Abstract:
A method for forming a superconducting wire with a tape substrate comprises dispensing the tape substrate, providing at least one reactor chamber to form at least one buffer material on the tape substrate based on determining at least one of a type of tape substrate, a type of superconductor material, and a type of buffer material, providing another reactor chamber to continuously form a layer of the superconductor material on a layer of the buffer material, and spooling the tape substrate with the layer of superconductor material.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of and claims priority to U.S. patent application Ser. No. 10/206,123 and also claims priority to U.S. Provisional Patent Application No. 60/539,055, the disclosures of which are hereby incorporated herein by reference. This application is related to co-pending and commonly assigned U.S. patent application Ser. No. 10/206,123, entitled “METHOD AND APPARATUS FOR FORMING SUPERCONDUCTOR MATERIAL ON A TAPE SUBSTRATE,” filed Jul. 26, 2002, to co-pending and commonly-assigned U.S. patent application Ser. No. 10/206,900, entitled “SUPERCONDUCTOR MATERIAL ON A TAPE SUBSTRATE,” filed Jul. 26, 2002, and concurrently filed and commonly assigned U.S. patent application Ser. No. 10/206,783, entitled “METHOD AND APPARATUS FOR FORMING A THIN FILM ON A TAPE SUBSTRATE,” filed Jul. 26, 2002, to U.S. patent application Ser. No. 11/039,711 filed concurrently herewith and entitled “SYSTEM AND METHOD FOR JOINING SUPERCONDUCTIVITY TAPE,” and to U.S. patent application Ser. No. 11/038,769 filed concurrently herewith and entitled “SYSTEM AND METHOD FOR QUALITY TESTING OF SUPERCONDUCTIVITY TAPE,” the disclosures of which are hereby incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     This invention relates in general to superconductors, and in specific to a method and apparatus for forming superconductor material on tape substrate 
     BACKGROUND OF THE INVENTION 
     Electrical resistance in metals arises because electrons that are propagating through the solid are scattered because of deviations from perfect translational symmetry. These deviations are produced either by impurities or the phonon lattice vibrations. The impurities form the temperature independent contribution to the resistance, and the vibrations form the temperature dependent contribution. 
     Electrical resistance, in some applications, is very undesirable. For example, in electrical power transmission, electrical resistance causes power dissipation, i.e. loss. The power dissipation grows in proportion to the square of the current, namely P=I 2 R in normal wires. Thus, wires carrying large currents dissipate large amounts of energy. Moreover, the longer the wire used in either larger transformers, bigger motors or larger transmission distances, the more dissipation, since the resistance in a wire is proportional to its length. Thus, as wire lengths increase more energy is lost in the wires, even with a relatively small currents. Consequently, electric power plants produce more energy than that which is used by consumers, since a portion of the energy is lost due to wire resistance. 
     In a superconductor that is cooled below its transition temperature T C , there is no resistance because the scattering mechanisms are unable to impede the motion of the current carriers. The current is carried, in most known classes of superconductor materials, by pairs of electrons known as Cooper pairs. The mechanism by which two negatively charged electrons are bound together is described by the BCS (Bardeen Cooper Schrieffer) theory. In the superconducting state, i.e. below T C , the binding energy of a pair of electrons causes the opening of a gap in the energy spectrum at E f , which is the Fermi energy or the highest occupied level in a solid. This separates the pair states from the “normal” single electron states. The size of a Cooper pair is given by the coherence length which is typically 1000 Å, although it can be as small as 30 Å in the copper oxides. The space occupied by one pair contains many other pairs, which forms a complex interdependence of the occupancy of the pair states. Thus, there is insufficient thermal energy to scatter the pairs, as reversing the direction of travel of one electron in the pair requires the destruction of the pair and many other pairs due to the complex interdependence. Consequently, the pairs carry current unimpeded. For further information on superconductor theory please see “Introduction to Superconductivity,” by M. Tinkham, McGraw-Hill, New York, 1975.) 
     Many different materials can become superconductors when their temperature is cooled below T C . For example, some classical type I superconductors (along with their respective T C &#39;s in degrees Kelvin (K)) are carbon 15K, lead 7.2K, lanthanum 4.9K, tantalum 4.47K, and mercury 4.47K. Some type II superconductors, which are part of the new class of high temperature superconductors (along with their respective T C &#39;s in degrees K), are Hg 0.8 Tl 0.2 Ba 2 Ca 2 Cu 3 O 8.33  138K, Bi 2 Sr 2 Ca 2 Cu 3 O 10  118 k, and YBa 2 Cu 3 O 7-   x  93K. The last superconductor is also well known as YBCO superconductor, for its components, namely Yttrium, Barium, Copper, and Oxygen, and is regarded as the highest performance and highest stability high temperature superconductor, especially for electric power applications. YBCO has a Perovskite structure. This structure has a complex layering of the atoms in the metal oxide structure.  FIG. 1  depicts the structure for YBa 2 Cu 3 O 7 , that include Yttrium atoms  101 , Barium atoms  102 , Copper atoms  103 , and Oxygen atoms  104 . For further information on oxide superconductors please see “Oxide Superconductors”, Robert J. Cava, J. Am. Ceram. Soc., volume 83, number 1, pages 5-28, 2000. 
     A problem with YBCO superconductors specifically, and the oxide superconductors in general, is that they are hard to manufacture because of their oxide properties, and are challenging to produce in superconducting form because of their complex atomic structures. The smallest defect in the structure, e.g. a disordering of atomic structure or a change in chemical composition, can ruin or significantly degrade their superconducting properties. Defects may arise from many sources, e.g. impurities, wrong material concentration, wrong material phase, wrong processing temperature, poor atomic structure, and improper delivery of materials to the substrate, among others. 
     Thin film YBCO superconductors can be fabricated in many ways including pulsed laser deposition, sputtering, metal organic deposition, physical vapor deposition, and chemical vapor deposition. Two typical ways for the deposition of thin film YBCO superconductors are described here as example. In the first way, the YBCO is formed on a wafer substrate in a reaction chamber  200 , as shown in  FIG. 2  by metal organic chemical vapor deposition (MOCVD). This manner of fabrication is similar to that of semiconductor devices. The wafer substrate is placed on holder  201 . The substrate is heated by heater  202 . The wafer substrate is also rotated which allows for more uniform deposition on the substrate wafer, as well as more even heating of the substrate. Material, in the form of a gas, is delivered to the substrate by shower head  203 , via inlet  204 . The shower head  203  provides a laminar flow of the material onto the substrate wafer. The material collects on the heated wafer substrate to grow the superconductor. Excess material is removed from the chamber  200  via exhaust port  208 , which is coupled to a pump. To prevent undesired deposition of material onto the walls of the chamber  200 , coolant flows through jackets  205  in the walls. To prevent material build up inside the shower head  203 , coolant flows through coils  206  in the shower head. The flanges port  207  allows access to the inside of the chamber  200  for insertion and removal of the film/substrate sample. Processing of the film may be monitored through optical port  209 . 
     In the second way, YBCO is formed by pulsed laser deposition on a substrate, including the possibility of using a continuous metal tape substrate  301 . The tape substrate  301  is supported by two rollers  302 ,  303  inside of a reaction chamber  300 . Roller  302  includes a heater  304 , which heats the tape  301  up to a temperature that allows YBCO growth. The material  305  is vaporized in a plume from a YBCO target by irradiation of the target by typically an excimer laser  306 . The vapor in the plume then forms the YBCO superconductor film on the substrate  301 . The rollers  302 ,  303  allow for continuous motion of the tape past the laser target thus allowing for continuous coating of the YBCO material onto the tape. Note that the laser  306  is external to the chamber  300  and the beam from the laser  306  enters the chamber  300  via optical port  307 . The resulting tape is then cut, and forms a tape or ribbon that has a layer of YBCO superconductive material. 
     Neither of the above described methods for forming thin film high temperature superconductors can produce a long length tape or ribbon of YBCO which can be used to replace copper (or other metal) wires in electric power applications. The first way only allows for the production of small pieces of superconductor material on the wafer, e.g. a batch process. The second way can only be used to make tape that is a few feet in length and uses multiple passes to generate a superconducting film of several microns thickness. The second way has a practical limitation of about 5 feet. Larger pieces of tape would require a larger heating chamber. A larger heating roller will also be needed. The tape will cool down after leaving roller  302 , and thus will need more time to heat back up to the required temperature. Heating on one side of the chamber, with a cool down on the other side of the chamber may also induce thermal cracks into the YBCO layer and other layers formed on the metal substrate. The smaller pieces of tape produced by the second method may be spliced together to form a long length tape, but while the pieces may be superconducting, splice technology is not yet at the point of yielding high quality high temperature superconductor splices. Consequently, current arrangements for forming superconductors cannot form a long, continuous tape of superconductor material. 
     BRIEF SUMMARY OF THE INVENTION 
     Embodiments of the present invention are directed to a system and method where there is a need in the art for an arrangement that would allow for the formation of a superconductor, preferably YBCO, onto a metal ribbon or tape or wire, in a continuous manner, so as to form a continuous, long-length superconductor ribbon or tape or wire. Note that the term superconducting wire, as used herein, includes any superconducting element used for transporting current. 
     These and other objects, features, and technical advantages are achieved by a system and method which continuously deposits materials used to grow a superconductor layer onto a moving tape. The embodiments use a pay-out reel to dispense the tape substrate at a constant rate. Embodiments then use an initialization stage to preheat and/or pretreat the tape substrate before growing the additional layers required for a superconducting wire. Preheating is desirable to lessen thermal shock of the tape substrate. Pretreating is desirable to reduce contaminants from the tape substrate before growing the additional layers required for a superconducting wire. Embodiments then use at least one reactor or reaction chamber to deposit one or more materials onto the tape substrate that is used to form the superconducting wire. The number of reactors needed depends upon the type superconductor material that is being formed, the type and number of buffer layers that are needed (if any) between the superconductor material and the tape substrate, and the type of tape substrate that is used to support the superconductor material. In addition, multiple reactors can be used to form a superconducting wire with multiple buffer layer/superconducting layer groups. Embodiments of the invention are modular such that reactors may be added or removed as needed. Embodiments use an anneal stage to finalize the superconductor layer and cool down the superconducting tape. Embodiments use a take-up reel to spool the superconducting tape. Embodiments may optionally use a coating stage that deposits a protective coating onto the superconducting tape and/or applies a protective interleaving layer to the tape. The interleaving layer is used in the storage, transportation, and packaging of the superconductor tape. This prevents the tape from sticking to itself when stored in reel form. Embodiments also may optionally use a quality control stage that ensures the proper characteristics of the superconducting tape. The embodiments may further optionally use a precleaning stage that removes grease and/or other contaminants from the tape prior to entry into the initialization stage. 
     Embodiments use transition chambers between the initialization stage and the reaction chamber, between the reaction chamber and the anneal stage, and between reaction chambers if more than one chamber is used. Additional reaction chambers or reactors may be used to provide buffer layers between the substrate and the high temperature superconducting (HTS) film, or coating layers on top of or in between layers of the HTS film. The transition chambers isolate each stage or reactor from the other stages and/or reactors, and thereby prevent cross-contamination of materials from one stage or reactor to another stage or reactor. The transition chamber is differentially pumped with narrow slits at either end through which the tape substrate is passed. The transition chamber includes a heating element that allows the temperature of the tape to be maintained and/or adjusted. The transition chamber includes at least one port to allow the introduction of at least one gas to control the environment in the transition chambers for optimal maintenance of the superconductor or buffer layers, and can incorporate tape monitoring for process control. The transition chamber may include at least one support that holds the tape during its transit through the transition chamber. 
     The reactor includes at least one support that holds the tape during its transit through the reactor. The reactor also includes a heating system that has a length in the direction of tape movement that is associated with the speed of the tape and the deposition of the material and/or growth rate of the superconductor layer. Thus, a portion of tape will be heated long enough so that a desired thickness of material (preferably, from 1 μm up to more than 10 μm) is achieved, as the portion of the tape is moved through the reaction region (thin film growth region) of the reactor. The reactor also uses a shower-head to provide a laminar flow of material onto the tape. The reactor further uses a cooling system to reduce the build up of material in undesired locations. 
     Embodiments of the invention may be used to form superconducting tape from different superconducting materials, including, but not limited to YBa 2 Cu 3 O 7-x , YBCO, NdBa 2 Cu 3 O 7-x , LaBa 2 Cu 3 O 7-x , Bi 2 Sr 2 Ca 2 Cu 3 O y , Pb 2-x Bi x Sr 2 Ca 2 Cu 3 O y , Bi 2 Sr 2 CaCu 2 O z , Tl 2 Ba 2 CaCu 2 O x , Tl 2 Ba 2 Ca 2 Cu 3 O y , TlBa 2 Ca 2 Cu 3 O z , Bi x Sr 2-y Ba y Ca 2 Cu 4 O z , TlBa 2 CaCu 2 O z , HgBa 2 CaCu 2 O y , HgBa 2 Ca 2 Cu 3 O y , MgB 2 , copper oxides, rare earth metal oxides, and other high temperature superconductors. Furthermore, the embodiments may operate for many different thin film deposition processes, including but not limited to metalo-organic chemical vapor deposition (MOCVD), pulsed laser deposition, dc/rf sputtering, vapor deposition, metal organic deposition, molecular beam epitaxy, and sol gel processing. 
     The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which: 
         FIG. 1  depicts a known atomic structure for a YBCO superconductor; 
         FIG. 2  depicts a first prior art arrangement for producing a YBCO superconductor; 
         FIG. 3  depicts a second prior art arrangement for producing a YBCO superconductor; 
         FIG. 4  depicts an example of an embodiment of the invention; 
         FIG. 5  depicts an embodiment of an initialization stage of the invention; 
         FIGS. 6A-6F  depict an embodiment of a reactor of a deposition stage of the invention; 
         FIGS. 7A and 7B  depict an embodiment of a transition chamber of the invention; 
         FIG. 8  depicts an embodiment of an anneal stage of the invention; and 
         FIGS. 9A-9D  depict different embodiments of the inventive superconductivity wire. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 4  is a schematic diagram of an embodiment of a system  400  that produces a continuous tape of high temperature super-conducting (HTS) material. The system  400  includes several stages that operate together to deposit superconducting material onto a metallic substrate, such that the HTS material is atomically ordered with large, well-oriented grains and principally low angle grain boundaries. The atomic ordering allows for high current densities, e.g. J C  greater than or equal to 100,000 amps per cm 2 . 
     The metallic substrate may be a metal foil tape  408  that is from 10/1000 to 1/1000 of an inch thick. The tape may be as wide as desired. For example, the tape may be wide so that the resulting HTS tape can carry a large amount of current, or the tape may be wide so that the resulting HTS tape can be cut into narrower strips. 
     The tape  408  may be composed of nickel and/or a nickel alloy, and has a predetermined atomic ordering which will promote growth of the HTS material. The tape may also comprise nickel, silver, palladium, platinum, copper, aluminum, iron, tungsten, tantalum, vanadium, chromium, tin, zinc, molybdenum, and titanium. Such a tape has been described by Oak Ridge National Laboratories. The tape  408  supports the HTS layer, and thus should be ductile or flexible, as well as strong. Note that as described herein, only one side of the tape is being coated with a HTS layer, however, both sides may be coated with a HTS layer. 
     The tape  408  is dispensed by pay-out reel  401 . The pay-out reel  401  is a continuous feed reel which provides the tape at a constant speed. The pay-out reel (along with take-up reel  406 ) is tension controlled to prevent sagging of the tape (too little tension) or stretching or breaking of the tape (too much tension). Either sagging or stretching the tape during processing (e.g. when the tape is heated to high temperature) can damage or destroy the HTS layer. A computer  409  may control the tension of tape, via tension controller  411 , as the tape transits from the pay-out reel  401  to the take-up reel  406 . Note that pay-out reel  401  is exposed to the room environment. Similarly, the take-up reel  406  is also exposed to the room environment. Thus, system  400  embodies air-to-air processing, which makes processing much easier. 
     The speed of the tape depends upon a number of factors, e.g. size of the reaction chambers, desired thickness of the deposited materials, growth rate of the layers, temperature of the reaction, photo/flux, etc. A speed of about 3 cm per minute is suitable to continuously grow a YBCO HTS layer of about 0.5 to 5 micrometers in thickness. However, a speed of from 1 to 20 cm per minute may be used, depending on factors such as (but not limited to) desired thickness, growth rates, materials being used, material concentrations, etc. A speed controller  410  that comprises a stepper motor, which can be adjustable set, is used to control the speed of the tape. A computer  409  may control the speed of tape, via speed controller  410 , as the tape transits from the pay-out reel  401  to the take-up reel  406 . Note that pay-out reel may also comprise a speed controller that may also be connected to the computer  409 . 
     The tape  408  should be clean and free of grease and/or other contaminants. Such contaminants can prevent deposition of materials, can chemically contaminate deposited materials, and can distort the resulting thin film structure, in most cases adversely affecting superconducting properties. A vapor degreaser or cleaner can be used in pre-clean stage  412  to clean the tape prior to its entry into the initialization stage  402 . Alternatively, a mechanical cleaner, e.g. a roller wiper can be used to clean the tape. Another alternative is to use an ultrasonic bath, with a liquid cleaner, e.g. acetone, to clean the tape. Residual cleaning agents would be evaporated and/or burned off of the tape by initialization stage  402 . Note that pre-clean stage  412  may comprise multiple applications of vapor, mechanical, or bath treatments, as well as combinations of vapor, mechanical, and/or bath treatments. Further note that this stage may be operated separately from system  400 . The resulting cleaned tape could then be re-spooled and used in system  400  as tape  408 . 
     Initialization stage  402  pre-heats and/or pre-treats the tape substrate  408  before growing the additional layers required for a superconducting tape. This stage raises the temperature of the tape  408  to about 500° C. This temperature is between room temperature and the temperature of the next stage. This will reduce thermal shock of the tape substrate. Pre-treating will reduce contaminants from the tape substrate before growing surface layers including the top superconductor layer. This stage also removes the native oxide that covers metals. This stage has a reducing atmosphere that preferably comprises an oxygen scavenger, e.g. hydrogen (H 2 ), and for ammonia (NH 3 ), and argon (and/or other non-reacting gas e.g. nitrogen). The scavenger reacts with the metal surface oxide to reduce it to bare metal. The surface metal oxide could disrupt the atomic order of the HTS layer, affecting its superconducting properties, and thus should be removed. 
     An example of an embodiment of the initialization stage  402  is shown in  FIG. 5 . This stage includes at least one support  501 , and is composed of stainless steel. Other materials could include quartz, gold, platinum, aluminum oxide, LaAlO 3 , SrTiO 3 , and/or other metal oxide materials. The support should be polished smooth, so as not to snag or kink the tape, which would damage the atomic ordering of the substrate, and result in reduced quality HTS film. Also, the support should only be as large as necessary to prevent sag, this will minimize contact with the tape and prevent contamination. Heater  502  is used to heat the tape. Heater  502  may comprise a plurality of stages, e.g.  502   a ,  502   b ,  502   c , wherein each stage incrementally heats the tape to a desired temperature. This will reduce thermal shock of the tape substrate. Note that in this embodiment, the heater includes supporting pipe  508 . This pipe has a plurality of ports (not shown), which allows the passage of gases and/or other materials into and/or out of the pipe. The tape feeds into this stage via tape port  506  and passes out of this stage via tape port  507 . Note that tape ports  506  and  507  are not required to be narrow slits, like those on the transition chambers  701 . Alternatively, the narrow slits may not be part of the transition chambers, and instead tape ports  506  and  507  may comprise narrow slits. Material port  504  provides an inlet for the gases (if any) that are to be used to define the environment in this stage. Ports  503 ,  505  may be connected to one or more vacuum sources  509  to prevent leakage of the atmosphere into an adjacent stage and/or leakage of the atmosphere of an adjacent stage into stage  402 . Note that instead of using coil heater(s), lamp heater(s) similar to those shown in  FIG. 8  may be used. 
     The following table provides a working example of the environment of the initialization stage. The values are preferred values, as well as useable values, that are provided by way of example only. Note that SCCM is standard cubic centimeters per minute. 
     
       
         
               
             
               
               
               
             
           
               
                 TABLE I 
               
             
             
               
                   
               
               
                 INITIALIZATION STAGE 402 
               
             
          
           
               
                 Variable 
                 Preferred 
                 Operating 
               
               
                   
               
               
                 Input Tape Temperature  
                 Room Temperature 
                 Room Temperature 
               
               
                 Output Tape Temperature 
                 600° C. 
                 200-650° C. 
               
               
                 Pressure 
                 5-30 Torr 
                 1-700 Torr 
               
               
                 Gas Flow Rate 
                 500-1000 SCCM 
                 100-2000 SCCM 
               
               
                 Gas Composition: H 2   
                  5% 
                  3%-30% 
               
               
                         Ar 
                 95% 
                 97%-70% 
               
               
                   
               
             
          
         
       
     
     The next stage is the deposition stage  403 . This stage preferably comprises at least one reactor or reaction chamber  601  to deposit one or more materials onto the tape substrate onto which the superconductor layer is deposited. The number of reactors needed depends upon the type superconductor material that is being formed, the type and number of buffer layers that are needed (if any) between the superconductor material and the tape substrate, and the type of tape substrate that is used to support the superconductor material. This system is modular such that reactors may be added or removed as needed. For example, suppose that the superconductor material is YBCO and the tape substrate is nickel. Further suppose that two buffer layers are going to be used, e.g. cerium oxide and yittria stabilized zirconia. Thus, a total of three reactor chambers would be needed, one for the YBCO, and one for each of the buffer layers. As another example, if only one buffer layer was to be used, e.g. Sm-doped or “Samarium-doped ceria,” then only two reactor chambers would be needed, i.e. one for the superconductor material and one for the buffer material. As a further example, if the superconductor material were to be directly formed on the tape substrate, then only one reactor chamber would be needed. In any event, the system is modular, such that the system may be modified to add or remove reactor chambers as needed. 
     Further note that an unused reactor chamber does not have to be physically removed from the system. For example a system may comprise three reactor chambers, however only two chambers are needed to produce the superconductor material. Thus, one reactor chamber may be physically removed from the system. Alternatively, one reactor may be set to a neutral operating mode. This mode would have the reactor not in an off mode, but rather would maintain the tape at a predetermined temperature and provide a non-reactive atmosphere to the tape substrate. Thus the tape would pass through the neutral reactor and not be changed by the reactor, and would exit the neutral reactor with essentially the same characteristics with which it entered the neutral reactor. 
     As shown in  FIG. 4 , this section may comprise multiple reaction chambers  601   a ,  601   b ,  601   c  which may be separated by transition chamber  701  in  FIG. 7A . Particular superconductors may require the deposition of different materials, different concentrations, different temperatures, different pressures, and/or combinations thereof that would require more than one different operating environment. Each reaction chamber is preferably similar, however the reaction chambers may be made larger or smaller in the direction of tape travel if a particular environment needs a particularly longer or shorter growing time, and/or the layer needs to be thicker or thinner. Note that since the tape is moving at a constant speed, time can be equated to distance, such that if a longer deposition time is needed (and/or a thicker film is needed), then the reactive zone would be longer or the film grows thicker, higher, and vice versa. Similarly, changing the tape speed will also change the deposition time, e.g. slowing the tape will result in longer deposition times and thicker films, and vice versa. 
       FIG. 6A  depicts an example of an embodiment of a reactor  601 . The reactor includes at least one support  604 , preferably composed of stainless steel. Other materials could include quartz, gold, platinum, aluminum oxide, LaAlO 3 , SrTiO 3 , and/or other metal oxide materials. The support should be polished smooth, so as not to snag or kink the tape, which would damage the atomic ordering of the substrate, and result in reduced quality HTS film. Also, the support should only be as large as necessary to prevent sag, this will minimize contact with the tape and prevent contamination. The support may include a heater to supplement heat provided by the heating element  613   b , e.g. a lamp. This prevents the support from acting as a heat sink. The sides of the reactor may comprise stainless steel or may comprise some other material, such as quartz, e.g., gold, platinum, aluminum oxide, LaAlO 3 , SrTiO 3 , and/or other metal oxide materials. Note that various sensors may be placed throughout the system to provide data regarding the operation of the system, e.g. environmental data, speed of the tap, tape temperature, etc. For example, temperature sensor  694  may be located in the support  604  as shown in  FIG. 6E . 
     The tape feeds into this stage via tape port  605  and passes out of this stage via tape port  606 . Note that tape ports  605  and  606  are not required to be narrow slits, like those on the transition chambers  701 . Alternatively, the narrow slits may not be part of the transition chambers, and instead tape ports  605  and  606  may comprise narrow slits. Material ports  607  provide an outlet for the materials that are to be used in this stage and are connected to vacuum pumps with gauging and valve control. As shown in the bottom view of a reactor  601  of  FIG. 6D , the ports  607  are arranged to facilitate a laminar flow of materials in the reactor  601 . In other words, material flows in from the shower head  603  and then out through ports  607 . 
     As shown in  FIG. 6F , the tape ports  605  and  606  may have adjacent supports  690   a  and  690   b , preferably composed of stainless steel. Other materials could include quartz, gold, platinum, aluminum oxide, LaAlO 3 , SrTiO 3 , and/or other metal oxide materials. The support should be polished smooth, so as not to snag or kink the tape, which would damage the atomic ordering of the substrate, and result in reduced quality HTS film. Also, the support should only be as large as necessary to prevent sag, this will minimize contact with the tape and prevent contamination. The support may include a heater to supplement heat provided by the heating element(s)  613   a , e.g. a lamp. This prevents the support from acting as a heat sink. 
     The reactor  601  includes a lamp housing  602  and shower head (or distribution head)  603 .  FIGS. 6B and 6C  depict a side view and a top view, respectively, of the lamp housing  602  and shower-head  603  arrangement shown in  FIG. 6A .  FIG. 6E  depicts a perspective view of the shower head, substrate, and support (note that the lamp housing  602  has been omitted in this view). Lamps  608  in the lamp housing  602  heats the tape to a desired temperature, which will allow for the deposition of materials. The lamp also provides ultraviolet and visible light which significantly enhances the growth rate, i.e. increases the speed of growth through enhanced surface diffusion of the reacting species, which in turn allows for rapid growth of thick layers, and faster tape speeds and/or smaller reactors. The lamp housing  602  uses a reflector to direct the light onto the reaction area  609 , which is the area immediately beneath the shower-head  603 . This reduces heat flux to the chamber walls. The lamp  608  is preferably a quartz halogen lamp with the light source in the reactor comprising a plurality of lamps  608  that extend along the length of the lamp housing  602 . Note that other ultra-violet/visible (UV/V) light sources may be used, for example xenon discharge, mercury vapor, or excimer laser light. The shower-head  603  provides a laminar flow of the reactant vapors mixed with a carrier gas to the deposition region of the reactor at the substrate tape  408 . The shower-head  603  is preferably made from stainless steel, but may also be another non-reacting material such as quartz, gold, platinum, aluminum oxide, LaAlO 3 , SrTiO 3 , and/or other metal oxide materials. 
     The area below the shower-head is the deposition region of the reactor. The size of this region is selected with respect to other system characteristics, e.g. the tape speed, deposition rate, chamber pressure, etc. to produce a film of a desired thickness. When not in the deposition region, the tape  408  is covered by shields  691  to prevent material from coating the tape. 
     The dimensions and placement of the distribution head  603  depend on the width of the substrate  408 . For example, as shown in  FIG. 6B , for a substrate  408  having a width B  612 , the width A  615  of the support  604  is preferably slightly smaller than B, e.g. B minus 2 mm. However, A may be operative for values in the range of B plus 2 mm to B minus 2 mm. The width C  620  of the shower head is preferably larger than B, e.g. B plus 10 mm. However, C may be operative for values in the range of B plus 15 mm to B minus 2 mm. The spacing D  621  between the shower head and the substrate is preferably greater than or equal to B. However, D may be operative for values of greater than or equal to B/2. 
     The lamp housing  602  also preferably includes a cooling jacket  610  as part of the lamp reflector. Different coolants may be used in the jackets, e.g. water, oil, glycol, etc. The sides of the reactor may also include cooling jackets and/or cooling pipes  614 . The cooling jacket(s) not only reduce the reaction chamber external temperature to a safe range, but also reduce unwanted buildup of deposition materials on the walls by reducing the wall temperature to a point where chemical reaction of species does not occur. 
     The reactor also may preferably include one or several quality control ports  611 . This port would allow viewing of the tape during the deposition process, and/or permit access for testing the quality of the tape. 
     The deposition materials (reactant chemicals) or precursors that react at the substrate to form the deposited film, e.g. HTS, buffer layer or overcoat layer, are provided by precursor system  407 . Known systems include gas, liquid, solid and slurry preparation systems. Solid precursor delivery systems typically volatilize the solid precursor in a separate heated vessel, pass a carrier gas through the vessel, and then pass the carrier gas/precursor vapor to the reaction chamber. The solid precursors could be separate or mixed as solids into one mass for vaporization. Slurry precursor delivery systems vaporize, in a separate chamber equipped with a hot zone, small amounts of a thick slurry containing all or a subset of all of the precursors dissolved in a solvent to form the slurry. The liquid precursor delivery system, vaporizes in a separate chamber equipped with a hot zone, small amounts of a liquid solution containing all or a subset of all of the precursors dissolved in a solvent. The vaporized precursors may then be injected into the reactor shower head for delivery to the tape  408 . A liquid precursor solution can also be atomized and then vaporized for injection into the reactor shower head. 
     For the integration of YBCO superconductors with continuous metal foil substrates, three reactors may be used. The first two reactors provide buffer layers, and the third reactor provides the YBCO layer. The first reactor  601   a  deposits a thin layer of buffer, preferably cerium oxide (CeO 2 ). The buffer layers suffice to prevent other diffusion of speed between the metal substrate and the superconducting layer, as well as provide an atomically ordered template onto which to grow atomically ordered subsequent buffer layers or superconductor layers. This layer is deposited at relatively low temperature, as compared to the next two reactors, and prevents the nickel from oxidizing, which would destroy the atomic structure of the nickel substrate surface on which the follow-on layers are grown. Note that this reactor may operate in a reducing environment of forming gas, e.g. hydrogen, but also grows an oxide layer, which means that oxygen may be also provided into the reactor. Because of the relatively low concentrations and pressures (as compared with a standard atmosphere), there is no risk of explosion. The following table provides a working example of the environment of the first reactor. The values are preferred values, as well as useable values, which are provided by way of example only. 
     
       
         
               
             
               
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 C E O BUFFER LAYER BY REACTOR 601A 
               
             
          
           
               
                   
                 Variable 
                 Preferred 
                 Operating 
               
               
                   
                   
               
               
                   
                 Reactor Temperature 
                 600-700° C. 
                 550-750° C. 
               
               
                   
                 Reactor Pressure 
                 2-4 Torr 
                 1-10 Torr 
               
               
                   
                 Carrier Gas Flow Rate  
                 100-400 SCCM 
                 100-400 SCCM 
               
               
                   
                 Oxygen Flow Rate 
                 250-700 SCCM 
                 200-1000 SCCM 
               
               
                   
                 Reducing Gas 
                 H 2  22-26% 
                  3-30% 
               
               
                   
                   
                 Ar 78-74% 
                 97-70% 
               
               
                   
                 Reducing Gas Flow Rate 
                 200-600 SCCM 
                 100-1000 SCCM 
               
               
                   
                   
               
             
          
         
       
     
     The second reactor  601   b  deposits a higher deposition temperature buffer layer, preferably yittria stabilized zirconia (YSZ) buffer. This buffer layer prevents the inter-diffusion of the first buffer layer and the metal substrate into the YBCO layer. This reactor operates in an oxidizer-rich environment composed of O 2 , N 2 O, O 3 , combinations thereof, or other oxidizing agents at a pressure of from 1 to 5 Torr, and at a temperature of 600-850° C. The following table provides a working example of the environment of the second reactor. The values are preferred values, as well as useable values, which are provided by way of example only. 
     
       
         
               
             
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 YSZ BUFFER LAYER BE REACTOR 601B 
               
             
          
           
               
                   
                 Variable 
                 Preferred 
                 Operating 
               
               
                   
                   
               
               
                   
                 Reactor Temperature 
                 780-830° C. 
                 750-850° C. 
               
               
                   
                 Reactor Pressure 
                 2-4 Torr 
                 1-10 Torr 
               
               
                   
                 Oxygen Flow Rate 
                 300-600 SCCM 
                 100-750 SCCM 
               
               
                   
                 Argon Flow Rate 
                  500-8000 SCCM 
                 200-2000 SCCM 
               
               
                   
                   
               
             
          
         
       
     
     The third reactor  601   c  deposits the YBCO layer also in an oxidizer-rich environment. The thickness of the YBCO layer and its chemical purity and crystalline quality determine the critical current of the fabricated superconducting tape. The critical current is the current beyond which the superconductor is no longer superconducting. The following table provides a working example of the environment of the third reactor for precursors in solid form. The values are preferred values, as well as useable values, which are provided by way of example only. 
     
       
         
               
             
               
               
               
               
             
           
               
                 TABLE 4 
               
             
             
               
                   
               
               
                 YBCO LAYER BY REACTOR 601C USING SOLID  
               
               
                 FORM PRECURSORS 
               
             
          
           
               
                   
                 Variable 
                 Preferred 
                 Operating 
               
               
                   
                   
               
               
                   
                 Reactor Temperature 
                 780-835° C. 
                 750-850° C. 
               
               
                   
                 Reactor Pressure 
                  2-4 Torr 
                  1-10 Torr 
               
               
                   
                 Precursor B a  Temperature 
                 270-280° C. 
                 265-285° C. 
               
               
                   
                 Precursor C u  Temperature 
                 165-185° C. 
                 150-190° C. 
               
               
                   
                 Precursor Y Temperature  
                 165-185° C. 
                 150-190° C. 
               
               
                   
                 Oxygen Flow Rate 
                 100-500 SCCM 
                 100-1000 SCCM 
               
               
                   
                 N 2 O Flow Rate 
                 100-300 SCCM 
                 100-1000 SCCM 
               
               
                   
                 Argon Flow Rate 
                 500-800 SCCM 
                 300-2000 SCCM 
               
               
                   
                   
               
             
          
         
       
     
     The following table provides a working example of the environment of the third reactor for precursors in liquid (Table 5) forms. The values are preferred values, as well as useable values, which are provided by way of example only. Note that M is molality. 
     
       
         
               
             
               
               
               
               
             
           
               
                 TABLE 5 
               
             
             
               
                   
               
               
                 YBCO LAYER BY REACTOR 601C USING LIQUID 
               
               
                 FORM PRECURSORS 
               
             
          
           
               
                   
                 Variable 
                 Preferred 
                 Operating 
               
               
                   
                   
               
               
                   
                 Reactor Temperature 
                 780-830° C. 
                 700-900° C. 
               
               
                   
                 Reactor Pressure 
                 2-3 Torr 
                 1-10 Torr 
               
               
                   
                 Precursor Temperature 
                 270-280° C. 
                 260-310° C. 
               
               
                   
                 Precursor Concentration 
                 0.05-0.1 M 
                 0.01-0.5 M 
               
               
                   
                 Argon Flow Rate 
                 400-500 SCCM 
                 200-1000 SCCM 
               
               
                   
                 Oxygen Flow Rate 
                 300-500 SCCM 
                 200-1000 SCCM 
               
               
                   
                 N 2 O Flow Rate 
                 200-500 SCCM 
                 100-1000 SCCM 
               
               
                   
                   
               
             
          
         
       
     
     Note that system  400  may be configured for a two reactor version, namely, one reactor for a single buffer layer and the other reactor for the superconductor layer. The first reactor would be configured as described in Table 2, but use a SM-doped CeO 2  as the buffer material. The second reactor may be configured as in either Table 4 or Table 5 for either solid form precursor or liquid form precursor, respectively, for the YBCO superconductor material. 
     The deposition stage  403  also includes transition chambers  701  between stage  402  and the first reactor, between reactors, and between the last reactor and stage  404 .  FIG. 7A  depicts an example of an embodiment of a transition chamber. The tape feeds into the transition chamber via narrow slit  703  and passes out of the transition chamber via narrow slit  704 . The slits are used to minimize the passage of gases and other materials from reactor chamber to transition chamber, and vice versa. Therefore, the transition chambers isolate each stage or reactor from the other stages and/or reactors, and thereby prevent cross-contamination of materials and/or gases from one stage or reactor to another stage or reactor. The transition chamber has a vacuum system  706  that controls any materials or gases leaking in from either end of the transition chamber, and may be operated at a pressure that is either higher or lower than the nominal reaction chamber pressure. 
     The transition chamber may include at least one support  702  for the moving tape substrate, preferably composed of stainless steel or a non-reactive material such as quartz, gold, platinum, aluminum oxide, LaAlO 3 , SrTiO 3 , and/or other metal oxide materials. The support should be polished smooth, so as not to snag or kink the tape, which would damage the atomic ordering of the substrate, and result in reduced quality HTS film. Also the support should only be as large as necessary to prevent sag, this will minimize contact with the tape and prevent contamination. 
     The transition chamber may include one or more heating elements  707  that allow the temperature of the tape to be maintained and/or adjusted while in the transition chamber. The heater  707  may maintain the temperature of the tape, or it may adjust the temperature (either higher or lower) to a point, e.g. midpoint, between the two stages connected to it. For example, if one reactor has a temperature of 550° C. and the other reactor has a temperature of 700° C., then the transition chamber may be set to have a temperature of 625° C. This will reduce thermal shock of the tape, as it moves between stages and/or reactors. Note that in this embodiment, the heating element  707  includes supporting pipe  711 . This pipe  711  has a plurality of ports  710 , which allows the passage of gases and/or other materials into and/or out of the pipe.  FIG. 7B  depicts a side view of the pipe  711  with ports  710 . 
     The transition chamber preferably includes at least one port  705  to allow the introduction of at least one gaseous specie into the transition chamber that could stabilize or enhance the buffer layer (s) or the superconductor layer(s) formed on the substrate, or enhance the formation of follow-on layers on the tape. For example, a transition chamber may provide oxygen to the tape, which would help maintain oxygen stoichiometry in the deposited films. Any introduced gaseous materials would be removed by vacuum system  706 . 
     The transition chamber also preferably includes a cooling jacket  708 . Different coolants may be used in the jackets, e.g. water, oil, glycol, etc. The cooling jacket not only reduce the external temperature to a safe range, but also may reduce unwanted buildup of deposition materials on the walls by reducing the wall temperature to a point where chemical reaction of species does not occur. 
     The transition chamber also may preferably include one or more quality control ports  709 . This port would allow viewing of the tape during the deposition process, and/or permit access for testing or monitoring the quality of the tape. 
     The following table provides working examples of the environments of the transition chambers  701 - 1 ,  701 - 2 ,  701 - 3 , and  701 - 4 . The values are preferred values, as well as useable values, which are provided by way of example only. 
     
       
         
               
             
               
               
               
               
             
           
               
                 TABLE 6 
               
             
             
               
                   
               
               
                 TRANSITION CHAMBER ENVIRONMENTS 
               
             
          
           
               
                 Chamber 
                 Variable 
                 Preferred 
                 Operating 
               
               
                   
               
               
                 701-1 
                 Temperature 
                 500° C. 
                 400-700° C. 
               
               
                   
                 Pressure 
                 3 Torr 
                 1-10 Torr 
               
               
                   
                 Gas Composition: H 2   
                 22-26% 
                  3-30% 
               
               
                   
                         Ar 
                 78-74% 
                 97-70% 
               
               
                   
                 Gas Flow Rate 
                 500 SCCM 
                 100-1000 SCCM 
               
               
                 701-2 
                 Temperature 
                 600° C. 
                 450-800° C. 
               
               
                   
                 Pressure 
                 3 Torr 
                 1-10 Torr 
               
               
                   
                 Gas Composition: O 2    
                 100% 
                 100% 
               
               
                   
                 Gas Flow Rate 
                 500 SCCM 
                 100-2000 SCCM 
               
               
                 701-3 
                 Temperature 
                 700° C. 
                 650-850° C. 
               
               
                   
                 Pressure 
                 3 Torr 
                 1-10 Torr 
               
               
                   
                 Gas Composition: O 2    
                 100% 
                 100% 
               
               
                   
                 Gas Flow Rate 
                 500 SCCM 
                 100-1500 SCCM 
               
               
                 701-4 
                 Temperature 
                 650° C. 
                 600-800° C. 
               
               
                   
                 Pressure 
                 10 Torr 
                 2-100 Torr 
               
               
                   
                 Gas Flow: O 2   
                 500 SCCM 
                 300-2000 SCCM 
               
               
                   
                      N 2 O 
                 300 SCCM 
                 300-2000 SCCM 
               
               
                   
               
             
          
         
       
     
     The next stage is the anneal stage  404 . This stage allows for increasing the oxygen stoichiometry in the superconducting layer on the substrate tape, and cools down the complete processed tape. After this stage, the tape can be exposed to normal air with no degradation of the superconducting layer, and thus no further transition chambers are required. The tape is in this stage for about 30-60 minutes. The tape is at about 800-650° C. when it enters this stage and is about 300° C. or lower when it exits this stage. The tape is in an oxygen atmosphere in this stage. 
       FIG. 8  depicts an example of an anneal stage. This stage includes at least one support  801 , preferably composed of stainless steel or a non-reactive material such as quartz, gold, platinum, aluminum oxide, LaAlO 3 , SrTiO 3 , and/or other metal oxide materials. The support should be polished smooth, so as not to snag or kink the tape, which would damage the atomic ordering of the substrate, and result in reduced quality HTS film. Also, the support should only be as large as necessary to prevent sag, this will minimize contact with the tape and prevent contamination. Heater  802  is used to heat the tape. Heater  802  may comprise a plurality of stages, e.g.  802   a ,  802   b ,  802   c , wherein each stage decrements the temperature of the tape to a desired temperature. This will reduce thermal shock of the tape substrate. Note that in this embodiment, the heater includes supporting pipe  808 . This pipe may have a plurality of ports (not shown), which allows the passage of gases and/or other materials into and/or out of the pipe. The tape feeds into this stage via tape port  806  and passes out of this stage via tape port  807 . Note that tape ports  806  and  807  are not required to be narrow slits, like those on the transition chambers  701 . Alternatively, the narrow slits may not be part of the transition chambers, and instead tape ports  806  and  807  may comprise narrow slits. 
     Material port  804  provides an inlet for the gases (if any) that are to be used to define the environment in this stage. Ports  803 ,  505  may be connected to one or more vacuum sources  809  to prevent leakage of the atmosphere into an adjacent stage and/or leakage of the atmosphere of an adjacent stage into stage  404 . Note that instead of using lamp heater(s), coil heater(s) similar to those shown in  FIG. 5  may be used. 
     The following table provides a working example of the environment of the anneal stage. The values are preferred values, as well as useable values, that are provided by way of example only. 
     
       
         
               
             
               
               
               
               
             
           
               
                 TABLE 7 
               
             
             
               
                   
               
               
                 ANNEAL STAGE ENVIRONMENTS 
               
             
          
           
               
                 Stage 
                 Variable 
                 Preferred 
                 Operating 
               
               
                   
               
               
                 Stage I 802a 
                 Temperature 
                 550° C. 
                 500-700° C. 
               
               
                   
                 Pressure 
                 760 Torr 
                 100-1500 Torr 
               
               
                   
                 O 2  Flow 
                 500 SCCM 
                 100-2000 SCCM 
               
               
                 Stage II 802b  
                 Temperature 
                 350° C. 
                 300-500% C. 
               
               
                   
                 Pressure 
                 760 Torr 
                 100-1500 Torr 
               
               
                   
                 O 2  Flow 
                 500 SCCM 
                 100-2000 SCCM 
               
               
                 Stage III 802c 
                 Temperature 
                 200° C. 
                 ≦300° C. 
               
               
                   
                 Pressure 
                 760 Torr 
                 100-1500 Torr 
               
               
                   
                 O 2  Flow 
                 500 SCCM 
                 100-2000 SCCM 
               
               
                   
               
             
          
         
       
     
     Optional sealing stage  405  may coat the tape with a protective coating, e.g. lacquer, plastic, polymer, cloth, metal (e.g. silver, gold, or copper). This materials are cited by way of example only as other coatings could be used. 
     Optional stage  418  performs quality control testing that ensures the proper characteristics of the final superconducting tape, as well as the tape under process. Note that this stage may use the ports  611  and/or  709 . Further note that quality control testing may be incorporated at any of the reactors  601   a, b, c , in any of the transition chamber chambers  701 , and/or at the pre-treat or post anneal stages. Further note that quality control testing may be performed separately from system  400 . This quality control may incorporate direct or indirect measurement of YBCO properties including atomic order, temperature, reflectivity, surface morphology, thickness, microstructure, T c , J c , microwave resistivity, etc., or the direct or indirect measurement of the properties of the buffer layers or the coating layers of the tape including atomic order, temperature, reflectivity, surface morphology, thickness, microstructure, etc. Note that J c  is the critical current density or the maximum amount of current that the wire can handle before breakdown. Some superconductor elements may have a J c  of 100,000 amps/cm 2  or greater. Good superconductor elements may have a J c  of 500,000 amps/cm 2  or greater. 
     The system uses a take-up reel  406  to spool the superconducting tape. Note that the length of the wire tape  408  is limited only by the size of the pay-out and take-up reels. Thus, the tape may be any desired length, depending on the length of the input/output reels. For example, the system may produce 1 or 2 kilometer (km) long wire tapes, or even longer. 
     Note that computer  409  can be used to control the different aspects of the system. For example, it can control the concentration of materials flowing into the reactors, the temperature of the reactors and/or the transition chambers the pressure in the reactors and/or transition chambers, the tape speed, the tape tension, the flow rate of the materials into the different reactors or stages, etc. This would allow feedback from the quality control testing to improve the characteristics of the wire tape. 
     The system  400  also may optionally include pressure control chambers  414  and  415 , which assist in controlling the pressure in the initialization stage  402  and the anneal stage  404 , respectively. A transition chamber  701  may be used as a pressure control chamber. In such a case, the heating element  707 , supporting pipe  711 , and/or water jacket  708  may not be needed. Also narrow slits may not be used between chamber  414  and stage  402 , and/or between chamber  415  and stage  404 . The system may also use an additional transition chamber  413  between initialization stage  402  and normal atmosphere, or between chamber  414  (if used) and normal atmosphere. Chamber  413  prevents the mixing of normal atmosphere and the environment of the initialization stage  402 . For example, chamber  413  prevents oxygen from the normal atmosphere from entering initialization stage  402 , as well as preventing hydrogen from the initialization stage from entering the normal atmosphere. 
     The system uses vacuum pumps  417  to achieve the desired pressure in the various components of the system. Liquid nitrogen traps and filters  416  are used to remove materials from the exhaust of the reactors  601  to prevent damage to the pumps  417 . The other components may also use such traps and/or filters to prevent damage to their associated pumps. 
       FIGS. 9A-9D  depict examples of different embodiment of the inventive superconducting wire produced by the system of  FIG. 4 .  FIG. 9A  depicts tape substrate  901  with buffer layer  902  and HTS layer  904 .  FIG. 9B  depicts tape substrate  901  with buffer layers  902 ,  903 , HTS layer  904 , and sealing layering  905 . 
       FIG. 9C  depicts a two HTS layer wire that includes substrate  901  with buffer layers  902 ,  903  and sealing layer  905 . Buffer layer  906  separates first HTS layer  904  and second HTS layer  907 . Note that the buffer layer  906  may be used here, and  906  is not necessarily equivalent to either  902  or  903 . This wire may be made by using additional reactors, transition chambers, and/or other components in the system of  FIG. 4  to form the additional layers. This wire may also be made by repeating the processing with the system of  FIG. 4 . In other words, after completion of the first HTS layer, the wire is spooled without adding the sealing layer. The spool is then moved to the pay-out reel  401 . Selected ones of the components of the system of  FIG. 4  are then used to form the subsequent layers including the second HTS layer. 
       FIG. 9D  depicts another example of a two HTS layer wire that has an HTS layer on each side of the substrate. his wire may be made by using additional reactors, transition chambers, and/or other components in the system of  FIG. 4  to form the additional layers. In order to form layers on the opposite side, additional pieces of equipment would be added to the system of  FIG. 4  that twists or flips the tape as needed to process the bottom side of the tape. This wire may also be made by repeating the processing with the system of  FIG. 4 . In other words, after completion of the first HTS layer, the wire is spooled without adding the sealing layer. To reverse the side of the tape, the take-up reel  406  would wind the tape from the bottom of the reel (counter-clockwise), instead of the top of the reel (clock-wise), as shown in  FIG. 4 . The spool is then moved to the pay-out reel  401 . The system of  FIG. 4  then processes the tape to form the subsequent layers including the second HTS layer. 
     The inventive wire may be used in the transporting of current, the distribution of power, in an electric motor, in an electric generator, in a transformer, in a fault current limiter, in superconducting magnetic energy storage (SMES) system, and a variety of magnets (including, but not limited to, MRI systems, magnetic levitation transport systems, particle accelerators, and magnetohydrodynamic power systems). 
     The inventive system may be used to form the inventive superconducting wire from different superconducting materials, including, but not limited to YBa 2 Cu 3 O 7-x , YBCO, NdBa 2 Cu 3 O 7-x , LaBa 2 Cu 3 O 7-x , Bi 2 Sr 2 Ca 2 Cu 3 O y , Pb 2-x Bi x Sr 2 Ca 2 Cu 3 O y , Bi 2 Sr 2 CaCu 2 O z , Tl 2 Ba 2 CaCu 2 O x , Tl 2 Ba 2 Ca 2 Cu 3 O y , TlBa 2 Ca 2 Cu 3 O z , Tl 1-x  Bi x Sr 2-y Ba y Ca 2 Cu 4 O z , TlBa 2 Ca 1 Cu 2 O z , HgBa 2 CaCu 2 O y , HgBa 2 Ca 2 Cu 3 O y , MgB 2 , copper oxides, rare earth metal oxides, and other high temperature superconductors. The invention may also include different buffer materials, including but not limited to CeO 2 (or CEO), Y 2 O 3 —ZrO 2  (or YSZ), Gd 2 O 3 , Eu 2 O 3 , Yb 2 O 3 , RuO 2 , La 1-x Sr x CoO 3 , MgO, SiN, BaCeO 2 , NiO, Sr 2 O 3 , SrTiO 3 , and Ba 1-x  Sr x TiO 3 . 
     Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.