المغنطرون - السيكلوترون - اهمية المغنطيسية .. الإلكترونيات

Magnetron - Cyclotron - Importance of Magnetism .. Electronics

Magnetron

It is an electronic valve dedicated to producing radio frequency energy. Figure (73) shows a magnetron with two anodes. In the event that no current passes through the coils surrounding it from the outside, negative electrons flow from the cathode to the positive anodes. When current is passed through the deflecting coils, a magnetic field is generated in them, the intensity of which increases with the increase in the passing current. This leads to bending the path of the electrons, so they surround the cathode instead of passing to the anode. If the two anodes are connected with an alternating voltage issued by a resonant circuit, the speed of the electrons approaching the anode with the higher potential increases.

While the speed of the electrons approaching the anode with the lower potential decreases. Thus, the electron clusters rotate around the cathode, thus maintaining the required vibrations.

Magnetrons operate for limited operating periods (less than 1% of the total time) to provide us with high energy at a high frequency. Radar magnetrons give us very high energy reaching thousands of watts and their oscillation is similar to the oscillation of centimeter waves. The magnetron that operates at very high frequencies is also equipped with elevators in the form of cavities that work like a resonant circuit, and both the cavities and the elevators are arranged in the form of a ring (74).

Cyclotron

The cyclotron (75) is a device used to provide particles with a large amount of energy in order to accelerate them. In its simplest form, it consists of two hollow chambers, each in the shape of the letter D, connected to a high-frequency alternating current with a high voltage of several kilovolts. The two chambers are placed inside an evacuated cylindrical shell and placed between the poles of a magnet. Therefore, the particles move in a curved path as a result of the existing magnetic field and approach one of the chambers as the applied voltage increases, so their speed increases and the particles continue to rotate inside the chambers and their speed increases until they exit from an opening at the end of the circular wire, at a very high speed, to collide with the atoms of other materials and work to emit other particles from the nuclei of these atoms. It is known that the cyclotron, which contains magnets placed around the circular path, works to accelerate the particles passing through it until their speed reaches almost the speed of light. The particles generated in it consist of protons, deuterons and alpha particles.
Electricity resulting from the flow of gases Magnetohydrodynamics It is known that if a conductor is moved to cut the lines of force of a certain magnetic field, it generates electromotive forces in it (76). The same is the case if a group of gas ions flow between the poles of a strong magnet, an electromotive force is generated in it. It is possible to obtain an electric current by using two conductive plates to collect the resulting electrons. 75 - Cyclotron. 76 - Generation of electricity by ionized gas.