32 results about "Superconducting critical temperature" patented technology

The invention relates to a circular section composite superconducting line based on a rare-earth barium-copper-oxide (ReBCO) coated superconductor and a niobium-titanium (NbTi) low temperature superconductor and belongs to the field of superconducting materials. An NbTi low temperature superconducting line with a circular section is coated by the ReBCO coating superconductor, and an Ag welding flux is used for welding a high temperature superconducting coating conductor in a high temperature superconducting coating conductor rolling joint to form a weld joint. According to the circular section composite superconducting line, the ReBCO coating superconductor and the NbTi low temperature superconducting line with the circular section are composited, the characteristics that n value of a ReBCO high temperature superconducting material is far lower than that of a low temperature superconducting material NbTi and superconducting stagnation temperature is high are utilized, so that the engineering current density, the shunting temperature and minimum quench energy are improved, whole voltage of low / high temperature superconducting composite superconducting line is prevented from increasing, temperature rising of the composite superconducting line is lowered, and compared with traditional low temperature and high temperature superconducting magnets, a superconducting magnet is stable in operation, high in efficiency, safe, and applied to a high magnetic field magnetic resonance imaging (MRI) magnet and a nuclear magnetic resonance (NMR) magnet.

The invention discloses an undulator which comprises a plurality of permanent magnet groups arranged sequentially, wherein each permanent magnet group comprises two groups of superconductive permanent magnets and two groups of rare-earth permanent magnets; the superconductive permanent magnets and the rare-earth permanent magnets are arranged on the two sides of a transmission path of an electron beam respectively; magnetic poles of the superconductive permanent magnets are opposite in direction; magnetic fields generated by the rare-earth permanent magnets strengthen magnetic fields generated by the superconductive permanent magnets on the transmission path of the electron beam; the temperature of the superconductive permanent magnets is lower than the superconductive critical temperature of the superconductive permanent magnets; and the magnetic induction intensity of magnetic fields generated by the permanent magnet groups on the transmission path of the electron beam has periodic variation in a direction of the transmission path of the electron beam. According to the undulator, a magnetic field with higher magnetic induction intensity is generated by the superconductive permanent magnets and the rare-earth permanent magnets in a magnetic field superposition manner, so that the performance of the undulator is improved.

The invention provides a superconducting quantum interference device (SQUID) chip comprising an SQUID device, a feedback coil, and a heater. The feedback coil and the heater are connected in parallel. When the feedback coil works in a superconducting state, the heater does not work and the SQUID device detects a magnetic flow signal and converts the signal into a voltage signal for outputting. When the feedback coil works in a quenching state, the heater starts to carry out heating so that the working temperature of the SQUID device rises; and when the temperature of the SQUID device exceeds a superconducting critical temperature, the SQUID device is in a quenching state. The SQUID chip and a sensing circuit are connected to form an SQUID magnetic sensor. According to the invention, the heating resistor and feedback coil in the traditional SQUID chip are connected in parallel; and with parameter matching, the heating resistor and the feedback coil works in a cooperation mode, thereby realizing dual-function operation. The metal lead number of the normal-temperature circuit and the low-temperature circuit is reduced so that the low-temperature losses can be substantially reduced and the cost is saved; the low-temperature environment keeping time is improved; and the system operation time is increased. The SQUID chip has the great economical and application value.

The invention relates to a high temperature superconducting material of gadolinium, thorium, oxygen, iron and arsenic, pertains to a ZrCuSiAs-type structure and has the same crystal structure as LaO1-yFyFeAs. The general formula of the high temperature superconducting material of gadolinium, thorium, oxygen, iron and arsenic of the invention is Gd1-xThx OFeAs, wherein, x is more than or equal to 0.05 and less than or equal to 0.30; the mole ratio of all elements content in the high temperature superconducting material gadolinium, thorium, oxygen, iron and arsenic is that Gd:Th: O: Fe: As is equal to 0.70 to 0.95: 0.3 to 0.05:1: 1: 1. According to the content of every element, the raw materials are mixed, ground, preformed, calcinated and quickly cooled, etc. so as to obtain a superconducting polycrystalline block. The high temperature superconducting material of gadolinium, thorium, oxygen, iron and arsenic of the invention has max superconducting critical temperature Tc which reaches 56.5 K, estimated upper critical field Bc2 exceeding 100 Tesla, is superior to the LaO1-yFyFeAs superconductor with similar structure and has obvious advantages in practical use.

The present invention relates to a superconducting nanowire single photon detector comprising a superconducting nanowire configured and arranged for incidence of photons on a region of the superconducting nanowire and for forming a local non-superconducting region or hot spot on the region. The superconducting nanowire is made of a high Tc cuprate superconductor material having a superconducting critical temperature above 77K. The invention also relates to a method of obtaining a superconducting nanowire single photon detector of the invention.

The invention provides a device for cooling a superconducting cable. The device comprises a superconducting energy pipeline, a base station cooler, a heat exchanger, an LNG immersed pump and a modulation device. A part of LNG in the superconducting energy pipeline is conveyed into the base station cooler to directly exchange heat with a power transmission terminal, so that the temperature of the power transmission terminal is maintained below the superconducting critical temperature; the temperature of the LNG subjected to heat exchange with the power transmission terminal rises to generate agas-liquid two-phase flow, and the gas-liquid two-phase flow enters the modulation device to be modulated into liquid and then, enters the LNG immersed pump; the LNG immersed pump conveys LNG to the heat exchanger for heat exchange; the heat exchanger reduces the temperature of the modulated LNG to be lower than the superconducting critical temperature; and then, the cooled LNG enters another power transmission terminal in the base station cooler for heat exchange; and the heat-exchanged LNG enters the superconducting energy pipeline, and the freezing point is reduced. According to the devicefor cooling the superconducting cable, LNG cold energy is fully utilized to make the temperature of the power transmission terminal maintained under the superconducting critical temperature, so that superconducting operation of the power transmission terminal is achieved.

The invention discloses a high temperature superconducting material, and a preparation method thereof. the general chemical formula of the high temperature superconducting material is Ti<z>-(Cu<0.5>Ti<0.5>)Ba<2>(Ca<2-x>Ti<x>)CuO<10-y>, wherein x ranges from 0.25 to 1.0, y ranges from 1.0 to 9.0, and z ranges from 2 to 8. The high temperature superconducting material is high in superconductive critical temperature, critical magnetic field intensity, and superconductive critical current intensity. The preparation method is simple; the adopted raw materials are cheap; quartz mortar is taken as anintermedium, full uniforming is adopted, and two times of high temperature baking are adopted, so that sample dispersibility is improved, and powder with a uniform particle size is obtained; pressinginto sheet materials is carried out using a tablet pressing machine so as to obtain the high temperature superconducting material; an additive is added into quartz mortar, so that the viscosity of the quartz mortar is reduced, and more uniform mixing of the high temperature superconducting material is achieved; at the same time, quartz mortar is capable of realizing more comprehensive contact ofBa(NO3)2, Ca(NO3)2, TiO2, and Cu(CN); the quartz mortar is subjected to baking in a tubular furnace at oxygen atmosphere at 800 to 900 DEG C, the quartz mortar is taken as a combustion improver, and combustion reaction of Ba(NO3)2, Ca(NO3)2, TiO2, and Cu(CN) is accelerated.

The invention provides a potassium-doped phenanthrene molecular crystal and a preparation method thereof. In the first aspect, the preparation method comprises the following steps: annealing under high-vacuum, anhydrous and anaerobic conditions, and controlling the annealing temperature and cooling rate to ensure that potassium atoms can be effectively doped into phenanthrene molecular crystal layers and among the phenanthrene molecular crystal layers, the c-axis length of a phenanthrene molecular crystal can be increased, and a high-quality crystal material with very good [001] oriented growth can be obtained; in the second aspect, the production of impurities such as potassium hydride can be effectively inhibited by controlling the annealing temperature and cooling rate, the high-purity potassium-doped phenanthrene molecular crystal can be obtained, and superconducting fractions of materials can be increased; and in the third aspect, the potassium atoms can be synchronously doped into the phenanthrene molecular crystal layers and among the phenanthrene molecular crystal layers so as to ensure that phenanthrene can be transformed into a stable metal state from a semiconductor state, and the superconduction critical temperature can be increased.

The invention relates to a magnesium diboride superconductive undulator which comprises two lists of superconductive coil arrays which are vertically arranged at intervals in parallel. Each list of the superconductive coil arrays comprise a high conductive coil framework, 2n+1 magnetic conductive baffles which are arranged axially at intervals in parallel and surround the surface of the high conductive coil framework and 2n magnesium diboride superconductive coil windings wound on the surface of the high conductive coil framework and located between every two adjacent conductive baffles, wherein n is a natural number. The undulator further comprises a direct current power supply supplying power to the magnesium diboride superconductive coil windings. The current direction of the direct current power supply is arranged to enable magnetic induction strength generated by two adjacent magnesium diboride superconductive coil windings to be identical in magnitude and opposite in direction. The undulator adopts magnesium diboride superconductive materials, the superconductive critical temperature is higher, running temperature is higher, and refrigerating cost is reduced effectively. Simultaneously, the undulator adopts the integral type coil framework and improves cycle length accuracy of the magnetic field of the undulator.

The invention discloses a preparation method of a rare earth barium copper oxygen high-temperature superconducting film. The preparation method comprises the following steps: a) weighing rare earth metal salt, barium salt, copper salt and a doping element compound according to a ratio, and dispersing the earth metal salt, the barium salt, the copper salt and the doping element compound into a solvent to obtain a precursor, wherein the doping element compound can generate doping element oxide at 300 to 650 DEG C and under the oxygen atmosphere; b) coating the precursor on a substrate to form a precursor film; c) placing the precursor film into a heat treatment furnace, introducing oxygen, heating the furnace to 300 to 650 DEG C, preserving heat for 0 to 5 hours, and introducing water vapor when the furnace temperature reaches 80 to 120 DEG C until thermal decomposition is finished; d) introducing oxygen nitrogen mixed gas and water vapor, heating the furnace to 700 to 825 DEC C, preserving heat for 20 to 250 DEG C, and stopping introducing the water vapor at the last 1 to 30 percent of time of heat preservation; and e) cooling the furnace to 400 to 500 DEG C and preserving heat for 0 to 240 minutes to obtain a product. According to the rare earth barium copper oxygen high-temperature superconducting film obtained by the preparation method, the thickness is more than 300 nm, the superconduction critical temperature is more than 90 K, and the critical current density at the temperature of 77 K and under the self-field condition is more than 1 mA / cm<2>.

Magnetic field attenuation in a persistent current mode operation is prevented, heat generation at a connecting part between the persistent current switch and the superconducting coil, and increase in a cooling temperature of the superconducting coil in a current supplying mode is suppressed to a minimum. The refrigerator cooling-type superconducting magnet J according to the present invention including a superconducting coil (2), a persistent current switch (1) for switch between a persistent current mode and a current supplying mode; a superconducting coil (2), first and second cryogenic refrigerators (3, 4) for respectively cooing the superconducting coil (2) and the persistent current switch (1); a vacuum vessel (10) for housing the super conducting coil (2), the persistent current switch (1), and cooling stages (31, 32, 41, 42) of the first and second cryogenic refrigerators (3, 4), the magnet includes a superconducting wire (5) for connecting the superconducting coil (2) to the persistent current switch (1) and a superconducting bypass line (6) electrically connected in parallel to the superconducting wire along a longitudinal direction, wherein a superconducting critical temperature of the superconducting bypass line (6) is higher than a superconducting critical temperature of the persistent current switch (5).

The invention provides Nb nanobelt / martensitic NiTi memory alloy matrix composite filament and a production method thereof. The Nb nanobelt / martensitic NiTi memory alloy matrix composite filament comprises the following components: 7-15% (atomic percent) of Nb, Ti and Ni with the atom ratio of (0.8-1.2):1, wherein the sum of atomic percents of Ti, Ni and Nb is 100%. The Nb nanobelt / martensitic NiTi memory alloy matrix composite filament is prepared by carrying out the following steps: selecting simple substances nickel, titanium and niobium with purity of more than 99wt%; smelting and casting, so that ingot casting is obtained; homogenizing and annealing the ingot casting; and then carrying out hot forging and moulding; carrying out plastic processing, annealing treatment, at least once uniaxial drawing-loading-unloading circular deformation treatment on a profile subjected to hot forging, wherein deformation is 1-9%, so that the Nb nanobelt / martensitic NiTi memory alloy matrix composite filament is obtained. The Nb nanobelt / martensitic NiTi memory alloy matrix composite filament can reserve great tensile elastic strain of Nb nanobelt in a free-state composite material, superconduction critical temperature of the free-state composite material is increased, and a magnetic field of the free-state composite material is enhanced.

The invention relates to a high temperature superconducting material of gadolinium, thorium, oxygen, iron and arsenic, pertains to a ZrCuSiAs-type structure and has the same crystal structure as LaO1-yFyFeAs. The general formula of the high temperature superconducting material of gadolinium, thorium, oxygen, iron and arsenic of the invention is Gd1-xThx OFeAs, wherein, x is more than or equal to 0.05 and less than or equal to 0.30; the mole ratio of all elements content in the high temperature superconducting material gadolinium, thorium, oxygen, iron and arsenic is that Gd:Th: O: Fe: As is equal to 0.70 to 0.95: 0.3 to 0.05:1: 1: 1. According to the content of every element, the raw materials are mixed, ground, preformed, calcinated and quickly cooled, etc. so as to obtain a superconducting polycrystalline block. The high temperature superconducting material of gadolinium, thorium, oxygen, iron and arsenic of the invention has max superconducting critical temperature Tc which reaches56.5 K, estimated upper critical field Bc2 exceeding 100 Tesla, is superior to the LaO1-yFyFeAs superconductor with similar structure and has obvious advantages in practical use.

A superconducting structure is presented. In some embodiments, the superconducting structure includes a first plane of material; a second plane of material; and a separating medium positioned between the first plane and the second plane, wherein a superconducting critical temperature of the superconducting structure is adjusted by control of one or more parameters.

The invention provides a device for cooling a superconducting cable. The device comprises a superconducting energy pipeline, a base station cooler, a heat exchanger, an LNG immersed pump and a modulation device. A part of LNG in the superconducting energy pipeline is conveyed into the base station cooler to directly exchange heat with a power transmission terminal, so that the temperature of the power transmission terminal is maintained below the superconducting critical temperature; the temperature of the LNG subjected to heat exchange with the power transmission terminal rises to generate agas-liquid two-phase flow, and the gas-liquid two-phase flow enters the modulation device to be modulated into liquid and then, enters the LNG immersed pump; the LNG immersed pump conveys LNG to the heat exchanger for heat exchange; the heat exchanger reduces the temperature of the modulated LNG to be lower than the superconducting critical temperature; and then, the cooled LNG enters another power transmission terminal in the base station cooler for heat exchange; and the heat-exchanged LNG enters the superconducting energy pipeline, and the freezing point is reduced. According to the devicefor cooling the superconducting cable, LNG cold energy is fully utilized to make the temperature of the power transmission terminal maintained under the superconducting critical temperature, so that superconducting operation of the power transmission terminal is achieved.