Investigation of the attenuation of the fluxes of the low-energy plasma component of electric rocket engines by the ventilation holes of the unpressurized instrument compartment of the spacecraft

The results of an experimental study of the attenuation of the fluxes of the low-energy component of the plasma formed during the operation of electric propulsion engines (ERE), ventilation holes (VH) of the non-sealed equipment compartment (NSEC) of the spacecraft (SC) are presented. Authors studied the attenuation of plasma fluxes by standard VHs made in honeycomb panels that form the NSEC. A Hall-effect engine of the SPT-70 type was used as a plasma source. The experiment consisted of measuring the plasma concentration at the inlet and outlet of the VH. The concentration at the inlet was measured with a flat Langmuir probe, and at the outlet with a Faraday probe, which allows collecting all ions passing through the VH. The aim of the work was to study the weakening of the fluxes of the lowenergy component of the EJE plasma when passing through the VH in the honeycomb-nels that form the NSEC. Based on the experimental data, a semi-empirical model was constructed that describes the dependence of the attenuation coefficient of plasma flows on the geometric parameters of the vent-holes. It has been established that a vent-holes of this design attenuates the plasma flows by 102 ... 104 times. The largest contribution to the weakening of plasma fluxes is made by the honeycomb filler, which is due to the recombination of ions during their collision with the channel walls. Taking into account the attenuation of the fluxes of the low-energy component of the plasma of electric rocket engines by ventilation holes is a key stage in assessing the effect of plasma on the power on-board equipment of spacecraft and should be used by spacecraft developers when analyzing the resistance to this factor.

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SIMULATION OF THE CURRENT-VOLTAGE CHARACTERISTICS OF SOLAR BATTERIES WITH CONSIDERING DECREASE OF LIGHTING DUE TO THE INFLUENCE OF JETS OF THE ELECTRIC PROPULSION

Space engineering and technology ◽

10.33950/spacetech-2308-7625-2019-4-56-64 ◽

2019 ◽

pp. 56-64

Author(s):

Ya.N. MIGUNOV ◽

V.V. ONUFRIEV

Keyword(s):

Solar Cells ◽

Temperature Gradient ◽

Electric Propulsion ◽

Protective Coatings ◽

Rocket Engine ◽

Solar Array ◽

Rocket Engines ◽

Lighting Conditions ◽

Main Equation ◽

Voltage Current Characteristic

A model for calculating the voltage-current characteristic of a solar array in the presence of a temperature gradient by its photovoltaic converters and their variable illumination due to possible pollution under the action of space factors, including operation of electric rocket engines, is described. The model is based on the main equation of a solar cell. In this case both a one-dimensional and a two-dimensional temperature gradients are taken into account. The principles of constructing a model are given, and the initial data selection is made. To simulate the lighting conditions of the solar array such a concept as effective illumination is used, i.e. the density of the radiation flux which falls on photovoltaic converters passing through the protective coatings. The features of simulation of the temperature distribution in the solar array and the effective illumination of its surface in cases of parallel, serial and mixed switching of solar cells are described. The calculation procedures and examples of solar cells are given. The construction of the model in universal mathematical package Mathcad is described. Some simulation results are discussed. Key words: solar array, mathematical simulation, illumination, temperature gradient, electric rocket engine, spacecraft, Mathcad.

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Photoproduction of Gravitational Radiation in Static Electromagnetic Fields. Radiative Corrections

Canadian Journal of Physics ◽

10.1139/p75-279 ◽

1975 ◽

Vol 53 (20) ◽

pp. 2315-2320 ◽

Cited By ~ 3

Author(s):

G. Papini ◽

S. -R. Valluri

Keyword(s):

Cross Section ◽

Gravitational Radiation ◽

Low Energy ◽

Radiative Corrections ◽

Third Order ◽

The Third ◽

Relativistic Approximation ◽

Effective Lagrangian ◽

Charge Renormalization ◽

Made In

The radiative corrections of second and third order for the process of photoproduction of gravitons in Coulomb and magnetic dipole fields have been calculated.All divergences have been removed either by charge renormalization or regularization. No approximations have been made in the calculation of the second order cross section. In the third order calculation only the extreme relativistic approximation is given. The forms of the effective Lagrangian, corresponding to the low energy approximations have been determined.

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Oxide Degradation Effects in Dry Patterning of Resist Using Neutral Oxygen Beams

MRS Proceedings ◽

10.1557/proc-268-41 ◽

1992 ◽

Vol 268 ◽

Cited By ~ 3

Author(s):

Walter E. Mlynko ◽

Srinandan R. Kasi ◽

Dennis M. Manos

Keyword(s):

Dielectric Breakdown ◽

Electrical Characterization ◽

Plasma Source ◽

Interface State ◽

State Density ◽

Low Energy ◽

Carrier Injection ◽

Polysilicon Gate ◽

Atomic Beams ◽

Novel Processing

ABSTRACTNovel processing methods are being studied to address the highly selective and directional etch requirements of the ULSI manufacturing era; neutral molecular and atomic beams are two promising candidates. In this study, the potential of 5 eV neutral atomic oxygen beams for dry development of photoresist is demonstrated for application in patterning of CMOS devices. The patterning of photoresist directly on polysilicon gate layers enables the use of a self-contained dry processing strategy, with oxygen beams for resist etching and chlorine beams for polysilicon etching. Exposure to such reactive low-energy species and to the UV radiation from the line-of-sight, high-density plasma source can, however, alter MOSFET gate oxide quality, impacting device performance and reliability. We have studied this process-related device integrity issue by subjecting polysilicon gate MOS structures to exposure treatments of 5–20 eV oxygen beams similar to those used for resist patterning. Electrical characterization shows a significant increase in the oxide trapped charge (30–90x) and interface state density (30–60x) upon low-energy exposure. Current-voltage(IV) and dielectric breakdown characterization show increased low-field leakage characteristics for the same exposure. High-field electron injection studies reveal that the 0.25–V to 0.5–V negative flatband shifts (measured after oxygen beam exposure) can be partially annealed by carrier injection. This could be due to positive charge annihilation or electron trapping, or some combination of both. SEM and electrical analysis of structures exposed to neutral beam processing are presented along with the results of thermal annealing treatments.

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