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"Confinement. Nonneutral plasmas can be confined for long periods of
time using only static electric and magnetic fields. One such configuration is called a Penning Trap, after the inventor F. M. Penning. The trap consists of a several cylindrically symmetric electrodes and a uniform magnetic field applied along the axis of the trap (see diagram below). A Penning trap is limited in the number of ions it can store due to the self-repulsion of the ions. If one does the analysis, it turns out the energy stored in the magnetic field of the trap must be at least as large as the rest energy of the stored ions. So, if you are storing highly charged ordinary ions, the ionization energy of those ions is a small fraction of the energy of the trap's magnets, and adds little to the stored energy of the system. Electrostatic quadrupole (Paul) traps may be able to evade this limit; I'm not clear on that. Paul |
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![]() Robert Clark writes: On Oct 11, 9:10 pm, Robert Clark wrote: In researching the amount of energy required to ionize gas for ion drives I was surprised by the total amounts of energy that would be required to *fully* ionize the gas. This amount of energy is quite large, actually huge, and so for actual ion drives the gas is only minimally ionized. .... This report gives the total ionization energy for uranium as 762.9 keV: Changing the atomic species does not change the fact that it would take far more energy density to maintain the trap than could ever be stored in the ionization energy. CM |
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On Oct 14, 4:35 pm, "Paul F. Dietz" wrote:
"Confinement. Nonneutral plasmas can be confined for long periods of time using only static electric and magnetic fields. One such configuration is called a Penning Trap, after the inventor F. M. Penning. The trap consists of a several cylindrically symmetric electrodes and a uniform magnetic field applied along the axis of the trap (see diagram below). A Penning trap is limited in the number of ions it can store due to the self-repulsion of the ions. If one does the analysis, it turns out the energy stored in the magnetic field of the trap must be at least as large as the rest energy of the stored ions. So, if you are storing highly charged ordinary ions, the ionization energy of those ions is a small fraction of the energy of the trap's magnets, and adds little to the stored energy of the system. Electrostatic quadrupole (Paul) traps may be able to evade this limit; I'm not clear on that. Paul Hmm. That's a very interesting point. The Brillouin limit does place a limit on the number of ions stored based on the square of the magnetic field magnitude and the rest energy of the particles. However, a large portion of the research on these magnetically confined non neutral plasmas is due to fusion research. If there was such a limit on the energy content of the ions that would also mean the possible fusion energy would be limited by the same amount. Perhaps its because the magnetic field term in the Brillouin limit is B^2, which is only the energy *density* of the magnetic field? I'll ask about that. Bob Clark |
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On Oct 14, 4:35 pm, "Paul F. Dietz" wrote:
"Confinement. Nonneutral plasmas can be confined for long periods of time using only static electric and magnetic fields. One such configuration is called a Penning Trap, after the inventor F. M. Penning. The trap consists of a several cylindrically symmetric electrodes and a uniform magnetic field applied along the axis of the trap (see diagram below). A Penning trap is limited in the number of ions it can store due to the self-repulsion of the ions. If one does the analysis, it turns out the energy stored in the magnetic field of the trap must be at least as large as the rest energy of the stored ions. So, if you are storing highly charged ordinary ions, the ionization energy of those ions is a small fraction of the energy of the trap's magnets, and adds little to the stored energy of the system. Electrostatic quadrupole (Paul) traps may be able to evade this limit; I'm not clear on that. Paul Yes, by the Brillouin limit the total rest energy of the particles must be less than the magnetic field energy, *under the specialized conditions for which the Brillouin limit holds*. Such traps operating under this limit are still useful for fusion research since you can inject more particles to continually get more fusion energy out while the magnetic field remains the same. I am informed that there is also a limit to the number of particles you can contain using electrostatic fields such as by the Paul trap, but I don't know yet if this also results in the rest energy of the particles being less than the energy of the containing electric fields. However, this report shows that the Brillouin limit on magnetic field containment can be exceeded for non-uniform magnetic fields: Confinement Of Pure Ion Plasma In A Cylindrical Current Sheet. Stephen F. Paul, Edward H. Chao, Ronald C. Davidson, Cynthia K. Phillips. Plasma Physics Laboratory Princeton University, Princeton, New Jersey 08543 "Abstract. A novel method for containing a pure ion plasma at thermonuclear densities and temperatures has been modeled. The method combines the confinement properties of a Penning-Malmberg trap and some aspects of the magnetic filed geometry of a pulsed theta-pinch. A conventional Penning trap can confine a uniform-density plasma of about 5x10^11/cm³.with a 30-Tesla magnetic field. However, if the axial field is ramped, a much higher local ion density can be obtained. Starting with a 10^7/ cm³. trapped deuterium plasma in a conventional Penning-Malmberg trap at the Brillouin limit (B = 0.6 Tesla), the field is ramped to 30 Tesla. Because the plasma is comprised of particles of only one sign of charge, transport losses are very low, i.e., the conductivity is high. As a result, the ramped field does not penetrate the plasma and a diamagnetic surface current is generated, with the ions being accelerated to relativistic velocities. To counteract the inward j x B forces from this induced current, additional ions are injected into the plasma along the axis to increase the density (and mutual electrostatic repulsion) of the target plasma. In the absence of the higher magnetic field in the center, the injected ions drift outward until a balance is established between the outward driving forces (centrifugal, electrostatic, pressure gradient) and the inward j x B force. An equilibrium calculation using a relativistic, 1-D, cold-fluid model shows that a plasma can be trapped in a hollow, 49-cm diameter, 0.2-cm thick cylinder with a density exceeding 4x10^14 / cm³.." http://www.pppl.gov/pub_report//2000/PPPL-3403.pdf This results in a particle density 1,000 times the Brillouin limit. It is possible that an optimized choice of the magnetic field geometry would result in it also requiring less energy to constrain the ions than what you can get out as energy in the electron recombination reactions. But such non-symmetric magnetic field containment methods already require far less containment energy than what you can get out by the matter-energy conversion of the stored particles. Then why not use such ion containment methods to store the full amount of energy in matter to energy conversion! The page with the list of energy density storage methods shows at the top of the list that this is a tremendous amount of energy: Energy density in energy storage and in fuel. http://en.wikipedia.org/wiki/Energy_..._an d_in_fuel There is already ongoing research with the research teams storing non neutral plasmas on storing antimatter versions as well, such as antiprotons and positrons. Then you could allow these stored antimatter particles to contact normal matter to get the full energy released as contained in their rest energy. This is probably closer to fruition with the positron traps since it so much easier to produce and trap positrons in large numbers than antiprotons. A problem though is that the energy released by combining electrons and positrons releases the energy as .5 MeV gamma rays. Such gamma rays are highly penetrating. So methods would have to be used to capture, absorb these gamma rays so they can be converted to useful forms of energy, electrical, heat, etc. Some possibilities might come from methods used by gamma ray detecting satellites to detect gamma rays from astronomical sources: Gamma-ray Detectors. http://www.airynothing.com/high_ener...tection05.html A recently proposed method for gamma ray detection might also be useful in this regard: Gamma Ray Fresnel lenses - why not? http://arxiv.org/abs/astro-ph/0602074 The methods described in the "Confinement Of Pure Ion Plasma In A Cylindrical Current Sheet" would result in milligrams per cubic meter of storage based on containment fields of 30 Tesla, about the highest for stable fields in use now. However, it is quite likely that stable fields of higher strength can be produced with advanced materials available now. As described in this report the limits on the strength of stable magnetic fields are due to the magnetic forces on the conducting elements that tend to tear them apart: Magnetic Radiation Shielding: An Idea Whose Time Has Returned? Geoffrey A. Landis "The limit to the mass required to produce a magnetic field is set by the tensile strength of materials required to withstand the magnetic self-force on the conductors [8]. For the min-imum structure, all the structural elements are in tension, and from the virial theorem, the mass required to withstand magnetic force can be estimated as [9]: M = (rho/S) (B^2 V)/(2 mu) (1) where rho is the density of the structural material, S is the tensile strength, B the magnetic field, V the characteristic volume of the field, and mu the permeability of vacuum." http://www.islandone.org/Settlements/MagShield.html You see the strength/density ratio of the material goes by the square of the magnetic field strength. The conducting wire commonly used for producing the electromagnets is made of copper because of its high conductivity and current carrying capacity. This page gives the tensile strength of copper as 220 MPa at a density of 8.92 g/cm³. The highest measured strength of carbon nanotubes has been 160 GPa at a density of 1.3 g/cm³. This is an increase of the strength to density ratio over copper of about 5,000. Then conceivably with this stronger material we could get higher magnetic fields strengths by a factor of the square root of this, 70; so to a magnetic field strength of 70 x 30 T = 2100 T. But the density of the confined ions is actually by the square of the magnetic field, so it would be increased by the full factor of 5,000. Then we could get kilogram storage of the ions within a volume less than 10 meters on a side. The nanotubes are only available so far at centimeter lengths. Still it would be interesting to find out on tests with small fields if their use would allow magnetic field strengths in the thousand tesla range. Also, it may be possible to get large amounts of contained ions by using very many of the short nanotubes to produce very many separate, small containment fields. For the nanotubes to be used for this purpose they would have to carry large amounts of current to generate the electromagnets. It has been shown experimentally that they can carry thousands of times the current of copper: Reliability and current carrying capacity of carbon nanotubes. APPLIED PHYSICS LETTERS, VOLUME 79, NUMBER 8, 20 AUGUST 2001. "From the experimental results described in this letter we can conclude that multiwalled carbon nanotubes can carry high current densities up to 10^9-10^10 A/cm2 and remain stable for extended periods of time at higher temperature in air. Furthermore, they conduct current without any measurable change in their resistance or morphology, indicating that the sp2 bonds that are dominant in carbon nanotubes provide much higher stability against electromigration than small metallic structures." http://www.rpi.edu/~ajayan/locker/pdfs/reliability.pdf We can estimate the strength of the magnetic field we can obtain from a given current flow and wire size from the formula B = 2(10^-7)I/r, for B the magnetic field in Tesla, I the current in amps, and r the distance from the center of the wire in meters, as described he Magnetic Field of Current. http://hyperphysics.phy-astr.gsu.edu...magcur.html#c2 For a 100 micron thick wire composed of carbon nanotube material, using a 10^10 A/cm2 current capacity, we could get 10^6 A of current through. Then 100 microns away from the center the magnetic field would be 2,000 T. Experiments at very high magnetic fields are very important for theoretical studies. It is likely the nanotubes could withstand the high stresses induced by the magnetic fields at even higher strengths than 2100 T for short times, especially for nanotubes chosen to be low in defects to have the highest strength. Then carbon nanotubes may be the ideal material to use for producing ultra high magnetic fields for theoretical work. Bob Clark |
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![]() Robert Clark writes: On Oct 14, 4:35 pm, "Paul F. Dietz" wrote: "Confinement. Nonneutral plasmas can be confined for long periods of time using only static electric and magnetic fields. One such configuration is called a Penning Trap, after the inventor F. M. Penning. The trap consists of a several cylindrically symmetric electrodes and a uniform magnetic field applied along the axis of the trap (see diagram below). A Penning trap is limited in the number of ions it can store due to the self-repulsion of the ions. If one does the analysis, it turns out the energy stored in the magnetic field of the trap must be at least as large as the rest energy of the stored ions. So, if you are storing highly charged ordinary ions, the ionization energy of those ions is a small fraction of the energy of the trap's magnets, and adds little to the stored energy of the system. Electrostatic quadrupole (Paul) traps may be able to evade this limit; I'm not clear on that. Paul Yes, by the Brillouin limit the total rest energy of the particles must be less than the magnetic field energy, *under the specialized conditions for which the Brillouin limit holds*. Such traps operating under this limit are still useful for fusion research since you can inject more particles to continually get more fusion energy out while the magnetic field remains the same. .... The magnetic field only confines the ions in one direction. You should probably estimate the magnitude of the *electric* field required. How does the energy in that field compare to the ionization energy? CM |
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On Oct 14, 2:11 pm, Robert Clark wrote:
On Oct 11, 9:10 pm, Robert Clark wrote: In researching the amount of energy required to ionize gas for ion drives I was surprised by the total amounts of energy that would be required to *fully* ionize the gas. This amount of energy is quite large, actually huge, and so for actual ion drives the gas is only minimally ionized. Some examples of the amount of ionization energy can be found he Ionization energies of the elements.http://en.wikipedia.org/wiki/Ionizat...f_the_elements You see for hydrogen it's 1312 kilojoules per mole. Since the atomic weight of hydrogen is 1, this is 1,312,000 joules per gram or 1.3 billion joules per kilo. Note that this amount of energy that needs to be added to ionize the gas will conversely be released when the electrons are recombined with the ionized gas. Then this is several times higher than the maximum energy density of chemical reactions on a per weight basis such as by chemically oxidizing neutral hydrogen: Energy density in energy storage and in fuel.http://en.wikipedia.org/wiki/Energy_...ity_in_energy_... Other elements can produce even higher amounts. By and large, the energy density gets higher for the heavier elements. For instance you can find the total for copper by adding up the amounts given on the "Ionization energies of the elements" page. You get 4,345,619.4 in kJ/ mol. Then since the atomic weight of copper is 64, this amounts to 68 billion joules per kilo. On the "Energy density in energy storage and in fuel" page, there is a huge gap in energy density between the chemical reactions to the nuclear reactions. Then these "electron recombination" reactions, if you will, would provide an intermediate level in energy storage density. However, for getting these amounts note that the element has to be in gas form since the energy required to release the electrons from orbit is different for solids, called the "work function", usually smaller. So the released amount of energy on recombination would also be smaller. Then for some elements such as metals you would also have to supply high heat to get the element in gas form. Then this energy storage method would probably be better in heavy gases, such as xenon. The ionization energy of xenon is incomplete on the "Ionization energies of the elements" page. A more complete list can be found on the page: NIST Atomic Spectra Database Levels Form.http://physics.nist.gov/PhysRefData/...vels_form.html by typing in for example Xe 53 to get the last (54th) electron ionization energy. However, not every ionization level for xenon is given on this page either. After a web search, I found the total amount of energy required to fully ionize xenon is about 200 keV. Since 1 eV is about 100 kJ/mol , this is about, 2 x 10^10 J/mol. Since the atomic weight of xenon is 130 this comes to 154 million joules per gram, 154 billion joules per kilo. ... This report gives the total ionization energy for uranium as 762.9 keV: Electron Emission Following the Interaction of Slow Highly Charged Ions with Solids.http://www.osti.gov/bridge/servlets/...webviewable/30... Since 1 eV is about 100 kJ/mol and the atomic weight of uranium is 238, this amounts to 320 billion joules per kilogram. Other elements with high total ionization energies are given in Fig. 1 in this report. To put this in perspective, the energy density of hydrogen burned with oxygen is 140 million joules per kilo of hydrogen. So the electron recombination reaction of uranium results in more than 2000 times the energy per kilogram. The space shuttle external tank contains about 100,000 kg of hydrogen and 600,000 kg of oxygen. Then the energy content here would be equivalent to only 50 kg of fully ionized uranium. (Note this is *not* a nuclear reaction.) And the oxygen also would not be required. Note this is only in regards to the energy content. It does not consider how the thrust would be generated. Bob Clark The problem with the storage of these ions at high density is that you have to overcome the large electrostatic repulsion between them when they are close together. Then what might work would be methods of screening out the electric field between the ions. I asked about methods of accomplishing this he Newsgroups: sci.physics, sci.physics.relativity From: Date: 7 Jul 2005 10:42:54 -0700 Local: Thurs, Jul 7 2005 1:42 pm Subject: Expelling an electric field. http://groups.google.com/group/sci.p...b2217b72369034 One suggested solution was the Faraday Cage: Faraday cage. http://en.wikipedia.org/wiki/Faraday_cage I had thought that the Faraday cage wouldn't prevent the electric field from escaping but as described in the wikipedia page if the cage is grounded then effectively the charge and the field inside would be contained. Would the ground though eventually drain off the charge inside? If this works we could have a highly conducting metal, ideally a "perfect" conductor, surrounding a group of charges thus reducing the electrostatic repulsion that had to be restrained. We would have to have a ground wire connected to each cage around the group of charges. Since we want high density each metal cage would have to be nanoscopically thin. Is there a limit to how well the cage can work dependent on its thickness? We would also have to have a method of accessing the ions to be able to extract the electron recombination energy in the case of ion storage or the matter-antimatter conversion energy in the case of positron storage. Bob Clark |
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On Oct 27, 5:36 pm, Robert Clark wrote:
... The problem with the storage of these ions at high density is that you have to overcome the large electrostatic repulsion between them when they are close together. Then what might work would be methods of screening out the electric field between the ions. I asked about methods of accomplishing this he Newsgroups: sci.physics, sci.physics.relativity From: Date: 7 Jul 2005 10:42:54 -0700 Local: Thurs, Jul 7 2005 1:42 pm Subject: Expelling an electric field.http://groups.google.com/group/sci.p...d/thread/aff52... One suggested solution was the Faraday Cage: Faraday cage.http://en.wikipedia.org/wiki/Faraday_cage I had thought that the Faraday cage wouldn't prevent the electric field from escaping but as described in the wikipedia page if the cage is grounded then effectively the charge and the field inside would be contained. Would the ground though eventually drain off the charge inside? If this works we could have a highly conducting metal, ideally a "perfect" conductor, surrounding a group of charges thus reducing the electrostatic repulsion that had to be restrained. We would have to have a ground wire connected to each cage around the group of charges. Since we want high density each metal cage would have to be nanoscopically thin. Is there a limit to how well the cage can work dependent on its thickness? We would also have to have a method of accessing the ions to be able to extract the electron recombination energy in the case of ion storage or the matter-antimatter conversion energy in the case of positron storage. Another possibility would be use the relativistic effect of magnetic and electric fields being interchanged at high relativistic velocities. Here is one online report that explains this effect of special relativity: The simplest, and the full derivation of Magnetism as a Relativistic side effect of ElectroStatics. http://www.chip-architect.com/physic...ics_and_SR.pdf Then we could cause the contained ions, electrons, or positrons to rotate within a magnetic field at relativistic velocities. The idea is that the relativistic charged particles would regard the constraining magnetic field as an intense electric field and thus we would be able to obtain denser storage. In regards to this possibility I saw this report that suggests relativistic speeds can cause the Coulomb self-repulsion to approach zero, with a proviso: Catalyzing Fusion with Relativistic Electrons. Authors: Hanno Essen http://arxiv.org/abs/physics/0607138 The proviso is that the charged particles have to be at high speeds relative to each other. We would have to find a way of achieving this while the particles remained in a constrained volume. Another possibility is that the containing magnetic field might regard the charged particles as having a smaller self-repulsion if they are moving at high speed with respect to the magnetic field. Then a smaller magnetic field might suffice to contain them. Because of the high energy required to accelerate particles to relativistic speeds, these methods might be best tried on electrons and positrons rather than on ions. Bob Clark |
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![]() "Robert Clark" wrote in message ups.com... : On Oct 27, 5:36 pm, Robert Clark wrote: : ... : The problem with the storage of these ions at high density is that : you have to overcome the large electrostatic repulsion between them : when they are close together. : Then what might work would be methods of screening out the electric : field between the ions. I asked about methods of accomplishing this : he : : Newsgroups: sci.physics, sci.physics.relativity : From: : Date: 7 Jul 2005 10:42:54 -0700 : Local: Thurs, Jul 7 2005 1:42 pm : Subject: Expelling an electric field.http://groups.google.com/group/sci.p...d/thread/aff52... : : One suggested solution was the Faraday Cage: : : Faraday cage.http://en.wikipedia.org/wiki/Faraday_cage : : I had thought that the Faraday cage wouldn't prevent the electric : field from escaping but as described in the wikipedia page if the cage : is grounded then effectively the charge and the field inside would be : contained. Would the ground though eventually drain off the charge : inside? : If this works we could have a highly conducting metal, ideally a : "perfect" conductor, surrounding a group of charges thus reducing the : electrostatic repulsion that had to be restrained. We would have to : have a ground wire connected to each cage around the group of : charges. : Since we want high density each metal cage would have to be : nanoscopically thin. Is there a limit to how well the cage can work : dependent on its thickness? We would also have to have a method of : accessing the ions to be able to extract the electron recombination : energy in the case of ion storage or the matter-antimatter conversion : energy in the case of positron storage. : : : Another possibility would be use the relativistic effect of magnetic : and electric fields being interchanged at high relativistic : velocities. : Here is one online report that explains this effect of special : relativity: : : The simplest, and the full derivation of Magnetism as a Relativistic : side effect of ElectroStatics. : http://www.chip-architect.com/physic...ics_and_SR.pdf : : Then we could cause the contained ions, electrons, or positrons to : rotate within a magnetic field at relativistic velocities. The idea is : that the relativistic charged particles would regard the constraining : magnetic field as an intense electric field and thus we would be able : to obtain denser storage. : In regards to this possibility I saw this report that suggests : relativistic speeds can cause the Coulomb self-repulsion to approach : zero, with a proviso: : : Catalyzing Fusion with Relativistic Electrons. : Authors: Hanno Essen : http://arxiv.org/abs/physics/0607138 : : The proviso is that the charged particles have to be at high speeds : relative to each other. We would have to find a way of achieving this : while the particles remained in a constrained volume. : Another possibility is that the containing magnetic field might : regard the charged particles as having a smaller self-repulsion if : they are moving at high speed with respect to the magnetic field. Then : a smaller magnetic field might suffice to contain them. : Because of the high energy required to accelerate particles to : relativistic speeds, these methods might be best tried on electrons : and positrons rather than on ions. : : : Bob Clark : Sorry to burst your bubble but you are dreaming. 1) To ionize, you need a lot of voltage as you've already noted. http://www.ilankelman.org/disasterdeaths/lightning.jpg 2) Vacuum is far from being an insulator where high voltages are concerned. http://www.astronomycafe.net/qadir/ask/TVtube.gif 3) Relativity is built upon "proof because I say so". Wackypedia has these proofs: 1 Direct proof 2 Proof by induction 3 Proof by transposition 4 Proof by contradiction 5 Proof by construction 6 Proof by exhaustion 7 Probabilistic proof 8 Combinatorial proof 9 Nonconstructive proof 10 Elementary proof Missing are these, even in wackypedia: 11 Proof by "everybody knows". 12 Proof by "because I say so". 'we establish by definition that the "time" required by light to travel from A to B equals the "time" it requires to travel from B to A' because I SAY SO and you have to agree because I'm the great genius, STOOOPID, don't you dare question it. -- Rabbi Albert Einstein http://www.androcles01.pwp.blueyonde...rt/tAB=tBA.gif |
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On Oct 27, 5:36 pm, Robert Clark wrote:
On Oct 14, 2:11 pm, Robert Clark wrote: On Oct 11, 9:10 pm, Robert Clark wrote: In researching the amount ofenergyrequired to ionize gas for ion drives I was surprised by the total amounts ofenergythat would be required to *fully* ionize the gas. This amount ofenergyis quite large, actually huge, and so for actual ion drives the gas is only minimally ionized. Some examples of the amount of ionizationenergycan be found he Ionization energies of the elements.http://en.wikipedia.org/wiki/Ionizat...f_the_elements You see for hydrogen it's 1312 kilojoules per mole. Since the atomic weight of hydrogen is 1, this is 1,312,000 joules per gram or 1.3 billion joules per kilo. Note that this amount of energythat needs to be added to ionize the gas will conversely be released when the electrons are recombined with the ionized gas. Then this is several times higher than the maximumenergydensity of chemical reactions on a per weight basis such as by chemically oxidizing neutral hydrogen: Energydensity inenergystorage and in fuel.http://en.wikipedia.org/wiki/Energy_...ity_in_energy_... Other elements can produce even higher amounts. By and large, the energydensity gets higher for the heavier elements. For instance you can find the total for copper by adding up the amounts given on the "Ionization energies of the elements" page. You get 4,345,619.4 in kJ/ mol. Then since the atomic weight of copper is 64, this amounts to 68 billion joules per kilo. On the "Energydensity inenergystorage and in fuel" page, there is a huge gap inenergydensity between the chemical reactions to the nuclear reactions. Then these "electron recombination" reactions, if you will, would provide an intermediate level inenergystorage density. However, for getting these amounts note that the element has to be in gas form since theenergyrequired to release the electrons from orbit is different for solids, called the "work function", usually smaller. So the released amount ofenergyon recombination would also be smaller. Then for some elements such as metals you would also have to supply high heat to get the element in gas form. Then thisenergy storage method would probably be better in heavy gases, such as xenon. The ionizationenergyof xenon is incomplete on the "Ionization energies of the elements" page. A more complete list can be found on the page: NIST Atomic Spectra Database Levels Form.http://physics.nist.gov/PhysRefData/...vels_form.html by typing in for example Xe 53 to get the last (54th) electron ionizationenergy. However, not every ionization level for xenon is given on this page either. After a web search, I found the total amount ofenergyrequired to fully ionize xenon is about 200 keV. Since 1 eV is about 100 kJ/mol , this is about, 2 x 10^10 J/mol. Since the atomic weight of xenon is 130 this comes to 154 million joules per gram, 154 billion joules per kilo. ... This report gives the total ionizationenergyfor uranium as 762.9 keV: Electron Emission Following the Interaction of Slow Highly Charged Ions with Solids.http://www.osti.gov/bridge/servlets/...webviewable/30... Since 1 eV is about 100 kJ/mol and the atomic weight of uranium is 238, this amounts to 320 billion joules per kilogram. Other elements with high total ionization energies are given in Fig. 1 in this report. To put this in perspective, theenergydensity of hydrogen burned with oxygen is 140 million joules per kilo of hydrogen. So the electron recombination reaction of uranium results in more than 2000 times theenergyper kilogram. The space shuttle external tank contains about 100,000 kg of hydrogen and 600,000 kg of oxygen. Then theenergycontent here would be equivalent to only 50 kg of fully ionized uranium. (Note this is *not* a nuclear reaction.) And the oxygen also would not be required. Note this is only in regards to theenergycontent. It does not consider how the thrust would be generated. Bob Clark The problem with the storage of these ions at high density is that you have to overcome the large electrostatic repulsion between them when they are close together. Then what might work would be methods of screening out the electric field between the ions. I asked about methods of accomplishing this he Newsgroups: sci.physics, sci.physics.relativity From: Date: 7 Jul 2005 10:42:54 -0700 Local: Thurs, Jul 7 2005 1:42 pm Subject: Expelling an electric field.http://groups.google.com/group/sci.p...d/thread/aff52... One suggested solution was the Faraday Cage: Faraday cage.http://en.wikipedia.org/wiki/Faraday_cage I had thought that the Faraday cage wouldn't prevent the electric field from escaping but as described in the wikipedia page if the cage is grounded then effectively the charge and the field inside would be contained. Would the ground though eventually drain off the charge inside? If this works we could have a highly conducting metal, ideally a "perfect" conductor, surrounding a group of charges thus reducing the electrostatic repulsion that had to be restrained. We would have to have a ground wire connected to each cage around the group of charges. Since we want high density each metal cage would have to be nanoscopically thin. Is there a limit to how well the cage can work dependent on its thickness? We would also have to have a method of accessing the ions to be able to extract the electron recombination energy in the case of ion storage or the matter-antimatter conversion energy in the case of positron storage. Bob Clark Hmm. An interesting question: would you have to have the electric fields prevented from exiting the Faraday cages? Would simply having the electric fields from the charges being prevented from entering the cages of the other charges be sufficient? In that case you wouldn't need to have the cages be grounded. Another question: could you have the cages contacting each other to save even more space? In this case it would be like having a 3- dimensional metal lattice of hollow little cubes with a charge or group of charges inside each cube. Bob Clark |
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On Oct 27, 6:23 pm, Robert Clark wrote:
On Oct 27, 5:36 pm, Robert Clark wrote: ... The problem with the storage of these ions at high density is that you have to overcome the large electrostatic repulsion between them when they are close together. Then what might work would be methods of screening out the electric field between the ions. I asked about methods of accomplishing this he Newsgroups: sci.physics, sci.physics.relativity From: Date: 7 Jul 2005 10:42:54 -0700 Local: Thurs, Jul 7 2005 1:42 pm Subject: Expelling an electric field.http://groups.google.com/group/sci.p...d/thread/aff52... One suggested solution was the Faraday Cage: Faraday cage.http://en.wikipedia.org/wiki/Faraday_cage I had thought that the Faraday cage wouldn't prevent the electric field from escaping but as described in the wikipedia page if the cage is grounded then effectively the charge and the field inside would be contained. Would the ground though eventually drain off the charge inside? If this works we could have a highly conducting metal, ideally a "perfect" conductor, surrounding a group of charges thus reducing the electrostatic repulsion that had to be restrained. We would have to have a ground wire connected to each cage around the group of charges. Since we want high density each metal cage would have to be nanoscopically thin. Is there a limit to how well the cage can work dependent on its thickness? We would also have to have a method of accessing the ions to be able to extract the electron recombination energyin the case of ion storage or the matter-antimatter conversion energyin the case of positron storage. Another possibility would be use the relativistic effect of magnetic and electric fields being interchanged at high relativistic velocities. Here is one online report that explains this effect of special relativity: The simplest, and the full derivation of Magnetism as a Relativistic side effect of ElectroStatics.http://www.chip-architect.com/physic...ectroStatics_a... Then we could cause the contained ions, electrons, or positrons to rotate within a magnetic field at relativistic velocities. The idea is that the relativistic charged particles would regard the constraining magnetic field as an intense electric field and thus we would be able to obtain denser storage. In regards to this possibility I saw this report that suggests relativistic speeds can cause the Coulomb self-repulsion to approach zero, with a proviso: Catalyzing Fusion with Relativistic Electrons. Authors: Hanno Essenhttp://arxiv.org/abs/physics/0607138 The proviso is that the charged particles have to be at high speeds relative to each other. We would have to find a way of achieving this while the particles remained in a constrained volume. Another possibility is that the containing magnetic field might regard the charged particles as having a smaller self-repulsion if they are moving at high speed with respect to the magnetic field. Then a smaller magnetic field might suffice to contain them. Because of the highenergyrequired to accelerate particles to relativistic speeds, these methods might be best tried on electrons and positrons rather than on ions. Bob Clark There are some more variations on this possibility. In particle physics there is a phenomenon at high relativistic speeds called Moeller scattering where an electron coming very close to a high Z nucleus will actually feel the Coulomb force being reversed to being repulsive. Does this work for same charge particles coming close to each at high relativistic speeds where the Coulomb force is reversed to being attractive? Also, in superconductivity there is the Meissner effect where a superconductor screens out a magnetic field as well as keeping one inside. Then when the charged particles are at high relativistic speeds with respect to the superconductor, the particles electric field will be felt by the superconductor to be a magnetic field and it will be prevented from leaving the superconductor. Then this will act as another method of screening the electric field between the charges if each charge of groups of charges is surrounded by its own superconductor. Bob Clark |
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