Niobium Superconductivity

It was discovered a long time ago that once the temperature is lowered to near absolute zero, the chemical properties of some substances suddenly change and they become "superconductors" with almost no resistance. The temperature at which a substance begins to have this strange "superconducting" property is called the critical temperature. Needless to say, the critical temperature of various substances is different.
It is important to realize that ultra-low temperatures are not easy to obtain, and people pay a huge price for them; the closer we get to absolute zero, the greater the price we have to pay. So our requirement for superconducting substances is, of course, the higher the critical temperature, the better.
There are many elements with superconducting properties, and niobium has one of the highest critical temperatures. And niobium alloy, the critical temperature up to the absolute temperature of 18.5 to 21 degrees, is currently the most important superconducting materials.
People once did such an experiment: a cold to the superconducting state of the metal niobium ring, pass the current and then disconnect the current, and then, the whole set of instruments closed up, to keep the low temperature. After two and a half years, people open the instrument, found that the niobium ring in the current is still flowing, and the current strength and just energized almost exactly the same!

From this experiment, it was clear that superconducting materials lose almost no current. If superconducting cables are used for power transmission, the efficiency of power transmission will be greatly improved because it has no resistance and there will be no energy loss when the current passes through.
Someone has designed a high-speed magnetic levitation train that has superconducting magnets installed in the wheel parts so that the whole train can float on the track for about ten centimeters. In this way, there will be no more friction between the train and the track, reducing the resistance to progress. A maglev train with a passenger capacity of one hundred can reach speeds of over five hundred kilometers per hour with only one hundred horsepower of propulsion.
With a niobium-tin belt twenty kilometers long, wrapped around the rim of a wheel with a diameter of one and a half meters, the windings are able to generate a strong and stable magnetic field strong enough to lift a weight of one hundred and twenty-two kilograms and make it levitate in the magnetic field space. If this magnetic field were used in a thermonuclear fusion reaction to bring the powerful thermonuclear fusion reaction under control, it would be possible to provide us with large amounts of almost endless cheap electricity.
People had made a DC generator out of niobium-titanium superconducting material. It has many advantages, such as small size, light weight, low cost, and it generates a hundred times more electricity compared to an ordinary generator of the same size.