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.txt Introduction:
There are 27 pure metals and more than a thousand different alloys, intermetallic compounds and some dielectric materials that can transition to a superconducting state. In the presentation, we will look at superconductors and cryoconductors and their differences.
Superconductors:
As mentioned earlier, materials that have the ability to transform into a superconducor when cooled to a very low temperature is called superconductors. The transition to the superconducting state is reversible. When the temperature rises, the material returns to its normal state.
The feature of superconductors is that the electric current created in a superconducting circuit will circulate for a long time along this circuit without reducing its strength.
Known superconductors have very low critical transition temperatures and devices that use superconductors must operate under liquid helium cooling. This complicates and increases the cost of production and operation of superconducting materials.
Superconductors are used in the creation of electric machines and transformers of small mass and size with high efficiency; cable lines for the transmission of high-power energy over long distances.
Cryoconductors:
Metals that can reach a small value of electrical resistivity at low (cryogenic) temperatures, which is hundreds or thousands of times less (but not zero!) than the electrical resistivity at normal temperature, are called cryoconductors. Physically, the phenomenon of cryoconductivity is not similar to the phenomenon of superconductivity because of cryoconductivity is a special case of normal electrical conductivity of metals, but at low (cryogenic) temperatures.
To achieve high values of cryoconductivity, high purity and absence of defects in the crystal lattice of the metal are necessary. Cryoconductors are, for example, pure copper and aluminum (with 0.001% impurities) at a temperature of liquid hydrogen (20 K), technically pure beryllium (0.1% impurities) at a temperature of liquid nitrogen (77.4 K).
If liquid helium is used as a cooling agent in superconducting devices, in cryoconductors devices cheaper refrigerants - liquid hydrogen or even iquid nitrogen. This simplifies and reduces the cost of production and operation of the device. If due to an accidental increase in temperature or magnetic induction, at least in a small section of the superconducting circuit, the superconductivity is destroyed, a large amount of energy will suddenly be released, which can cause a serious accident. In the case of a cryoconductor circuit, an increase in temperature will only cause a gradual increase in the resistance of this circuit without an explosion.
Conclusion:
Thus, the use of cryoconductors in electrical machines, cables, etc. has a significant advantage over superconductors, and the risks when working with cryoconductors are lower.
There are 27 pure metals and more than a thousand different alloys, intermetallic compounds and some dielectric materials that can transition to a superconducting state. In the presentation, we will look at superconductors and cryoconductors and their differences.
Superconductors:
As mentioned earlier, materials that have the ability to transform into a superconducor when cooled to a very low temperature is called superconductors. The transition to the superconducting state is reversible. When the temperature rises, the material returns to its normal state.
The feature of superconductors is that the electric current created in a superconducting circuit will circulate for a long time along this circuit without reducing its strength.
Known superconductors have very low critical transition temperatures and devices that use superconductors must operate under liquid helium cooling. This complicates and increases the cost of production and operation of superconducting materials.
Superconductors are used in the creation of electric machines and transformers of small mass and size with high efficiency; cable lines for the transmission of high-power energy over long distances.
Cryoconductors:
Metals that can reach a small value of electrical resistivity at low (cryogenic) temperatures, which is hundreds or thousands of times less (but not zero!) than the electrical resistivity at normal temperature, are called cryoconductors. Physically, the phenomenon of cryoconductivity is not similar to the phenomenon of superconductivity because of cryoconductivity is a special case of normal electrical conductivity of metals, but at low (cryogenic) temperatures.
To achieve high values of cryoconductivity, high purity and absence of defects in the crystal lattice of the metal are necessary. Cryoconductors are, for example, pure copper and aluminum (with 0.001% impurities) at a temperature of liquid hydrogen (20 K), technically pure beryllium (0.1% impurities) at a temperature of liquid nitrogen (77.4 K).
If liquid helium is used as a cooling agent in superconducting devices, in cryoconductors devices cheaper refrigerants - liquid hydrogen or even iquid nitrogen. This simplifies and reduces the cost of production and operation of the device. If due to an accidental increase in temperature or magnetic induction, at least in a small section of the superconducting circuit, the superconductivity is destroyed, a large amount of energy will suddenly be released, which can cause a serious accident. In the case of a cryoconductor circuit, an increase in temperature will only cause a gradual increase in the resistance of this circuit without an explosion.
Conclusion:
Thus, the use of cryoconductors in electrical machines, cables, etc. has a significant advantage over superconductors, and the risks when working with cryoconductors are lower.