Electronic air plasma propulsion

Abstract

The invention describes an air plasma propulsion system and method comprising: an air turbine plant adapted to receive supply air from an external environment, and a plasma propulsion unit adapted to increase a speed of said air after a corresponding ionization and passage into air plasma phase. The plant comprises a turbine compressing air which transits in the plasma propulsion unit which ionizes it strongly and accelerates it through a frequency or microwaves in magnetic field produced by a laser beam.

Description

[0001] ELECTRONIC AIR PLASMA PROPULSION

[0002] DESCRIPTION

[0003] Field of the invention

[0004] The present invention relates to a plasma propulsion method and system.

[0005] Still more specifically, the present invention comprises an air turbine plant and plasma propulsion unit and the following description relates to this application field.

[0006] Background

[0007] The experimental work of the engine has been in progress for more than 50 years and it is performed by NASA and by the United States department for energy research and development in plasma physics and space propulsion technology.

[0008] Preceding operating implementations are known, for example, through the European patent EP3275291 B1. As the gas (air) enters, after a first compression step, it is bombarded, that is heated, with electro-thermal arcs and immediately after with high voltage and frequency the electrons are pulled away from atoms, by determining a gas ionization. In this moment a passage to the plasma state is determined where ions and electrons, both of them speeded up, seek an original stability. In a second step the magnetic and electric energy is increased, with frequency heating, and thus a strong “thrust” outflow speed is imposed, for example, not lower than 10-30 km / sec before a dangerous thermal diffusion takes place.

[0009] Helicon Double Layer is a method for circumscribing the gas flow with (helical) helicon winding which discharges inside thereof a suitable frequency. The outside is surrounded by crowns of super-magnets which energize in combination with the helicon frequency by generating plasma. The whole occurs, as in the Vasimr propulsion unit, without moving accessories.

[0010] Object of the present invention The propulsion system according to the invention comprises a ionic plasma propulsion unit as defined in the independent claim Nr. 1.

[0011] The present invention further relates to a method for the plasma propulsion as defined in the independent claim Nr. 8.

[0012] Additional aspects of the invention are defined in the corresponding dependent claims.

[0013] The invention, generally, provides at least two parts: the fluid dynamic part relative to the turbine and the subsequent electromagnetic plasma part. The invention, aimed at improving the plasma propulsion technology, has several purposes, thereamong at least: simplicity compared to the complexity of the known solutions.

[0014] No polluting fuel is required, compared to the propensity to pollution of the environment of the known solutions. High autonomy and, then, freedom of movement and consequent safety in motions.

[0015] Advantageously, according to the invention, the thermo-fluid electrodynamic and ionic-plasma cycle uses one single gas: air. The air plasma is a mass in which the neutral atoms or diatomic molecules are separated into electrons and electrically charged ions. The main objects the present invention are:

[0016] • implementing a plasma propulsion system / method which is easy to be implemented / operated.

[0017] • implementing a plasma propulsion system / method as eco-compatible as possible.

[0018] • implementing a plasma propulsion system which is as independent and autonomous as possible.

[0019] These and other objects are achieved by a propulsion method / system according to what described hereinafter and defined in the enclosed claims.

[0020] Summary of the invention

[0021] According to a first aspect, the invention defines a plasma propulsion system comprising: an air turbine plant adapted to receive supply air from an external environment, and a plasma propulsion unit adapted to increase the air speed after a corresponding ionization and passage into air plasma phase. Wherein the plant for the air turbine comprises: first compressing means adapted to implement a first compression of the air; second compressing means adapted to implement a second compression of the air pre-compressed by the first compressing means; first heating means adapted to heat the air previously compressed by the first and second compressing means; an alternator and an electric generator starter adapted to produce electric energy; a counter-rotating power turbine which can be actuated by the heated air to produce expanded air, wherein the power turbine is adapted: to perform compression work through the first compressing means and the second compressing means; to produce electric energy; to discharge residual expanded air, as a function of the air compressed and heated with part of the produced electric energy.

[0022] The plasma propulsion unit, associated to the air turbine plant, comprises: a duct for the plasma flow adapted to receive the residual expanded air discharged by the power turbine; a connection portion placed between the power turbine and the duct for the plasma flow wherein the connection has a decreasing section and in the direction of the duct for the plasma flow and comprises an anode and a cathode configured to generate a thermal arc obtained through a RF oscillator so that the residual air in the connection portion subjected to the thermal arc becomes a ionized and heated air; magnetic means fixed so as to surround the duct for the crown plasma flow adapted to produce a corresponding magnetic field, wherein said anode, said cathode and said thermal arc are placed in said magnetic field, wherein said magnetic means is configured to generate a plasma from said ionized and heated air; a source of frequency or microwaves applied with adjacent helical antennas enveloping the duct for the plasma flow in the magnetic field generated by the magnetic means; discharging means to discharge the plasma generated in the duct for the plasma flow comprising a supersonic divergent nozzle with an antenna and shaped like a bell where the discharging means in the outlet of the plasma implements a thrust power produced by the propulsion system. Preferably, the first compressing means comprises two stators and two rotors associated to a fixed shaft of the turbine plant.

[0023] Preferably, the second compressing means 5 comprises a counter-rotating axial compressor comprising a first plurality of blades rotating inversely with respect to a second plurality of blades. Preferably, the AC alternator is adapted to produce a three-phase alternating current and it is characterized by a stator placed in the carter of the power turbine and by a reinforced magnetic rotor, with external magnets fixed to the counter-rotating duct of the body-turbine assembly.

[0024] Preferably, the first heating means comprises several series of micro blades, counter-rotating with to each other, made of metal alloys which are hard and resistant to the heat, placed in a circular gap defined by the two cylindrical ducts and adapted to rotate in counter-rotation with each other with respect to a fixed shaft, thus implementing, with continuous rotations, a plurality of mini thermal arcs adapted to raise immediately the temperature of the air compressed in transit.

[0025] Preferably the annular magnetic means comprises one or more among: magnetic and electromagnetic rings; an accelerator with multi-phase solenoid provided, inside thereof, with additional magnetic circular crowns of Array Halbach type.

[0026] In an additional example, the system comprises a processing unit configured to correlate the frequencies by ionization, helicon, discharge nozzle and magnetic density produced by the magnetic means and by the solenoid. In a second aspect, the invention defines a plasma propulsion method comprising the steps of: arranging an air turbine plant adapted to receive supply air from an external environment and a plasma propulsion unit equipped with a duct for the plasma flow, associated to the air turbine plant and adapted to increase the air speed after a corresponding ionization and passage into air plasma phase; in the air turbine plant: performing a first compression of the air and a second compression of the previously compressed air; heating by thermal arc the air previously compressed by the first and second compression; deviating part of air through a centripetal compressor inwards and in the axis of the power turbine where a coaxial vircator is placed; expanding in a power turbine the heated air to perform compression work through the first compressing means and the second compressing means; producing electric energy; discharging residual expanded air as a function of the air compressed and already heated with part of the produced electric energy; performing contemporarily the steps of:

[0027] • increasing the speed of the residual air so as to reduce the pressure by reducing the transit section of the residual air at the outlet of the power turbine;

[0028] • applying to the residual air a thermal arc through a pulsed frequency in magnetic field wherein the magnetic field is generated by annular magnetic means and multi-phase solenoids fixed so as to surround like a crown the connection for plasma flow;

[0029] • where the two steps of increasing the speed of the residual air and of applying to the residual air a thermal arc, performed simultaneously, determine, starting from the residual air that had dropped in temperature at the end of the preceding passage in the power turbine, a ionized, heated, speeded up air, suitable for a passage to the plasma state ("discharge diffusor");

[0030] • receiving the ionized, heated and speeded-up air Ai in the duct 201 for the plasma propulsion unit;

[0031] • determining a passage to the plasma state and subsequent step of energizing and accelerating the plasma, through excitation means comprising: a frequency or hybrid microwaves with one or more antennas winding the duct.

[0032] In an additional example, the pulsed thermal arc can be at the inlet of the duct and at the power turbine, and it is configured to operate in frequency with an oscillator in the magnetic field and it is combined at a second frequency reflected and distant from the first one by 90° - 180°, wherein the pulsed thermal arc is in association with triggering means identified as a cathode and an anode arranged in circular order, in ordered coaxial position and immersed in the magnetic field generated by the magnetic means.

[0033] Preferably, the magnetic means can comprise an accelerator with multiphase solenoid provided, inside thereof, with additional magnetic circular crowns of Array Halbach type wherein the direction of the magnetic field generated by the multi-phase solenoid in position parallel to axis of the propulsion duct substantially determines the plasma longitudinal thrust direction with a helical motion towards the discharge nozzle.

[0034] Preferably, the step of energizing and accelerating the plasma can be implemented through excitation means comprising one or more quadruple helical antennas with rectangular section to energize and accelerate with frequency or microwaves the plasma wherein the applied frequency is 500 Mhz (for a duct with diameter of 50 centimetres).

[0035] Preferably, the method can comprise a step implemented through electronic computer configured to synchronize or correlate the resonance and repetition cyclotronic frequencies in the process for generating plasma with magnetic densities produced by the solenoid and to ease a process for ionizing and accelerating the plasma at the same frequency.

[0036] The technical advantages of the invention will result from the more detailed description, made hereinafter, with embodiment examples provided by way of example and not for limitative purposes with reference to the enclosed drawings.

[0037] Brief description of figures

[0038] Such description is provided hereinafter with reference to the enclosed figures, provided by pure way of example and not for limitative purposes too, wherein: figure 1 shows a diagram of the propulsion system of the invention in an embodiment wherein the parts are numbered to make the figure more easily understandable in the specific details of the present embodiment; figure 1 A shows the propulsion unit section taken along the line A-A of figure 1 ; figure 1 B shows the enlarged detail numbered with 13 in figure 1 ; figure 1C shows the enlarged arrangement and rotation direction of the blades of the turbine and of the compressor (P1 , P2, 13 in figure 1); figure 2 shows a detail of figure 1 C; figures 3A to 3B show several examples of helical antennas which can be used in the system of figure 1 ; figure 4 shows, schematically, the construction and drawing in section of a coaxial vircator.

[0039] Detailed description of the invention

[0040] The invention describes a propulsion system comprising an air turbine plant adapted to receive supply air from an external environment and a plasma propulsion unit adapted to generate a thrust power, and associated to the air turbine plant so as to receive the air heated by the air turbine plant. In other terms, the propulsion system of the invention comprises a fluid dynamic stage related to the turbine and a stage for generating electromagnetic plasma.

[0041] According to the invention, in the fluid dynamic stage related to the turbine, the propulsion gas is air; hereinafter in the description the air will be always considered as gas, in particular a mainly diatomic, neutral gas with symmetric molecules.

[0042] In fact, it is well known that the air which surrounds us, apart from helping us to live, is also very useful for a plasma-ionic propulsion unit in the terrestrial atmosphere. The air mainly consists of two important gases: nitrogen 78.08% and oxygen 20.95%, metalloids with good electronic affinity and electronegativity.

[0043] Nitrogen is the most abundant gas in our atmosphere, it is diatomic like oxygen, neutral, colourless, odourless, tasteless and plasmogen, apart from absorbing heat very quickly. The excited and de-energized nitrogen, that is when the electron returns in a position in the atom in a femtosecond, emits a photon with rows of emission of UV rays visible as blue light. In a function for reducing the environment pollution, the nitrogen reacts only the oxygen of air in presence of high temperatures and pressure determining the nitrogen oxide (NO) and the nitrogen dioxide (NO2). The nitrogen dioxide can react with water and forms nitric acid HNO3 which soon becomes nitrate. Nitrates are very useful for the plants as nutrients and fertilizers for growth. Every other type of compound deriving therefrom is always useful to man and to the heating of the earth. Hereinafter in the description some components used in the invention itself and physical phenomena connected thereto will be described.

[0044] The start of plasma is obtained when the atom is subjected to an elastic and instantaneous deformation only in presence of an external electric field. It does not depend upon the temperature nor upon the frequency of stress and the polarization factor only depends upon the atom size and not upon the atomic number.

[0045] It is possible to improve the ionization effectiveness by applying strong electric fields which generate in plasma a considerable amount of energetic electrons. This allows to improve the ionization level and consequently to reduce the energy cost for produced electron. If the electric charge is lower than 15 eV the related ionization results to be weak and the discharge is dissipated in collisions which increase only their vibrational energy. Moreover, the pulsed discharges require a lower power and have a higher effectiveness. The length of the pulsed plasms and the related repetition frequency reduce the molecular recombination phenomenon.

[0046] By engaging a strong electric or electromagnetic field (higher than 34 kv / cm), which to say the truth is an electromagnetic shock wave, there is the electric breakdown of air and this causes a strong increase in current which propagates along complex and predefined trajectories. The start of a discharge occurs when the density depression on the axis reaches the threshold discharge value. The electrons most external to the air atoms (valence electrons) are pulled away from the atoms themselves (frequency radiation) and as they are lighter than the ions (by a factor of 1836) they separate from ions by creating a charge imbalance and then a perturbation. This process is called ionization of the atoms in the medium. This occurs when the density depression on the axis reaches the threshold discharge value (threshold frequency - the density is proportional to the width of the applied electric field). The electrons so-separated from the atoms are accelerated by the electric field. These electrons become like bullets hitting (colliding) other atoms, they ionize them by pulling away other electrons. At this point the air charged with free electrons has become a conductor. The cross effect (focusing) of an electromagnetic wave is effectively transformed in longitudinal fields of a plasma wave.

[0047] This takes place in structures with charged waveguides and the electrons which are pushed more quickly than ions are followed late by the ions themselves since the longitudinal (accelerating) electric field and the transversal one create a strong continuous gradient and a very strong speed potential or expulsion from the plasma trail or kinetic energy. The electric field must have necessarily oscillating feature (to preserve the electrostatic field) and then the distribution of electromagnetic charges are forced to oscillate with a pulsation or with a frequency similar to the applied electric field. This trail is excited by a laser pulse.

[0048] According to the invention, the magnets contribute to produce the plasma, to limit and guide (confine) and accelerate the plasma beam which gives the thrust. The research is proposing increasingly powerful permanent magnets without renouncing the advantageous Array Halbach system.

[0049] The energy saving prevents also possible electrostatic instability side effects.

[0050] After pre-ionization to avoid thermal exchanges, which apart from reducing the plasma temperature would destroy the container, it is necessary to insulate thermally the plasma.

[0051] Then a radial or orthoradial magnetic structure is created, that is perpendicular to the plasma flow which confines the plasma particles in a reduced volume inside the tubular container. The property of charged particles to travel helical paths around the force lines of a magnetic field is at the basis of the methods for confining / magnetically insulating the plasma.

[0052] The density of the magnetic field orthoradial to the horizontal flow lines has to be lower than the same horizontal lines of the applied magnetic flow. The confinement so created by the magnetic field limits the number of degrees of freedom of the motion to only one in the direction of the force lines towards the outlet. The magnetic component of electromagnetic wave produces negligible effects in the air since, as it is transparent, behaves (from a magnetic point of view) like vacuum.

[0053] The electromagnetic accelerators have different implementations. For example, in the present invention they are implemented as multi-phase solenoids and as helical antennas with reference to figures 3, 3A and 3B.

[0054] There is externally an annular multi-phase solenoid 16 adapted to produce a magnetic induction flow determining with pulses a variable electric field or a f.e.m. distributed over the whole length. The applied fields and the internal currents can be stationary, pulsed or alternated on a frequency range and different ionization systems and electric power releasing modes can be used. In reality, there are many effects which alter the situation and play a crucial role in determining the effectiveness in the accelerating process. The alignment of the magnetic field is tangential to the system components; for example, in the present invention these components are the ceramic cylindrical duct 201 and the helical antennas.

[0055] The important property of the magnetic induction field is its capability of interacting mechanically with the electric current. In fact, it exerts a bending force on the particles which can be called: angular acceleration. The electric current could have been generated by a flow of electrons generated by a thermionic tube. This effect, the whole duct section being material support of the charges, constitutes an interaction by involving a ponderomotor effect or electrodynamic forces. In this way the particles confined in the plasma state are constrained to spiral around the lines of magnetic field by the Lorenz force. The multi-phase solenoid guarantees a better and suitable confinement as a guarantee and function of the achieved electronic densities. The ratio between internal magnets of several alternated poles and solenoid has to be 1 / 3 of the solenoid (magnetism). The magnetic field is pulsed (induction) and it is homogeneous and uniform.

[0056] The perpendicular component will have uniform circular motion. The parallel component will have rectilinear motion. The two motions together will be a spiral or helical motion. The electromagnetic fields have covariant, that is invariant, shape under Lorenz transformation (electromotor field of “electrodynamic” nature) and they allow wave solutions.

[0057] The adjustment of a variety of conditions and approximations of the overall geometries of the magnetic fields and of the magnets requires a careful evaluation of the thermal and structural problems inside the cylindrical duct. The magnets must have the density suitable to absorb sufficiently the RF waves of plasma. The intensity of the magnetic field corresponds to the sizes of the ionization chamber. During acceleration all magnetic fields are increased to follow the energy increase. The details on the topology of the magnetic field have very complex effects on the process. A real neurological network of electronics.

[0058] The ponderomotive force is the force applied on the plasma by the density of the high-frequency electromagnetic field. It also depends upon the ionized and charged gas amount. The duct is made of material coated internally with radioactive radioisotopes with rate of emission of secondary electrons: this increases the electronic density and increases ionization. Generally the value of the presence of the electromagnetic field is equal to 20-35% of frequency where an electromagnetic field, at the beginning of the ceramic duct, 201 , is maximum. The last circular magnet is provided with lower magnetic density than the other preceding magnets and this to favour the easy outflow of plasma. An intense laser pulse can excite the collective motions of the plasma electrons through the ponderomotive force. This ponderomotive force acts so as to modulate the density and so it creates a plasma electronic wave. This bond between ponderomotive force and laser pulse intensity in its propagation characterizes and generates a phase speed of the plasma wave equal to the speed of the group of laser pulses.

[0059] A frequency hitting in magnetic field the molecules, the atoms and the electrons creates anelastic impacts (collisions) of the electrons which increase significantly the temperature. Moreover, the collision speed of ions leads to an increase in pressure, thus decreasing the distance between atoms.

[0060] The collisions (anelastic impacts) create mini swirling and energetic flows which unbalance any possible motion direction. A sequence of collisions of the particle makes it to jump randomly on other circular orbits having centres following a “random walk” which can lead the particle after several impacts to hit the duct wall and then to be lost. Other effects cause the “drift motions” which, if they are not balanced in time, can affect negatively the magnetic confinement properties. The electric drift speeds are much lower than the thermal speeds of the electrons and of the ions. When the waist of the laser beam, for example laser 2 in the figures, is greater than the plasma wavelength, the longitudinal component of the ponderomotive force is the dominant one and it determines the formation of positive and negative charge areas, that is of a return electrostatic field (wakefield).

[0061] It should be noted that generally the electrons, since they are lighter than ions (thousands of times), are more subjected to the effect of a RF. This greater heating of the electrons activates a phenomenon of collisions with the ions by heating them. Since the electrons are at a much higher electronic temperature and since they are lighter than ions, the speed of thermal electron is much higher than that of the thermal ion. Considering that the electrons are originally entrapped by electrostatic charges, the ions succeed in gaining acceleration since they are provided with positive potential and this phenomenon optimizes when the flows of electrons and ions become equal, reaching an equilibrium (saturation).

[0062] The plasma discharge is almost neutral, which means that ions and electrons exist in equal number and more simply that ions-electrons recombine to neutralize the outlet plume.

[0063] In this way there is no need for a hollow cathode / electronic cannon. Moreover, the particles passing in a magnetic field which expands by decreasing its density, accelerate axially to the detriment of their rotary motion. During expansion upon discharge, the plasma cools down by generating a thrust and therefore it accelerates axially. A possible additional acceleration can be applied to the discharge cone (nozzle) with a radiofrequency antenna for example designated with 15 in figure 1. The detachment from the divergent discharging nozzle is obtained when the density of kinetic energy, parallel to the magnetic flow, becomes bigger than the density of the magnetic energy. Then, it is necessary that the gas (plasma) is at the outlet of the (necessarily convergent) duct under conditions of saturation, that is critical conditions, that is at sonic speed (M1). Only afterwards, the gas can pass in the divergent channel where the expansion waves, which generate due to the negative pressure existing in the outlet section of the nozzle and which travel at the speed of sound, spread with small oblique shock waves inside the nozzle and, taking into account the limit layers, succeed in rising up the subsonic current present in the divergent nozzle by making to accelerate the fluid towards the outlet by transforming it into a uniform current (axial speed).

[0064] Thus, there is a considerable increase in the supersonic speed since the increase in section favours the expansion with decrease in density and pressure in the most precise respect of the flow rate and amount of motion which are constant; this only occurs with supersonic speed in a duly proportioned divergent or rather bell-like nozzle. In case that the speed of sound is exceeded there is no more the need for the bell-like nozzle, but a nozzle articulated like “petals”. It will be a convergent-divergent nozzle with variable geometry to optimize the pressure of the air flow by adjusting the throat section with the purpose of maximizing the outlet speed, thus improving by 15% the thrust increases. Moreover, a vectorial thrust will be possible by hinging the discharge nozzle so as to direct the thrust.

[0065] It was already said that the air has higher dielectric resistivity than other gases, diatomic molecule, high average atomic weight, and the nitrogen is a neutral gas. The air consists of nitrogen + oxygen and indeed the oxygen is not neutral and then, having lower dielectric resistance and enthalpy than nitrogen, it can release free electrons which allow to initialize ionization and then to drag the beginning of plasma in cycloidal gyrokinetic carousel. The easiest ionization is obtained by raising the air temperature (standard pressure and temperature) since compounds and couplings of less dielectric resistance and less effect of emission by recombination are created. The air is heated by engaging a thermal arc, as ionizing source which moves in the air electrons, by producing a flow.

[0066] According to the invention, the pulsed thermal arc X is located at the inlet of the plasma duct 201 and cathode 11 and anode 12 are in magnetic field (figure 1).

[0067] Upon alternating this electric charge (thermal arc) a flow variation is created, by favouring an electromotive force due to the few electrons produced previously and then a discharge is ignited with increasingly numerous electrons due to the impacts between electrons and neutral atoms (nitrogen) and current, by determining a considerable increase in temperature with consequent passage to the plasma state. This current by Joule effect heats plasma.

[0068] When a neutral atom (nitrogen) loses an electron, the same atom becomes ion by transferring high energy to plasma and then it will remain almost always positive.

[0069] Electrons and ions in motion create electric currents and therearound create oscillating magnetic fields, that is electromagnetic waves. These electromagnetic waves in combination with microwaves or frequencies are absorbed by the plasma and exalt new oscillatory phenomena until reaching the magnitude of the applied frequency by becoming its own resonance energy which transforms into kinetic energy of the involved particles. The heating and acceleration methods in plasma are three:

[0070] Ionic cyclotronic resonance ICRH

[0071] Electronic cyclotronic resonance ECRH (its frequency goes in resonance if equal to the electronic one).

[0072] Lower hybrid resonance LHRH (1-4 Ghz).

[0073] The plasma frequency depends upon the square root of its density. The density also depends upon the homogeneity required to plasma. The critical density is formed when the applied frequency correspond to the plasma frequency. In case of nitrogen in which binary, and then not ubiquitous and not homogeneous, collisions are obtained, the problem remains.

[0074] This spatial inhomogeneity connected to the partial ionization, induces defocusing and the laser pulse focuses until the electronic density is not satisfying. This problem can be solved by applying characteristic frequencies of the much higher laser pulses than the plasma frequency. The mechanisms for the interaction between laser and compressed air are rather complex.

[0075] The amount of laser energy, apart from nourishing the ponderomotive force, can be varied to alter the force of the magnetic fields. By modifying the wavelength and / or the laser energy and the frequency of the pulses, the resulting magnetic wavelength can be synchronized on the wished harmonics. A double frequency (or wave radio) or powerful pulsation and a weaker one applied to an antenna in magnetic field, apart from the cross and self modulation phenomena, also determine a considerable increase in the intensity of the sideband waves associated to the interacting ones and of the powerful wave pulsation harmonics (lower hybrid waves: double frequency with modulation).

[0076] The (very useful) higher density of laser reduces its power. The resonance cyclotron electron arises from the effect of the Lorenz force which opposes to the magnetic field by activating a motion of cycloidal flow with an angular frequency.

[0077] When an alternating and pulsed electric field is applied by a RF, or microwave, which is synchronous with the gyrokinetic period of the free electrons, their gyrokinetic energy is increased so as to become higher than the ionization energy of the diatomic molecule of air (oxygen + nitrogen). In the ionization by (transversal) electronic impact the ionization potential and then the probability of extraction will be maximum if the applied energy will be three or four times the ionization one, that is the charge or speed of the incident electron does not have to differ much from the orbital electron. Then the electronic ionization energy will have to exceed the ionization energy of the bond with the electron.

[0078] The collisions which the kinetic energy produces are only binary and moreover in our case there is a residual pressure (from the power turbine designated with 10 in figure 1) which favours an easy recombination. The optimum solution is to create precise resonance conditions between the RF frequencies, laser frequencies, repetition frequency, which work in multi-phase and pulsed systems. The provided solution prevents an increase in the magnetic field and in the electric field from being necessary. The problem is not solved by increasing the energy costs.

[0079] The power turbine 10 comprises a fixed shaft 6. It is formed by an external and fixed tubular cylinder having inside thereof two other coaxial cylinder ducts rotating in in counter-rotation. These allow to house an external rotor. The initial compression prepares the air for the cooling path and for the subsequent entry in the counter-rotating compressor. The initial compressors consist of two stages but they can also consist of three stages (by-pass ratio is increased) and the stators are fixed to the external carter (101) which is fixed.

[0080] The counter-rotating axial compressor preferably comprises six blade rotors rotating inversely to six other blade rotors. The outermost rotors have the base distributed in horizontal line (cylindrical surface 101) and this is ideal for a better fluid dynamic effect. They will have a modelized profile and the achieved technical effect is an optimum compression and a better stability and symmetry between the speed triangles: six + six blade rotors. The air thus compressed at about 18 / 26 Atm (kg / cm2) reaches a temperature of above 600°C and then it passes in a gap (circular crown) comprising the same two cylinders which rotate in counter-rotation.

[0081] The two cylinders have in their gap 104 other rotors (figure 1) implemented with smaller blades, made of metal alloys which are hard and resistant to heat, for example made of HSS3, special steel which is very hard and resistant to high temperatures and however with a small percentage of Berillio alloy to avoid emission of sparks. These small blades are shorter and they have to be more distant from the surface of the cylindrical wall which rotates counterclockwise (and which constitutes the top of the blade height end) and they must have a distance closer to the other blade which in counter-rotation hits it by approaching and then by favouring a voltaic or thermal arc on the flow of already compressed air in transit. In this way high temperatures can be obtained. The pressure conditions, the shapes of electrodes, the surfaces in contact with air, the distance of the electrodes, are all variable which condition the final selection of the type of applied electric discharge. All blades are mainly used to increase the air heating up over 1000°C and temperatures up to 2000°C can be reached in case of coating made of ceramics of the blades of the power turbine 10 (thermal barrier).

[0082] In this case if the counter-rotation is referred to 15,000 rpm the respective cylinders (ducts) rotate on the whole at 15,000 + 15.000 rpm that is 30,000 rpm. Therefore, there is a continuous series of thermal shocks due to the several minithermal disturbances (30 KV only initially) which occur in succession every time a blade of a cylinder meets the other one of the counter-rotated coaxial cylinder. Moreover, the arrays of blades-rotors have an additional purpose: coordinating the transit of the compressed air which can be defined as a fan or circulating pump.

[0083] The compressed air already partially heated during the compression step thus reaches the temperature of 1 ,000° - 2,000°C and is pushed to the power turbine 10 where during expansion produces the power to operate the compressor, the generator starter and the alternator which is on the external wall. A temperature not higher than 1500°C for the inlet in turbine is preferred.

[0084] The air transit speed in the compressor can be selected between 140 and 200 m / sec, the inlet air flow rate can be of 50 m3 / sec, the external diameter of the counter-rotating compressor can be of 70 cm. The number of revolutions can be designated as 15,000 rpm. The increase in the transit speed in the counter-rotating axial compressor can be of 10-15% from inlet to outlet.

[0085] The discharge or power turbine 10 too is counter-rotating and has 3+3 blade rotors.

[0086] The production of electric energy is implemented by two designs: a three- phase AC alternator and a DC generator. On the cylinder of the external compressor and power turbine 10 a three-phase AC alternator is housed, having the magnetic rotor, inside the stator, which is fixed to the wall of the external rotating cylinder with diameter larger than 70 cm, rotating too at 15,000 rpm; the stator is wound by a package of fibres made of graphene / copper and it is anchored to the walls of the fixed external cylinder (carter 101) as in figure 1. The magnetic rotor is provided, inside thereof, with an additional series of magnets of Array Halbach type, since it allows a greater magnetic density towards the inside of the rotor itself and is at the boundary with another stator comprising two stator pieces (thin gap) which support laterally as in figure 1 . This DC starter-generator produces a direct current; it is useful to assume the function of starter and to charge a battery. In an embodiment, magnets resistant at a higher temperature can be used, so as to avoid cases of demagnetisation. The production of electric current is higher than 600 KW and it can produce up to 1400 KW; in case of superconductors like graphene, stanene, germanene, there is no need for a particular heating. The group of production of both three-phase AC and DC generator electric energy have in common the same rotor with two crowns of coaxial magnets: and external one and an internal one (harray halbach) for the generator. The whole is crossed by air initially compressed for cooling. At this point, we are in presence of pressure + temperature. The air passes through the counter-rotating power turbine 10 which, after heating and expansion, discharges, in fluid communication, in the subsequent duct prepared for plasma and at the same time actuates in motion the counter-rotating compressor and with it the magnetic rotor. The air discharged in the magnetic duct 201 is still characterized by a residual pressure and a good temperature: it is possible to detect + 600° 1 1000°C useful and functional for the subsequent ionization process and for a sensible increase in temperature.

[0087] In fact, the flow at the inlet of the plasma duct, transits in a thermal arc (alternating) in magnetic field (discharge diffusor). This thermal arc uses a frequency with oscillator in magnetic field and combines with a second frequency reflected and distant from the preceding one by 90°-180°. The applied voltage is 50 KV - 100 KV and, however, no less than 30 KV / cm; the distance in cm is measured between anode and cathode. Said pulsed thermal arc X is in association with triggering means 11 and 12 identified as cathode 11 and anode 12 arranged in circular order, in an ordered coaxial position and immersed in the magnetic field B generated by magnetic means 14 and multi-phase solenoids 16 and positioned in arrangement adapted to favour the maximum ionizing effectiveness; the smaller distance between cathode and anode AK-GAP allows to increase the frequency. The previous electric discharges produced elastic and non-elastic impacts of the electrons with the ions and the neutral atoms with discharge and recombination exchange exceeding the dielectric rupture and creating a continuous trigger with small production of ions. It is known that the ions of the nitrogen atom return to their position in the time period of a femtosecond. It is to be said that in the electric arc the following is highlighted: thermal ionization and cathodic emission. In this way there is ionization of air whose ions, strongly accelerated by the electric field of the arch, hit the cathode by transferring energy during impact and by determining a localized heating which emits electrons due to the thermionic effect: air ionization. The temperatures can reach (up to) 20,000°C and a thermal energy (up to) 300 Kcal / m2. The arch regime is widely determined by the thermionic emission of the cathode. The considerable increase in the flow of electrons given by the thermionic emission causes a second transition wherein the voltage applied to the electrodes decreases with relative considerable increase in the electric current (ampere).

[0088] The duct 201 constituting a thrust axis and which is not conductive is wound by annular permanent magnets or by electromagnetic coils or by solenoids. At the beginning of this duct the air is ionized. The air ionization allows the conduction of electric current so that the subsequent step is strongly magnetized, energised and accelerated by the RF frequency of the electromagnetic force. In this state for the diameter of 50 cm of the duct 201 a frequency of 500 Mhz is used, which at first by Ampere - Maxwell law (magnetic field), then by Faraday law (electric field) is an “inductive coupling” and in this case the “Lorenz force” acts. As magnetic charge an overall density of 5-6 Tesla is meant and estimated, placed on the duct perimetry. This Lorenz force (electromotor field of “electrodynamic” nature) causes a uniform circular motion perpendicular to the direction of the frequency called “cyclotron frequency”. If the magnetic field is not constant, a drift speed is obtained. The cross trajectory (Lorenz) whose cross size has to be larger than the wavelength, is a pseudo-sinusoid - torsion - which is function of the magnetic field. It is further possible to adjust in conformity the magnetic charges and it will be easier to apply the same frequency for ionization and acceleration. The frequency is provided at a strip of copper, with rectangular section, wound as a helical to the ceramic duct with low permittivity or consisting of materials with high rate of emissions of secondary electrons like BN, alumina AL2 O3, B4C or silicon nitride Sis N4 and it allows to create immediately a plasma which can be defined even a pre-plasma or cold plasma. The supply system is Helicon Double Layer. In fact, the presence of a magnetic field directed along the axis of Helicon antenna creates an operation mode with high ionization effectiveness and a greater electronic density of a typical ICP. All magnets (5 - 6 Tesla) winding like a crown the “duct” have important functions in activating the plasma, they further contribute in increasing the ponderomotive force and confinement.

[0089] The first magnets engaged in the duct - ionization area - must have a greater magnetic charge so as to favour the confinement, the ponderomotive, the transit speed direction. It should be noted that the frequency, not the electro-magnetic field, ionizes.

[0090] Upon applying the amount of frequency in the magnetic field it can be provided to use a range not far from what can be granted by an applied magnetic or electromagnetic field.

[0091] The ions are insensitive to the magnetic field even if when it is excessive they are disturbed and, if this is created in the ionization area - inside the duct - it improves the effectiveness in the frequency intervention. It should be noted that the ions are limited radially by the magnetic fields and entrapped longitudinally by the electric fields.

[0092] For the configuration of the magnetic elements of the plasma propulsion unit an accelerator with multi-phase solenoid with magnetic rings is preferred.

[0093] According to the invention, a lower hybrid wave LHRH is preferred to a ECR for heating since the hybrid wave, apart from having a lower frequency, does not require to make the frequency to coincide with the magnetic field. The greater, if not double, frequency required for a ECR system produces a significant loss of energy since the excessive heating of the electrons is so that the same do not comply any more with the adiabatic invariant and carry away with them the greater absorbed heat with a useless energy and greater than that required for a plasma RF. The adopted micro-wave is in the band II (UHF).

[0094] In this case it is preferred to align a lower hybrid wave close or similar to a ECR of 500 Mhz by adjusting, possibly reducing (modulation) the intensity of the magnetic field. In this way, it is possible to vary the thrust power by increasing ionization and Frequency power. Moreover, it is possible to form electronic transportation barriers generated by the combination of lower hybrid waves and ECR waves. The lower hybrid frequencies are electromagnetic heating devices focused on its own frequencies of plasma intermediate between the cyclotronic ones of ions and electrons. (500 Mhz). The hybrid wave resonance frequency is a perturbated cyclotronic frequency which has the effect of moving the ionic and electronic resonance frequencies proportionally to the electronic density. The lower hybrid frequencies lie in the field of microwaves and then waveguides can be used for the generator and plasma with satisfying technologies for powers and performances and they have a “current drive” effectiveness.

[0095] The preferred embodiment is with a microwave propulsion unit and with a multi-phase solenoid.

[0096] The constant application of electric energy with sequential phase variation produces a more unidirectional thrust. The direction of the magnetic field performed by the multi-phase solenoid, in position parallel to the axis of the propulsion duct (201), substantially provides the longitudinal thrust direction with vigorous helical motion.

[0097] The continuous basic rotation favours a more centred plasma. The multiphase solenoid is characterized by the possibility of varying the magnetic field in relation to the other existing electronic conditions. It performs an action focusing on the radii of charged particles. The phase displacement can be implemented by a multi-phase solenoid (figure 3) consisting of six concentric turns axially rotated mutually by 60° from one another and supplies from progressive RF sources with radial influence of 0°-60o-120o-180o-240o-300°, or remembering that in this case there is at the edge a three-phase produced current, having three concentric turns rotated mutually by 120° from one another in radial progressive order of 0° - 120°- 240°. The wave frequency for the wavelength is equal to the wave propagation speed.

[0098] Moreover, inside the multi-phase solenoid an Array-Halbach magnetic system is provided, also useful to increase the radial confinement of the plasma in motion thus with presence of a pulsed multi-phase magnetic field and with one single direction (for the neutral gases one pole per phase is designated). The system of magnets of Array Halbach type consists of three consecutive stages: 1 stage: 3 poles, 2 stage: 6 poles, 3 stage (outlet): 3 poles.

[0099] The antenna (figures 3A-3B) is with helicon with rectangular section, quadruple and can be double with right distance therebetween at the density magnetic fields. There is the problem that the applied frequency has no electromagnetic interaction with the already existing plasma since it does not succeed in penetrating what circumscribed and confined magnetically. For this it is suitable to use phase-shifted (+ / -) antennas with rectangular waveguides (grill) placed at the plasma edge (duct) so as to meet the required conditions of comparison between electric field and wave. In this way that is by wave-particle resonant interactions implemented with the phase difference (phase shift) between the arrays of rectangular waveguides it is possible to maximise the power transfer.

[0100] It should be noted that the antenna and solenoid are two different elements included in the invention, arranged so that the magnets result to be interposed therebetween. In particular, the configuration is so that the solenoid is arranged externally with respect to the antenna, whereas the (rectangular) antenna is arranged internally.

[0101] The plasma duct can be coated internally with reflecting material. In this way a more powerful almost isotope confinement is given without electrostatic acceleration and the charge-mass ratio can be zero, that is neutral plasma with almost isotope collisions. The multi-phase accelerators act with radial and longitudinal frequency which translates into a vigorous helical motion and with correct frequency - as preferred indication for application to hot and compressed air a (lower hybrid wave) micro-wave of 500 Mhz (UHF) is applied, suitable to interact with any gas by producing continuous unidirectional thrust. On the contrary, the electric field acts on the still charges and on those in motion and puts them in motion with oscillating motion in which the acceleration varies continuously. Any electric charge which activates this motion, in turn, emits an electromagnetic wave. The emission type depends upon the applied charges and since the electrodes are much more receptive they oscillate with a much wider width. The air molecules too are subjected to the effect of radiations of electromagnetic waves (up to the ultraviolet waves). It would be interesting to know with certainty how the interaction of the electromagnetic waves of high frequency laser occurs with a plasma provided with electrons and positive ions. The oscillating electric field of a (laser) light beam can be absorbed, reflected, diffused and / or refracted by a surface. The phenomenon that is interesting to be highlighted is directed to the absorption and to the conversion of the electromagnetic energy of the laser beam in thermal energy. The fact is that the free electrons of plasma collect quickly energy from the incident oscillating electric field (pulsed laser). Their energy is subsequently transferred to the plasma ions by attractive interactions: a real mediation of the oscillating electrons.

[0102] A real impact (collisions), whereas the laser performs a quicker heating of electrons. An intriguing manifestation of physics in systems of thousands of particles with the formation of vortexes (reels with angular motions).

[0103] Under a condition of fluid dynamics where a proportionality between the fluid element (plasma) and the magnetic field is favourable: if the plasma density increases, the density of the magnetic field too will have to increase. In the plasma duct there are plasma viscosity, since under pressure, and fluid vorticity. The capability of the magnetic field is to confine the particles and then to produce a collective behaviour even if the collisions for various impact parameters and for the intrinsic complexity of plasma cause different phenomena in which electrons and ions respond differently, by favouring the propagation of waves. If the magnetic field is not constant a drift speed is obtained.

[0104] A strong magnetic field which guarantees the confinement in presence of a congruous pressure of air already designed to plasma allows an absorption of an appreciable fraction of the incident laser energy. If the plasma were at a low or null pressure the energy expenses of laser would have low effectiveness and a bigger amount of laser energy would be required. The fact is that while the laser starts heating the plasma subsequently the oscillating electric field decreases.

[0105] Between wave and corpuscular nature there is a principle of complementarity since they have common properties. There is its own quantum dualism: wave - particle. When the frequency corresponding to the interaction energy is greater than the electronic excitation, the transfer between the two magnitudes (photons) occurs with a phase coherence lasting longer to complete the energy exchange.

[0106] In the area after the counter-rotating compressor and subsequently to the blades designed to implement a heating with mini thermal arcs, there is a partial deviation (an escape) of the flow of air compressed and heated inside the counterrotating cylinder with smaller diameter. This so-spilled air is further compressed and heated by means of a centripetal compressor 13 (figure 1) designed to raise it by additional pressure and temperature and to introduce it in the coaxial vircator which is positioned inside the wide central axis of the power turbine 10. Subsequently, it is discharged in the axial centrum of the plasma duct 201 .

[0107] The laser or a source of electromagnetic beam creates radii of particles which act with the confining or adjacent particles which in turn are modified by the plasma duct (resonance chamber). This affects the existing frequencies by producing instability which is called collective effects whose force depends upon the flow density. These oscillations (collisions) are guided by the presence of the magnetic field whose intensity speed them up, favours and encourages a “closed” (that is correct) orbit, but sinusoidal along the whole duct. The transverse oscillations of the electrons and the radiations of the electromagnetic wave are with the same phase that is they have to be synchronized.

[0108] Even when the electromagnetic wave exceeds the electron by an amount equal to two or more wavelengths the synchronism condition is met and this condition constitutes an harmonic. When the plasma starts forming (initially cold) there are no limits to increase the electric fields by using laser beams focused to excite longitudinal plasma waves with the purpose of accelerating the electrons. The wave frequency for the wavelength is equal to the wave propagating speed.

[0109] A frequency electromagnetic wave cannot propagate in plasma if it is not higher than the plasma density (under-critical plasma), otherwise the wave is reflected. An excitation (wakefield) is more effective when the plasma wavelength is equal to the laser pulse duration.

[0110] It is necessary to slow down the phase speed of the electromagnetic wave so that the electrons result to be quicker than the same wave. In this way the electrons which are decelerated will be higher than those which are accelerated and the energy lost by the electrons will be transferred to the electromagnetic field (since there has been a radiation amplification). The absorption of the electromagnetic waves is very effective if the wave frequency is equal to one of the characteristic plasma oscillation frequencies (resonance frequencies).

[0111] Moreover, the wave frequency for the wavelength is equal to the wave propagation speed. In order to have high powers per frequency units it is necessary to reduce the “emission spectral width” that is to obtain longer pulses. That is the laser-plasma accelerator will be (by principle) a thousand times shorter than the frequency counterpart. The plasma wave width (which is the force of the electric field) is proportional to the laser intensity.

[0112] In the pulse laser with “self focusing” the pulse is broken intermittently (button) by creating instability which through the ponderomotive force supplies the plasma oscillation. The intense laser pulses to fms cause a quick increase in temperature and ionization leading to a non thermal heating originated by the sudden increase in positive ions and free electrons in the duct. This involves a relevant situation of greater energy. The advantages of the SMLWFA regime with respect to LWFA are the absence of the condition of almost resonance on the pulse duration by producing a more intense acceleration due to the greater electric field associated to the plasma high density.

[0113] This regime increases the plasma instability and the subsequent considerable increase in temperature lowers the “WAVEBREAKING” limit so that a portion of electrons has thermal speed close to the wave phase speed, thus favouring the acceleration of electrons with very high energies.

[0114] Therefore, there is the advantage of creating an increase in the wave vector with low disordered energy loss. The characteristic frequencies of the laser pulses are much higher than the plasma frequencies. The real and ideal regime of the laser duration is around some tens of femtoseconds thereto a plasma density of about 1018el / cm3(l= 1018W / cm2) corresponds.

[0115] For an optimum implementation, the intensity of the laser pulse has to be higher than the electromagnetic field which keeps bound the electron in the nitrogen atom. Only in this way a ionization of nitrogen can be obtained, by transforming it into plasma. The double, ultra-short and ultra-dense laser pulse, with suitable repetition frequency, has to be adapted to the plasma wavelength; it must have a contrast value between pre-pulse and main pulse; the first one is a precursor in plasma, it has energy equal to 10% of the one available to laser, it excites the rotational states of the molecules by creating a gyrokinetic re-alignment therebetween; during this phase the second pulse arrives with delay, which is the main one, more intense and powerful, it starts at a distance of a period from the first one and it has an energy of 90%; it forms a polarization angle of the molecules with the direction of the axis formed by the first pulse by creating harmonics; it also has a doubled frequency with respect to the first pulse, it is ultra-short and produced acceleration through “LWFA”. The pulses have to be similar as well as the related frequencies so that the sum constitutes the laser excitation frequency. The synchronization of the pulses with the resonant absorption of plasma have to coincide perfectly (autocorrelation). Its initial delay of a period of the second pulse creates a spectrum of harmonics which can create if in resonance a provisory delocalization of the electrons by positioning them in an atomic orbital without taking into account the effect of their electronegativity. The magnitude of the spectrum of produced harmonics depends upon the delay of the second laser pulse.

[0116] Moreover: the difference in temperature between the external circular portion of the duct and the internal portion of the duct (which is at higher temperature) generates an electric voltage proportional to the power of the incident radiation. The bigger the diameter of the laser beam is, the lower its temperature is. The desire to create an unexpensive high power microwave system brought to the selection of technologies immediately available as components of primary power.

[0117] The coaxial vircator is an oscillator, that is a source of high power microwaves. It is suitable to be used in this design since it allows to produce very powerful radiation pulses, it is mechanically simple, small and robust and can operate above a relatively wide band of frequencies of microwaves. Generally, the performances of the vircator are repeatable and reliable. The inner surfaces are mirror polished to reduce the probability of emissions from the metal surface. Diameter of the anode thread (grid) = 0.25 mm. Opening width 1.2 mm. If the electrothermal arc is stronger, they will be increased.

[0118] The anode can be made of polished pyrolytic graphite. The cathode can include bimodal emitters made of carbon fibres pyrolytically bonded to a graphite substrate.

[0119] The electro-thermal arcs occur between cathode and anode. The physics of arcs is not well understood and the relation between voltage V and current A has never been explored and described exhaustively.

[0120] It is a phenomenon linked to the physics of energy transportation. The voltage, which produces an electric discharge (breakdown voltage) applied in an arc provided with electrodes, is strictly linked to frequency, pressure and distance of the electrodes. It is to be reminded that in the air, gas diatomic, nitrogen and oxygen are homonuclear molecules, symmetric with metastable level, the collisions are by impact and the breakdown voltage is higher. It is believed that the diluted plasma transports ions with wide diffusion of energies. The position of the active areas of the resonant coaxial tubes produces better distribution of the reactive current in the electrodes of the device with the effect of doubling the outlet power.

[0121] The distribution of electronic energy is not known. The exact nature of the transition is not known. The cathode and the whole wall holding it have the same potential (100 KV).

[0122] Electro-thermal arcs (30 KV) are with pulses of short duration to avoid electric arc (short circuits) and deformity of the laser medium. The energy and duration of the radioactive pulse has to be proportional to pressure: the energy = directly. The pulse = inversely to pressure.

[0123] The duration of pulses generally is limited by the time required to the plasma to fill-in the GAP (anode-cathode) with the result that the energy of the beam of electrons converts into microwaves with effectiveness of 40%.

[0124] In the vircator the electrons are emitted by the cathode (through saw teeth and better if arranged in a sinusoidal way) and accelerated through the anode. The vircator produces microwaves through two mechanisms: one is of the electrons passing between real cathode and virtual cathode; the other one is the amount implemented in the virtual cathode. When the potential energy of a beam of electrons which has passed through the anode with transparent mesh (70%) is greater than its kinetic energy, a cloud of electrons (oscillating electrons) is formed called: virtual cathode. This 70% transparent mesh represents the geometry related to a constant of spatial charge (oscillating electrons) or perveance to obtain a current which is function of V. The frequency of the beam of electrons produced by the cathode combines with the frequency to which the virtual cathode is subjected and the same adapts or is obliged (since subordinated) to oscillate at the same frequency of the original beam of electrons. This combination in one single frequency produces very high effectiveness. The diameter of the cathode of vircator is between 10 and 16 cm. The diode laser (mentioned in this example) is positioned to transit to the centre of the vircator and it crosses the "cloud" of the virtual cathode. In this passage the laser has to have a same frequency or a multiple of the frequency used by the cathode (2.45 Ghz = 2.45 Ghz or in the duct 201 : 500 Mhz x 5 = 2.5 Ghz). (UHF - SHF).

[0125] This laser passing by the centre of cavity of vircator and crossing the field of electrons accelerated by the anode, (virtual cathode), contributes in raising temperatures and very high heat enthalpic and anthropic contents. The power peak is proportional to the square of pressure. The laser output then is a pulse provided with great power. A generation of laser pulses is then necessary with femtoseconds of few optical cycles and high energy in application to the dynamics of the electronic states of a gas (air) in cold plasma to increase the excitations of levels and strongly correlated electronic energy systems which are subjected to variations by the presence of pressure. The selected diode, but the selections can be different, is the multimodal type (but it can be monomodal if of very high power) if with high power optical fibre it does not require the resonator. In the coaxial vircator the reflectors (which absorb energy) allow to change the modes from TM 01 to TE 11 with related new frequency from band S to band L. The modes of higher order (TE and TM modes) can propagate in coaxial at higher frequencies and one wishes to avoid these modes since the conversion from mode TEM to TE or TM constitutes a power loss. The mode TE11 , which is also a cutoff frequency, represents the mode with the lowest frequency with a better management of power. The electric arc is an electric discharge in air with temperatures which can reach 10,000° - 20,000°C.

[0126] The electrons crossing the anode in the cavity of the vircator form a charge which will oscillate at the frequencies of the microwaves with very high power: that is emissions of electrons with their transfer of positive and negative ions and reaching high temperatures. Thus, a strongly ionized gaseous channel is constituted. In this way ions and electrons with very high impact sections, protagonist of elastic and inelastic impacts, acquire a strong kinetic energy. Since the air consists of two components, the excitation occurs even between atoms or molecules of different type through a typical resonant excitation transfer. Nitrogen is a diatomic and neutral gas which absorbs heat quickly with consequent increase in temperature and then it is easily at a thermal difference from the oxygen gas of air = KT where K = constant of Boltzmann.

[0127] Then, it is obtained that after impact (pulsed passage of electric current) one of the two gases has difference in energy levels, it results probable that a situation is created so that the atom of a gas is excitation energy reserve of the atom of the other gas and then if metastable it has time to excite the other gas (secondary collision). This resonant transfer occurs even between electron and atom, between atom and molecule, by resulting an energy transfer on the vibrational states of the molecules (neutral molecule excitation).

[0128] In this way the excited atoms can decay towards the fundamental status after having transferred energy by collision: electron - atom, atoms of the two different gases, collision atom wall of the container, spontaneous emission (without spatial and temporarily coherence).

[0129] In order to establish a “conversion effectiveness”, that is a net transfer of energy, the mechanism for the synchronization of the phase between speed for propagating the beam of electrons (which vibrate near the cathode) and speed of the phase of the radiation field (microwaves) has to occur. Moreover, the radiation frequency has to be greater than the plasma frequency (critical density). The waveplasma power transfers have to occur in privileged way at certain frequencies. There are resonant relations between the wave speed and the speed of the particles.

[0130] A coaxial cathodic oscillator (vircator) has as geometry many physical parameters which can be modified to alter the system performances. The parameters of interest include: the diode length, the distance between anodes and cathodes. The expansion of the anode radius involves the collection of an excessive number of electrons with consequent decrease in the produced microwaves. The decrease in the radius produces a reduced effect. The simulations with variations of parameters can provide and simulate different geometries intended for the best performances. The frequency depends upon the distance between anode and cathode and upon the applied tension.

[0131] There is a complex dynamics of the electrons in the path of the interaction space.

[0132] Upon starting oscillations there are groups of electrons passing through the half-permeable anode (70%) by forming a virtual cathode; those travelling parallel to the cylindrical anode (and then in circles or like crown); and those wandering which are expelled by reaching the output. Upon succeeding to reduce the “wandering” electrons, an increase of 50% of the output power can be obtained by the vircator.

[0133] A solenoid in the vircator (even if not necessary) produces a magnetic field which applied to the cathode could increase the effectiveness. An incident laser pulse generates a charge of particles constituting an exponential energy beam and an important angular divergence. Then, it is necessary to collimate or compact and focus this beam by applying a solenoid winding the cathode of the vircator and which is applied even in the plasma duct 201 (Figure 1) with the purpose of making the laser suitable for entering the cavity. Moreover, the magnetic component of the solenoid will activate a helical path of the electrons with the probability of ionizing additional free atoms.

[0134] A wide experimentation (set up - simulation) using a computer is required and the impedance and frequency should "be in agreement".

[0135] The installation of the Rogowski coil is provided to monitor the electric energy.

[0136] An optical pyrometer and a pressure sensor are required. Moreover, a phonic wheel with speed sensor is useful.

[0137] Expansion and laser.

[0138] The situation includes the laser using transitions of vibrational and rotational type. Energy of a diatomic molecule: electronic energy, rotational energy, vibrational energy. A very effective way to spread and increase heat, coming from a preceding compression and heating by blades with thermal arc, is to make compressed air to flow and at temperature in direction orthogonal to the electric discharge. In order to avoid using excessively high voltages a series of electrodes is arranged along the whole transversal path. Then, there will be the possibility of applying lower voltages. The laser allows to transfer the gaseous mixture at high temperature and high pressure after transit in the vircator and that is in the plasma duct 201 where pressure and temperature are at a much lower level. In this way and in this area which is wider (and it has a constant transversal section) a quick expansion is obtained which causes a quick decrease in temperature. The decrease in temperature and pressure allows that the energy transferred by the nitrogen molecules tends to pass towards the lower levels and, since the air mixture is in quick transit in an area of not thermodynamic equilibrium, the population inversion occurs which continues also after the compressed air has reached a high temperature. This expansion, which takes place at supersonic speed, has the effect of lowering the temperature and the related pressure in a period of time which is lower than the higher average life and longer than the lower average life of the laser beam. The speed of sound is determined by the gas properties: (diatomic y = 1.4) R = constant of gas and temperature.

[0139] The increase in the population inversion, that is a (stimulated) absorption of energy, produces a drift speed and a widespread with a penetration depth of the quick electrons in the compressed air (accelerated slope). A lower consumption of electric current is noted.

[0140] The undulatory nature of the electromagnetic radiations exerts an electromagnetic force with shifting of the particles of oscillatory type, thus creating that the atoms of the compressed air are put into vibration. Thus, interaction between compressed air and electromagnetic radiations is produced, with direct and strong increase in temperature.

[0141] The pulsed laser acts so that the voltage pulse travels with speed equal to that of the light so that the laser pulse and the electric one travel with synchronism and thus a high gain is obtained: (frequency > (10) - 100 Hz and (100) - 500 Kv). The application of 500 kv is very dangerous since it is destructive to materials.

[0142] The stimulated emission has to be higher than the spontaneous emission and then the condition of causing the stimulated emission (Einstein), which has to be higher than absorption, requires (in the duct) a high temperature and a corresponding low energy adapted to promote a population inversion.

[0143] The resonance cyclotron electron arises from the effect of the Lorenz force which opposes the magnetic field by activating a cycloidal flow motion with angular frequency.

[0144] Upon applying an alternating or pulsed electric field, which is synchronous with the gyrokinetic period of the free electrons, their kinetic energy is increased so as to to become greater than the ionization energy of the air diatomic molecule. The motions of cycloidal flow (Lorenz force) provide a vibro-rotational effect which is also a dragging effect. A real centrifugal and centripetal vortexing orthogonal to the helical advancement axis with consequent increase in energy. All these increases in energy heat or even work on a flow involves a considerable variation in its enthalpy so that it represents the thermal energy content of the flow. This obtained energy becomes propulsive with a kinetic energy controlled by pressure. Due to the excessive thermal increase in the vircator a strong cooling with a closed circuit cryocooler is required, with pre-cooling implemented by a cryocooler with pulse tube which uses liquid helium. This liquid helium will circulate around the surface of the vircator’s cathode and exactly in the provided circular cavity (sheath) placed outside the solenoid applied between cathode and the axis of the power turbine 10. The forced cooling to all the magnets present in the duct 201 is useful and necessary.

[0145] By using preferably a duct 201 with diameter of about 50 cm (but it is possible to make it with 30 cm: and in this case the frequency will be of 2.45 Ghz LHRH hybrid wave) a dense plasma will be obtained with a dominion of collective phenomena. Unbalances and collisions inherent in these conditions are ri- equilibrated in a very short period of time. In case the laser pulse is of few fms the thermalization time exceeds the duration of the laser pulse with a greater difference in temperature of the ions and neutral atoms from the electrons.

[0146] With the finished sizes of the cylindrical duct 201 there are amounts of disturbed waves, of torsional waves and magneto-acoustic waves and there has to be superimposition between the accelerating electric field and the arc tension so as to produce a beam intensity in this pulse duration.

[0147] In the turbulence the sinusoidal rotational effect (due to the Lorenz force) and the expansion arise from the arrival of the power laser (which passed through the vircator and reached the plasma duct), and they appear with a very strong sound. This sound that is sound waves which rotate due to centrifugal effect (twisted waves) with a lower frequency than the previous one, have a limited circular space and then they are twisted and their frequency decreases whereas the centrifugal speed increases. Then, however, the sound starts again since there has been a frequency variation and the sound waves become more noisy as well as by doppler effect. The whole with helical motion in the field direction.

[0148] The turbulence stabilization is required since its lack can weaken the confinement effect. The variation in the applied electric fields causes a variation in speed by preventing the turbulence development. During the plasma heating, it is necessary to favour a directionality aspect, so that the wave spectrum only resonate with the particles having a preferred direction. The speed of the electromagnetic wave depends upon its frequency and refraction index. The oscillation frequency of the electric field has to be modulated to preserve phase synchronism between the rotation frequency and the frequency of the accelerating electric field. An effective rotary turbulence creates instability. A turbulence constitutes a perturbative method in the heat diffusion. A propagation and absorption of microwaves constitute an electronic heating of plasma in collisional regime. The collisional effects do not check the distribution of the plasma current density.

[0149] The collisions bring the particles at different temperatures by creating a collisional resistance which decreases quickly when the temperature increases until reaching the equilibriums and causes reciprocal “collision” interactions, suitable to level the different temperatures. The collisions are complex processes which cause losses but level the temperatures among particles.

[0150] The collisions decrease only with high temperature. A very short and intense pulse can excite plasma waves. Therefore, the non linear force with the help of the laser pulse (ponderomotive force) generates a charge separation by creating a trail of electronic waves (wakefield).

[0151] A greater wavelength and a smaller phase speed correspond to more intense plasma waves and the wave fronts curve: at this regime the breaking of the plasma wave occurs when the radius of curvature of the wave front decreases without reaching its transversal sizes. During additional compression step the gas becomes more turbulent to end then with collisions. The collisions consume much energy through shock waves and turbulence in the air gas (real physical mechanisms). In case of diatomic molecule that is with two identical atoms for the pulsed laser, a voltage of 100,000 I 500,000 V would be useful. The use of inductances is useful to make that the voltage pulse travels in direction of the resonator axis with speed equal to that of the light.

[0152] In this way the laser pulse and the electric one travel in synchronism and a very high gain is obtained. In this way powers up to 50 MW and with pulse frequencies up to 100 Hz are possible. An increase in vibrational energy consequently causes a positive vibrational transition and consequently a rotational transition which is called vibro-rotational transition.

[0153] The electric power engaged in the (compressed) air plasma has to be higher than 25 eV so as to produce a large number of energy electrons which allow to improve the ionization degree and consequently the energy cost of produced electron. The pulsed discharges of non-equilibrium have a greater effectiveness and require a lower power with respect to the sinusoidal discharges. Apart from a high electric discharge, a repetition frequency (of the pulses) and a lower pulse length than the molecular recombination period of time are required. There must be superimposition between the electric field and the arc voltage so as to produce a beam intensity in this pulse duration. High repetition rates could replace the current.

[0154] The analytical formulation is of poor interest for the same description of all processes and behaviour related to ionization.

[0155] It is understood that every small variation in energy, magnetic and electronic density, pressure, frequency or pulse leads to the need for providing a continuous refining already described with words such as: equilibrium, tuning, resonance, phasing, modelling. For each implemented project it is necessary a real set up of the features of the existing parameters. For this problem a computational software of plasma is used.

[0156] The varied and very high computational complexity of the plasma phenomena forces to parallelize (with distributed memory) the operations related to the solutions of the linear solution system. There is a diversity in the plasma software. This software allows, by implementing data and calculation acquisition codes, to guarantee maximum performances even of complex systems. The application of some software for controlling and monitoring specific instruments and hardware allows to monitor the operation and to set the related parameters.

[0157] This, then, remedies the rheological behaviour of plasma which provides non linearity, a large number of degrees of freedom, lack of symmetry. The computational software is a decision-solving tool to support the stabilization performed by means of magnetic fields, to improve the reliability of the process in progress, to multi-scale optimization and fidelity management. The magnets and the portions of the power turbine 10 must be cooled down. These magnets are located in the same rotor in coaxial positions: those of the alternator and those of the starter-generator and the subsequent ones where plasma is formed (duct 201). The problem of cooling is solved by introducing a portion of compressed air produced by the first rotors composing the compressor (3) (by-pass system), that is before the air becomes too hot. The tapping or use of compressed air preferably occurs after the second rotor (or stage) of the compressor (secondary air flow). The compressed air passes through the axis (6) (underpassage) to reach even the area of the power turbine 10, it will go out from the last blade of the power turbine 10 where the discharge pressure of the cooling air is slightly higher than the discharge or expansion residual one or in the blades of the bigger rotor - the last one of the discharge - of the power turbine 10.

[0158] These blades will have a greater thickness and holes discharging in direction of the turbine flow path. Another way to cool the entire turbine-engine body is the compressed air of the first two stages (but there could be also three stages) which is channelled and pushed in the gap existing between the external cylindrical tube, which is fixed, and the other more internal tube which rotates at 15000 rpm (bypass). This gap with circular crown is crossed by this air flow which after having cooled the magnetic rotor arrives as far as the area outside the plasma duct 201 where it can enter until winding the magnets to then discharge outside. Apart from cooling and magnetic confinement it is also possible to create a double chamber in the plasma duct - where fresh air flows which crosses in direction of the outlet the pouring holes by moving away from the surfaces the plasma as it happens in the combustion chambers of the gas turbines. Cooling by convention (air film cooling).

[0159] The invention has been described in all its peculiarities with reference to the enclosed figures; such description and such figures obviously represent an exemplification of the described inventive techniques. The present invention is defined by the enclosed claims.

[0160] The components in the figures are listed hereinafter with the respective identification numbers. 1. AIR INLET

[0161] 2. LASER

[0162] 3. AIR PRE-COMPRESSOR

[0163] 4. REFRIGERANT CIRCULATION AIR

[0164] 5. COUNTER-ROTATING AXIAL COMPRESSOR

[0165] 6. FIXED SHAFT

[0166] 7. DC GENERATOR STATOR

[0167] 8. ROTOR WITH DOUBLE SERIES OF INTERNAL AND EXTERNAL MAGNETS

[0168] 9. THERMAL ARC

[0169] 10. COUNTER-ROTATING TURBINE

[0170] 11. CATHODES

[0171] 12. ANODES

[0172] 13. CENTRIPETAL COMPRESSOR

[0173] 14. MAGNETS

[0174] 15. ANTENNA

[0175] 16. MULTI-PHASE SOLENOID

[0176] 17. BELL-LIKE SUPERSONIC NOZZLE

[0177] Ai IONIZED AIR

[0178] Ar RESIDUAL EXPANDED AIR

[0179] E ELECTRIC ENERGY

[0180] 3a ROTOR

[0181] 3b STATOR

[0182] P1 COUNTER-ROTATING BLADES

[0183] P2 COUNTER-ROTATING BLADES

[0184] W COAXIAL VIRCATOR WITH SOLENOID ON THE CATHODE.

[0185] PL PLASMA

[0186] PW THRUST POWER

[0187] 100 TURBINE BODY

[0188] 101 EXTERNAL CYLINDRICAL TUBE WITH AC ALTERNATOR STATOR

[0189] 102 COUNTER-ROTATING CYLINDRICAL TUBE WITH BLADES

[0190] 103 COUNTER-ROTATING CYLINDRICAL TUBE, INSIDE THE TUBE 102, WITH BLADES

[0191] - 104 CIRCULAR GAP PLACED BETWEEN 102 AND 103

[0192] - 200 PLASMA PROPULSION UNIT WITH THERMAL ARC X IN AREA 202

[0193] - 201 PLASMA DUCT

[0194] - 202 THERMAL ARC X PROVIDED BY THE CATHODES 11 AND ANODES

[0195] 12.

Claims

CLAIMS1. A plasma propulsion system comprising an air turbine plant (100) adapted to receive supply air (A) from an external environment, and a plasma propulsion unit (200) adapted to increase a speed of said supply air (A) after a corresponding ionization and passage in plasma phase of the supply air (A), wherein said plant (100) comprises: first compressing means (3) adapted to implement a first pre-compression of said speeded-up supply air (A); second compressing means (5) adapted to implement a second compression of the air (AP) pre-compressed by the first compressing means (3); first heating means (9) adapted to heat said air pre-compressed previously by said first (3) and second (5) compression means; a coaxial vircator (W) provided with solenoid; a centripetal compressor (13) adapted to produce a partial air flow in said coaxial vircator (W); a three-phase AC alternator adapted to produce three-phase current; a DC electric generator starter suitable to produce electric energy (E); a counter-rotating power turbine (10) which can be actuated by said heated air to produce residual expanded air (Ar), wherein the power turbine (10) is adapted: o to perform compression work through the first compressing means (3) and the second compressing means (5); o to perform compression work through a centripetal compressor (13); o to produce electric energy (E); o to apply a radiofrequency of 2.45 Ghz; o in the coaxial vircator (W), to discharge residual expanded air (Ar) as a function of said compressed air heated with part of the produced electric energy (E); wherein said plasma propulsion unit (200), associated to said air turbine plant (100), comprises:- a duct (201) for plasma flow adapted to receive said residual expanded air (Ar) discharged by said power turbine (10);- a connection portion (202) placed between the power turbine (10) and the plasma flow duct (201) wherein said connection portion (202) has a section decreasing in direction of the plasma flow (201) and comprises an anode (12) and a cathode (11) configured to generate a thermal arc (X) obtained through a RF oscillator so that said residual expanded air (Ar) passing in said connection portion (202) subjected to said thermal arc (X) determines a ionized and heated air (Ai);- magnetic means (14, 16) fixed so as to surround like a crown said duct (201) for the crown-like plasma flow and adapted to generate a corresponding magnetic field, wherein said anode (12), said cathode (11) and said thermal arc (X) are placed in said magnetic field, wherein said magnetic means (14, 16) is configured to generate a plasma of said heated and ionized air;- a radiofrequency or microwave source applied with adjacent helical antennas and winding said duct (201) for plasma flow in the magnetic field (B) generated by said magnetic means (14, 16);- a laser source (2) configured to emit a laser source with double pulse passing linearly by the centre of the coaxial vircator (W) and subsequently in the centre of the duct (201) to accelerate and increase said plasma just generated in said magnetic field (B) generated by said magnetic means (14, 16);- discharging means (17) to discharge the plasma (PL) generated in said duct (201) comprising a supersonic divergent nozzle (17) with antenna (15) shaped like a bell wherein said discharging means (17) in the outlet of said plasma (PL) implements a thrust power (PW) produced by said propulsion system; in case the speed of the plasma flow exceeds the speed of sound, the divergent nozzle is replaced by a nozzle shaped like “petals”.

2. The plasma propulsion system according to claim 1 , wherein said first compressing means (3) comprises a stator (3b) and a rotor (3a) associated to a fixed shaft (6) in said turbine plant (100).

3. The plasma propulsion system according to one or more of the preceding claims, wherein said compression means (5) comprises a counter-rotating axialcompressor having a first plurality of blades (P1) and a second plurality of blades (P2) rotating inversely with respect to each other.

4. The plasma propulsion system according to one or more of the preceding claims, wherein the electric current is produced by: said three-phase AC alternator adapted to produce three-phase current and said DC electric generator starter adapted to produce electric energy (E), wherein said electric starter-generator is adapted to produce a direct current and it is characterized by a fixed stator at the sides and by an external magnetic rotor of Array Halbach type fixed to an internal counter-rotating tube (8).

5. The plasma propulsion system according to one or more of the preceding claims, wherein said first heating means (9) comprises one or more series of micro blades, counter-rotating with each other, made of metal alloys which are hard and resistant to heat situated in a circular gap (104) defined by two cylindrical tubes (102) and (103) adapted to rotate in counter-rotation with each other with respect to a fixed shaft (6) thus implementing, with continuous rotations, a plurality of mini thermal arcs adapted to raise the temperature of the compressed air in transit.

6. The plasma propulsion system according to one or more of the preceding claims, wherein said annular magnetic means (14, 16) comprises one or more among: magnetic and electromagnetic rings; accelerator with multi-phase solenoid (16) provided with additional magnetic circular crowns of Array Halbach type inside thereof (14).

7. The system according to claim 1 , wherein said compression means (5) comprises a single centripetal compressor (13) adapted to produce a partial flow of air, further compressed and heated, in said coaxial vircator (W) provided with solenoid.

8. A plasma propulsion method comprising the steps of: providing an air turbine plant (100) adapted to receive supply air (A) from an external environment and a plasma propulsion unit (200) provided with a duct for plasma flow (201) associated to said plant (100) and adapted to increase a speed of said air after a corresponding ionization and passage into air plasma phase; performing, in said plant (100), a first pre-compression of said air and a second compression of said previously pre-compressed air; performing an additional separated centripetal compression of air tapped before entering the power turbine (10) and then compressed and heated to introduce it into a coaxial vircator (W) crossed by a laser; applying a radiofrequency of 2.45 Ghz; heating through thermal arc (X) said air compressed previously by means of said first and second compression; expanding in a power turbine (10) said heated air:- to perform compression work through the first compressing means (3) and the second compressing means (5);- to produce electric energy (E);- to discharge residual expanded air (Ar) as a function of said compressed air, already heated with part of the produced electric energy (E); to perform contemporarily the steps of: a) increasing the speed of said residual air (Ar) so as to reduce the pressure through reduction of the transit section (202) of said residual air (Ar) outgoing from said power turbine (10); b) applying to the residual air (Ar) the thermal arc (X) through generation of a pulsed radiofrequency in magnetic field (B) wherein said magnetic field (B) is generated through annular magnetic means (14) and multi-phase solenoids (16) fixed so as to surround like a crown the duct (201) for plasma flow; wherein the two steps a) and b) contemporaneously determine, starting from said residual air (Ar), a ionized and heated air (Ai) suitable for a passage to the plasma state;receiving said ionized and heated air (Ai) in said duct (201) for plasma flow of said plasma propulsion unit (200); determining a passage to the plasma state and subsequent step of energizing and accelerating the plasma, through excitation means comprising: a radiofrequency or lower hybrid microwave with one or more helical antennas winding the duct (201) for plasma flow; a laser source emitting a laser wave with double pulse which passes linearly by the centre of said duct (201) for plasma flow, after having passed at a frequency of 2.45 Ghz in the coaxial vircator (W) and produced an increase in thermal energy; discharging the plasma (PL) generated in said duct (201) comprising a supersonic divergent nozzle (17) with radiofrequency antenna (15), implementing an outlet of said plasma (PL) from said propulsion unit (200) representative of a produced thrust power (PW); in case the speed of the plasma flow exceeds the speed of sound, the divergent nozzle is replaced by a nozzle shaped like “petals”.

9. The plasma propulsion method according to claim 8, wherein the magnetic means (14, 16) comprises an accelerator with multi-phase solenoid provided inside with additional magnetic circular crowns of Array Halbach type wherein the direction of the magnetic field generated by said multi-phase solenoid in position parallel to the axis of the propulsion tube substantially determines the direction of longitudinal thrust of said plasma (PL) with a helical motion towards the discharging nozzle (17).

10. The plasma propulsion method according to claim 8, comprising a step of energizing and accelerating the plasma (PL) implemented through said excitation means comprising one or more quadruple helical antennas (15) with rectangular section by using a lower hybrid wave adapted to energize and accelerate the plasma (PL) wherein the applied radiofrequency is 500 Mhz, which determines a duct (201) of diameter of 50 cm for the plasma flow.

11. The plasma propulsion method according to any one of claims 8 to 10, wherein said laser source emits a first pulse and a second pulse, wherein the first pulse has an energy equal to 10% of the energy available to the laser, and the second pulse starts from a distance of a period from the first pulse and it has an energy equal to 90% of the energy available to the laser, wherein said second pulse has a double frequency of the first pulse.

12. The plasma propulsion method according to any one of claims 8 to 11 , comprising a step actuated by electronic computer configured to synchronize and / or correlate the resonance and repetition cyclotronic frequencies in the plasma generation process with magnetic densities produced by the solenoid and to ease a process for ionizing and accelerating the plasma at the same radiofrequency.

Images