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1982 Vol. 4, No. 1
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1982, 4(1): 1-7.
Abstract:
The interactions between theories of physics and cathode electronics are discussed. Some laws in solid state physics, derived from bulk effect, can not be effectively applied to electron emission which is mainly a surface phenomenon. On the other hand, most effects of electron emission can be used to probe a solid surface, giving more information to the building up of surface science. The present status and trend of development of cathode electronics are also discussed.
The interactions between theories of physics and cathode electronics are discussed. Some laws in solid state physics, derived from bulk effect, can not be effectively applied to electron emission which is mainly a surface phenomenon. On the other hand, most effects of electron emission can be used to probe a solid surface, giving more information to the building up of surface science. The present status and trend of development of cathode electronics are also discussed.
1982, 4(1): 8-19.
Abstract:
In this paper, from the generalized telegraph equations waveguide cavities with slowly varying cross-section are studied. The mode resonant frequencies and the quality factors (Q s) of these cavities and the field distributions are found when the boundary conditions at the ends and at discontinuities are given. Honp modes in an opend circu-lar waveguide cavity with slowly varying cross-section are studied in some details, espe-cially the diffractive losses of these modes at the opened ends of the cavity are obtained. Finally, two sets of universal curves for resonant frequencies and Q's are given fro the double conic opened cavities which are most frequently used in practice. Some results of experiments prove their use rather reliable.
In this paper, from the generalized telegraph equations waveguide cavities with slowly varying cross-section are studied. The mode resonant frequencies and the quality factors (Q s) of these cavities and the field distributions are found when the boundary conditions at the ends and at discontinuities are given. Honp modes in an opend circu-lar waveguide cavity with slowly varying cross-section are studied in some details, espe-cially the diffractive losses of these modes at the opened ends of the cavity are obtained. Finally, two sets of universal curves for resonant frequencies and Q's are given fro the double conic opened cavities which are most frequently used in practice. Some results of experiments prove their use rather reliable.
1982, 4(1): 20-34.
Abstract:
This paper, using analytical methods, describes the calculation methods of external and internal short circuit currents in three-phase bridge rectifiers. a part of the analytical methods is first introduced by the author.
This paper, using analytical methods, describes the calculation methods of external and internal short circuit currents in three-phase bridge rectifiers. a part of the analytical methods is first introduced by the author.
1982, 4(1): 35-45.
Abstract:
An investigation for the system initialization command file of ALPHA MICKO computer is described. Methods for reducing the size of the operating system have been studied. Some problems of the original file are pointed out and improvements have been made. The file improved contains five terminals and five jobs while the size of the operating system is less than 16 K bytes. Two methods are presented to avoid the abnormal running of the computer caused by users using the MEMORY0 command simultaneously. A sample of the new file and its experimental result are given. The maximum number of terminals and jobs is also evaluated in view of actual effect.
An investigation for the system initialization command file of ALPHA MICKO computer is described. Methods for reducing the size of the operating system have been studied. Some problems of the original file are pointed out and improvements have been made. The file improved contains five terminals and five jobs while the size of the operating system is less than 16 K bytes. Two methods are presented to avoid the abnormal running of the computer caused by users using the MEMORY0 command simultaneously. A sample of the new file and its experimental result are given. The maximum number of terminals and jobs is also evaluated in view of actual effect.
1982, 4(1): 46-52.
Abstract:
In kinescope electron gun design there are three chief factors which affect the final electron beam spot size. Thes are the magnification factor, the spherical aberration and the space charge effect. In this paper the interrelation between these factors and the resolution is discussed.In order to reduce beam crossover and divergence angle, some methods which make nse of reducing the aperture diameter of G1 and increasing the spacing between G1 and G2 are proposed. By adjusting the position of the electron gun in the kinescope i.e.increasing the distance between the gun and the yoke, the deflection defocusing which is caused by scattering magnetic field of deflection yoke is reduced. Therefore, focnsing performance of kinescope is improved effectively and its edge resolution is increased. Test data show that the above methods are excellent, the increment of edge resolution is better than 50 lines.
In kinescope electron gun design there are three chief factors which affect the final electron beam spot size. Thes are the magnification factor, the spherical aberration and the space charge effect. In this paper the interrelation between these factors and the resolution is discussed.In order to reduce beam crossover and divergence angle, some methods which make nse of reducing the aperture diameter of G1 and increasing the spacing between G1 and G2 are proposed. By adjusting the position of the electron gun in the kinescope i.e.increasing the distance between the gun and the yoke, the deflection defocusing which is caused by scattering magnetic field of deflection yoke is reduced. Therefore, focnsing performance of kinescope is improved effectively and its edge resolution is increased. Test data show that the above methods are excellent, the increment of edge resolution is better than 50 lines.
1982, 4(1): 53-59.
Abstract:
The stimulated emission of 16 m was obtained as a result of optical pumping CF4 molecules with the 9R(12) line of TEA CO2 laser. The pump efficiency has been increased by narrowing the frequency bandwidth of CO2 pump laser with a CW gain cell, and by matching well the pump source to the pumped resonator.With a pump source energy of 700 mJ, a 25 mJ pulse energy of 16 m laser output, an optical quantum efficiency of 7%, a pulse width of less than 150 ns were obtained. This laser can be operated pulsewise several thousand times with a repetition rate of 0.5 Hz. The relations between the output energy of CF4 laser and some parameters (T, p, Ep) have been determined experimentally. The result of 9R(10) pump line is also observed, and compared with the result obtained with high pressure continously tunable CO2 laser.
The stimulated emission of 16 m was obtained as a result of optical pumping CF4 molecules with the 9R(12) line of TEA CO2 laser. The pump efficiency has been increased by narrowing the frequency bandwidth of CO2 pump laser with a CW gain cell, and by matching well the pump source to the pumped resonator.With a pump source energy of 700 mJ, a 25 mJ pulse energy of 16 m laser output, an optical quantum efficiency of 7%, a pulse width of less than 150 ns were obtained. This laser can be operated pulsewise several thousand times with a repetition rate of 0.5 Hz. The relations between the output energy of CF4 laser and some parameters (T, p, Ep) have been determined experimentally. The result of 9R(10) pump line is also observed, and compared with the result obtained with high pressure continously tunable CO2 laser.
1982, 4(1): 60-68.
Abstract:
The channel electron multiplier arrays (CEMAs), also known as microchannel plates (MCPs) are parallel arrays of many thousands of single eleetron multiplier channels made with special type glass. MCPs are versatile detectors of ions, electrons and photons, providing a large active area of high gain and uniformity.In this paper, the principle of fundamental operation of the MCP is described briefly. Major process of production of MCPs is presented. Fundamental characteristics and applieations of MCP are discussed briefly.
The channel electron multiplier arrays (CEMAs), also known as microchannel plates (MCPs) are parallel arrays of many thousands of single eleetron multiplier channels made with special type glass. MCPs are versatile detectors of ions, electrons and photons, providing a large active area of high gain and uniformity.In this paper, the principle of fundamental operation of the MCP is described briefly. Major process of production of MCPs is presented. Fundamental characteristics and applieations of MCP are discussed briefly.
1982, 4(1): 69-70.
Abstract:
In this paper, a highly reliable and long life cathode is described. The emission cur-rent density of the cathode is higher than 400 mA/cm2 at 730℃, and has a value of 50-70 mA/cm2 at 550℃. The life of the cathode under different conditions is over than 60000 hrs. The result of oxygen poisoning test is also given.
In this paper, a highly reliable and long life cathode is described. The emission cur-rent density of the cathode is higher than 400 mA/cm2 at 730℃, and has a value of 50-70 mA/cm2 at 550℃. The life of the cathode under different conditions is over than 60000 hrs. The result of oxygen poisoning test is also given.
1982, 4(1): 71-72.
Abstract:
High electric field intensity fluorescent screen (HEFIFS) plays an important role in low light level imaging devices of the second and third generation image intensifiers. This paper gives a preliminary result in HBFIFS which can operate under electric field intensity of 10-12 kV/mm. Other characteristics of the HEFIFS such as relative luminosity, spectrum and resolution are comparable to the conventional fluorescent sereen of the first generation image intensifier.
High electric field intensity fluorescent screen (HEFIFS) plays an important role in low light level imaging devices of the second and third generation image intensifiers. This paper gives a preliminary result in HBFIFS which can operate under electric field intensity of 10-12 kV/mm. Other characteristics of the HEFIFS such as relative luminosity, spectrum and resolution are comparable to the conventional fluorescent sereen of the first generation image intensifier.
