A new approach to solve the self-consistent problem for electron gun with arbitrary-shaped cathode is suggested. The main feature of the approach is that the most effective numerical techniques of charged particle optics, namely finite-difference and integral equation methods for field calculation on the one hand, and direct ray-tracing and aberration analysis for trajectory calculation on the other, are integrated within a versatile iterative procedure. Some testing problems are considered and analysed in details.

The fifth order aperture aberration is investigated in three types of quadrupole lens systems: the conventional regular antisymmetric quadruplet, the quadruplet made of combined quadrupole-octupole systems in which the third order aperture aberration is eliminated, and the mid- acceleration quadruplet produced by applying an accelerating voltage to the two middle lenses that results in the essential reduction of the aperture aberration. It is shown that for small initial trajectory slopes (less than 0.02) the quadrupole-octupole system provides smaller image blurring. For higher trajectory slopes when the fifth order aperture aberration becomes dominant the smallest beam spot is formed by the mid-acceleration quadruplet.

Long focus eletrostatic objective of simplest geometry with plane cathode has been investigated. Main feature of the immersion objective is telescopic mode and its linear magnification is almost constant in wide range of electrode potential changing. The spherical and chromatical aberration dependence on electrodes potential was studing. The results can be useful for optimization of geometrical size of low- voltage immersion objectives and for quick evaluation of electron optical properties of immersion lens.

The collection coefficient for secondary electrons is calculated for a two-detector system. The coefficient is an important parameter that determines the accuracy of line-width measurements in electron beam plants. Calculations of the chamber electrostatic field for various boundary conditions are presented. Trajectories of secondary electrons are found.

The paper looks into the applicability of two models of Coulomb interactions - space charge interaction and couple interaction - for image deformation calculations in the SCALPEL projection system. In contrast to [1-3], the paper takes into consideration thet electron beam structure which is determined by the image structure and focusing and diaphragming conditions. The calculations show that with the increasing electron current the space charge interaction becomes stronger than couple interactions. In a qualitative sense spherical aberrations caused by Coulomb interactions are the same in the both models. The inference is that a Coulomb decrease in resolution in this particular system is largely due to space charge interactions. The calculations of the central point spread show that the resolution can be increased several times by correction choosing the location of the image plane. With the beam enery of 100 KV and current of 50 (mu) A the highest resolution is 25 nm.

The paper presents a new approach to corpuscular optics - isotrajectory corpuscular optics - that can remove many principal limitations inherent in optics of static systems. The freedom from the limitations makes it possible to develop novel corpuscular-optical elements for pulsed flows of particles with much better or even unique performance parameters. The isotrajectory lateral differential invariant that is similar to Helmholtz-Lagrange invariant for static corpuscular-optical systems has been derived. The concept of space and time aberration (STA) and its computation algorithms are considered. Possible applications of STA in corpuscular optics is discussed.

The main parameters of the electron beam multicharge ion source IMI-2 are given. Experimental results are also given. The IMI-2 electron-beam system (EBS) includes a short-focus electron gyn with a spherical cathode of diameter 16 mm and curvature radius of 9.5 mm. The perveance of the gun is 1,6 (mu) A/V^3/2. The electron beam current can reach 2.5 A. An electrostatic and magnetic beam compression of ~10³ allows one to obtain a density of the electron beam of not less than ~10³ A/cm² on a 30 cm length. A specific method of dosed injection of the atoms of solid-state elements to an ion trap by means of local pulse deflection of the electron beam was used in the facility ¹. The electron-beam ion source (EBIS) IMI-2, Fig. 1, has a vertical design with an electron gun in the top section. The electron gun is mounted in a vacuum chamber of diameter 160 mm and length 500 mm. The vacuum chamber having a drift structure is inside the classical water-cooled solenoid with a completely closed magnetic circuit. An electron collector, an ion line, and a magnetic analyzer are located in the lower section of the facility. Like IMI-1 ^7-9, IMI-2 ^2-6 was also designed at the Budker Institute of Nuclear Physics for production of multicharge beams of gaseous and solid elements. In the EBS parameters, IMI-2 is intermediate between first-generation EBIS and those that can be used at acceleration complexes developed at the present time.

Results obtained in designing of the electron-optic system (EOS) of the multicharge ion source (MIS-1) are reported. This system forms an extended (~2 m) electron beam of power 1 MW. The length of the MIS-I ion trap with an electron beam density greater than 2x10³ A/cm² in increased to 1.5 m. Recuperation of the electron beam energy is envisaged in the collector. The electron-optic system (EOS) of the source being designed consists of three basic sections. The first section includes an electron gun and electron-beam injection to the solenoid focusing field. The second section is the electron-beam drift region in the solenoid focusing field, where the working region of the ion source is created in a stationary magnetic field, i.e., an ion trap. The third section is electron-beam rejection to the collector with maximum possible recuperation to decrease the power scattered on the collector and also to decrease the energy consumed during EOS operation. In an electron-beam ion source (EBIS), the capacity of the electron trap should be equal to the number of electrons of an ionizing beam in its volume. The time for which the required ion-charge distribution is attained is proportional to the electron beam density ¹. IN using EBIS in modern accelerating heavy ion facilities ², it is necessary to ensure a capacity of ion traps no smaller than 10¹² at a electron beam density of 10³ A/cm² in it. This problem can be solved most effectively by means of an EOS with double compression of the electron beam. That is, the electron beam is compressed electrostatically in an electron gun and at the second stage compression is ensured by an increasing focusing magnetic field. To do this, the magnetic field in the cathode - crossover region is distributed in such a way that the force lines of the magnetic field coincide with electron trajectories. The magnetic field increases behind the crossover and provides additional smooth compression of the electron beam with its laminar character preserved.

The paper presents a method that helps take into account all components of the magnetic field in analyzing electron paths. Optimal parameters for computer simulation are chosen using test models. The beam profile is computed in the through mode of electron-optical system analysis using actual parameters of both reverse and uniform magnetic field. The limiting value of the transverse component of magnetic field is assessed.

The paper considers differences between basic operations of the microelectromechanical systems (MEMS) and microelectronic manufacturing processes. The design and fabrication of the vibration microgyroscope are discussed to exemplify the inadequacy of standard microelectronic techniques for needs of MEM technologies and necessity of developing new basic technologies.

The concept of a second generation Hall-current plasma accelerator (ATON-thruster), which has record performance characteristics is described. A method is proposed for analyzing the operation parameters of the accelerator on the basis of its performance characteristics. The results of measurements of plasma parameters in the accelerator channel and outflowing jet are presented. Influence of backmoving of particles from vacuum chamber to thruster one has been discussed.

The radiation spectrum and energy of Xe plasma in the range of 0.23 (mu) m to 1.2 (mu) m are investigated for the second-generation ATON-type plasma thruster. About 90% of the ration is found to be in infrared, nine IR emission line taking 70% of the energy. By our estimation, two intensive lines at (lambda) equals 8819.41A and (lambda) equals 8220.12A can be used to investigate the channel and jet plasma with the help of the crown model.

The experimental study of charge relaxation while electron beam processing of dielectrics has shown that under irradiation with an intensive and concentrated electron beam some dielectrics reveal strange behavior. The electron emission from their surface much exceeds the value expected frmo the conventional theory of the secondary electron emission. Moreover, the time dependence of the emission is quite different. The measured current changes rapidly with time and, under some circumstances, oscillates while the secondary emission is always proportional to the electron beam's current. The target of the present paper is to construct the physical model of this effect employing the theory of hot electrons.

In recent years vacuum microelectronics (VM) based on field emiuer array1 (FEA) concept has experienced tremendous growth. VM devices benefit from collision-free motion of electrons in vacuum, enabling faster modulation and higher electron energies than possible with solid-state structures. In addition TM devices can operate in a wide temperature range, 4K<T<1000K, and in high-radiation environment. Applications include FEA flat-panel displays, microwave amplifiers, digital IC, electron and ion guns, sensors, high energy accelerators, electron beam lithography, free electron lasers, and electron microscopes and microprobes. Innovative approaches to FEAs were made in latest years with respect to PEA materials, structure, and applications. A number of TM devices have by now moved beyond the research laboratories to actual prototypes and commercial products. Now silicon is considered as one of the most suitable material for FEA fabricating in batch technology (see e.gJ21). Silicon, though has orders of magnitude fewer conduction band electrons than metals, has emitting characteristics comparable to metals, and highly developed silicon batch technology can be applied to make various VM devices, including transistor-like structures. There are many specific aspects and special requirements for VM, and comprehension of physics of VM devices functioning play a key role in its successful development. One of the most important problem is the creation of FEA with sufficiently high, controlled, and stable emission ability. Field emission from semiconductors has some peculiar features which should be taken into account in silicon-based VM. High electric field penetrates deep enough into the semiconductor and results in intense electron heating near the emitting surface. Since the tunnelling coefficient exponentially depends on energy, this drastically effects the emission characteristics and heat dissipation. Thus the electron transport in semiconductor field emitter is in fact highly nonequilibrium hot electron process. It was well demonstrated in3'4 for one-dimensional model. However two-dimensional (2D) approach is principal for real cathodes modelling57. It is an actual physical and practical problem which is rather complicated and can be solved accurately enough by means of numerical methods only. In this paper we report on 2D numerical simulation offleld emission from silicon wedge microcathode structure.

Electron-optical approximation of the electron diffraction in the periodic lattice field ^1,2 is used to analyze the intensity patterns of equal-thickness fringes and hunting curves. The results are used for explaining anomalous absorption observed in transmission electron microscopy investigations of monocrystalline objects.

The fulfillment of the new project of creation of the industrial prototype of a technological gyrotron on permanent magnets are discussed. The permanent magnet system was designed, constructed and successfully tested for a gyrotron. A 30 Ghz gyrotron (nequals2) with rf- output power of 10 kW is under development with the TE₁₂ operating mode. An output power of 12 kW was obtained (efficiency 24%).

The analytic theory for formation of intense helical electron beams in gyroresonance derives in a longitudinally inhomogeneous magnetic field is advanced. Criteria for the required degree of non-adiabaticity of the magnetic field sufficient to produce high oscillatory energy of electrons in the resonator cavity are formulated. Estimates for basic parameters of the beam (oscillatory velocities, position of the guiding center, velocity spread) are given for the step-wise and bell-shaped approximations of the magnetic field. The factors affecting the velocity spread are considered.

The paper considers a new type of electron devices - electron-beam valves (EBV). The use of anode deceleration in forming the e-beam in the EBV allows devices with improved characteristics. The EBV can be used to generate wide pulses (milliseconds to seconds in width) and provide fast switching off of the apparatus (a few microseconds). The paper also describes three eletron-optical system designs using the EBV. The ways of improving the systems are outlined.

The review of researches performed by JINR-CERN-ITEP collaboration in 1994-1995 [10 and by JINR group in 1996-1998 years is presented. The research has the goal to study theoretically and experimentally a possibility of electron beam space neutralization and formation of a stable and intense neutralized electron beam (NEB).

Problems connected with design of high-power beam-plasma microwave devices are discussed. Special attention is given to optical systems of intense electron beams for those new type microwave tubes.