ball lightning - spherical microwave confinement (bill robinson)

8/22/2019 Ball Lightning - Spherical Microwave Confinement (Bill Robinson)

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Spherical Microwave

Confinement

for the preliminary exam November 15, 2007

Bill Robinson


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History

February 1995: Scientific American article onsonoluminescence and fusion got me startedlooking for exotic energy sources

1996-99; investigated various cold fusion ideas,

usually shock waves through hydride aerosols;gave up for lots of reasons July 2000; started investigating idea of helical

antennas in a sphereand thought of coming toNCSU for physics

2003; started interest in Ball Lightning (BL) 2004; began grad school in hopes of building a

reactor


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More History

2004-2006; went through large number of

possible designs with this geometry (includingInertial Electrostatic Confinement [IEC]); endedup with magnetic SMC theory, BL on the side,formal papers

August 2006; started construction in 102-AResearch II with Dr. Aspnes as advisor Spring 2007; obvious that magnets are beyond

my capacity in cost, manpower, time; foundflaws in theory; concentrating on BL and SMC

with no magnets September 2007; first plasma October 13 2007; back to SMC as IEC idea


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SMC Reactor Design

20 helical antennas for 2.45 GHz

circularly polarized RF, 1 wavelengthlong, 4 turns; aluminum sphere isgroundplane at 4th zero ofj1 = sin kr/(kr)

2 cos kr/kr (TE)

20 magnetrons (1kW each) fire from

cap bank (6kV to 4kV), ~1/10 sec Each hemisphere mounted on

independent framework on casters

2 windows 2 diameter

Polar pipes (1 ) for access, gasin/out, probes, sparker, fiberoptic

Can accommodate eitherhemispherical magnets or neutronshields 1 inches off of surface,totally enclosing the sphere


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A Tour of the Lab I


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A Tour of the Lab II

Back of controlpanel and uppercapacitor bank

From 5 magnetrons to coax Distributing power to the trons

Baffles keep thetrons from goingKERPOW


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Video Stills

1) Sparker explodes aerosol 2) Magnetrons start breakdown

3) One of 3 frames, hot plasma 4) Winding down, helix cores last to cool

Early shot; 3 torr, sparker loaded with flour and graphite; 30 fps; sparkershould be delayed to have maximum during microwave discharge (is now!)


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Abstract for Ball Lightning Research

By experimenting with a variety of targets, gases, and pressures,the objective is to create an analog to natural ball lightning (BL),discover optimal conditions more favorable than atmospheric, andinvestigate the anomaly

The spherical aluminum chamber confines the gas and aerosol at a

wide range of pressures A strong pulse of circularly polarized microwaves from all directions

hits vaporized organic material

As natural BL emits microwaves, the BL should resonate in thechamber and move to the center

Any microwaves emitted can be gathered by the antennas and thepower rectified to DC with high efficiency

A wide range of measurements and analysis would be possible forthe first time, instead of just field reports, leading to theory of BLand reactor design


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Abstract for SMC-IEC Research

Using the same geometry as for BL, withaddition of bias rings at the antennabases, waves of electrons flow into thecenter and cause a virtual cathode at the

center, to which ions flowAs long as electrons are turned back

before collision with the antennas, the

result is gridless IEC with the potential forneutron production and possibly fusionpower


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Ball Lightning

We KNOW it does exist, unlike other exoticschemes. Ideal power source when harnessed

Extreme BL (EBL) has unmatched energy density(109 J/m3), beyond any chemistry fromenergy/molecule; no neutrons or gammas

EBL emits high levels of microwaves which areeasily rectified (90+% efficiency) to DC Hardly likely that Nature gives optimum conditions,

but doesgive possibleconditions Can be made with common materials. Fuel likely to

be abundant; best fuel unknown Key is to take field observations at face value when

possible without modification to fit preconceptions


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Mysteries of BL: confinement Typical lifetime is 10 sec (range 1 to 150 sec typically)

instead of microseconds to cool, recombine Neutral buoyancy; tends to hover over ground and can

move upwind instead of rising Cant have separation of charges sustained in conductor,

thus no E

B requires current which would need superconductingloop; plasmas have finite resistance. Density is too highfor B confinement due to high collision rate >>gyrofrequency (density is atmospheric).

Neutralsmay be confined since no cooling from

convection, and pop on collapse evidence for internalpressure >> partial pressure of ionized fraction. Noknown mechanism for that. Would be ~15 atm!

If neutrals not confined, then plasmoid should cool andcollapse in < 1 ms; would help explain BL moving

upwind (but leaves most of the mystery)


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More Mysteries of BL

Power output of BL not associated with cooling orreduction in size

Energy flows out continuously from visible light(recombination), RF (static recorded), sometimes heat

Energy out on explosion can include microwaves;

unknown origin. Evidence from cooked meat, hot water Total energy can be >> initial input especially when not

generated by linear lightning, and energy is generatedduring lifetime of BL;evidence of anomalous sustainingreaction

Most powerful recorded BL formed underwater off coastof Japan


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Using the reactor for BL Magnetron cap bank charged mostly by an oven

Sparker (2kV) throws hot organic material into center Microwaves hit and react with hot aerosol and fill gas for 50 to 130

ms as capacitor bank goes from 6000 to 4000 V, ~1000 J energy Current equipment only goes down to 3 torr and cannot withstand

positive internal pressure required to explore full range of conditions After upgrade with flange, new antenna feedthroughs, and turbo

pump, can do much lower pressures and over atmospheric May use baffles, especially for higher pressures; requires seed

plasma to absorb microwaves, otherwise can damage magnetrons;no problem now at 3 torr with baffles. Mysterious malfunction at 1atm

Recently added Teflon shields at base of antennas to avoid

breakdown, damage If successful there is potential for explosive dissolution For low pressures can use biasing rings at antenna bases (-6 kV to

start with, described in next section)


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How to make BL; a Best Guess Take field evidence seriously; smell, aerosol, microwave

damage, environment where formed Smell indicates rotten egg (hydrogen sulfide) and ozone.

O3 ubiquitous with sparks so may not be useful indicator Solids required for aerosol formation; only solids in air

are biological (birds, bats, bugs), so tests will use

organic fuel for sparker Closest atmospheric lab plasmas to BL are microwave

discharges; must measure plasmoid duration aftermicrowave power input stops

If BL puts out microwaves, makes sense to put in a

potentially resonant chamber where it will tend towardsthe center Should get it started with pulse of extreme conditions


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How This Is New for BL Synthesis

Since microwaves come out of BL, makes senseto try making BL with a pulse of microwaves

Can expect BL to resonate in a spherical metalshell and tend to float in center; not tried before

Circularly polarized RF keeps constantmagnitude fields; not tried before

Helical antennas in both rotations will receive allradiation efficiently regardless of direction

Chamber controls gas pressure and species,protects from explosions and BL microwaves

Sparker allows controlled introduction of aerosol


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BL Diagnostics Easy one is most important; does it last after power cuts off?

Must have accurate measure of when microwave input stops Currently have video at 30 fps; would like higher speeds,

shielded from EMF Will set up computer for data acquisition By using coax relay can divert antenna for outgoing power

after magnetrons stop, rectify and measure DC voltage to find

microwave output. More ideal setup would have hybridcouplers but too expensive now

Can insert emissive probe along polar axis to find plasmapotential regardless of electron drift [1]

Spectrometer probably via fiberoptic; need to borrow one!

(From NE?) Need good leak testing to improve vacuum Gas analysis before and after pulse to detect reactants and

products; gear available in lab


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HOWEVER!

Making BL in this reactor is a long shot Next; an explanation of a way of using this same

geometry with minor changes at low pressures forElectron Accelerated Inertial Electrostatic Confinement(EXL IEC) without grids for conventional fusion reactions

(D-D, D-T, proton-B11) Unlike BL, the physics is known; critical point is to

reverse electrons by near-field RF and inward-flowingelectron waves before they reach the antennas, insteadof requiring transit through grids

If this is correct, the existing hardware could producelarge numbers of neutrons. The concept might bedeveloped for power generation in larger and moreefficient reactors


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Inertial Electrostatic Confinement

(Ref. 2)


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IEC single potential well [3]

Fig. 2: Single potential well structure. The minimum normalized potential,Ymin, coincides with the core potential, Ycore = Y(r = 0). The fractional welldepth, FWDis defined as FWD = 1-Ymin.


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IEC double potential well [3]

Fig. 3: Double potential well structure. The double well depth (DWD) is YpeakYmin. Here, Ypeakcoincides with Ycore.


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Existing IEC Large increase of plasma density in potential wells, fosters high rate

of reaction there; BUT net reaction rate ~ 1/pressure IEC with grids cannot (yet) go above Q~10-5 Big advantages: no B fields, easy high T, simple geometry, some

fusion does occur at center and in mantle (zone between grids) High T makes advanced fuels tempting but elusive so far

IEC operates at too low density for power reactor (need ~1021

m-3

insizable volume) [5] IEC is the cheapest way to fusion by a very large factor; reactors

are mostly vacuum, thus low mass. Existing grid reactor can be a practical, portable, simple neutron

source (like the STAR reactor), but not efficient enough yet for sub-

critical fission or large-scale transmutation. Maximum so far; 2x1010

neutrons/sec by Hirsch in the 60s [6] and Nebel in late 90s Other attempts for either gridless IEC (Bussard) or to protect grids

magnetically from collision have failed


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Some recent experiments

Richard Nebels Los AlamosTriple-gridded POPS IEC1010 n/s, $500 k, 25 kW [4]

Hitachi IEC, Japan, 7 x 107 n/s


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Unavoidable Loss Problems in grid IEC

Collisions with grids; Pgridloss/Pfusion > 3000; particle paths

MUST cross grids to be confined [5] Ion upscatter and energetic tail loss time ~10-3 fusion

rate Ion neutral capture and escape from potential well Fusion reaction products escape, do not heat plasma

(direct energy conversion probably wont work) [8] Ion collisions increase angular momentum and throw

ions out of dense center region (may not be so bad,double wells can work)

No way to keep plasma non-thermal; collision x-section

>> fusion x-section by factor of at least 105 Bremsstrahlung same or worse as other reactors, makes

advanced non-neutronic fuels probablyimpractical (fueltouted as ideal for IEC)

Both ion and electron loss times


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Critical IEC Scaling Problem: 1/n

As density drops, longer mean free path, moreacceleration between grids, higher energy,increased , fewer ion-neutral collisions,tighter focus at center, more head-on collisions.[9]

Thus fusion reactions scale as 1/n instead of n2.IEC reactors operate at very high vacuum


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Critical IEC scaling problem; Power ~ 1/a

a= radius of spherical active zone, q= total charge, fa

= potential at r= a, neand niare average densities inthe active zone, P= power from fusion

For grid IEC, q= |neni| ~ ni fa~ q/a ~ nia

3/a2= nia2

Since fa

is within a small range, ni~ 1/a2

P ~ ni2*Volume, so P ~ 1/a

Probably NOT true for SMC since source of ions,electrons, and charge balance is not the same as forgrids; qis not ~ ni

Proof of this is the use of ion or electron beams to alterthe charge/density relationship in grid IEC to increase P Result is IEC devices are very small (a few inches) and

cannot scale up while SMC probably can


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Antennas as e- accelerators Antennas are insulated with ceramic and do not short out to plasma

Will apply -6 kV (or more) bias to base rings, 4 diameter, 1 fromwall. Next reactor could put (+) bias on antennas Microwaves cause breakdown starting in core, rapidly saturates to

critical density (opaque plasma) Electron cascade bunches in waves and flows toward center; same

process turns back electrons from center (thermalized after crossingreactor core)

Uncoordinated antenna phases now; may be better in phase forinwards-moving spherical waves

Existing rig; ~5 x108 e/cycle at ~25 keV(~0.2 amp) assumingdelivering 5 kW to waves from microwaves (efficiency of 0.25)

Bias on base rings limited to no more than electron wave energy ~

virtual cathode potential; 10 kV for D-T reactor, 50 kV for D-D Ions do not bunch in waves, follow e- inwards; qi(t)= Inner charge during microwave increase;

qtotal = qi - qe = - d (qe = # inner electrons) For each 5 microseconds ion delay, can create 1 kV potential if low

electron loss


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Periodically Oscillating Plasma Sphere (POPS)

(a) Temporal evolution of plasma potential at the center of thevirtual cathode with and without rf modulation. (b) Delay in the virtual cathodedestruction due to rf modulation as a function of modulation frequency.(Reproduced from Ref. 4.) This is for just a few hundred volts and 10 -6 torr

Uses RF modulation of grids and emitters to oscillate the potential well inresonance with the orbital frequency of the ions to extend life of virtual cathode


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POPS & SMC? POPS in grid IEC cannot scale to a reactor since

With rvc = virtual cathode radius, fo = potential well depth; note changein radius and compression ratio

Resonant frequency:

At fusion reactor conditions, 10-30 MHz (D-D); milder plasmas down to 1

MHz

Works by throwing a few ions out of potential well. Might use by RFimposed on bias grid or injected beams of e- or ions

Grid IEC needs addition of electrons at center to reduce ion space chargeand allow compression, may also in SMC

2 2 2

max min

2

3( / ) ( / )

2

i e ofusion fusion

VC

n n r r P v

e r

2

2o

POPS

VC i

e

r m


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Magnetic SMC: a possible future addition Two hemispherical coils,

counter-rotating Uses cylindrical cusp to make

electron cyclotron resonance(ECR) on spheroidal Bisosurface at 875 gauss

Could help make plasma

transparent outside plasmoid Would heat electrons at ECR

surface efficiently andselectively

reactor is constructed toaccommodate the coils

Expensive and uses a lot ofpower if not superconducting

Could funnel reaction productsout poles and equator fordirect energy conversion

Arrows are B field; center circle is plasmoid

surface; outer circle is magnet coil


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Magnetic SMC

Coil windings in amp-turns for testreactor, one hemisphere (otherhemisphere is negative of this)

-0.4 -0.2 0 0.2 0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

Tickmarks are meters; contours areB field magnitudes; dark circle is 875gauss (ECR); outer circle is magnet;next circle in is pressure wall; dotted

circle is inner end of antennas

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20coils

5000

10000

15000

20000

25000

30000

Amp turns


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Current and Future Research

THEORY; Ion heating; magnetrons are a few MHz out ofphase, causes Landau damping [8] Shock dynamics, if they apply, with antennas in phase or

random (current setup is random); compression, heating Confinement mechanism for electrons in SMC-IEC (no BL

theory yet) HARDWARE; Diagnostic tools are first priority; computer DAQ,

plasma probes, spectrometer, gas analysis, and detectors forx-rays, gammas, neutrons, alphas

Upgrade of vacuum system for lower pressures and secureuse of H2S for BL, or D2 and boranes for SMC

Installation of bias rings at antenna bases, -6 kV for now GOALS; BL creation then reactor design, orSMC to scale up

for D-D or D-T reactor, sub-critical fission, etc. FUNDING! And a way to continue doing this after

graduationhere if possible; post-doc?


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References

1) A. Siebenforcher, Rev. Sci. Instrum. 67(3), March 1996 2) Tom Ligon, Infinite Energy Issue 30, 2000 3) IEC thesis by Ryan Meyer, U. of Missouri-Columbia December 2007 4) J. Park, R.A. Nebel, S. Stange, Phys. Plasmas 12, 056315 (2005) 5) A general critique of intertial-electrostatic confinement fusion

systems, Todd Rider, Phys. Plasmas 2 (6), June 1995 6) R. L. Hirsch, J. Appl. Physics 38, 4522 (1967) 7) M. Rosenbluth, F. Hinton, Plasma Phys. Control. Fusion 36 (1994)

1255-1268 8) F. Chen, Plasma Physics and Controlled Fusion, 1984 9) Development of a High Fluence Neutron Source for Nondestructive

Characterization of Nuclear Waste, M. Pickrell, LANL Technical Report(1999)

M. Bourham, class notes Many BL articles in Nature over the last 80 years Personal interviews with BL witnesses and their relatives (including Dr.

Hallen)

www billrobinsonmusic com/Physics for pictures papers latest news
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ball lightning - spherical microwave confinement (bill robinson)

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