In the present work, we exhibited the experimental results of the direct current glow discharge electron gun source (DCEG) and their consecutive developments as electron beam energy lower than 5 keV and high intensity beams of tens microamperes to be used in some applications. A new type of direct current glow discharge electron gun was developed and modified for an improved treatment which supplies low –power and high electron-current density applications. This electron source is working on the condition of the abnormal glow discharge. The best working conditions were found to be at discharge pressure in the range of 10-4 mbar and gap distance between the cathode and the anode = 3 mm and a disk of Teflon insulator diameter of 5 mm, finally, the distance between the cathode exit and the extractor (focusing electrode) is equal to 4 mm. Internal and external operational characteristics (discharge and output ion beam currents) have been studied at this optimum distance using hydrogen, ...

This article reviews experiments on the production of low-energy, high-current electron beams ~LEHCEB! and their use for surface modification of materials. It is shown that electron guns with a plasma anode and an explosive emission cathode are most promising for the production of this type of beams. The problems related to the initiation of explosive emission and the production and transportation of LEHCEBs in plasma-filled diodes are considered. It has been shown that if the rise time of the accelerating voltage is comparable to or shorter than the time it takes for an ion to fly through the space charge layer, the electric field strength at the cathode and the electron current density in the layer are increased. Experimentally, it has been established that the current of the beam transported in the plasma channel is 1–2 orders of magnitude greater than the critical Pierce current and several times greater than the chaotic current of the anode plasma electrons. Methods for improving the uniformity of the energy density distribution over the beam cross section are described. The nonstationary temperature and stress fields formed in metal targets have been calculated. The features of the structure-phase transformations in the surface layers of materials irradiated with LEHCEBs have been considered. It has been demonstrated that in the surface layers quenched from the liquid state, nonequilibrium structure-phase states are formed. These states, together with the surface smoothing and cleaning, improve some surface-sensitive properties of the irradiated materials, such as the electric strength of metal-electrode vacuum gaps, the fatigue properties of titanium alloys, and the wear resistance of cutting tools made of high-speed steels and hard alloys. It has also been demonstrated that the pulsed melting of film–substrate systems makes it possible to execute efficient surface alloying. A description of an LEHCEB source with a plasma anode based on a high-current reflected discharge is given and the results of its testing and application are presented.

Generation of intense electron beams by superposing two discharges, namely a low pressure DC glow discharge and a high current pulsed discharge at pressures and voltages very similar to that of the pseudo-spark gap devices, has been reported previously. The small diameter, high peak current and short pulse length are the characteristics of the electron beam generated using this technique. In this technique, no high vacuum facilities are necessary, and many applications such as micro processing, X-rays generation, preionization for high-power lasers are feasible. The electron beam current is in the range of 10-30 A. A full characterization of the electron beam that is utilized in this work has been given in a previous work. In this work it is reported that the most energetic part of the electron beam is about 5-nanosecond pulse duration. The beam is magnetically deflected to the specific point.

The paper is devoted to electron beam guns based on the emission of electrons from plasma of a hollow-cathode reflective discharge. The measuring of the diameter and brightness of beam with the rotating wire sensor and scanning slit device were performed. A gun capable of producing strongly focused electron beams of power up to 6 kW and ener gy up to 60 keV. The test piece welding was confirmed a good beam quality. A key finding from t hese studies was that the brightness of the electron beam generated by the gun with a plasma ca thode is not inferior brightness beams obtained by thermionic cathodes. For example, the brightness of the beam with power up to 4 kW and energy of 60 keV was approximately 10 10 A·m·sr at the focal distance of 0,5 m. Beam diameter does not exceed 460 μm.