FulanoDetailThey already do that, partially:
That’s why there are these weird shapes at the bottom.
If you can make it interact with matter, doesn't that mean that you could have cold plasma be manipulated like a hand made out of gas. Maybe like a ghost? lol
I mean, you could make a literal cushion of cold plasma and maintain yourself floating like a hovercraft…
But I doubt it would be that easy to make something like this in real life…
If you can manipulate air with plasma like this, wouldn’t that mean that you could make a plasma driven jet engine?
Where instead of physical blades compressing and moving air, you’d have plasma blades doing it?
Wouldn’t that also be useful for supersonic and hypersonic propulsion?
Actually, no.
Its property of separating air from vacuum is based on its temperature, and without high temperature, it cannot be viscous.
Also I can’t find a single article making plasma windows using non-thermal plasma, so this is just my conjecture.
What is the viscosity of thermal plasma anyway?
ChatGPT:
“The viscosity of ion plasma windows varies based on factors such as gas type, temperature, and pressure. Generally, plasma viscosity increases with temperature. For instance, in a plasma window operating at approximately 12,000 K, the viscosity of argon plasma is about 2.42 × 10⁻⁴ Pa·s, which is ten times higher than that of argon at room temperature.
This elevated viscosity significantly reduces gas flow through the plasma, enabling the plasma window to effectively separate regions of different pressures. The high viscosity, combined with the plasma's low density, allows the plasma window to withstand substantial pressure differentials while remaining transparent to charged particle beams.
It's important to note that these values are specific to the conditions under which the plasma window operates and can vary with different configurations and applications.
The viscosity of ion plasma windows (typically in the range of 10−4to10−310−3Pa·s, or 0.0001 to 0.001 Pa·s) can be compared to the viscosities of other common fluids as follows:
Water (at 20°C):
Viscosity: 1 mPa·s (0.001 Pa·s) or 0.01 poise
Air (at 20°C):
Viscosity: 18.2 µPa·s (0.0000182 Pa·s) or 0.00018 poise
Honey (at 20°C):
Viscosity: 2,000 to 10,000 mPa·s (2-10 Pa·s) or 20-100 poise
Olive oil (at 20°C):
Viscosity: 80 mPa·s (0.08 Pa·s) or 0.8 poise
Glycerol (at 20°C):
Viscosity: 1,490 mPa·s (1.49 Pa·s) or 14.9 poise
Comparison:
Ion plasma window viscosity (0.0001 to 0.001 Pa·s) is much lower than that of liquids like honey, olive oil, or glycerol, which are highly viscous.
It is also lower than water's viscosity but still significantly higher than the viscosity of air.”
Sources: https://arxiv.org/pdf/1308.5524 https://www.techbriefs.com/component/content/article/1834-0598etb1?utm_source=chatgpt.com plasma-school.org/files/lectures/2016/Murphy16.pdf https://hydramotion.com/en/technical/units-of-viscosity
Well… Kinda disappointing to be honest, I thought it would be way higher.
Anyway, what is the viscosity of non-equilibrium plasma at ambient pressure?
Transport Coefficients of Two-temperature Lithium Plasma for Space Propulsion Applications | Request PDF In this one it generally stays around 10^-5 and 10^-4 kc/m/s in this one.
Transport Properties of Non-Equilibrium Plasmas In this one it stays around 14 to 20 10^-5 kg/m.s.
Non-equilibrium synergistic effects in atmospheric pressure plasmas | Scientific Reports In this one I’m not very sure, but it uses S(mm²), so I’m assuming that it is viscosity, which varies from 100 to 240.
Now, how does that compare to thermal plasma?
“The viscosity of non-equilibrium plasma at ambient pressure can vary significantly based on several factors, including the type of gas, temperature, and the specific conditions of the plasma. Generally, the viscosity of non-equilibrium plasma is lower than that of thermal plasma.
Viscosity of Non-Equilibrium Plasma
Typical Range: The viscosity of non-equilibrium plasma is reported to be around 1 0 − 5 10 −5 to 1 0 − 4 10 −4 kg/m·s, which translates to 1 0 − 5 10 −5 to 1 0 − 4 10 −4 Pa·s
Specific Values: In some studies, the viscosity of non-equilibrium plasmas, such as lithium plasma, has been noted to stay around 14 × 1 0 − 5 14×10 −5 to 20 × 1 0 − 5 20×10 −5 kg/m·s
Viscosity of Thermal Plasma
High Temperatures: For thermal plasmas, such as argon plasma at approximately 12,000 K, the viscosity is significantly higher, measured at about 2.42 × 1 0 − 4 2.42×10 −4 Pa·s, which is roughly ten times higher than that of argon at room temperature
Comparison
To compare the viscosities:
Non-Equilibrium Plasma Viscosity: Approximately 10−510−5to10−410−4Pa·s. Thermal Plasma Viscosity: Approximately 2.42 × 1 0 − 4 2.42×10 −4 Pa·s.
Percentage Comparison
To express the viscosity of non-equilibrium plasma as a percentage of thermal plasma viscosity:
If we take a representative value for non-equilibrium plasma viscosity as 2 × 1 0 − 4 2×10 −4 Pa·s (the upper limit), the comparison would be:
Percentage=(2.42×10−42×10−4)×100≈82.64>#/i###
Conversely, if we consider the lower limit of non-equilibrium plasma viscosity at 1 × 1 0 − 5 1×10 −5 Pa·s, the percentage would be:
Percentage=(2.42×10−41×10−5)×100≈4.13>#/i###
Thus, the viscosity of non-equilibrium plasma can range from about 4.13% to 82.64% of the viscosity of thermal plasma, depending on the specific conditions and values used for comparison.”
Sooooo…
Non-equilibrium plasma windows could work, but it will need to be verified on a basis to basis case.
I could find just two sources on the subject and they don’t work with oxygen or nitrogen (I mean, I think the second one doesn’t explore these gases, I can’t access it), so it is hard to say that this is conclusive.
But assuming it works: I don’t think it would be possible to make plasma shields that would stop any kind of projectile as a solid, but they could melt them. But you wouldn’t be able to make plasma windows that could interact with the things around you like telekinesis.
I tried again.
At ambient temperature and pressure argon gas has a viscosity of around 22 µPa·s, while nitrogen gas has 17 µPa·s and air has 18 µPa·s. Absolute (dynamic) viscosities of some common gases.
In this article it says that the non-thermal argon plasma at ambient pressure has 25.2453 µPa·s of viscosity: Fluid Modeling of a Non-Thermal Plasma with Dielectric Barrier Discharge and Argon as a Diluent Gas
In this one says that non-thermal nitrogen plasma at atmospheric pressure achieved a maximum viscosity of around 25 10^-5 kg m^-1 s^-1, which is also 0.00025 or 25 µPa·s: Thermophysical properties of nitrogen plasmas under thermal equilibrium and non-equilibrium conditions
In this article, although it doesn’t focuses on the viscosity of non-thermal air plasma, it shows a graph showing the viscosity of air-plasma at 1 atm based on temperature, which indicate that its viscosity is around 0.00003 kg/m-s = pascal second = 30 µPa·s: Density and dynamic viscosity of the air-based plasma at 1 atm. | Download Scientific Diagram
Of course, the viscosity peaks at a certain 10,000 Kelvins and then starts to decline. But still, more viscous than ambient air.
While in this article it says that thermal argon and nitrogen plasma has 3 micropoise of viscosity, which is around 0.3 µPa·s: Argon and Nitrogen Plasma Viscosity Measurements
In this one it is said to be around 0.3 µPa·s also, so I guess this value is accurate: Measurement of the Viscosity of Atmospheric Argon from 3500 to 8500°K
In this one, at ambient pressure, the viscosity of thermal air plasma is around 25 µPa·s: (PDF) Calculation of air-water vapor mixtures thermal plasmas transport coefficients
This means that non-thermal plasmas have in fact viscosities higher than gases at ambient pressure.
However, the difference is really small and I don’t know how well it would work since thermal plasmas can have 10 times more viscosity than gas at 10,000 kelvin.
So, non-thermal plasmas windows have around 15% to 20% the viscosity of thermal plasma windows.
So, assuming that thermal plasma can separate up to 9 bars of pressure difference, non-thermal plasma would be able to separate 1.8 bar of atmosphere difference.
If thermal plasma can only separate 1 bar of pressure difference, then non-thermal plasma can only separate 0.2 bars.
If you take the cross-section area of a M1 Abrams tank (30 m²), it would be able to sustain 60 tons of weight (the Abrams weighs 70 tons).
I mean, assuming that the growth of viscosity is linear and that it linearly stops the atmospheric pressure difference linearly.
It would be better to have a graph for this, but I couldn’t find any…
But maybe you could make a solid state jet engine that accelerates air with plasma windows due to its viscosity.
It can support up to 5 bar of pressure difference, right?
So you could make as many parallel tubes as possible and as long as possible in order to accelerate air pockets as much as possible.
Each generating 1 to 5 bar of thrust (I think).
1 bar = 1 atm = 1 kilogram force per square centimeter x 5 bar = 5 kgf/cm².
One thing that may or may not be interesting:
Some while ago I remember seeing somewhere (ChatGPT probably) that there were ideas on exploring artificial black holes and/or warp drives by making incredibly strong magnetic fields.
The idea was to pump a spiral crystal/glass with a really strong laser in order to make a magnetic field with hundreds of teslas.
After all, electromagnetic radiation is still electromagnetic to some capacity, no?
Maybe you could make a continuously operated strong magnetic field using this, since you wouldn’t need to use windings made out of copper or aluminum.
No, I was wrong, it definitely does not work like that.
Researching | Generation of strong magnetic fields with a laser-driven coil
HEDS | Laser driven coils; how well do they work?
Laser-driven coils, how well do they work?
From what I could understand, a super strong laser pulse is applied to a metal surface. Once the laser hits it, it rips off the electrons from the target, which hits another target, working like one of those Newton’s Cradle toys. But instead of pushing metal spheres, it is pushing the atom's electrons, generating an electromagnetic wave, since that’s more or less how electricity works (if I’m not soundly mistaken).
ChatGPT said it works by using heat, since heat generates the flow of electrons, such as the seebeck effect.
It seems there are other approaches that directly use lasers to generate strong magnetic fields, but these are normally microscopic and complex.
A new idea for rapid generation of strong magnetic fields using laser pulses
'Radiation friction' could make huge magnetic fields with lasers – Physics World
Wouldn’t that be useful for tokamak fusion reactors either way?
Generating magnetic fields using lasers would allow for lighter and more compact approaches, no?
… Which makes me wonder if they would work for electric motors also…
Now that I think of it³… Wouldn’t it be possible to use cold plasma to work in a pneumatic system?
So you could make an air compressor with no moving parts that compresses cold plasma?
Now that I think of it⁴… Since cold plasma is normally used for sterilization and to make chemical reactions more easily due to the fact that it is a cloud of free electrons, wouldn’t that mean that you could use it as a catalyst in Fuel Cells?
Catalysts in fuel cells are normally made out of really expensive materials such as palladium, platinum, cobalt, nickel, titanium etc.
This would work just like catalytic condensers, which promised to act like that for cheaper catalysts, but I never could find any information on the subject of Fuel Cells…
(PDF) Conversion of CO 2 by non- thermal inductively-coupled plasma catalysis
Now that I think of it⁵… Since plasma/non-thermal plasma can be used for optics, lenses and the like, wouldn’t that mean it could also be used for “invisibility” fields?
Hmmmmmmmm… No.
As much as I am stocked for the infinite possibilities of using non-thermal plasma, I don’t think that in this case it would be possible to do that to visible light.
Source: Plasma mirrors - IRAMIS
Although I was thinking of using plasma to distort the light around a bubble, in practice it wouldn’t be much different than a plasma display (plasma TV).
In any manner, the subject is really interesting:
This Cloaking Device Actually Works!
4 Ways To Make Yourself Invisible
This Invisibility Cloth Makes You Invisible in Pictures
PSW 2385 Invisibility Cloaks and Other “Impossible” Optics | David R. Smith
Metamaterials and the Science of Invisibility — Prof. John Pendry
The physics of invisibility | Royal Society
Autonomous aeroamphibious invisibility cloak with stochastic-evolution learning
Anyway, I feel that I didn’t actually efficiently try to find a better solution to ion thrusters.
(I will add everything that I could find on the subject, but I don’t think many of these are even that useful, since they don’t intend on accelerating the plasma in atmospheric air breathing thrusters)
Wikipedia: Ion thruster - Wikipedia
“Ion thrusters in operation typically consume 1–7 kW of power, have exhaust velocities around 20–50 km/s (Isp 2000–5000 s), and possess thrusts of 25–250 mN and a propulsive efficiency 65–80%[3][4] though experimental versions have achieved 100 kW (130 hp), 5 N (1.1 lbf).[5]”
This is extremely disconcerting and demotivating, but I don’t know, maybe it could work in the atmosphere, just like ion lifters/ionocrafts also work.
Ion-propelled aircraft - Wikipedia
Designing A Self Propelling Ionic Thrust Wing
The Next Generation of Ionic Plasma Thrusters (BSI MARK 2)
By the way, the rotors in helicopters are said to have 60% efficiency and airplane wings more or less 50%.
https://en.wikipedia.org/wiki/Helicopter_rotor
How much of an airplane's forward energy is lost to lift? - Aviation Stack Exchange
My first thought would be to use a laval nozzle, but that one is used to turn low speed high pressure flow into high speed low pressure flow.
If this non-equilibrium air breathing atmospheric plasma thruster (NEABAPT) reaches high speed and low pressure, don’t see a reason to apply it.
Why wouldn't plasma propulsion work within the atmosphere of the earth?
“Plasma thrusters are monumentally energy-inefficient compared to turbojets and turbofans. This is not a temporary obstacle, but a fundamental property of the engine type, because they rely on accelerating the exhaust to very high speeds (like 10000+ meters per second). Therefore, these engines dump most of the energy they produce into the exhaust, and very little into the thing they are propelling.”
It seems that you might need it, actually.
Dunno if it would be more efficient to use a single reverse laval nozzle to make the air-jet reach the speeds normally seen in airplanes/helicopters or use a reverse laval nozzle then to a normal laval nozzle optimized to the thrust you want.
I mean, do I really need to do this?
I “just” need to choke the movement of electrons and ions in order to give them as much strength/momentum as possible.
Magnetoplasmadynamic thruster - Wikipedia
Pulsed inductive thruster - Wikipedia
Electrodeless plasma thruster - Wikipedia
Variable Specific Impulse Magnetoplasma Rocket - Wikipedia
Magnetohydrodynamics - Wikipedia
Inductively coupled plasma - Wikipedia
I was wondering about the most efficient way of turning ambient air into plasma, so I asked WebGPT:
“Assessing the energy efficiency of various air ionization methods for generating non-equilibrium plasma is crucial for their practical application. Here's an overview of the efficiencies associated with each method:
High-Voltage Nanosecond Pulsed Discharges (HVNPD): These discharges deliver rapid, high-voltage pulses, producing energetic electrons that ionize air molecules. This method effectively ionizes air without significantly heating the gas, leading to efficient energy use. However, specific numerical efficiency values are not readily available in the literature.
Dielectric Barrier Discharge (DBD): DBD operates by applying high voltage across electrodes separated by a dielectric barrier, creating micro-discharges that ionize the air. While DBD is effective for generating non-equilibrium plasma at atmospheric pressure, its energy efficiency varies based on design and operating conditions. For instance, studies on CO₂ conversion using DBD have reported energy efficiencies up to 23% under specific conditions.
Piezoelectric Direct Discharge (PDD) Plasma: PDD utilizes a piezoelectric transformer to generate high-voltage AC discharges, producing cold plasma efficiently. The efficiency of plasma generation in PDD systems can reach up to 90>#/i###, with the remaining energy lost due to mechanical and dielectric heating of the transformer.
Microwave-Induced Plasma: This method employs microwave energy to ionize air, creating plasma with high electron densities. It is particularly useful for applications requiring high-temperature plasmas and has demonstrated energy efficiencies up to 50>#/i###.
Radiofrequency (RF) ionization: RF plasma generation systems typically achieve energy efficiencies around 30%. For instance, magnetic nozzle RF plasma thrusters have demonstrated thruster efficiencies of about 30%, the highest recorded for this type of thruster.
Piezoelectric transformers are 88% efficient and conventional AC transformers are 97% efficient, so I don’t think that the electrical discharge specifically generated by piezoelectric would be that much different, no?
What is the most efficient way to ionize air? - Engineering Stack Exchange
Build Your Own Class-E Musical Tesla Coil | Hackaday
Piezoelectric direct discharge plasma
(PDF) Power Density of Piezoelectric Transformers Improved Using a Contact Heat Transfer Structure
“Piezoelectric direct discharge (PDD) plasma is a method of generating cold, non-equilibrium plasma using a piezoelectric transformer. This approach is noted for its compactness, efficiency, and cost-effectiveness, with plasma generation efficiencies reaching up to 90%.
Regarding transformer efficiencies, piezoelectric transformers typically achieve efficiencies between 82% and 92%, depending on design and operating conditions.
In contrast, conventional electromagnetic transformers can reach efficiencies up to 97%.
The high efficiency of PDD plasma generation is not solely due to the transformer's efficiency but also to the direct integration of the high-voltage generation and discharge mechanisms. This integration minimizes energy losses associated with external high-voltage cabling and components, which are common in traditional plasma generation methods. By reducing these ancillary losses, PDD systems can achieve overall higher efficiencies in plasma generation, despite the piezoelectric transformer itself having a slightly lower efficiency compared to conventional transformers.
In summary, while piezoelectric transformers may have lower efficiency compared to conventional transformers, the design of PDD systems allows for minimized energy losses in other areas, resulting in high overall efficiency in air ionization and plasma generation.”
Sources: Piezoelectric direct discharge plasma - Wikipedia
Fundamental Limits On Energy Transfer And Circuit Considerations For Piezoelectric Transformers
Scaling Up of Non-Thermal Gliding Arc Plasma Systems for Industrial Applications
This one achieved 80-90% plasma arc efficiency.
Yes, I’m aware that high voltage discharges can erode electrodes, especially based on their amperage.
But instead of simply increasing the amperage, you could add the amount of electrodes. Example, if one needle electrode uses 1 watts (or even less), then add parallel electrodes until the desired power rating is achieved.
Another idea would be to have a single high voltage low wattage generator to distribute the discharge to all electrodes and then using a secondary conventional high amperage generator with a single-way diode to distribute the current to the electrodes. So you could control the amount of current the electrodes would receive without the risk of lethal discharges.
Think of it like a vacuum ejector, but using electricity.
I mean, I THINK it would work like that, I’m not an electrical engineer, and thus, I’m probably really wrong.
I asked ChatGPT:
“Let's say that I have 2 wires in parallel converging in a single one. One of the wires has 100 volts and 1 watt of power while the other has 100 amps and 100 watts. What will be the resulting voltage and amperage in the converging wire?”
Its answer:
“When connecting two components in parallel, the voltage across both components must be the same. However, in this scenario, the two wires have different voltages (100 V and 1 V), which makes a direct parallel connection problematic. In practical electrical systems, connecting sources with significantly different voltages in parallel can lead to circuit faults, potential damage, or safety hazards due to the large potential difference.
Using diodes to connect two voltage sources in parallel is a common technique known as "diode ORing." This method allows the higher voltage source to supply power to the load while preventing current from flowing back into the lower voltage source.
Understanding Diode ORing:
In a diode ORing configuration, each voltage source is connected to the load through a diode. The diodes ensure that only the source with the higher voltage supplies power to the load, as the diode connected to the lower voltage source will be reverse-biased and thus block current flow. This setup provides automatic selection of the input source without manual intervention.
When implementing diode ORing, the source with the higher voltage (in this case, 100 volts) will dominate and supply power to the load. The diode connected to the 1-volt source will be reverse-biased due to the higher voltage from Source 1 and will prevent current from that source from reaching the load.”
So, in other words: it wouldn’t work.
I would need to apply the extra amperage directly into the source.
But now I wonder: the article in question used 50-60 hertz AC to generate an arc plasma with 90%, but what if you increased the frequency to microwave frequency or radiofrequency of this arc plasma generator?
It is still a direct discharge, it is still an AC, but the frequency is increased. How would that affect the air ionization?
The Impact of Radio Frequency Waves on the Plasma Density in the Tokamak Edge
“It is found that the density in front of a radio frequency antenna is affected by the presence of the launched electromagnetic waves: the plasma is pushed away from the antenna and a density asymmetry along the strap is created. Both effects are gradually more pronounced when the launched power is bigger.”
How do arcs generate radio-frequency - Electrical Engineering Stack Exchange
“A circuit with an electric arc in it is actually (well, usually) a 'relaxation oscillator'...”
“...Each discharge in the cycle is very rapid, making broadband RF pulses, as stated in other answers.”
How can radio radiation ionize gases? - Physics Stack Exchange
“The way this actually works to generate a plasma is to make electrons dance. As the polarity of the RF source switches, an electron will feel an electric (or magnetic - either will work, just different configurations) field that pulls it first one way, then another. The amount of acceleration that the electron can pick up during each oscillation is determined by the voltage for any given frequency - higher voltage, faster electron, more energy added to the gas. Free electrons in the gas will hit neutral molecules, and if you make the oscillation voltage high enough, eventually those collisions start to happen with enough energy to knock electrons off the neutrals, and create more ions. There are some factors that impact the rate of ionization, such as recombination, energy absorption into the plasma, and energy loss through de-excitation (light emission) and thermal collisions, but fundamentally if you keep pumping in power from these RF oscillations, and the voltage is sufficient, you will end up with a lot of free electrons, which will maintain a very highly ionized plasma.”
ChatGPT said that in this article efficiencies around 92% are reached: Highly efficient plasma generation in inductively coupled plasmas using a parallel capacitor But I can’t access it, not even through Sci-hub.
In this article it is explored how to control the amount of negative and positive ions within plasma using free electrodes which can be interesting for the application of electrets.
“At the resonance, the source has a larger total equivalent resistance that is 3–18 times larger than that at the non-resonance. As the resistance increases at the fixed RF power, the RF current decreases accordingly, which indicates that the power loss in the powered antenna including the impedance matching circuits is significantly reduced. The experimental result shows that the power transfer efficiency is improved by about 30%–70% and the plasma density at the resonance increases 2–8 times higher than that at the non-resonance.”
It is 70% maximum efficiency or 70% of 20% efficiency?
https://www.thierry-corp.com/plasma-knowledgebase/plasma-frequencies
“40 kHz is the lowest of the Plasma Frequencies. Though it may sound the weakest, a low frequency can make the biggest difference in quality. At 40 kHz, there is the highest ion density of the three main frequencies meaning that there will be more particles of the plasma per square inch than the other two. This will easily increase the efficiency and improve the uniformity of the particles. Although it might be the slowest to etch materials, it will be the best in quality.
In the middle we have the frequency 13.56 MHz. One of the standard frequencies used world wide for industrial, scientific, and medical uses. This frequency is used for a faster etching process, but has to be fine tuned for each piece of material that would be placed in the chamber.
Lastly there is the 2.45 GHz frequency. This is the fastest setting to do any etching, but will require the most energy to operate.”
So the lower the frequency, the more efficient, right?
But what is the ideal frequency of an arc plasma generator?
Well, WebGPT didn’t tell anything useful, with the exception of one bit:
“2. Plasma Stability
At higher frequencies, the plasma arc can become more stable because the current oscillates too quickly for the plasma to extinguish between cycles. This improves efficiency and reduces sputtering or instability in the arc.”
Well then, a good approach to help solve this issue would be to use 3 phase AC, no?
A new electro-burner concept for biomass and waste combustion
Application-oriented non-thermal plasma in chemical reaction engineering: A review - ScienceDirect
“3.1.2. Temporal restriction
The temporal scale is usually directly controlled via the frequency of applied electric potential. DC, pulsed DC, AC, radio frequency (RF) and microwave sources can be and have been used to excite microplasmas in various configurations. Simple DC plasmas can have inherent pulsing frequencies in the range of 1∼1000 Hz, but most electrically generated plasma studies that discuss pulsing frequency do so in the context of applied pulse frequency modulation (Fridman and Kennedy, 2021). The energy efficiency of DC microplasma with nanosecond pulses is much higher than that of the regular DC operation (Schoenbach and Zhu, 2012). Fig. 9 illustrates the reduction of the electrostatic potential at 1 torr as frequency increases (Xue and Hopwood, 2009).”
Non-Thermal Atmospheric Pressure Plasma - ScienceDirect
6x10^13 = 60,000,000,000,000 = 60 terahertz.
I tried to find ways of making terahertz pulses, but for the life of me I can’t.
Every source says that the terahertz frequency is the frequency of optical light, supposedly, you can’t make a terahertz arc discharge system.
Terahertz radiation - Wikipedia
Yet, there it is, in plain picture.
In any manner, I was wondering if I could use a similar process used in slow motion cameras.
Certain slow motion cameras actually work at a limited frame rate (around 30 frames per second), so what they do is synchronize multiple cameras so the frames align in-between each other.
So, maybe you could have multiple pulsed DC or AC sources pulsating at whatever frequency, but always synchronizing each single one so they pulse in between each other pulses.
But that sounds like 3 phase current, and all of the waves are together.
Terahertz annular antenna driven with a short intense laser pulse
This article uses laser driven coils to reach terahertz
Maybe I’m overthinking it, capacitors can release pulses of energy in the picoseconds to femtoseconds.
So a terahertz (or higher) frequency using capacitors synchronized for pico to femtosecond pulses would be able to achieve such frequencies, no?
DeepSeek (the better chinese GPT) said the following:
“Your question touches on an intriguing intersection of capacitor-based pulse generation and terahertz (THz) frequency production. Let’s break down the key points and address them systematically:
1. Terahertz Frequencies: Optical vs. Electrical Methods
Terahertz waves (0.1–10 THz) straddle the boundary between microwave and infrared regions. While optical methods dominate THz generation (e.g., nonlinear frequency conversion in crystals like PPLN or photoconductive antennas excited by femtosecond lasers)3 12, electrical methods involving capacitors or circuits face challenges due to inherent physical limitations:
Capacitor Limitations: Traditional capacitors in circuits are constrained by their RC time constants. For example, generating 1 THz (period = 1 ps) would require sub-picosecond charging/discharging, which is difficult to achieve with conventional components due to parasitic inductance/resistance and material response times12.
Plasma-Based THz: The dielectric barrier discharge plasma you mentioned (60 THz) operates via non-thermal electron acceleration in ionized gas, not capacitor discharge alone. Such plasmas generate THz through rapid electron collisions and transient electric fields, which are distinct from capacitor-driven circuits12.
2. Capacitors in Advanced THz Systems
Recent advancements in metamaterials and waveguide structures suggest capacitors can play a role in THz systems, albeit indirectly:
Waveguide Metatronics: Researchers have engineered negative capacitors and inductors in waveguides by exploiting structural dispersion. These "meta-elements" enable wideband impedance matching and THz signal manipulation, achieving >40% bandwidth enhancement in experiments. For instance, dielectric slabs in waveguides mimic lumped elements, allowing THz circuits to operate at subwavelength scales1.
Ultrafast Switching: Capacitors synchronized for picosecond/femtosecond pulses could theoretically generate THz frequencies if paired with nanostructured materials (e.g., graphene or resonant tunneling diodes). For example, RTD-based emitters already achieve THz oscillations via quantum tunneling effects, bypassing traditional RC limitations12.
3. Practical Feasibility of Capacitor-Driven THz
While capacitors alone are unlikely to generate THz frequencies directly, hybrid approaches show promise:
Photoconductive Switches: These devices use ultrafast laser pulses to trigger capacitor-like discharges in semiconductors (e.g., GaAs), producing THz pulses. The laser excites carriers, creating a transient current that radiates THz waves—a process combining optical excitation and capacitive discharge3 12.
Plasma-Assisted Systems: Capacitors could drive pulsed plasmas (as in dielectric barrier discharges), where rapid electric field changes induce THz emission. However, this relies on plasma dynamics rather than pure capacitor discharge12.
4. Key Challenges
Material Response: Even with femtosecond pulses, dielectric materials in capacitors exhibit finite polarization/relaxation times, limiting THz efficiency12.
Losses: Ohmic losses and radiative inefficiencies degrade high-frequency signals in conventional circuits1.
Scalability: Integrating nanoscale capacitors (e.g., in metamaterials) requires precision fabrication, which remains technically demanding1 13.”
“Depending on the operating frequency, a pure nitrogen discharge with an input power of about 650 W displays an electron density between 1.7×1021m−3 and 2.0×1021m−3 with electron temperatures in the range of 40,000 K and heavy particle temperatures of about 6000 K in the core of the discharge channel. Furthermore, a relatively slow electron recombination rate in the range of 20 µs is observed.”
“5. Conclusions
The main objective of this work has been to experimentally determine the influence of different operating conditions, i.e., pulse frequencies and pulse current amplitudes, on the relevant plasma parameters, in particular the electron number density and the electron temperature of a pulsed low-current, high-voltage discharge operated at atmospheric pressure. No information on these values could be found in published works so far. According to these results, depending on the operating frequency, an electron density between 1.7×1021m−3 and 2.0×1021m−3 with electron temperatures in the range of 40,000K can be expected for a pure nitrogen discharge operated at atmospheric pressure. A heavy particle temperature of about 6000K is reached in the core of the discharge channel, with the values decreasing further downstream on the axis of the effluent plasma jet from 4000K to 2000K at typical treatment distances of 10–15mm from the nozzle outlet. Due to the complex nature of the de-excitation processes of nitrogen, relatively slow electron recombination rates are observed, and thus the once ionized channel does not extinguish between consecutive pulses at the considered pulse frequencies of 43kHz and 60kHz but rather undergoes a transition from a glow discharge to a spark with each current pulse. The observed influence of the temporal changes of the excitation current on the estimated plasma parameters is slightly less than 20%. Based on the obtained findings, the hypothesis that the temperature of heavy particles is determined by dissipated power, while the electron parameters, and therefore, to some extent, the chemical reactivity of the plasma, are defined by the shape of the excitation pulse could be confirmed for this type of discharge. Furthermore, a coupling of the pulse shape and frequency with the resulting plasma properties is now possible.”
Well, now I got even more confused, since the article using AC arc discharge already achieved 90% efficiency with 50-60 hertz, why then…?
Well, I found the answer, I went back to the article, checked the sources and none of them talk about the efficiency of the plasma arc.
… Or maybe not:
Source: Characterization of a dc atmospheric pressure normal glow discharge - IOPscience
0.4 milliamps x 340 volts = 0.136 watts 10 milliamps x 380 volts = 3.8 watts
I’m assuming that these are the values that were measured in the discharge, so if they added 0.136 watts and only got 0.136 watts, then there was some minimal loss, right?
“3.2. Current–voltage characteristics: Figure 4 is a plot of discharge voltage versus discharge current for electrode spacings between 20µm and 3 mm. Errors in the electrode spacing of ±5µm are due to thermal expansion of the wire and shortening of the gap at higher currents. Errors in current are ±20µA and errors in voltage are less than 5 V. These plots are for a stainless steel anode and cathode and with the upper wire electrode 0.8 mm in diameter as anode. The current was varied by changing the dc power supply voltage with a constant ballast resistor. Oscilloscope traces and Fourier power spectrums of the discharge current showed the current to be constant with no significant ac components other than a <1% 60 Hz noise (probably from the building) and a <0.1% ∼50 kHz signal. Over the range of currents shown all the discharges were similar in structure to those of figure 3.”
“This work investigates the influence of pulse modulation frequency ranging from 50 Hz- 10 kHz on the helium RF atmospheric pressure plasma jet's fundamental characteristics. The impact of modulation frequency on plasma jet discharge behavior, geometrical variation, reactive species emission, and plasma parameters (gas temperature Tg, electron excitation temperature Texc, and electron density (ne) are studied using various diagnostics such as optical imaging, emission spectra, and thermal diagnostics. From the experiments, it is observed that operating the plasma jet at low pulse modulation frequencies (around 50 Hz) provides enhanced plasma dimensions, higher electron densities and greater optical emission from reactive species (viz., He I, O, OH, N2+, etc.) as compared to the higher modulation frequencies.”
Now what gives?
Well, in any manner: there is alternating current (AC), continuous current (DC) and pulsed continuous current (PDC).
The difference between AC and PDC is that the first alternates between positive and negative, while the second alternates from zero to positive.
In the specific case of this plasma thruster I’m proposing, where it uses air Arc Discharge Plasma, I do think it would be better to use pulsed DC currents.
AC currents are used for induction of the plasma state in the gas, while Arc Discharge generates the plasma state in the air through the distance between the electrodes. Which results in it being extremely reliant on the direction of the arc.
How Electricity Works - for visual learners How Electricity Actually Works (relevant)
This image illustrates better how I intend to make the pulsed direct current.
You can also add other phases to the system, like the common 3 phase.
Well now I’m wondering how efficiently electromagnets move plasma.
WebGPT said that thermal or non-thermal plasmas are normally assumed to have the same magnetic permeability of vacuum (1), but when you try to calculate it, it is actually pretty complex:
Calculating the magnetic permeability of a known plasma - Physics Stack Exchange
Strong magnetic fields change how friction works in plasma - Michigan Engineering News
In any manner, if the electromagnetic field doesn’t move plasma with much efficiency given it has a magnetic permeability of 1, this explains why most of the plasma thrusters rely on electrical discharge to move the ionized gas rather than electromagnetism.
Optimization of Plasma-Propelled Drone Performance Parameters
“Electromagnetic fields are indeed effective in moving plasma, a principle utilized in various plasma thrusters. The magnetic permeability of plasma is generally considered equivalent to that of a vacuum (μ₀), simplifying certain analyses. However, the plasma's permittivity can vary, adding complexity to precise calculations.
Plasma thrusters, such as Magnetoplasmadynamic (MPD) thrusters, employ the Lorentz force—generated by the interaction between electric currents and magnetic fields—to accelerate ionized gas. This method can achieve efficiencies between 40% and 60%, with exhaust velocities up to 60 kilometers per second.
Another example is the Variable Specific Impulse Magnetoplasma Rocket (VASIMR), which uses radiofrequency power to ionize and heat the propellant, subsequently accelerating it through a magnetic nozzle. This design aims for high efficiency and specific impulse, with ongoing research to optimize its performance.
Recent advancements have demonstrated significant improvements in efficiency. For instance, a magnetic nozzle radiofrequency plasma thruster (VASIMR) has achieved efficiencies approaching 20% in the kilowatt power range, marking a notable advancement in this technology.
Efficiency Considerations:
Electrostatic Thrusters: They are known for high specific impulse but lower thrust. Their efficiency is influenced by factors such as ionization efficiency and grid losses.
Electromagnetic Thrusters: They can provide higher thrust levels and specific impulse. For instance, the VASIMR engine has demonstrated efficiencies approaching 70% with argon propellant at full power. “
(yes, it keeps giving contradicting information)
“The efficiency of different methods for accelerating plasma in plasma thrusters varies significantly based on the technology used. Here’s a summary of the efficiencies associated with each method:
1. Electricity Only
Efficiency: Traditional electric propulsion systems, such as gridded ion thrusters, typically achieve efficiencies in the range of 30% to 50%. However, some advanced designs may reach efficiencies slightly above this range under optimal conditions.
2. Electromagnets in Conjunction with Electric Fields
Efficiency: Hybrid systems that utilize both electric fields and magnetic fields, such as magnetic nozzle (MN) radiofrequency plasma thrusters, have shown significant improvements in efficiency. Recent advancements have achieved conversion efficiencies of around 30%, with ongoing research aiming to push this figure higher. Some studies indicate that efficiencies could potentially reach up to 50% or more as technology develops [1][3].
3. Electromagnets Alone
Efficiency: Systems that rely solely on electromagnets, such as magnetoplasmadynamic (MPD) thrusters, generally have lower efficiencies. These systems can achieve efficiencies in the range of 20% to 30%, but they often struggle with energy losses and require substantial electrical input to generate the necessary magnetic fields [1][3].
Summary
Electricity Only: 30% to 50>#/i###
Electromagnets + Electric Fields: Around 30% (potentially higher with advancements)
Electromagnets Alone: 20% to 30>#/i###
Overall, the most efficient method currently appears to be the combination of electromagnets and electric fields, particularly as research continues to improve these systems.”
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