الاستعمالات الاخرى للمفاعلات - الانصهار النووي - الطاقة النووية .. الفيزياء

Other uses of reactors - Nuclear fusion
- Nuclear energy .. Physics

Other uses of reactors

In addition to the increasing use of reactors in power plants, small and programmed reactors were built for other purposes, perhaps the most important of which was the operation of ships. In this type, pressurized water was used to perform cooling tasks and reduce the speed of neutrons at the same time.

The first nuclear submarine to be launched into the sea was the American submarine Nautilus in 1954. It is known that the use of nuclear energy in submarines gives them the ability to dive for long periods of time.

A regular submarine has to surface many times in order to charge its batteries using a diesel generator that requires quantities of air to do its job. The first Nautilus submarine was able to stay underwater for a distance of 62,000 miles, during which it crossed the North Pole without any need to refuel.

Several countries have begun building nuclear ships: however, these ships are still unable to compete with ships that run on oil except in special cases such as icebreaking in polar waters, where they have proven their superiority over ordinary ships. It should be noted that nuclear reactors have begun to appear in peaceful programs. In 1965, an American space satellite was equipped with a fast reactor that provided it with its energy needs for 43 days, and the heat was converted into electricity by thermocouples. There are American designs to build a nuclear missile consisting of a thermal reactor in which graphite is used as a neutron speed reducer and hydrogen, which reaches a temperature of 2,000 degrees Celsius, to cool the reactor and drive the missile. The missile nozzle is cooled by liquid hydrogen stored in the missile.

Nuclear Fusion

The graph of binding energy on page 122 shows that energy can be generated by the fusion of light atoms as well as by the fission of heavy atoms. Fusion occurs in the sun and stars, and its reactions produce the energy without which life on Earth would be impossible. It is believed that stars, like the sun, began their first stages of life as a cloud of hydrogen - that is, of protons, neutrons, and electrons - and the forces of attraction between the atoms made the density inside greater than the density outside, which increased the number of collisions in the center of the star and its energy, resulting in an increase in pressure and temperature. The higher the temperature, the more electrons move away from their orbits and the atoms become displaced. It is worth noting that the displaced gas in this form indicates the existence of a fourth state of matter called plasma.

When the temperature of the plasma rises, the protons in it combine with the neutrons and form the nuclei of deuterium atoms, which combine with each other to form the nuclei of tritium and helium together. This fusion does not occur except at a temperature called the ignition temperature. However, if the temperature remains below this temperature, part of the energy is wasted due to what is called braking radiation - that is, the direct conversion of kinetic energy into X-rays, a conversion that results from a close collision between an electron and a proton or between an electron and a nucleus. The energy released by the fusion reaction is estimated at about 13 × 10-12 joules. Since one kilogram of deuterium contains 3 × 2610 nuclei, the energy resulting from the conversion of deuterium into helium is 3 × 1410 joules, which is equivalent to six times the energy resulting from the fission of one kilogram of uranium. For this reason, fusion is a potential source of enormous amounts of energy, in addition to being a sufficiently abundant fuel. The sea is full of hydrogen, and it contains deuterium atoms at a rate of 15 atoms per 100,000 of its atoms. However, the ignition temperature necessary to launch the reaction from the deuterium atoms must be reached (estimated at about 50 million degrees). It is worth noting that the only source of reaching this temperature is the atomic (fission) bomb. The first fusion reaction on Earth was achieved in 1952 when a fission bomb was surrounded by a layer of hydrogen material - this formed the first hydrogen bomb - which had a much greater destructive effect than the atomic bomb itself. The atomic bomb dropped on Hiroshima was equivalent to 20 kilotons of TNT. T. As for the fusion fission bomb, it is equivalent to 20 megatons of tant. It must be noted that lithium dimerate is a fusionable material.