# Journal of Technological and Space PlasmasLatest Publications

11
(FIVE YEARS 11)

## H-INDEX

1
(FIVE YEARS 1)

2616-647x

2021 ◽
Vol 2 (1) ◽
pp. 70-92
Author(s):
Reiner L Stenzel ◽
Johannes Grünwald ◽
Codrina Ionita ◽
Roman Schrittwieser ◽
Manuel Urrutia
Keyword(s):

The properties of sheaths and associated potential structures and instabilities cover a broad field which even a review cannot cover everything. Thus, the focus will be on about a dozen examples, describe their observations and focus on the basic physical explanations for the effects, while further details are found in the references. Due to familiarity the review focuses mainly on the authors work but compared and referenced related work. The topics start with a high frequency oscillations near the electron plasma frequency. Low frequency instabilities also occur at the ion plasma frequency.The injection of ions into an electron-rich sheath widens the sheath and forms a double layer. Likewise, the injection of electrons into an ion rich sheath widens and establishes a double layer which occurs in free plasma injection into vacuum. The sheath widens and forms a double layer by ionization in an electron rich sheath. When particle fluxes in "fireballs" gets out of balance the double layer performs relaxation instabilities which has been studied extensively. Fireballs inside spherical electrodes create a new instability due to the transit time of trapped electrons. On cylindrical and spherical electrodes the electron rich sheath rotates in magnetized plasmas. Electrons rotate due to $\mathbf E \times \mathbf B_0$ which excites electron drift waves with azimuthal eigenmodes. Conversely a permanent magnetic dipole has been used as a negative electrode. The impact of energetic ions produces secondary electron emission, forming a ring of plasma around the magnetic equator. Such "magnetrons" are subject to various instabilities. Finally, the current to a positively biased electrode in a uniformly magnetized plasma is unstable to relaxation oscillations, which shows an example of global effects. The sheath at the electrode raises the potential in the flux tube of the electrode thereby creating a radial sheath which moves unmagnetized ions radially. The ion motion creates a density perturbation which affects the electrode current. If the electrode draws large currents the current disruptions create large inductive voltages on the electrode, which again produce double layers. This phenomenon has been seen in reconnection currents. Many examples of sheath properties will be explained. Although the focus is on the physics some examples of applications will be suggested such as neutral gas heating and accelerating, sputtering of plasma magnetrons and rf oscillators.

2021 ◽
Vol 1 (1) ◽
pp. 63-69
Author(s):
Javier Lopez Segura ◽
Arpan Pal ◽
Nicolas Urgoiti
Keyword(s):

The measured results of two tests T3073 and T3074 performed in 28 August, 2020 are presented in this paper. Tests are conducted in the z-pinch type nuclear fusion reactor Pulsotron-3 with the target loaded with Hydrogen-Boron (H+B11) thermonuclear fuel. A group of Energy Recovery Coils (ERCs) were mounted to recover the electric energy directly from the plasma for the first time in the world and ERCs stored the energy in several large capacitors. During the test T3073 and T3074 the energy recovery capacitors recovered 22.59% and 17.74% of the injected energy at the target. A magnetic sensor MAG-4 consisting of inductor coils and dipoles were installed in Pulsotron-3 to measure the Time Of Flight (TOF) of the plasma and the magnetic field generated due to nuclear fusion. Magnetic fields more than 4 megateslas are obtained during the two tests. It is also observed that Pulsotron-3 with the target loaded with thermonuclear fuel generated 20-34 times larger peak magnetic fields and 12-18 times larger stabilized magnetic fields compare to the tests done using unloaded target (dummy loads). In this proposed technology Pulsotron-3 utilizes thermonuclear fuel to generate clean electric power without CO2 footprint and reduce the operational cost. This industrial approach is a promising solution that can reduce world emissions to zero in less than 8 years.

2020 ◽
Vol 1 (1) ◽
pp. 54-62
Author(s):
Dmitry Levko
Keyword(s):

Self-oscillations of non-neutral plasma diode operating in the anode-glow mode are analysed using the self-consistent one-dimensional Particle-in-Cell Monte Carlo collisions model. In order to obtain these states, the current exceeding the space-charge limited current has to be emitted from the cathode, the electron mean free path must be much longer than the cathode-anode gap, and the cathode voltage must be slightly larger than the ionization potential of the background gas. It is obtained that in such a case, immobile ions form the electrostatic trap for the electrons generated in the cathode-anode gap. These electrons oscillate between the cathode and the anode causing the self-oscillations of the plasma potential. It is shown that the increase of the emission current leads to the increase of the frequency of the obtained self-oscillations. Starting at some value of the emission current, a lot of the emitted electrons are got trapped in the electrostatic well, which leads to the transition to chaos.

2020 ◽
Vol 1 (1) ◽
pp. 45-53
Author(s):
Antonina Malinina
Keyword(s):

2020 ◽
Vol 1 (1) ◽
pp. 36-44
Author(s):
Javier Lopez Segura ◽
Nicolas Urgoiti
Keyword(s):

An AC magnetic sensor is presented for measuring the high speed and high strength magnetic field generated in Z-pinch fusion machines. The proposed magnetic sensor provides the measurement of magnetic fields across a broadband frequency range. The simulation of magnetic probe is presented using a SPICE simulation software LTspice. The magnetic sensors are installed in a Pulsotron-3 Z-pinch machine and measured performance of the sensor are presented. This sensor also can be used to check the ignition conditions of the Z-Pinch by measuring the magnetic field generated by the output streams of large number of reacted alpha particles. The equations for measuring non-stationary magnetic field due to rapidly varying electric currents and a LTspice simulation file are provided to help the engineers to design, build, and install this kind of sensors.

2020 ◽
Vol 1 (1) ◽
pp. 27-35
Author(s):
Rajesh Prakash Guragain ◽
H B Baniya ◽
S Dhungana ◽
S Gautam ◽
B P. Pandey ◽
...
Keyword(s):

The low surface energy of HDPE limits its industrial uses as it is not suitable for printing and adhesion. The main aim of this work is to improve the wetting properties of high-density polyethylene (HDPE) using air dielectric barrier discharge (DBD) operating at the line frequency (50 Hz). The estimation of electron temperature and electron density has been done by electrical and optical methods. The surface roughness of the control and plasma treated polymer film is analysed by contact angle (CA) measurement, surface energy measurement and scanning electron microscope (SEM) analysis. The contact angle was found to be suppressed from 93.180±2.00 to 63.750±0.880 after 10s of plasma treatment which implied that the surface property had changed to a hydrophilic state caused by an increase in the surface roughness.

2020 ◽
Vol 1 (1) ◽
pp. 00021-00025 ◽
Author(s):
Gregor Filipič ◽
Johannes Gruenwald

In this work we present a copper oxide nanostructured analysed as a gas sensor but the focus of the paper is on the temperature dependance of the sensor sensing properties. As a case study temperature dependent diethylamine sensing is presented.The CuO nano flakes were deposited and evenly distributed on intercalated electrodes by an atmospheric pressure plasma source. The sensor was electrically connected to ohmmetre and inserted in an oven chamber where it was isolated from atmosphere and heated to desired tempearuteres. The intrinsic resistnace of the sensor was measured in dependence of the temperature and the temperature change rate. Then the possibility to detect diethylamine was investigated and the sensor response studied. Finally, the temperature dependence of the detection of the amine was explored. It was possible to demonstrate reliable sensing of the amine down to temperatures of 100 °C and below.

2019 ◽
Vol 1 (1) ◽
pp. 12-20
Author(s):
Javier Lopez Segura ◽
Nicolas Urgoiti Moinot ◽
Enzo Lazzaro
Keyword(s):

Several tokamaks structures containing 500 keV protons to be used in P-B11 fusion were simulated. In order to find the optimal confinement configuration, the simulation was helped by an evolutionary algorithm running 145,000 simulations. The results are presented in this paper. According to the simulations the tokamak structure can be operated to reach ignition using the proposed plasma mode that includes the use of low electron temperature and high thermal energy protons in the plasma (500 keV).

2018 ◽
Vol 1 (1) ◽
pp. 5-11
Author(s):
Johannes Gruenwald
Keyword(s):

In this paper the possibility of utilising a plasma centrifuge for oxygen generation in outer space is discussed. It is proposed that a plasma centrifuge can not only create oxygen for human consumption very efficiently but is also able to produce useful by-products. Special emphasis is given to life support systems working in the atmosphere of Mars, where oxygen and carbon raw materials can be obtained directly from the atmosphere. The system under consideration in this work is a plasma centrifuge with axial circulation that contains a fully ionised plasma. Under these conditions the carbon dioxide from the Mars atmosphere will be entirely dissociated. Thus, the atomic oxygen and carbon can easily be separated.

2018 ◽
Vol 1 (1) ◽
pp. 0
Author(s):
Johannes Gruenwald

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