Plasma probe characteristics in low density hydrogen pulsed plasmas

Probe theories are only applicable in the regime where the probe's perturbation of the plasma can be neglected. However, it is not always possible to know, a priori, that a particular probe theory can be successfully applied, especially in low density plasmas. This is especially difficult in the case of transient, low density plasmas. Here, we applied probe diagnostics in combination with a 2D particle-in-cell model, to an experiment with a pulsed low density hydrogen plasma. The calculations took into account the full chamber geometry, including the plasma probe as an electrode in the chamber. It was found that the simulations reproduce the time evolution of the probe IV characteristics with good accuracy. The disagreement between the simulated and probe measured plasma density is attributed to the limited applicability of probe theory to measurements of low density pulsed plasmas. Indeed, in the case studied here, probe measurements would lead to a large overestimate of the plasma density. In contrast, the simulations of the plasma evolution and the probe characteristics do not suffer from such strict applicability limits. These studies show that probe theory cannot be justified through probe measurements

Numerical and experimental studies of the carbon etching in EUV-induced plasma

We have used a combination of numerical modeling and experiments to study carbon etching in the presence of a hydrogen plasma. We model the evolution of a low density EUV-induced plasma during and after the EUV pulse to obtain the energy resolved ion fluxes from the plasma to the surface. By relating the computed ion fluxes to the experimentally observed etching rate at various pressures and ion energies, we show that at low pressure and energy, carbon etching is due to chemical sputtering, while at high pressure and energy a reactive ion etching process is likely to dominate

ДОСЛІДЖЕННЯ ПРОЦЕСІВ ВИЯВЛЕННЯ ВИБУХОНЕБЕЗПЕЧНИХ ПРЕДМЕТІВ ІНДУКЦІЙНИМ ТА РАДІОХВИЛЬОВИМ МЕТОДАМИ НА ОСНОВІ РЕЗУЛЬТАТІВ ОДНОФАКТОРНИХ ЕКСПЕРИМЕНТІВ

The experience of conducting military operations in modern military conflicts has shown that one of their dangerous consequences is the contamination of territories with explosive objects, which pose a threat to both the military and the civilian population. Ukraine is no exception, which today is among the countries most polluted by explosive objects in the world. With the beginning of the Russian Federation's undeclared war against Ukraine in 2014 and the subsequentlarge-scale invasion in February 2022, this problem has become more acute. The relevance of the issue of reconnaissance and demining of the area from explosive-proof objects both during the conduct of hostilities and in their absence hasincreased many times. The experience of the war shows that the enemy, despite international conventions on the prohibition of certain types of mine weapons, uses its entire available arsenal of mines and improvised explosive devices,which are often set to non-removable. In addition to mines and improvised explosive devices, the territory of Ukraine, where hostilities are conducted or released, is contaminated by a large number of various unexploded ordnance.The execution of the tasks of reconnaissance of the area for the presence of explosive objects and demining during hostilities is mainly entrusted to the engineering units of the Armed Forces of Ukraine, and in the absence of hostilitiesto the pyrotechnic groups of the State Emergency Service of Ukraine. Analysis of the execution of reconnaissance and demining tasks by engineering units of the Armed Forces of Ukraine and pyrotechnic groups of the State Emergency Service shows that the main method today remains manual, which is extremely dangerous for the lives of personnel. To ensure the safety of the performance of these tasks, work is underway to create domestic means of remote reconnaissance and demining. One of the components of such means is to search elements for explosive objects that work on different physical principles. In addition to theoretical provisions, one of its important stages is conducting an experimental study.The article, based on previously developed theoretical provisions, provides simulations of the processes of detecting explosive objects by induction and radio wave methods using mine detectors that are in service with the Armed Forcesof Ukraine and the State Emergency Service, namely IMP, RVM-2(M), MMP (two-channel), during the of a one-factor experiment to substantiate individual indicators of the effectiveness of search elements for explosive objects of remotecontrolled demining complexes.Досвід ведення бойових дій у сучасних воєнних конфліктах показав, що одним із небезпечних їх наслідків є забруднення територій вибухонебезпечними предметами, які становлять загрозу як військовим, так і цивільномунаселенню. Не є винятком і Україна, яка сьогоднішні опинилася в числі найбільш забруднених вибухонебезпечними предметами країн світу. З початком ведення неоголошеної війни російської федерації проти України у 2014 році, а надалі широкомасштабного вторгнення у лютому 2022 року, ця проблема загострилась. Актуальність питання розвідки та розмінування місцевості від вибухобезпечних предметів як під час ведення бойових дій, так і завідсутності їх збільшилось в рази. Досвід війни показує, що противник незважаючи на міжнародні конвенції щодо заборони певних видів мінної зброї, застосовує весь свій наявний арсенал мін та саморобні вибухові пристрої, якічасто встановлюються на невилучуваність. Окрім мін та саморобних вибухових пристроїв територія України, де ведуться бойові дії або звільнена, забруднена великою кількість різноманітних боєприпасів, які не розірвалися.Виконання завдань з розвідки місцевості на наявність вибухонебезпечних предметів та розмінування під час ведення бойових дій в основному покладено на інженерні підрозділи ЗС України, а за відсутності бойовихдій - на піротехнічні підрозділи Державної служби України з надзвичайних ситуацій. Аналіз виконання завдань щодо розвідки та розмінування інженерними підрозділами ЗС України та піротехнічними групами Державної служби України з надзвичайних ситуацій показує, що основним способом на сьогоднішні залишається ручний, який є вкрай небезпечним для життя особового складу. З метою забезпечення безпеки виконання цих завдань ведеться робота зі створення вітчизняних засобів дистанційної розвідки та розмінування. Однією із складових таких засобів є пошукові елементи вибухонебезпечних предметів, які працюють на різних фізичних принципах. Окрім теоретичних положень одним із важливих його етапів є проведення експериментального дослідження. В статті на основі раніше розроблених теоретичних положень наведено моделювання процесів виявлення вибухонебезпечних предметів індукційним та радіохвильовим методами з використання міношукачів, які перебувають на озброєнні ЗС України та ДСНС, а саме ИМП, РВМ-2(М), ММП (двоканальний), під час проведення однофакторного експерименту з метою обґрунтування окремих показників ефективності елементів пошуку вибухонебезпечних предметів дистанційно-керованих комплексів розмінування

Разработка систем управления станков с ЧПУ при помощи программной среды MexBIOS Development Studio

The application of the Lorentzian plasma theory for the calculation of the properties of multicomponent electric arc plasma is considered. It is shown that this model gives satisfactory results in the temperature range, which is corresponding to the weakly ionized arc plasma and arc plasma with dominant first ionization. The calculations are provided for the arc plasmas of noble gases and their mixtures between them and also that with metals. It is also pointed that the discrepancy between the electron temperature and gas temperature can be significant even at relatively weak electric fields, that fact must be taken into account under the simulation of arc discharges

МЕТОДИКА ОБРАБОТКИ ЭКСПЕРИМЕНТАЛЬНЫХ ДАННЫХ ПРИ МОДЕЛИРОВАНИИ ДИСПЕРСИИ ИМПЕДАНСА БИОЛОГИЧЕСКИХ ТКАНЕЙ С ПОМОЩЬЮ СХЕМЫ ЗАМЕЩЕНИЯ ФРИКЕ

Purpose. Modeling the dispersion of the biological tissue impedance of vegetable and animal origin using the Fricke equivalent circuit; development of a technique for experimental data processing to determine the approximation coefficients of the dispersion of the biological tissue impedance for this equivalent circuit; study of the features of the equivalent circuit at modeling the dispersion of the impedance, resistance, and reactance; the definition of the frequency domain in which using of the equivalent circuit is correct; revealing and generalization of the main regularities of dissipation of biological tissue impedance of vegetable and animal origin. Methodology. The technique is based on the scientific provisions of theoretical electrical engineering – the theory of the electromagnetic field in nonlinear media in modeling the dispersion of the biological tissue impedance. Results. The electric circuit of the Fricke equivalent circuit allows modeling the dependences of the impedance module of biological tissues, active and reactive components of impedance with acceptable accuracy for practical purposes in the frequency domain from 103 to 106 Hz. The equation of impedance of the Fricke equivalent circuit for biological tissues makes it possible to approximate the frequency dependences of the impedance modulus, active and reactive parts of the total resistance only by using the approximation coefficients corresponding to each part. The developed method for determining the values of the approximation coefficients of the impedance equation for the Fricke equivalent circuit for biological tissues allows to determine these values with high accuracy for various biological tissues. It is shown that the frequency dependences of the active component of the total resistance for tissues of vegetable and animal origin are similar. Originality. The developed technique operates with the normalized values of the impedance modulus of the Fricke equivalent circuit, the active and reactive components of the impedance as a function of frequency, which allows a comparative analysis of the dependencies of these parameters of various biological tissues of plant and animal origin. Practical value. The approximate dependences of the absolute impedance modulus, active and reactive components of the impedance allow modeling processes occurring in biological tissues with the passage of a current of different frequency. Dependence of the impedance of biological tissue can be applied to the design of diagnostic and control equipment to determine the properties of tissues of animal and vegetable origin, including developing more effective medical equipment.Разработана методика обработки экспериментальных данных для определения коэффициентов аппроксимации импеданса биологических тканей растительного и животного происхождения при моделировании дисперсии импеданса с помощью схемы замещения Фрике. Проведен анализ свойств схемы замещения Фрике, ее возможностей и особенностей при моделировании дисперсии импеданса, резистанса и реактанса. Показано, что при нормировании дисперсии активные составляющие импеданса для тканей растительного и животного происхождения подобны

МЕТОДИКА ОБРАБОТКИ ЭКСПЕРИМЕНТАЛЬНЫХ ДАННЫХ ПРИ МОДЕЛИРОВАНИИ ДИСПЕРСИИ ИМПЕДАНСА БИОЛОГИЧЕСКИХ ТКАНЕЙ С ПОМОЩЬЮ СХЕМЫ ЗАМЕЩЕНИЯ ФРИКЕ

Purpose. Modeling the dispersion of the biological tissue impedance of vegetable and animal origin using the Fricke equivalent circuit; development of a technique for experimental data processing to determine the approximation coefficients of the dispersion of the biological tissue impedance for this equivalent circuit; study of the features of the equivalent circuit at modeling the dispersion of the impedance, resistance, and reactance; the definition of the frequency domain in which using of the equivalent circuit is correct; revealing and generalization of the main regularities of dissipation of biological tissue impedance of vegetable and animal origin. Methodology. The technique is based on the scientific provisions of theoretical electrical engineering – the theory of the electromagnetic field in nonlinear media in modeling the dispersion of the biological tissue impedance. Results. The electric circuit of the Fricke equivalent circuit allows modeling the dependences of the impedance module of biological tissues, active and reactive components of impedance with acceptable accuracy for practical purposes in the frequency domain from 103 to 106 Hz. The equation of impedance of the Fricke equivalent circuit for biological tissues makes it possible to approximate the frequency dependences of the impedance modulus, active and reactive parts of the total resistance only by using the approximation coefficients corresponding to each part. The developed method for determining the values of the approximation coefficients of the impedance equation for the Fricke equivalent circuit for biological tissues allows to determine these values with high accuracy for various biological tissues. It is shown that the frequency dependences of the active component of the total resistance for tissues of vegetable and animal origin are similar. Originality. The developed technique operates with the normalized values of the impedance modulus of the Fricke equivalent circuit, the active and reactive components of the impedance as a function of frequency, which allows a comparative analysis of the dependencies of these parameters of various biological tissues of plant and animal origin. Practical value. The approximate dependences of the absolute impedance modulus, active and reactive components of the impedance allow modeling processes occurring in biological tissues with the passage of a current of different frequency. Dependence of the impedance of biological tissue can be applied to the design of diagnostic and control equipment to determine the properties of tissues of animal and vegetable origin, including developing more effective medical equipment.Разработана методика обработки экспериментальных данных для определения коэффициентов аппроксимации импеданса биологических тканей растительного и животного происхождения при моделировании дисперсии импеданса с помощью схемы замещения Фрике. Проведен анализ свойств схемы замещения Фрике, ее возможностей и особенностей при моделировании дисперсии импеданса, резистанса и реактанса. Показано, что при нормировании дисперсии активные составляющие импеданса для тканей растительного и животного происхождения подобны

A TECHNIQUE FOR EXPERIMENTAL DATA PROCESSING AT MODELING THE DISPERSION OF THE BIOLOGICAL TISSUE IMPEDANCE USING THE FRICKE EQUIVALENT CIRCUIT

Purpose. Modeling the dispersion of the biological tissue impedance of vegetable and animal origin using the Fricke equivalent circuit; development of a technique for experimental data processing to determine the approximation coefficients of the dispersion of the biological tissue impedance for this equivalent circuit; study of the features of the equivalent circuit at modeling the dispersion of the impedance, resistance, and reactance; the definition of the frequency domain in which using of the equivalent circuit is correct; revealing and generalization of the main regularities of dissipation of biological tissue impedance of vegetable and animal origin. Methodology. The technique is based on the scientific provisions of theoretical electrical engineering – the theory of the electromagnetic field in nonlinear media in modeling the dispersion of the biological tissue impedance. Results. The electric circuit of the Fricke equivalent circuit allows modeling the dependences of the impedance module of biological tissues, active and reactive components of impedance with acceptable accuracy for practical purposes in the frequency domain from 103 to 106 Hz. The equation of impedance of the Fricke equivalent circuit for biological tissues makes it possible to approximate the frequency dependences of the impedance modulus, active and reactive parts of the total resistance only by using the approximation coefficients corresponding to each part. The developed method for determining the values of the approximation coefficients of the impedance equation for the Fricke equivalent circuit for biological tissues allows to determine these values with high accuracy for various biological tissues. It is shown that the frequency dependences of the active component of the total resistance for tissues of vegetable and animal origin are similar. Originality. The developed technique operates with the normalized values of the impedance modulus of the Fricke equivalent circuit, the active and reactive components of the impedance as a function of frequency, which allows a comparative analysis of the dependencies of these parameters of various biological tissues of plant and animal origin. Practical value. The approximate dependences of the absolute impedance modulus, active and reactive components of the impedance allow modeling processes occurring in biological tissues with the passage of a current of different frequency. Dependence of the impedance of biological tissue can be applied to the design of diagnostic and control equipment to determine the properties of tissues of animal and vegetable origin, including developing more effective medical equipment

A TECHNIQUE FOR EXPERIMENTAL DATA PROCESSING AT MODELING THE DISPERSION OF THE BIOLOGICAL TISSUE IMPEDANCE USING THE FRICKE EQUIVALENT CIRCUIT

Purpose. Modeling the dispersion of the biological tissue impedance of vegetable and animal origin using the Fricke equivalent circuit; development of a technique for experimental data processing to determine the approximation coefficients of the dispersion of the biological tissue impedance for this equivalent circuit; study of the features of the equivalent circuit at modeling the dispersion of the impedance, resistance, and reactance; the definition of the frequency domain in which using of the equivalent circuit is correct; revealing and generalization of the main regularities of dissipation of biological tissue impedance of vegetable and animal origin. Methodology. The technique is based on the scientific provisions of theoretical electrical engineering – the theory of the electromagnetic field in nonlinear media in modeling the dispersion of the biological tissue impedance. Results. The electric circuit of the Fricke equivalent circuit allows modeling the dependences of the impedance module of biological tissues, active and reactive components of impedance with acceptable accuracy for practical purposes in the frequency domain from 103 to 106 Hz. The equation of impedance of the Fricke equivalent circuit for biological tissues makes it possible to approximate the frequency dependences of the impedance modulus, active and reactive parts of the total resistance only by using the approximation coefficients corresponding to each part. The developed method for determining the values of the approximation coefficients of the impedance equation for the Fricke equivalent circuit for biological tissues allows to determine these values with high accuracy for various biological tissues. It is shown that the frequency dependences of the active component of the total resistance for tissues of vegetable and animal origin are similar. Originality. The developed technique operates with the normalized values of the impedance modulus of the Fricke equivalent circuit, the active and reactive components of the impedance as a function of frequency, which allows a comparative analysis of the dependencies of these parameters of various biological tissues of plant and animal origin. Practical value. The approximate dependences of the absolute impedance modulus, active and reactive components of the impedance allow modeling processes occurring in biological tissues with the passage of a current of different frequency. Dependence of the impedance of biological tissue can be applied to the design of diagnostic and control equipment to determine the properties of tissues of animal and vegetable origin, including developing more effective medical equipment