University of Houston System

Sierra Lobo, Inc.

Kamel Salama

Venkatakrishnan Selvamanickam

Krishnaswamy Ravi-Chandar

Phil Putman

Devamanohar Ponnusamy

Philip Travis Putman

Hui Fang

Apparatus for inductive braking of a projectile are disclosed. Embodiments include a receiver that has a unidirectional conductor having a closed conductive pathway that encircles a passageway for a moving projectile. The unidirectional conductor permits current to flow through it in substantially only one direction around the passageway. As the projectile and its associated magnetic field move past the unidirectional conductor, the moving magnetic field induces a current flow through the closed conductive pathway, which in turn generates a magnetic field behind the projectile having the same polarity as the projectile's field. The two fields attract one another, which both exerts a braking force on the projectile and tends to align the two fields. Alignment of these fields centers the projectile away from the passageway wall. Because the unidirectional conductor permits current to flow in substantially only the direction that produces a field having the same polarity as the moving field, the opposite-polarity repulsive magnetic field that would otherwise be generated ahead of the projectile, which would otherwise deflect the projectile from its path, is suppressed. Methods of inductive braking are also disclosed.

Nondestructive capture of projectiles

An electrically powered launcher is disclosed that can accelerate small payloads to orbital velocities. The invention uses a novel geometry to overcome limitations of other design, and allows full exploitation of existing superconducting materials.

Linear motor geometry for use with persistent current magnets

A method of manufacturing a Fe-sheathed MgBwire includes the steps of:

Method of manufacturing Fe-sheathed MgB2 wires and solenoids

The fabrication of superconducting wires and rods having desired and consistent electrical and mechanical properties, in particular those based on Yttrium Barium Copper Oxide (YBCO) and Bismuth Strontium Calcium Copper Oxide (BSCCO), is disclosed. The first fabrication step is to form an extrudable paste by mixing YBCO or BSCCO superconducting powder with a set of organic additives, which include binder, plasticizer, lubricant, dispersant, and a solvent. The following additional steps are performed on both YBCO and BSCCO based wires or rods: (i) using a piston extruder to extrude the superconducting wire or rod; (ii) drying the wire or rod to remove the solvent; and (iii) subjecting the wire or rod to a binder burn-out treatment to remove the remaining organic additives. In addition, YBCO wires and rods also require a sintering step, while BSCCO wires and rods also require cold isostatic pressing and heat treatment steps. The formation of cracks in thicker YBCO and BSCCO based rods during the drying and heating process steps is avoided by extruding hollow rods. The additives, processing parameters, and processing stages used to fabricate the superconducting wires and rods help achieve desired and consistent electrical and mechanical properties.

Fabrication of superconducting wires and rods

A superconductor material having a current density, J, of from about 30,000 to about 85,000 amps/cm.sup.2 at zero magnetic field and 77.degree. K is disclosed. The 123 superconductor, of the formula L.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. wherein L is preferably yttrium, is capable of entrapping sufficiently high magnetic fields and exhibits a low microwave surface resistance. The process of preparing the superconductor comprises compacting the bulk product, L.sub.1 Ba.sub.2 Cu.sub.3 O, and then sintering the reaction product at a temperature between about 40.degree. C. to about 90.degree. C. below its melting point, i.e., for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. at a temperature of approximately 940.degree. C. The composition is then heated in a preheated chamber maintained at approximately 1090.degree. C. to about 1,200.degree. C. (approximately 1,100.degree. C. for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta.) until it has been decomposed, and is then rapidly cooled to a temperature between about 10.degree. C. to about 30.degree. C. above its melting point, i.e. for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub. 6 +.delta. a temperature of 1030.degree. C., and then is controlled cooled at a rate of 1.degree. C./hr until it reaches a temperature of about 20.degree. C. to about 40.degree. C. below its melting point, i.e., for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. a temperature of 980.degree. C. The composition is steadily held at this temperature for at least eight hours, and then cooled to a temperature of approximately 400.degree. C. below its melting point (for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. approximately a temperature of 600.degree. C.). The material is then slowly cooled by another 200.degree. C. and is then annealed in oxygen.

Process of preparing superconductive oxide complexes containing L, Ba,

A method of fabricating articles from segments of anisotropically conducting 123 superconductor such that the current transport properties of the article are comparable to those of the individual segments. The segments to be joined are examined to determine the orientation of the ab plane. Contact surfaces are formed where necessary and the segments are brought into contact and the ab planes are brought into parallel alignment. The contacted segments are elevated in temperature and static pressure is applied to accelerate reaction across the interface of the contact surfaces. The so-formed coherent article is then cooled at a controlled rate.

Method for joining superconductor segments to form a superconducting

A superconductor material having a current density, J, of from about 30,000 to about 85,000 amps/cm.sup.2 at zero magnetic field and 77.degree. K. is disclosed. The 123 superconductor, of the formula L.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. wherein L is preferably yttrium, is capable of entrapping sufficiently high magnetic fields and exhibits a low microwave surface resistance. The process of preparing the superconductor comprises compacting the bulk product, L.sub.1 Ba.sub.2 Cu.sub.3 O, and then sintering the reaction product at a temperature between about 40.degree. C. to about 90.degree. C. below its melting point, i.e., for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. at a temperature of approximately 940.degree. C. The composition is then heated in a preheated chamber maintained at approximately 1090.degree. C. to about 1,200.degree. C. (approximately 1,100.degree. C. for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta.) until it has been decomposed, and is then rapidly cooled to a temperature between about 10.degree. C. to about 30.degree. C. above its melting point, i.e. for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub. 6 +.delta. a temperature of 1030.degree. C., and then is controlled cooled at a rate of 1.degree. C./hr until it reaches a temperature of about 20.degree. C. to about 40.degree. C. below its melting point, i.e., for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. a temperature of 980.degree. C. The composition is steadily held at this temperature for at least eight hours, and then cooled to a temperature of approximately 400.degree. C. below its melting point (for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. approximately a temperature of 600.degree. C). The material is then slowly cooled by another 200.degree. C. and is then annealed in oxygen.

Oriented grained Y-Ba-Cu-O superconductors having high critical currents

A superconductor material having a current density, J, of from about 30,000 to about 85,000 amps/cm.sup.2 at zero magnetic field and 77.degree. K. is disclosed. The 123 superconductor is of the formula L.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. wherein L is preferably yttrium. The process comprises compacting the solid state reaction product of L.sub.1 Ba.sub.2 Cu.sub.3 O and then sintering the reaction product at a temperature between about 40.degree. C. to about 90.degree. C. below its melting point, i.e., for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. at a temperature of approximately 940.degree. C. The composition is then heated in a preheated chamber maintained at approximately 1090.degree. C. to about 1,200.degree. C. (approximately 1,100.degree. C. for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta.) until it has been decomposed, and is then rapidly cooled to a temperature between about 10.degree. C. to about 30.degree. C. above its melting point, i.e. for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. a temperature of 1030.degree. C. and then is control cooled at a rate of 1.degree. C./hr until it reaches a temperature of about 20.degree. C. to about 40.degree. C. below its melting point, i.e., for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. a temperature of 980.degree. C. The composition is steadily held at this temperature for at least eight hours, and then cooled to a temperature of approximately 400.degree. C. below its melting point (for Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.6 +.delta. approximately a temperature of 600.degree. C.). The material is then slowly cooled by another 200.degree. C. and is then annealed in oxygen.

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Houston, TX, United States of America

Kamel Salama