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2009 MAGNET DEVELOPMENT AND INSTRUMENTATIONTowards developing a high T c superconducting magnetHigh critical temperature superconductors (HTS) open extremelyinteresting perspectives for high field applicationssuch as high field magnets for NMR, SMES or physicalinvestigations [J. Schwartz et al., IEEE trans. on Appl. Superc.,18,pp. 70, (2008)]. The demand is high for 25, 30 andeven 50 T magnets and is beyond the possibilities offeredby low critical temperature superconductors, for exampleNb 3 Sn. The superconducting solutions for very high fieldsmeet the requirements for sustainable development.Rutherford cable. These data show that the wires withstandthe cabling process and that they are magnetically isotropic.It will be possible to test the HTS magnets in liquid/gascooling or conduction cooling.Recently, the interest for Bi-2212 round wire has been reinforcedfor high field applications [Shen et al., Appl. Phys.Lett. 95, 152516, (2009)] These wires show very high performancein terms of critical currents at ultra high fields,at least on short samples. The main issue with Bi-2212 remainsthe heat treatment, which should be very preciselycontrolled. The melting temperature plays a crucial part andshould be within a window of one or two degrees to obtainthe required highest critical currents densities. Even morerecently, the second generation (2G) HTS conductors, theYBaCuO coated conductors, show also very exciting performancesin terms of current capacities under very highfields whereas their mechanical properties are excellent forthe IBAD route. The mechanical performance is of greatimportance for very high field magnets. Substantial advanceshave been achieved with the 2G HTS and they havenow reached a stage, in terms of lengths, where it is possibleto use them in real devices.Several laboratories in Grenoble (IN, LNCMI, CRETA andG2Elab) have begun works on HTS magnets. IN andG2Elab have built and successfully tested an importantHTS magnet (800 kJ) operating at 20 K in the context of aDGA project. The present works are carried out in the contextof a European Project ”EuCARD” and an ANR project”SUPER-SMES”. The purpose is to study the most suitableHTS materials and develop the technology for veryhigh field and high performance HTS magnets for SMES(storage) or high energy physics (magnets for accelerators)purposes. An identified issue with HTS magnets is theirprotection and studies have begun both from simulation andexperimental points of view. In the development program,the critical characteristics remain the fundamental data required.Advanced characterization tools have been developed,in particular to obtain the critical characteristic underhigh fields at variable temperatures and variable field orientations.After delicate adjustments, the system works perfectly.Figure 174 shows the sample holder and the newcryostat under construction to test HTS coils at variabletemperatures in two LNCMI high field magnets. Figure 175shows two PIT Bi-2212 short samples round wires criticalcharacteristics. These wires are extracted from a NexansFigure 174: Sample holder and variable temperature cryostat.Figure 175: Bi-2212 I c (B) performance for round wires.F. Debray, J. P. Domps, E. Mossang, S. DufresnesP. Brosse-Maron, J. P. Leggeri (Institute Neel, Grenoble), J. M. Rey (CEA, IRFU, Saclay), P. Tixador (INP, Grenoble)123