleagues in Dresden. This coil (nicknamedXXL - see figure 168) is an up-scaled version of the X-coil. This coil produced 300 T 2 .m and is an improvementof 1100% compared to the former X-coils. The split coil,specially designed for synchrotron X-ray experiments, wasfinally tested inside its cryostat after some problems due tothe complicated integration of the coil-body with the liquidnitrogen cryostat. Last, but not least, a mini-coil madefrom Cu-stainless wire was produced by Jérome Béard andhe was able to break with this coil (used as an insert in astandard 60 T coil) the record field of the Toulouse laboratorythat now stands at 81 T. This test was partly made tovalidate our multi-coil design code that was used to designa large two-coil magnet (ARMS4).Technical developmentsMost of the time in coil winding is spent on applying thezylon reinforcement, therefore we decided to improve thezylon spinhead by making it more reliable (new frictionbrakes) and easier to maintain (the spinhead modules canbe exchanged in 2 minutes, to be cleaned and maintained).Since the main progress in coil performance has to comefrom progress in materials it is of utmost importance tostudy the materials used in coil construction under realisticconditions (cryogenic temperature and high mechanicalloads). To test the efficiency of the fibre reinforcement wedecided to continue the explo-vessel studies (as first developedin at the Universiteit van Amsterdam). Unfortunatelyonce the setup was running (using the high-pressure rig atthe Clarendon Laboratory in Oxford) and 30 pressure vesselshad been produced, it turned out that this installationwas not longer available to us due to changing priorities inOxford. Another high-pressure rig was identified in Franceand we expect to restart the explo-vessel tests before theend of the year. These tests will be used to determine forthe first time the properties of zylon reinforcement underrealistic conditions, study the influence of various impregnatesand impregnation methods, and last but not least toinvestigate other high-strength fibres that could be used as afall back solution in case zylon would not be available anymore.Apart from the mechanical strength of the conductorand the fibre reinforcement the quality of the isolation underhigh mechanical load at cryogenic temperature is of greatimportance to have coils with a long lifetime. In order totest various types of insulations we developed an isolationtest on wires applying realistic loads to the isolation. Thisinstallation has started to work and the first results will beavailable before the end of the year.OutlookThe success of pulsed fields combined with large-scale neutronand X-ray sources has created a demand for more timeat high magnetic fields per 24 hour period. This will be realizedby improving the duty cycle of the coils by increasingthe pulse duration (to prolong lifetime) combined with a reductionof the cool down time. Some test with liquid nitrogenbased on techniques used up to now in dc fields lookedvery promising (cool down times of only a few minutes). Itis likely that by implementing these techniques in our coilswe can gain at least a factor of ten in the duty cycle.J. Béard, J. Billette, P. Frings, F. Giquel , J.-M. Lagarrigue, J. Mauchain119
MAGNET DEVELOPMENT AND INSTRUMENTATION 2009High strength conductors for pulsed magnetsR&D of high strength composite conductors- for B > 80 T in the coilin/coilex system: the developmentof Cu/SS wires, for the coilin, with 60% of stainless steel(UTS(77 K)>1550 MPa) and a cross section of 2.00×1.25mm 2 allowed us to reach 81 Tesla (the LNCMI record) inspring 2009.- Cu alloys for magnets with optimized current distribution:conductors made of copper alloys like GlidCop(CuAl 2 O 3 ) or CuAg (with low silver content 0.08%) havebeen processed by industrial companies to be combinedwith Zylon fibers in the user’s magnet with optimized reinforcementdistribution.Ultra-high strength nanocomposite Cu/Nb conductorsThe development of reinforced conductors, with high electricalconductivity and high strength, is essential to providenon-destructive high pulsed magnetic fields over 80 Tesla:the best compromise is obtained with copper-based continuousnanofilamentary wires (UTS = 2 GPa and ρ =0.6 µΩcm at 77 K). The fabrication process of thesenanocomposite wires is based on severe plastic deformation(SPD) applied by accumulative drawing and bundling,leading to a multi-scale copper matrix containing up toN = 85 4 (∼ 50×10 6 ) continuous and parallel niobium nanotubes[Vidal et al., Scripta Mat., 60, 171 (2009)].In 2007, the extrusion of the nanocomposite conductorshas been stopped at the “Centre de Recherche” of TRE-FIMETAUX because of its closure. We decided to pursueour development in collaboration with the CEA/LTMEX inSaclay where a 575 tons extrusion press is available.Development of a new co-axial CuNbCuNb nanocompositewiresA new nanocomposite structure has been designed with asuperposition of Nb and Cu nanotubes (figure 169). Weadded nanometric phases remembering that the extraordinarystrengthening of the co-cylindrical structure is relatedto: (i) an increase of Cu-Nb interfaces surface acting asdislocations barriers; (ii) a rapid and controlled access tonanometre scale where size effect operates on the plasticitymechanisms; (iii) the contribution of an additional reinforcingphase: the Cu-f nanofibers embedded in the Nbnanotubes behave as whiskers with strong size dependence.A conductor containing 85 3 Nb nanowhiskers, Cu nanotubesand Nb nanotubes, embedded in a copper matrixhas been obtained. This Cu/Nb/Cu/Nb system is thereforemore efficient than Cu/Nb filamentary and Cu/Nb/Cu cocylindricalsystems for high-strength applications in magnets(figure 170): it exhibits a controlled microstructureand an efficient strengthening in the nanocomposite zones,where size and also geometry play major roles.Figure 169: Co-axial conductors: (a) N = 85; (b) N = 85 3 .Figure 170: Ultimate tensile strength of co-axial CuNbCuNb andco-cylindrical CuNbCu nanocomposite wires versus diameter.The improvement of the drawing conditions led us to applythe same procedure for the optimization of the extrusionconditions. In the framework of the NANOFILMAGproject, funded by the ANR and involving the PHYMAT,two CEA laboratories (DAPNIA, LTMEX), and an industrialpartner (Alstom/MSA), a program has been defined tooptimize the extrusion conditions. The aim is the preventionof fractures during the extrusion step of the ADB processand the scale-up of the size of the nanocomposite billets.A Ph.D student, J.B Dubois, is involved in the projectand shares his activity between LNCMI and PHYMAT.In addition, in-situ neutron diffraction (POLDI-PSI) and exsitulaboratory x-ray diffraction experiments (PHYMAT-Poitiers, ESRF) have been performed for different heattreatments to study the formation of the texture. Textureand microstructure in the copper after heat treatmentspresent radical differences depending on the size of the consideredcopper channels [to be published].F. Lecouturier, N. Ferreira, L. Bendichou, J.M. Lagarrigue, J.B. DuboisL. Thilly, P.O Renault (PHYMAT, Poitiers, France), H. van Swygenhoven, S. van Petegem (POLDI-Paul ScherrerInstitut, Switzerland), P. Olier (CEA-DEN-LTMEX, Saclay, France), C. Berriaud (CEA-IRFU-SACM, Saclay)120
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LABORATOIRE NATIONAL DES CHAMPS MAG
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TABLE OF CONTENTSPreface 1Carbon Al
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Coexistence of closed orbit and qua
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2009PrefaceDear Reader,You have bef
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2009 CARBON ALLOTROPESInvestigation
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2009 CARBON ALLOTROPESPropagative L
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2009 CARBON ALLOTROPESEdge fingerpr
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2009 CARBON ALLOTROPESObservation o
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2009 CARBON ALLOTROPESImproving gra
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2009 CARBON ALLOTROPESHow perfect c
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2009 CARBON ALLOTROPESTuning the el
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2009 CARBON ALLOTROPESElectric fiel
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2009 CARBON ALLOTROPESMagnetotransp
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2009 CARBON ALLOTROPESGraphite from
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2009Two-Dimensional Electron Gas25
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TWO-DIMENSIONAL ELECTRON GAS 2009Di
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TWO-DIMENSIONAL ELECTRON GAS 2009Sp
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TWO-DIMENSIONAL ELECTRON GAS 2009Cr
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TWO-DIMENSIONAL ELECTRON GAS 2009Re
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TWO-DIMENSIONAL ELECTRON GAS 2009In
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TWO-DIMENSIONAL ELECTRON GAS 2009Ho
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TWO-DIMENSIONAL ELECTRON GAS 2009Te
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2009 SEMICONDUCTORS AND NANOSTRUCTU
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2009Metals, Superconductors and Str
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METALS, SUPERCONDUCTORS... 2009Anom
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METALS, SUPERCONDUCTORS... 2009Magn
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METALS, SUPERCONDUCTORS ... 2009Coe
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METALS, SUPERCONDUCTORS ... 2009Fie
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METALS, SUPERCONDUCTORS... 2009High
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METALS, SUPERCONDUCTORS... 2009Angu
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Page 79 and 80: METALS, SUPERCONDUCTORS... 2009Temp
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Page 84 and 85: 2009 MAGNETIC SYSTEMSY b 3+ → Er
Page 86 and 87: 2009 MAGNETIC SYSTEMSMagnetotranspo
Page 88 and 89: 2009 MAGNETIC SYSTEMSHigh field tor
Page 90 and 91: 2009 MAGNETIC SYSTEMSNuclear magnet
Page 92 and 93: 2009 MAGNETIC SYSTEMSStructural ana
Page 94 and 95: 2009 MAGNETIC SYSTEMSEnhancement ma
Page 96 and 97: 2009 MAGNETIC SYSTEMSInvestigation
Page 98 and 99: 2009 MAGNETIC SYSTEMSField-induced
Page 100 and 101: 2009 MAGNETIC SYSTEMSMagnetic prope
Page 102: 2009Biology, Chemistry and Soft Mat
Page 105 and 106: BIOLOGY, CHEMISTRY AND SOFT MATTER
Page 108 and 109: 2009 APPLIED SUPERCONDUCTIVITYMagne
Page 110 and 111: 2009 APPLIED SUPERCONDUCTIVITYPhtha
Page 112: 2009Magneto-Science105
Page 115 and 116: MAGNETO-SCIENCE 2009Study of the in
Page 117 and 118: MAGNETO-SCIENCE 2009Magnetohydrodyn
Page 119 and 120: MAGNETO-SCIENCE 2009112
Page 122 and 123: 2009 MAGNET DEVELOPMENT AND INSTRUM
Page 136 and 137: 2009 PROPOSALSProposals for Magnet
Page 138 and 139: 2009 PROPOSALSSpin-Jahn-Teller effe
Page 140 and 141: 2009 PROPOSALSQuantum Oscillations
Page 142 and 143: 2009 PROPOSALSThermoelectric tensor
Page 144 and 145: 2009 PROPOSALSDr. EscoffierCyclotro
Page 146 and 147: 2009 PROPOSALSHigh field magnetotra
Page 148 and 149: 2009 THESESPhD Theses 20091. Nanot
Page 150 and 151: 2009 PUBLICATIONS[21] O. Drachenko,
Page 152 and 153: 2009 PUBLICATIONS[75] S. Nowak, T.
Page 154 and 155: Contributors of the LNCMI to the Pr
Page 156 and 157: Institut Jean Lamour, Nancy : 68Ins
Page 158 and 159: Lawrence Berkeley National Laborato
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