....I want to point out a discrepancy I found. Perhaps I'm the discrepancy, because I don't agree with my old post or any of the other sources, which is highly unlikely. First here's what I have about mode numbering from various sources:ME from thread 1: T(MorE)mnp. m is the # of 1/2 wavelengths around a half circumference, n is the # of 1/2 wavelengths across a radius, p is the # of 1/2 wavelengths of length of the cavity.Navy Neets mod 11 (screenshot below): The first subscript indicates the number of full-wave patterns around the circumference of the waveguide. The second subscript indicates the number of half-wave patterns across the diameter.........(p left out).Oracle: http://en.wikipedia.org/wiki/Transverse_mode In circular waveguides, circular modes exist and here m is the number of half-wavelengths along a half-circumference and n is the number of half-wavelengths along a radius.......(p left out).Rodal: The first subscript (m) is the azimuthal mode number: it indicates the number of full-wave patterns around the circumference of the waveguide. The second subscript (n) is the radial mode number: it indicates the number of half-wave patterns across the diameter. The third subscript (p) is the longitudinal mode number. It indicates the number of full-wave patterns along the longitudinal length of the waveguide. So there is conflicting information. Rodal and the Navy agree, the oracle and me are different. I'll see if I can clear it up.....and find deal here.Using the coke can example from http://www.engr.sjsu.edu/rkwok/EE172/Cavity_Resonator.pdf slide 17, for a radius of 1.25"(or diameter of 2.5"), depth of 5". This comes out to a TE111 f,res of 3.01ghz, which gives me a wavelength of 3.923". So first, to test the first subscript m, the circumference of a circle with r 1.25" is 7.85". 7.85"inch is 2 wavelengths @3.01ghz. So it appears that m should be the # of full wavelengths around half a circumference.or If you don't do any rounding with the coke can example, @3.01ghz you get 3.923928113636958 inches, multiply that by 2 you get 7.847856227273916 inches, which is just shy of the calculated circumference of 7.85, which technically is not a FULL cycle of 2 wavelengths. Which means this example sits on the edge of TE111 and TE211. Technically that 0 wasn't crossed yet.So is that the answer? FULL wavelengths must be counted, the rest is dropped? Meaning if you go around 2.6 times for example, you just get an m of 2?This is important because soon I'm going to be cutting copper shapes and making stupid mistakes can be very expensive.I've found fault with the Navy references before on other things, and we all know that everything on the Oracle needs to be verified, and I'm frequently wrong, but Rodal is usually right. So what's going on there?As far as n or p go, I'm not even going to look at them until I get some feedback about the m discrepancies. I just want to clear this up. I don't mind getting egg on my face.Break:You know, I think this got overlooked: "We performed some very early evaluations without the dielectric resonator (TE012 mode at 2168 MHz, with power levels up to ~30 watts) and measured no significant net thrust." I got a lot of grief before for my approach to deriving the cavity dimensions (starting with the 6.25 inch small end, using the dimensions of the PE discs from 14 of Brady et al Anomalous thust...., but I think those dimensions, (see screenshot below) are exactly spot on and here's empirical proof. So my calculated cavity length in Autocad after scaling based on 6.25inch small ends size, was 10.88". If you look at the frequency of 2168mhz, you'll find the wavelength is 5.4479". Take two wavelengths of this, you'll arrive at 10.8958, my cavity length was 10.88". Converted to meters, it is: Dsmall=0.15875m (0.159m)Dlarge=0.30098m (0.3m) amazingly round numberLength=0.27637m (.276m)

The first subscript (m) is the azimuthal mode number: it indicates the number of full-wave patterns around the circumference of the cylindrical cavity. It is zero for modes in which there is no variation in the circumferential direction.The second subscript (n) is the radial mode number: it indicates the number of half-wave patterns across the diameter. The radial mode number (n) plus one indicates the number of nodes across the diameter (counting as nodes the end nodes).The third subscript (p) is the longitudinal mode number. It indicates the number of full-wave patterns along the longitudinal length of the waveguide. It is zero for modes in which there is no variation in the longitudinal direction.

The naturally conforming reflecting end for a conical Wave-guide is such a sphere, just as the conforming end for a cylindrical wave-guide is a flat plate. It is believed that the reason that the spherical end is superior is that fewer higher order modes need be excited in reflection from such an end than from a fiat end, or that the degree of such excitation is less. It is further believed that higher order modes can be excited in the large end of the resonator which are undetectable through the input and output structures located at the small end, where these modes are below cut-off. They are however, detectable in that such coupling between modes may cause a reduction in the Q factor of the desired mode.Since the curvature of the end plate cannot be altered as the resonator is tuned, the curvature of this end plate is also a factor which does not scale during the tuning of the cavity. It thus will cause slight perturbation of the modes. It appears to be possible to employ this perturbation to offset the effects of the perturbation due to the gap around the plunger, which also varies during tuning. This generally requires empirical adjustment of the plunger radius of curvature until the Q factor remains good over the tuning range.As a feature of the third concept, an absorber is provided in the back cavity, behind the plunger or base plate and around the rim of the base plate. Successful use has also been made in experiment of grooves made in the face of the plate and partially filled with absorbing material.

Thank you @Mulletron for looking at this discrepancy, which enables me to correct this mistake: My description of the quantum mode number "p" for the longitudinal direction of a cylindrical cavity in http://forum.nasaspaceflight.com/index.php?topic=36313.msg1318217#msg1318217 should be corrected from "number of full-wave patterns along the longitudinal length " to "number of half-wave patterns along the longitudinal length "QuoteThe first subscript (m) is the azimuthal mode number: it indicates the number of full-wave patterns around the circumference of the cylindrical cavity. It is zero for modes in which there is no variation in the circumferential direction.The second subscript (n) is the radial mode number: it indicates the number of half-wave patterns across the diameter. The radial mode number (n) plus one indicates the number of nodes across the diameter (counting as nodes the end nodes).The third subscript (p) is the longitudinal mode number. It indicates the number of full-wave patterns along the longitudinal length of the waveguide. It is zero for modes in which there is no variation in the longitudinal direction.to:The first subscript (m) is the azimuthal mode number: it indicates the number of full-wave patterns around the circumference of the cavity. It is zero for modes in which there is no variation in the circumferential direction.The second subscript (n) is the radial mode number: it indicates the number of half-wave patterns across the diameter. The radial mode number (n) plus one indicates the number of nodes across the diameter (counting as nodes the end nodes). The radial mode number (n) minus one indicates the number of middle nodes across the diameter (not counting as nodes the end nodes). The radial mode number (n) cannot be zero.The third subscript (p) is the longitudinal mode number. It indicates the number of half-wave patterns along the longitudinal length of the cavity. It is zero for modes in which there is no variation in the longitudinal direction.I double-checked the others (m and n) and I am sure that they are correct. The US Navy reference is correct. GO NAVY !Concerning, "m" "the azimuthal mode number: it indicates the number of full-wave patterns around the circumference of the cavity, all the descriptive references you brought up agree (as we previously discussed in this thread).Concerning "n" (the radial mode number that "indicates the number of half-wave patterns across the diameter"), the Wikipedia link is incorrect -I didn't have the time to check the history of that Wiki entry to see what is the history of that Wikipedia error. When I have the time I will examine that and I will correct the entry in Wikipedia.To make the long story short, the quantum mode numbers have to respect the boundary conditions:1) In the circumferential direction there is really no boundary, the condition is one of periodicity, hence m must be the number of full waves in the circumferential direction. All references agree2) In the radial and longitudinal directions, the boundary conditions (electrical conductivity at the surfaces) are at each end of the diametral direction or at each end of the longitudinal direction. There is no boundary condition at the center of the circular cross-section other than symmetry or antisymmetry (unless it would be a double-concentric cylinder having an inner conductive cylinder in addition to the outer conductive cylindrical surface) hence a half-wave can be supported within the diameter direction and a half-wave can be supported within the longitudinal direction. Hence the radial and longitudinal directions n and p are the number of half-waves in both directions, just like a rectangular cavity.

..I figured out the confusion I had over the m subscript after studying the KWOK 3.01ghz coke can, and the 2.45ghz example. The issue is, wavelengths is NOT the same as wave pattern. For both the frequency examples, you get pretty much exactly 2 wavelengths around the circumference, which breaks TE111. So wavelengths is where I got it wrong. My old n subscript was jacked up too. As the Navy example states, and @Rodal did too. It is wave PATTERN. Glad I got that sorted out. So the Navy example is correct, and then add the p subscript from my old post, and it all falls in to place, as Rodal typed it out above the Navy logo, which is perfect. So around a circumference there is of course no E field boundary condition, so trying to quantify it in wavelengths makes no sense. Pattern variation does. On the other hand, across a diameter or along the length, standard E field boundary conditions apply, so pattern or half wavelengths works equally well. I'm being super cautious before I sink cash on a large copper sheet, so I'm testing everything.

...Concerning "n" (the radial mode number that "indicates the number of half-wave patterns across the diameter"), the Wikipedia link is incorrect -I didn't have the time to check the history of that Wiki entry to see what is the history of that Wikipedia error. When I have the time I will examine that and I will correct the entry in Wikipedia....

I've attached a video that Tom Ligon made for me some time ago. Can anyone tell me what mode this is, in particular, what is "p" . As for the operating frequency - it is consistent within meep and Harminv but these last few pages of discussion have shaken my confidence that it is consistent with the real world for those cavity dimensions.The cavity is similar to the Brady cavity in perfect metal, but the dielectric constant is to high. I don't expect to make a new video until I get the frequencies and modes sorted out.

The third subscript (p) is the longitudinal mode number. It indicates the number of half-wave patterns along the longitudinal length of the cavity. It is zero for modes in which there is no variation in the longitudinal direction.

The second subscript (n) is the radial mode number: it indicates the number of half-wave patterns across the diameter. The radial mode number (n) plus one indicates the number of nodes across the diameter (counting as nodes the end nodes). The radial mode number (n) minus one indicates the number of middle nodes across the diameter (not counting as nodes the end nodes). The radial mode number (n) cannot be zero.

I was wondering if this phenomena might have an effect on this system?http://gizmodo.com/sub-atomic-particles-could-accelerate-themselves-1681765188

@RodelI believe that your answer is that the mode is TX a,1,3 where X = (E or M) it could be that a = 1, 2, ... or more.There must be an upper limit on the value of a, but ......

.....I am looking into ParaView, an open source data visualization tool. With it, I might be able to generate some 3D views of interest but movies are to hard. Making of that movie took 12 hours of CPU, another 8 hours to upload the PNG files to Box, and I don't know how long to download and make the movie, then send it back. To hard just for simple exploration of the data.

...'m still working that problem but have determined that it is either an issue with Harminv or with my use of Harminv. But it's not geometry or frequency input values, rather it is signal amplitude, run time and wait time issues. Most likely all of them. In the video I posted, it is clear that the cavity is resonating strongly at the drive frequency. The drive frequency is only moderately near the Brady experimental drive frequency. I took that to be a result of the relatively higher dielectric constant used, 2.3 compared to the 1.76 value that gives the Brady experimental value of 1.8804 GHz. ...

Cavity optomechanics studies the interaction between light and mechanical systems, most often mediated by radiation pressure—the force exerted by photons hitting on a mirror. In a typical optomechanics setup, microwave or optical photons travel in a cavity formed by two or more mirrors, one of which is free to move and acts like a mechanical oscillator whose position changes because of radiation pressure and thermal fluctuations. A recent milestone in the field was the cavity cooling of mechanical oscillators to a regime in which they have less than one quantum of motion [1]. This could have important applications, ranging from the observation of quantum behavior in macroscopic systems to the development of ultrasensitive detectors that could reveal the tiny vibrations caused by the still-elusive gravitational waves. However, to-date-demonstrated schemes require that the frequency of the cooling light be lower than the cavity resonant frequency by an amount corresponding to the frequency of the mechanical oscillator. These two frequencies can be measurably different only if the oscillator’s frequency is sufficiently large. This poses an important limitation, as low frequency, heavy oscillators cannot be cooled by this method.Now a team led by Roman Schnabel at the Albert Einstein Institute in Hannover, Germany has reported an optomechanical cooling scheme that gets rid of this frequency-detuning requirement [2]. The key to their achievement is a novel form of optomechanical coupling. Optomechanics has been mainly investigated using “dispersive coupling,” in which displacements of the oscillating mirror change the resonant frequency of the cavity [3]. Here, the authors rely instead on “dissipative coupling,” in which the mirror oscillations modify the coupling between the cavity and its environment, for instance by modulating the speed at which cavity photons are lost (i.e., the cavity bandwidth).In the dispersive coupling regime, the most widely used cooling approach is “cavity cooling” [3]. In this method, light cools a mechanical mode via a “parametric” process: quanta of mechanical excitations are up-converted into cavity photons, which are then dissipated through the cavity. The light frequency must be detuned from the cavity resonant frequency: the mechanical oscillator produces lower-frequency (red) and higher-frequency (blue) sidebands, which are shifted from the cavity resonance by multiples of the mechanical frequency ωM. When the driving frequency is tuned to the first red sideband, photons entering the cavity take away phonons with energy ħωM from the mechanical system, cooling the oscillator. In a number of previous studies, this method allowed researchers to bring mechanical oscillators to their quantum ground state (i.e., states in which the average number of mechanical excitations is reduced below unity) [1] and to realize the coherent conversion of photons to mechanical motion and of microwave photons to optical photons [4]. But these realizations required the system to be in the “resolved sideband regime”: for the red sideband to be distinguishable from the cavity frequency, the frequency of the mechanical oscillator (determining the shift of the sidebands) has to be larger than the cavity bandwidth. Ground-state cooling has been achieved for frequencies down to hundreds of megahertz, but reaching lower frequencies (such as the ∼100-kilohertz frequency of the mechanical resonator used by Schnabel’s team) would require cavities with extremely narrow bandwidths, which are currently not available.However, a recent theory shows that cavity cooling could be possible without the requirement to resolve the mechanical-oscillator sidebands [5] if the optomechanical coupling is dissipative [6]. In dissipatively coupled systems, two types of fluctuating forces act on the mechanical resonator: the noise in the light injected into the cavity and the quantum fluctuation of the cavity field. These two types of noise, which have different spectra, can interfere destructively. With proper parameter choice, such interference can reduce the spectral density of the noise at the frequency (-ωM) of the oscillator, effectively cooling it. This mechanism, which does not require to resolve the sidebands, can work with a low oscillator frequency.

...I have made progress though. Using the frequency formula to adjust cavity length so that the formula gave 2.45GHz, required a cavity length about 0.0965 meters. Iteratively running meep and adjusting the cavity length to force resonance at 2.45 GHZ independently produced a cavity length of 0.0936 meters. I emphasize that I worked those problems independently of each other so the fact that they are in near agreement is telling. I would like to find a combination length and radius that would give the frequency without the length being so close to 3/4 wavelength. In fact, I would like for the length to be exactly one wavelength and for which I knew the mode. TE 1,1,1 would be good, but TE 1,4,1 might also work. Maybe now that I have found one solution, I can find more solutions.

I found this very interesting (expired) 1969 patent by Grant, owned by JOHNSON CONTROLS INTERNATIONAL, that deals with conical cavities !http://www.google.com/patents/US3425006It has a lot of interesting practical stuff, for example dealing with spherical ends (like in Greg Egan's solution http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html ) instead of flat end plates (NASA Brady et.al., Shawyer(Experimental and Demo) and Prof. Juan Yang in China's EM Drives all have flat ends):

It has been found possible to predict the resonances approximately by defining a phase shift per unit length as 21r/ \g, where Ag is given by the usual formula for circular wave-guides of diameter D, but where D and hence Ag vary along the cone. If this phase shift is integrated from the location of the cut-off diameter to the position of the plunger or movable end wall, resonances will be found when the integral has values of 11 pi."

Quote from: Rodal on 01/25/2015 11:35 pmI found this very interesting (expired) 1969 patent by Grant Wolf, owned by JOHNSON CONTROLS INTERNATIONAL, that deals with conical cavities !http://www.google.com/patents/US3425006It has a lot of interesting practical stuff, for example dealing with spherical ends (like in Greg Egan's solution http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html ) instead of flat end plates (NASA Brady et.al., Shawyer(Experimental and Demo) and Prof. Juan Yang in China's EM Drives all have flat ends): Found some time to read over this patent. It is a gold mine of good info. Great find. A couple takeaways I found is that it confirms that TE modes are highly desirable compared to TM. Also this caught my eye:QuoteIt has been found possible to predict the resonances approximately by defining a phase shift per unit length as 21r/ \g, where Ag is given by the usual formula for circular wave-guides of diameter D, but where D and hence Ag vary along the cone. If this phase shift is integrated from the location of the cut-off diameter to the position of the plunger or movable end wall, resonances will be found when the integral has values of 11 pi." Looks like math for predicting resonant modes for cones. It looks like some of the text got messed up in the character translation over to Google patents, see the bold part.

I found this very interesting (expired) 1969 patent by Grant Wolf, owned by JOHNSON CONTROLS INTERNATIONAL, that deals with conical cavities !http://www.google.com/patents/US3425006It has a lot of interesting practical stuff, for example dealing with spherical ends (like in Greg Egan's solution http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html ) instead of flat end plates (NASA Brady et.al., Shawyer(Experimental and Demo) and Prof. Juan Yang in China's EM Drives all have flat ends):