Physical research in space

The study of cosmic rays will have to discover many of the secrets of life on Earth. Cosmic rays are known to have been registered during flights made by automatic space stations. In case the scientists had studied them they would have investigated the process on the Sun. Cosmic rays are supposed to consist of the particles. One of method of the cosmic rays nature study is to investigate them at the stations situated in the mountains. Were there a special accelerator being put into operation in 1967 it produced particles with low energies.

To reach a new stage in the comprehensive study of cosmic rays, man created a powerful rocket to put the largest automatic space stations into orbit round the Earth. The main instrument to be installed in these stations is called the calorimeter. It is able to isolate particles of superhigh energies from the cosmic rays and to measure the energy of each particle.

A few words about pentode

Pentode is a tube with five electrodes, a plate or anode, a cathode, a control grid, a screen and suppressor grid.

The cathode emits electrons, the plate collects them. The grid near the cathode is the control grid for controlling the electron flow. The screen grid shields the cathode from the plate helping the plate collect electrons. Moreover the screen grid reduces the capacity between the control grid and the plate. The grid nearest the anode is a suppressor grid. The latter repels secondary electrons and prevents bombardment of the screen grid. Having the negative potential the suppressor grid returns the secondary emission back to the plate and thus eliminates it in the tube.

Emission caused by bombardment of an electrode by electrons from the cathode is called secondary emission as the effect is secondary to the original cathode emission. The control grid is negatively biased. The plate current limitation is removed when a fifth electrode is placed within the tube between the screen and plate. It is usually connected to the cathode.

Power amplifier

The final tube in an audio amplifier which is feeding audio frequencies into a loudspeaker mast be essentially a power amplifier. Its task is to deliver undistorted power to the loudspeaker, and not to develop any great amount of voltage amplification. The task of the previous amplifier stages is to build up the small output voltages of the detector so that the large voltages necessary to swing the grid of the power tube may be obtained. The A-C power in the plate circuits of tubes previous to the power stage is small; what is required is that each previous stage will give a maximum of voltage amplification without distortion. The fact that maximum power may not be developed in these plate circuits is not important. These tubes work at very high impedances in which it is not possible to generate much more power although it is possible to build up considerable voltages across them.

The a-c plate current of the last tube then must be large that in turn means that the curve of this tube must have a long and straight, line part.