I was surprised that I had never heard of this powerful accelerator. Then I realize I am not the only one who have not.
Quote from: PotomacNeuron on 12/01/2016 05:53 pmI was surprised that I had never heard of this powerful accelerator. Then I realize I am not the only one who have not.Long links break the page spanning on NSF. Use this link instead: http://scitation.aip.org/content/aip/magazine/physicstoday/article/69/12/10.1063/PT.3.3397
Quote from: WarpTech on 12/01/2016 02:10 pmQuote from: TheTraveller on 12/01/2016 11:55 amQuote from: flux_capacitor on 12/01/2016 11:31 amQuote from: TheTraveller on 12/01/2016 09:41 amSee the attached for clarification. Note the force direction arrows in the bottom images that point to the end plate with the shortest 1/2 wave, that has the highest photon momentum & radiation pressure.TT, you're showing data for Eagleworks' frustum with dielectric at small end and TE012 mode, where max E & H fields are located near small end.Whereas zellerium, WarpTech and Star-Drive are discussing Eagleworks' frustum with dielectric at small end and TM212 mode, where max E & H fields are located near big end. Besides, in that particular mode only 10% of the RF energy resides in the PE discs.Your "shorter vs longer 1/2 wave" conjecture may still apply, but the two field configurations are very different, and their max strength values are located opposite from each other.We only have data for TE012 for both dielectric and non dielectric forces and direction.It is which end has the shortest 1/2 that is of interest as the shortest 1/2 wave has the highest momentum and radiation pressure.As Roger has shown, without dielectrics, as attached, the static force is generated small to big as Paul and I also measured and observed. Any theory needs to be able to explain the force direction and why it swaps direction with and without dielectric when excited in the same mode.I may be that where the highest energy density is located is not what is creating the measured static force with a direction big to small when a dielectric is at the small end.Please note the measured force direction, big to small is the same for ALL the EW tests and seems to be mode independent.The EW mode map I have seen has shown the TM212 dielectric frustum also has the shortest 1/2 wave at the small end, which is consistent with the measured force direction being big to small.Zellerium's mode map in TM212 also shows the shortest 1/2 wave at the small end, which us consistent with the EW TM212 mode map.TT,For the NASA TE012 mode data, my theory did predict the reversed direction of force when the dielectric was added. However, the TM212 mode simulation that @zellerium just posted shows a different configuration of energy, wavelength and losses. IMO, the only issue is that I went by what was shown on the graphs as "Volume Loss Density", when I believe we should be looking at "Surface Loss Density", to have an accurate representation. Then it would be obvious that in the TM212 mode the majority of losses are at the big end, when the dielectric is present "shielding" the small end from those surface losses.So one side has losses in the volume and the other has losses on the surface... But somehow the surface losses dissipate momentum differently than the volume losses? If we wanted to optimize a cavity for thrust, would we want a balance between highest surface losses on one side, highest volume losses on the other side, and quality?
Quote from: TheTraveller on 12/01/2016 11:55 amQuote from: flux_capacitor on 12/01/2016 11:31 amQuote from: TheTraveller on 12/01/2016 09:41 amSee the attached for clarification. Note the force direction arrows in the bottom images that point to the end plate with the shortest 1/2 wave, that has the highest photon momentum & radiation pressure.TT, you're showing data for Eagleworks' frustum with dielectric at small end and TE012 mode, where max E & H fields are located near small end.Whereas zellerium, WarpTech and Star-Drive are discussing Eagleworks' frustum with dielectric at small end and TM212 mode, where max E & H fields are located near big end. Besides, in that particular mode only 10% of the RF energy resides in the PE discs.Your "shorter vs longer 1/2 wave" conjecture may still apply, but the two field configurations are very different, and their max strength values are located opposite from each other.We only have data for TE012 for both dielectric and non dielectric forces and direction.It is which end has the shortest 1/2 that is of interest as the shortest 1/2 wave has the highest momentum and radiation pressure.As Roger has shown, without dielectrics, as attached, the static force is generated small to big as Paul and I also measured and observed. Any theory needs to be able to explain the force direction and why it swaps direction with and without dielectric when excited in the same mode.I may be that where the highest energy density is located is not what is creating the measured static force with a direction big to small when a dielectric is at the small end.Please note the measured force direction, big to small is the same for ALL the EW tests and seems to be mode independent.The EW mode map I have seen has shown the TM212 dielectric frustum also has the shortest 1/2 wave at the small end, which is consistent with the measured force direction being big to small.Zellerium's mode map in TM212 also shows the shortest 1/2 wave at the small end, which us consistent with the EW TM212 mode map.TT,For the NASA TE012 mode data, my theory did predict the reversed direction of force when the dielectric was added. However, the TM212 mode simulation that @zellerium just posted shows a different configuration of energy, wavelength and losses. IMO, the only issue is that I went by what was shown on the graphs as "Volume Loss Density", when I believe we should be looking at "Surface Loss Density", to have an accurate representation. Then it would be obvious that in the TM212 mode the majority of losses are at the big end, when the dielectric is present "shielding" the small end from those surface losses.
Quote from: flux_capacitor on 12/01/2016 11:31 amQuote from: TheTraveller on 12/01/2016 09:41 amSee the attached for clarification. Note the force direction arrows in the bottom images that point to the end plate with the shortest 1/2 wave, that has the highest photon momentum & radiation pressure.TT, you're showing data for Eagleworks' frustum with dielectric at small end and TE012 mode, where max E & H fields are located near small end.Whereas zellerium, WarpTech and Star-Drive are discussing Eagleworks' frustum with dielectric at small end and TM212 mode, where max E & H fields are located near big end. Besides, in that particular mode only 10% of the RF energy resides in the PE discs.Your "shorter vs longer 1/2 wave" conjecture may still apply, but the two field configurations are very different, and their max strength values are located opposite from each other.We only have data for TE012 for both dielectric and non dielectric forces and direction.It is which end has the shortest 1/2 that is of interest as the shortest 1/2 wave has the highest momentum and radiation pressure.As Roger has shown, without dielectrics, as attached, the static force is generated small to big as Paul and I also measured and observed. Any theory needs to be able to explain the force direction and why it swaps direction with and without dielectric when excited in the same mode.I may be that where the highest energy density is located is not what is creating the measured static force with a direction big to small when a dielectric is at the small end.Please note the measured force direction, big to small is the same for ALL the EW tests and seems to be mode independent.The EW mode map I have seen has shown the TM212 dielectric frustum also has the shortest 1/2 wave at the small end, which is consistent with the measured force direction being big to small.Zellerium's mode map in TM212 also shows the shortest 1/2 wave at the small end, which us consistent with the EW TM212 mode map.
Quote from: TheTraveller on 12/01/2016 09:41 amSee the attached for clarification. Note the force direction arrows in the bottom images that point to the end plate with the shortest 1/2 wave, that has the highest photon momentum & radiation pressure.TT, you're showing data for Eagleworks' frustum with dielectric at small end and TE012 mode, where max E & H fields are located near small end.Whereas zellerium, WarpTech and Star-Drive are discussing Eagleworks' frustum with dielectric at small end and TM212 mode, where max E & H fields are located near big end. Besides, in that particular mode only 10% of the RF energy resides in the PE discs.Your "shorter vs longer 1/2 wave" conjecture may still apply, but the two field configurations are very different, and their max strength values are located opposite from each other.
See the attached for clarification. Note the force direction arrows in the bottom images that point to the end plate with the shortest 1/2 wave, that has the highest photon momentum & radiation pressure.
Quote from: Monomorphic on 12/01/2016 05:59 pmQuote from: PotomacNeuron on 12/01/2016 05:53 pmI was surprised that I had never heard of this powerful accelerator. Then I realize I am not the only one who have not.Long links break the page spanning on NSF. Use this link instead: http://scitation.aip.org/content/aip/magazine/physicstoday/article/69/12/10.1063/PT.3.3397We went from Sci ti SciFi. Maybe get back to topic.
Static force: Causes a scale or torsion pendulum to record a force acting against or with the scale or torsion pendulum. Equation F = (2 Qu Pwr Df) / c.Dynamic force: Causes the free to accelerate acceleration of mass and is measured via F = A * M.Can't measure both forces at the same time.
Quote from: zellerium on 12/01/2016 02:49 pmQuote from: WarpTech on 12/01/2016 02:10 pmQuote from: TheTraveller on 12/01/2016 11:55 amQuote from: flux_capacitor on 12/01/2016 11:31 amQuote from: TheTraveller on 12/01/2016 09:41 amSee the attached for clarification. Note the force direction arrows in the bottom images that point to the end plate with the shortest 1/2 wave, that has the highest photon momentum & radiation pressure.TT, you're showing data for Eagleworks' frustum with dielectric at small end and TE012 mode, where max E & H fields are located near small end.Whereas zellerium, WarpTech and Star-Drive are discussing Eagleworks' frustum with dielectric at small end and TM212 mode, where max E & H fields are located near big end. Besides, in that particular mode only 10% of the RF energy resides in the PE discs.Your "shorter vs longer 1/2 wave" conjecture may still apply, but the two field configurations are very different, and their max strength values are located opposite from each other.We only have data for TE012 for both dielectric and non dielectric forces and direction.It is which end has the shortest 1/2 that is of interest as the shortest 1/2 wave has the highest momentum and radiation pressure.As Roger has shown, without dielectrics, as attached, the static force is generated small to big as Paul and I also measured and observed. Any theory needs to be able to explain the force direction and why it swaps direction with and without dielectric when excited in the same mode.I may be that where the highest energy density is located is not what is creating the measured static force with a direction big to small when a dielectric is at the small end.Please note the measured force direction, big to small is the same for ALL the EW tests and seems to be mode independent.The EW mode map I have seen has shown the TM212 dielectric frustum also has the shortest 1/2 wave at the small end, which is consistent with the measured force direction being big to small.Zellerium's mode map in TM212 also shows the shortest 1/2 wave at the small end, which us consistent with the EW TM212 mode map.TT,For the NASA TE012 mode data, my theory did predict the reversed direction of force when the dielectric was added. However, the TM212 mode simulation that @zellerium just posted shows a different configuration of energy, wavelength and losses. IMO, the only issue is that I went by what was shown on the graphs as "Volume Loss Density", when I believe we should be looking at "Surface Loss Density", to have an accurate representation. Then it would be obvious that in the TM212 mode the majority of losses are at the big end, when the dielectric is present "shielding" the small end from those surface losses.So one side has losses in the volume and the other has losses on the surface... But somehow the surface losses dissipate momentum differently than the volume losses? If we wanted to optimize a cavity for thrust, would we want a balance between highest surface losses on one side, highest volume losses on the other side, and quality?I think the volume losses could only model the solid dielectric, but could not model the losses of the skin effect in the copper, due to the planar nature of these losses. The surface losses look more accurate, but I think the total losses would be the combination of the two.If we wanted to optimize cavity for thrust, we would want the highest surface losses at one end and the highest energy stored without losses, at the other end. The magnetic flux stored in a cavity exerts pressure on the walls of the cavity. a voltage drop, resulting in losses in the walls of the cavity, is like poking a hole in it and letting the pressure out.
Quote from: WarpTech on 12/01/2016 07:25 pmI think the volume losses could only model the solid dielectric, but could not model the losses of the skin effect in the copper, due to the planar nature of these losses. The surface losses look more accurate, but I think the total losses would be the combination of the two.If we wanted to optimize cavity for thrust, we would want the highest surface losses at one end and the highest energy stored without losses, at the other end. The magnetic flux stored in a cavity exerts pressure on the walls of the cavity. a voltage drop, resulting in losses in the walls of the cavity, is like poking a hole in it and letting the pressure out.So,.... What? An inside shiny metal surface for one half of the cavity, and a "thin" dielectric coating for the other half? Would that work? A "thin" layered dielectric still reflecting the MW waves like interference based mirrors do... That wouldn't be thin That would be kind of like a reflection not based on induced E and B from free electron rich metal surface but on return capacitance of the surface... Am I making any sense?
I think the volume losses could only model the solid dielectric, but could not model the losses of the skin effect in the copper, due to the planar nature of these losses. The surface losses look more accurate, but I think the total losses would be the combination of the two.If we wanted to optimize cavity for thrust, we would want the highest surface losses at one end and the highest energy stored without losses, at the other end. The magnetic flux stored in a cavity exerts pressure on the walls of the cavity. a voltage drop, resulting in losses in the walls of the cavity, is like poking a hole in it and letting the pressure out.
Quote from: M.LeBel on 12/01/2016 08:55 pmQuote from: WarpTech on 12/01/2016 07:25 pmI think the volume losses could only model the solid dielectric, but could not model the losses of the skin effect in the copper, due to the planar nature of these losses. The surface losses look more accurate, but I think the total losses would be the combination of the two.If we wanted to optimize cavity for thrust, we would want the highest surface losses at one end and the highest energy stored without losses, at the other end. The magnetic flux stored in a cavity exerts pressure on the walls of the cavity. a voltage drop, resulting in losses in the walls of the cavity, is like poking a hole in it and letting the pressure out.So,.... What? An inside shiny metal surface for one half of the cavity, and a "thin" dielectric coating for the other half? Would that work? A "thin" layered dielectric still reflecting the MW waves like interference based mirrors do... That wouldn't be thin That would be kind of like a reflection not based on induced E and B from free electron rich metal surface but on return capacitance of the surface... Am I making any sense? Not really. Where is the voltage drop, in the dielectric? Personally, I think it will do better without a dielectric. It might do better with nickel at one end, copper at the other end, but it will perform best with the largest amount of stored energy, exerting the maximum amount of pressure on the cavity.
Quote from: WarpTech on 12/01/2016 09:16 pmQuote from: M.LeBel on 12/01/2016 08:55 pmQuote from: WarpTech on 12/01/2016 07:25 pmI think the volume losses could only model the solid dielectric, but could not model the losses of the skin effect in the copper, due to the planar nature of these losses. The surface losses look more accurate, but I think the total losses would be the combination of the two.If we wanted to optimize cavity for thrust, we would want the highest surface losses at one end and the highest energy stored without losses, at the other end. The magnetic flux stored in a cavity exerts pressure on the walls of the cavity. a voltage drop, resulting in losses in the walls of the cavity, is like poking a hole in it and letting the pressure out.So,.... What? An inside shiny metal surface for one half of the cavity, and a "thin" dielectric coating for the other half? Would that work? A "thin" layered dielectric still reflecting the MW waves like interference based mirrors do... That wouldn't be thin That would be kind of like a reflection not based on induced E and B from free electron rich metal surface but on return capacitance of the surface... Am I making any sense? Not really. Where is the voltage drop, in the dielectric? Personally, I think it will do better without a dielectric. It might do better with nickel at one end, copper at the other end, but it will perform best with the largest amount of stored energy, exerting the maximum amount of pressure on the cavity.? A voltage drop is how you lose energy; voltage drop - eddy current - etc. This is what you want at one end (metallic) of the cavity. We do have a voltage drop across the dielectric coatingt; metal surface behind on one side and MW on the other side, causing minimal charge movement ... essentially a variable polarization of the dielectric,i.e. much much less loss of energy.... Better than nickel ?
Quote from: zellerium on 12/01/2016 02:49 pmQuote from: WarpTech on 12/01/2016 02:10 pmQuote from: TheTraveller on 12/01/2016 11:55 amQuote from: flux_capacitor on 12/01/2016 11:31 amQuote from: TheTraveller on 12/01/2016 09:41 amSee the attached for clarification. Note the force direction arrows in the bottom images that point to the end plate with the shortest 1/2 wave, that has the highest photon momentum & radiation pressure.TT, you're showing data for Eagleworks' frustum with dielectric at small end and TE012 mode, where max E & H fields are located near small end.From your description, I envision a superconducting plate at the big end, with the interior of the silver plated copper frustum containing a polyethylene or polytetrafluorethylene hollow cone "wall liner", with wall thickness tapering from zero at the big end to maximum (an internal point) at the small end.Whereas zellerium, WarpTech and Star-Drive are discussing Eagleworks' frustum with dielectric at small end and TM212 mode, where max E & H fields are located near big end. Besides, in that particular mode only 10% of the RF energy resides in the PE discs.Your "shorter vs longer 1/2 wave" conjecture may still apply, but the two field configurations are very different, and their max strength values are located opposite from each other.We only have data for TE012 for both dielectric and non dielectric forces and direction.It is which end has the shortest 1/2 that is of interest as the shortest 1/2 wave has the highest momentum and radiation pressure.As Roger has shown, without dielectrics, as attached, the static force is generated small to big as Paul and I also measured and observed. Any theory needs to be able to explain the force direction and why it swaps direction with and without dielectric when excited in the same mode.I may be that where the highest energy density is located is not what is creating the measured static force with a direction big to small when a dielectric is at the small end.Please note the measured force direction, big to small is the same for ALL the EW tests and seems to be mode independent.The EW mode map I have seen has shown the TM212 dielectric frustum also has the shortest 1/2 wave at the small end, which is consistent with the measured force direction being big to small.Zellerium's mode map in TM212 also shows the shortest 1/2 wave at the small end, which us consistent with the EW TM212 mode map.TT,For the NASA TE012 mode data, my theory did predict the reversed direction of force when the dielectric was added. However, the TM212 mode simulation that @zellerium just posted shows a different configuration of energy, wavelength and losses. IMO, the only issue is that I went by what was shown on the graphs as "Volume Loss Density", when I believe we should be looking at "Surface Loss Density", to have an accurate representation. Then it would be obvious that in the TM212 mode the majority of losses are at the big end, when the dielectric is present "shielding" the small end from those surface losses.So one side has losses in the volume and the other has losses on the surface... But somehow the surface losses dissipate momentum differently than the volume losses? If we wanted to optimize a cavity for thrust, would we want a balance between highest surface losses on one side, highest volume losses on the other side, and quality?I think the volume losses could only model the solid dielectric, but could not model the losses of the skin effect in the copper, due to the planar nature of these losses. The surface losses look more accurate, but I think the total losses would be the combination of the two.If we wanted to optimize cavity for thrust, we would want the highest surface losses at one end and the highest energy stored without losses, at the other end. The magnetic flux stored in a cavity exerts pressure on the walls of the cavity. a voltage drop, resulting in losses in the walls of the cavity, is like poking a hole in it and letting the pressure out.
Quote from: WarpTech on 12/01/2016 02:10 pmQuote from: TheTraveller on 12/01/2016 11:55 amQuote from: flux_capacitor on 12/01/2016 11:31 amQuote from: TheTraveller on 12/01/2016 09:41 amSee the attached for clarification. Note the force direction arrows in the bottom images that point to the end plate with the shortest 1/2 wave, that has the highest photon momentum & radiation pressure.TT, you're showing data for Eagleworks' frustum with dielectric at small end and TE012 mode, where max E & H fields are located near small end.From your description, I envision a superconducting plate at the big end, with the interior of the silver plated copper frustum containing a polyethylene or polytetrafluorethylene hollow cone "wall liner", with wall thickness tapering from zero at the big end to maximum (an internal point) at the small end.Whereas zellerium, WarpTech and Star-Drive are discussing Eagleworks' frustum with dielectric at small end and TM212 mode, where max E & H fields are located near big end. Besides, in that particular mode only 10% of the RF energy resides in the PE discs.Your "shorter vs longer 1/2 wave" conjecture may still apply, but the two field configurations are very different, and their max strength values are located opposite from each other.We only have data for TE012 for both dielectric and non dielectric forces and direction.It is which end has the shortest 1/2 that is of interest as the shortest 1/2 wave has the highest momentum and radiation pressure.As Roger has shown, without dielectrics, as attached, the static force is generated small to big as Paul and I also measured and observed. Any theory needs to be able to explain the force direction and why it swaps direction with and without dielectric when excited in the same mode.I may be that where the highest energy density is located is not what is creating the measured static force with a direction big to small when a dielectric is at the small end.Please note the measured force direction, big to small is the same for ALL the EW tests and seems to be mode independent.The EW mode map I have seen has shown the TM212 dielectric frustum also has the shortest 1/2 wave at the small end, which is consistent with the measured force direction being big to small.Zellerium's mode map in TM212 also shows the shortest 1/2 wave at the small end, which us consistent with the EW TM212 mode map.TT,For the NASA TE012 mode data, my theory did predict the reversed direction of force when the dielectric was added. However, the TM212 mode simulation that @zellerium just posted shows a different configuration of energy, wavelength and losses. IMO, the only issue is that I went by what was shown on the graphs as "Volume Loss Density", when I believe we should be looking at "Surface Loss Density", to have an accurate representation. Then it would be obvious that in the TM212 mode the majority of losses are at the big end, when the dielectric is present "shielding" the small end from those surface losses.So one side has losses in the volume and the other has losses on the surface... But somehow the surface losses dissipate momentum differently than the volume losses? If we wanted to optimize a cavity for thrust, would we want a balance between highest surface losses on one side, highest volume losses on the other side, and quality?
Quote from: TheTraveller on 12/01/2016 11:55 amQuote from: flux_capacitor on 12/01/2016 11:31 amQuote from: TheTraveller on 12/01/2016 09:41 amSee the attached for clarification. Note the force direction arrows in the bottom images that point to the end plate with the shortest 1/2 wave, that has the highest photon momentum & radiation pressure.TT, you're showing data for Eagleworks' frustum with dielectric at small end and TE012 mode, where max E & H fields are located near small end.From your description, I envision a superconducting plate at the big end, with the interior of the silver plated copper frustum containing a polyethylene or polytetrafluorethylene hollow cone "wall liner", with wall thickness tapering from zero at the big end to maximum (an internal point) at the small end.Whereas zellerium, WarpTech and Star-Drive are discussing Eagleworks' frustum with dielectric at small end and TM212 mode, where max E & H fields are located near big end. Besides, in that particular mode only 10% of the RF energy resides in the PE discs.Your "shorter vs longer 1/2 wave" conjecture may still apply, but the two field configurations are very different, and their max strength values are located opposite from each other.We only have data for TE012 for both dielectric and non dielectric forces and direction.It is which end has the shortest 1/2 that is of interest as the shortest 1/2 wave has the highest momentum and radiation pressure.As Roger has shown, without dielectrics, as attached, the static force is generated small to big as Paul and I also measured and observed. Any theory needs to be able to explain the force direction and why it swaps direction with and without dielectric when excited in the same mode.I may be that where the highest energy density is located is not what is creating the measured static force with a direction big to small when a dielectric is at the small end.Please note the measured force direction, big to small is the same for ALL the EW tests and seems to be mode independent.The EW mode map I have seen has shown the TM212 dielectric frustum also has the shortest 1/2 wave at the small end, which is consistent with the measured force direction being big to small.Zellerium's mode map in TM212 also shows the shortest 1/2 wave at the small end, which us consistent with the EW TM212 mode map.TT,For the NASA TE012 mode data, my theory did predict the reversed direction of force when the dielectric was added. However, the TM212 mode simulation that @zellerium just posted shows a different configuration of energy, wavelength and losses. IMO, the only issue is that I went by what was shown on the graphs as "Volume Loss Density", when I believe we should be looking at "Surface Loss Density", to have an accurate representation. Then it would be obvious that in the TM212 mode the majority of losses are at the big end, when the dielectric is present "shielding" the small end from those surface losses.
Quote from: flux_capacitor on 12/01/2016 11:31 amQuote from: TheTraveller on 12/01/2016 09:41 amSee the attached for clarification. Note the force direction arrows in the bottom images that point to the end plate with the shortest 1/2 wave, that has the highest photon momentum & radiation pressure.TT, you're showing data for Eagleworks' frustum with dielectric at small end and TE012 mode, where max E & H fields are located near small end.From your description, I envision a superconducting plate at the big end, with the interior of the silver plated copper frustum containing a polyethylene or polytetrafluorethylene hollow cone "wall liner", with wall thickness tapering from zero at the big end to maximum (an internal point) at the small end.Whereas zellerium, WarpTech and Star-Drive are discussing Eagleworks' frustum with dielectric at small end and TM212 mode, where max E & H fields are located near big end. Besides, in that particular mode only 10% of the RF energy resides in the PE discs.Your "shorter vs longer 1/2 wave" conjecture may still apply, but the two field configurations are very different, and their max strength values are located opposite from each other.We only have data for TE012 for both dielectric and non dielectric forces and direction.It is which end has the shortest 1/2 that is of interest as the shortest 1/2 wave has the highest momentum and radiation pressure.As Roger has shown, without dielectrics, as attached, the static force is generated small to big as Paul and I also measured and observed. Any theory needs to be able to explain the force direction and why it swaps direction with and without dielectric when excited in the same mode.I may be that where the highest energy density is located is not what is creating the measured static force with a direction big to small when a dielectric is at the small end.Please note the measured force direction, big to small is the same for ALL the EW tests and seems to be mode independent.The EW mode map I have seen has shown the TM212 dielectric frustum also has the shortest 1/2 wave at the small end, which is consistent with the measured force direction being big to small.Zellerium's mode map in TM212 also shows the shortest 1/2 wave at the small end, which us consistent with the EW TM212 mode map.
Quote from: TheTraveller on 12/01/2016 09:41 amSee the attached for clarification. Note the force direction arrows in the bottom images that point to the end plate with the shortest 1/2 wave, that has the highest photon momentum & radiation pressure.TT, you're showing data for Eagleworks' frustum with dielectric at small end and TE012 mode, where max E & H fields are located near small end.From your description, I envision a superconducting plate at the big end, with the interior of the silver plated copper frustum containing a polyethylene or polytetrafluorethylene hollow cone "wall liner", with wall thickness tapering from zero at the big end to maximum (an internal point) at the small end.Whereas zellerium, WarpTech and Star-Drive are discussing Eagleworks' frustum with dielectric at small end and TM212 mode, where max E & H fields are located near big end. Besides, in that particular mode only 10% of the RF energy resides in the PE discs.Your "shorter vs longer 1/2 wave" conjecture may still apply, but the two field configurations are very different, and their max strength values are located opposite from each other.
Quote from: M.LeBel on 12/01/2016 09:37 pmQuote from: WarpTech on 12/01/2016 09:16 pmQuote from: M.LeBel on 12/01/2016 08:55 pmQuote from: WarpTech on 12/01/2016 07:25 pmI think the volume losses could only model the solid dielectric, but could not model the losses of the skin effect in the copper, due to the planar nature of these losses. The surface losses look more accurate, but I think the total losses would be the combination of the two.If we wanted to optimize cavity for thrust, we would want the highest surface losses at one end and the highest energy stored without losses, at the other end. The magnetic flux stored in a cavity exerts pressure on the walls of the cavity. a voltage drop, resulting in losses in the walls of the cavity, is like poking a hole in it and letting the pressure out.So,.... What? An inside shiny metal surface for one half of the cavity, and a "thin" dielectric coating for the other half? Would that work? A "thin" layered dielectric still reflecting the MW waves like interference based mirrors do... That wouldn't be thin That would be kind of like a reflection not based on induced E and B from free electron rich metal surface but on return capacitance of the surface... Am I making any sense? Not really. Where is the voltage drop, in the dielectric? Personally, I think it will do better without a dielectric. It might do better with nickel at one end, copper at the other end, but it will perform best with the largest amount of stored energy, exerting the maximum amount of pressure on the cavity.? A voltage drop is how you lose energy; voltage drop - eddy current - etc. This is what you want at one end (metallic) of the cavity. We do have a voltage drop across the dielectric coatingt; metal surface behind on one side and MW on the other side, causing minimal charge movement ... essentially a variable polarization of the dielectric,i.e. much much less loss of energy.... Better than nickel ?A voltage drop in the metal allows magnetic flux (and momentum) to escape the frustum. A dielectric inside does not. I realize that the voltage drop is a loss of power and will result in a lower Q, and there will be a compromise between higher Q vs higher divergence of the flux, but unless something is getting out, or at least out of the cavity and into the copper, it's not going to move. My theory is the only one here that is proposing something observable that can get out of the cavity. PS: I expect the nickel to be the higher losses and the copper to be lower loss. My expectation is, if you want the small end leading, then the small end and side walls should be low loss and the big end plate should be higher loss material. But not a lot higher loss, just enough to cause a gradient. It still requires a large Q to create any thrust.
Quote from: WarpTech on 12/01/2016 10:01 pmA voltage drop in the metal allows magnetic flux (and momentum) to escape the frustum. A dielectric inside does not. I realize that the voltage drop is a loss of power and will result in a lower Q, and there will be a compromise between higher Q vs higher divergence of the flux, but unless something is getting out, or at least out of the cavity and into the copper, it's not going to move. My theory is the only one here that is proposing something observable that can get out of the cavity. PS: I expect the nickel to be the higher losses and the copper to be lower loss. My expectation is, if you want the small end leading, then the small end and side walls should be low loss and the big end plate should be higher loss material. But not a lot higher loss, just enough to cause a gradient. It still requires a large Q to create any thrust.I was not talking about a dielectric insert but rather a dielectric coating for one of the reflective end walls of the cavity. in order to minimize losses... at one end. But, it appears that microwave dielectric manipulation is done using meta-materials with macroscopic dielectric resonators structures... New, probably hard to get ...https://arxiv.org/pdf/1605.07487v1.pdf
A voltage drop in the metal allows magnetic flux (and momentum) to escape the frustum. A dielectric inside does not. I realize that the voltage drop is a loss of power and will result in a lower Q, and there will be a compromise between higher Q vs higher divergence of the flux, but unless something is getting out, or at least out of the cavity and into the copper, it's not going to move. My theory is the only one here that is proposing something observable that can get out of the cavity. PS: I expect the nickel to be the higher losses and the copper to be lower loss. My expectation is, if you want the small end leading, then the small end and side walls should be low loss and the big end plate should be higher loss material. But not a lot higher loss, just enough to cause a gradient. It still requires a large Q to create any thrust.
I recall this issue being raised before, but it was a while ago and the situation may have changed. Is it reasonably possible to 3D print an emdrive, or a major portion of it? I mean direct fab and not making a wax model, a mold, and then casting it.I am not asking if the typical $800 hobbyist unit can do this, though it would be interesting if such a device could. I am talking about the big expensive machines from places like Stratasys...can they do this? If so, does it economically make sense?The reason I ask is because I have tax reasons to quickly spend money (six figures) on industrial equipment (before the end of the year). If buying a high-end 3d printer and using it to make some money by producing emdrive prototypes for people has a chance of being economically feasible, I'd like to know and get started ASAP.