[en] The main grounds of a rather accurate calculation of accelerator gas gaps breakdown voltage for variable electrode geometry are given. On the 2nd stage of the calculation technique development a variable composition of binary mixture N₂/CO₂ is considered. (author)

[en] A set of systematic errors of a potential and a normal derivative for finite-difference method and numerical differentiation is considered. Methods for estimating errors based on the simulation of real gaps are described. The complete compensation of an error increases an accuracy and an efficiency of an numerical analysis. (author)

[en] Based upon classification of error types a method is suggested of component assessment in a full error of potential numerical computation with a subsequent upper relaxation method depending on a square pitch and boundary surface curvature. An error is studied in case of rectilinear internal boundaries. A possibility of ensuring higher precision is also considered. An error has been experimentally assessed pertaining to the subsequent upper relaxation method in a complex of REP programs. A potential computation error in the field of EhG-2.5 electrostatic accelerator is not less than 2.10^-3 with a pitch of 0.009 and a relative average radius of boundary surface curvature exceeding or equal to 6.5

No abstract available

[en] Under modernization of 2.5 MV accelerator high-voltage design in the initial (EhG-2.5) and improved (EhG-3) structures the following aspects are investigated: static breakdown voltages, crater (breakdown trace) distribution on the electrode surface as well as the breakdown probability properties. It is shown that breakdown voltage is first of all determined by maximum intensity, effective electrode area and gas density. The model of insulation system breakdown - ''single-staged high voltage accelerator'' - is clarified and methods for precise calculation of breakdown voltage for the element with weakly-inhomogeneous field proposed

[en] A comparatively accurate method for breakdown voltage calculation allows to optimize the accelerator geometry for obtaining maximum operating voltage. Due to complex approach, the breakdown voltage can be increased up to 1.5 times or more relative to usual structure. In addition to the EGP-15 project the paper studies how much variation of forms and dimensions of accelerator electrodes is powerful as to the increasing of an insulation gap breakdown voltage. (author)

[en] Efficiency of the program complex for electrostatic field calculation developed to optimize the high-voltage accelerator structure is estimated. A system of optimal factors of the high-voltage structure is suggested. A method for modernization of the column - ''twice oriented oval'' - realized with the EhG-2.5 accelerator provides the increase of both break-down voltage and service life of high-voltage elements of the accelerator accounting low cost of modernization

[en] The method for calculating the breakdown voltage of gas insulation of gaps in an accelerator has been developed. Firstly a new model of the insulation system element has been proposed according to the results of tests for the EG-2.5 Van de Graaff accelerator, IPPE. Then a complete-enough set of causes (factors) for the gas breakdown has been defined based on the experimental and calculational study. The calculation method includes a combination of some analytical equations coupled with the results of a special experiment with breakdown. A conclusion is made based on the comparison of experimental and calculated findings for the EG-2.5, MP and FN accelerators and other insulation structures that the accepted element model and the dependencies of the breakdown voltage on the main factors used here are adequate to the gas discharge nature of different gases. Since the calculation error is within the limit for the input data, the method described allows to predict the breakdown voltage for insulation gaps of an accelerator with accuracy of 1-5%

[en] An algorithm to calculation of the high-voltage accelerator asymmetric electrostatic field based on the two-dimensional analysis is suggested. Calculation accuracy of the spark gap field and the high-voltage accelerator structure is investigated. In the vicinity of maximum field strength the accuracy is ± 2 - 3%. Two-dimensional analysis of the asymmetric field allows to eliminate the calculational model roughness. 4 refs., 5 figs

[en] The dependence of the error in maximal field strength on two primary and one secondary factors is determined for numerical methods of finite differences (FDM) and differentiation. The investigations were conducted via numerical experiments using one-dimensional models. It was possible to establish a contact between the field numerical calculation error and differential-geometrical parameters of the boundaries, numeric parameters of problem digitization and estimation of error in the determination of the potential in the grid nodes. 6 refs., 5 figs