1

A

Seminar Report Submitted in partial fulfillment for award of Bachelor’s degree in

Electronics and Communication Engineering

“BUBBLE POWER”

Department of Electronics & Communication Engineering

Rajasthan Technical University, Kota 2013-14

2

A

Seminar Report ON

(BUBBLE POWER) Submitted in partial fulfillment for award of Bachelor’s degree in

Electronics & Communication Engineering

Guided by: Submitted by: Ms. Ankita Sharma Hitesh Khatri

Dept. of ECE. Roll No- 10EMEEC044

MarudharEngg. College VIII Sem ECE

Submitted to: Mr. Mayank Joshi

Seminar Incharge Department of Electronics & Communication Engineering

Rajasthan Technical University, Kota 2013-14

Appendix

I

3

TABLE OF CONTENTS

1. INTRODUCTION ………………………………..…………………10

2. SONOLUMINESCENCE…………………………………..…………11

2.1 RAYLEIGH- PLESSET EQUATION ………………………...……12

2.2 MECHANISMS OF THE PHENOMENON.……………………….13

2.3 QUANTUM EXPLANATIONS ……………………………...….…14

2.4 NUCLEAR REACTION …………………….……………………...15

2.5 NUCLEAR REACTION …………………….……………………...15

3. THE IDEA OF SONOFUSION.………………..…...………………...17

3.1. EXPERIMENTAL SETUP …………………………………….…...17

4. SONOFUSION ………………………………………………………..20

4.1. ACTION OF VACUUM PUMP …………………....………..………20

4.2. ACTION OF THE WAVE GENERATOR ………..………………....20

4.3. ACTION OF THE NEUTRON GENERATOR …….………...21

4.4. ACTION IN THE FLASK …………………….…………..………....21

4.5. FUSION REACTIONS …………………………………..…………..24

4.6. IF TRITIUM IS PRODUCED ………………………...……………...25

4.7. SCHEMATIC OF SONOLUMINESCENE & SONOFUSION

PHENOMENON ………………………………………..………........26

4.8. SEQUENCE OF EVENTS DURING SONOFUSION………….........27

4.9. THE EVOLUTION OF LIQUID PRESSURE WITH IN BUBBLE

CLUSTER………..……………………………………..…………….28

5. SEPARATION OF DEUTERIUM FROM ORDINARY

HYDROGEN (PROTIUM) ………………………………………..….29

Appendix IV

4

5.1. SEPARATION FROM ORDINARY HYDROGEN BY DIFFUSION

PROCESS………………………………………………..……………29

5.2. SEPARATION FROM ORDINARY HYDROGEN BY

FRACTIONAL DISTILLATION………..………………...…………30

5.3. SEPARATION FROM ORDINARY HYDROGEN BY

ADSORPTION ON CHARCOAL…………………………………....30

5.4. SEPARATION FROM ORDINARY HYDROGEN BY CHEMICAL

METHODS……………………………………………...………….....30

6. OTHER APPROACHES OF FUSION REACTION………………..31

6.1. LASER BEAM TECHNIQUE…………………………………......…31

6.2. MAGNETIC CONFINEMENT FUSION………………………….....31

7. EVIDENCE TO SUPPORT TABLE TOP NUCLEAR FUSION

DEVICE………………………………………………………………...32

8. ADVANTAGES AND APPLICATIONS OF BUBBLE POWER

OVER OTHER APPROACHES……………………………………..37

8.1. ADVANTAGES……………………………………………...……….37

8.2. APPLICATIONS……………………………………………...……....37

9. FUTURE DEVELOPMENTS………………………………………...38

9.1. FULLY SELF SUSTAINED……………….……………..………38

9.2. TO CREATE A FULL-SIZE ELECTRICITY PRODUCING

NUCLEAR GENERATOR……………………...………………...38

10. CONCLUSION………………………………………………………...39

5

11. REFERENCES………………………………………………………...40

6

LIST OF FIGURES

1. Figure 2.1 From left to right: apparition of bubble, slow expansion, quick

and sudden contraction, emission of light ……………….…………….…13

2. Figure 3.1 EXPERIMENTAL SETUP …………………………………….18

3. Figure 4.1 Action in the flask stage 1…………………….…....………….21

4. Figure 4.2 Action in the flask stage 2 ……………………………………..22

5. Figure 4.3 Action in the flask stage 3 ……………………………………..23

6. Figure 4.4 Fusion Reactions ………………………………………………24

7. Figure 4.5 Reaction with tritium …………………………………………..25

8. Figure 4.6 Schematic of Sonofusion&Sonoluminescene phenomenon .….26

9. Figure 4.7 Sequence of Events during Sonofusion ………………………..27

10. Figure 4.8 Evolution of liquid pressure with in Bubble cluster……………28

11. Figure 5.1 Process of Diffusion……………………………………………29

7

CERTIFICATE

This is to certify that Mr. Hitesh Khatri, a student of B.Tech. (Electronics

& Communication Engineering) VIII semester has submitted His/her

Seminar report entitled “ Bubble Power ” under my/our guidance.

Ankita Sharma

Designation of Seminar Guide

Appendix II

8

AKNOWLEDGEMENT

I am grateful to Seminar Guide Ms.Ankita Sharmafor giving guidelines to make the seminar successful. I want to give sincere thanks to the Principal, Dr. R.P.S. Jakhar for his

valuable support.

I extend my thanks to Mr. AbhishekTiwari Head of the Department for

his cooperation and guidance.

Yours Sincerely,

Hitesh Khatri

Appendix III

9

Marudhar Engineering College, Bikaner

Department of Electronics & Communication

Engineering

Bubble Power

Abstract

In sonofusion a piezoelectric crystal attached to liquid filled Pyrex flask send pressure

waves through the fluid, exciting the motion of tiny gas bubbles. The bubbles

periodically grow and collapse, producing visible flashes of light. When a gas bubble

in a liquid is excited by ultrasonic acoustic waves it can emit short flashes of light

suggestive of extreme temperatures inside the bubble. These flashes of light known as

sonoluminescence, occur as the bubble implode or cavitates. It is show that chemical

reactions occur during cavitations of a single, isolated bubble and yield of photons,

radicalsand ions formed. That is gas bubbles in a liquid can convert sound energy in

to light. Sonoluminescence also called single-bubble sonoluminescence involves a

single gas bubble that is trapped inside the flask by a pressure field. For this loud

speakers are used to create pressure waves and for bubbles naturally occurring gas

bubbles are used. These bubbles can not withstand the excitation pressures higher

than about 170 kilopascals. Pressures higher than about 170 kilopascals would always

dislodge the bubble from its stable position and disperse it in the liquid. A pressure at

least ten times that pressure level to implode the bubbles is necessary to trigger

thermonuclear fusion. The idea of sonofusion overcomes these limitations.

Submitted by:

Name: Hitesh Khatri

Year/Sem: 4th

/ 8th

Guided by: Ankita Sharma Submitted to:

Name with Signature: Mr. Mayank Joshi

Designation: Assistant Professor Seminar Incharge

10

1. INTRODUCTION

The standard of living in a society is measured by the amount of energy consumed. In the

present scenario where the conventional fuels are getting depleted at a very fast rate the

current energy reserves are not expected to last for more than 100 years.Improving the

harnessing efficiency of non-conventional energy sources like solar, wind etc. as a

substitute for the conventional sources is under research.

One of the conventional methods of producing bulk energy is nuclear power. There are

two types of nuclear reactions, namely fission & fusion. They are accompanied by the

generation of enormous quantity of energy.The energy comes from a minute fraction of

the original mass converting according to Einstein’s famous law: E=mc2, where E

represents energy, m is the mass and c is the speed of light. In fission reaction, certain

heavy atoms, such as uranium is split by neutrons releasing huge amount of energy. It

also results in waste products of radioactive elements that take thousands of years to

decay. The fusion reactions, in which simple atomic nuclei are fused together to form

complex nuclei, are also referred to as thermonuclear reactions. The more important of

these fusion reactions are those in which hydrogen isotopes fuse to form helium. The

Sun’s energy is ultimately due to gigantic thermonuclear reaction.The waste products

from the fusion plants would be short lived, decaying to non-dangerous levels in a decade

or two. It produces more energy than fission but the main problem of fusion reaction is to

create an atmosphere of very high temperature and pressure like that in the Sun.

A new step that has developed in this field is ‘Bubble Power’-the revolutionary new

energy source. It is working under the principle of Sonofusion. For several years

Sonofusion research team from various organizations have joined forces to create

Acoustic Fusion Technology Energy Consortium (AFTEC) to promote the development

of sonofusion. It was derived from a related phenomenonknown as sonoluminescence.

Sonofusion involves tiny bubbles imploded by sound waves that can make hydrogen

nuclei fuse and may one day become a revolutionary new energy source.

11

2. SONOLUMINESCENCE

Sonoluminescence is the emission of short bursts of light from imploding bubbles in a

liquid when excited by sound. Sonoluminescence is a phenomenon that occurs when a

small gas bubble is acoustically suspended and periodically driven in a liquid solution at

ultrasonic frequencies, resulting in bubble collapse,cavitation, and light emission.

Sonoluminescence can occur when a sound wave of sufficient intensity induces a gaseous

cavity within a liquid to collapse quickly. This cavity may take the form of a pre-existing

bubble, or may be generated through a process known as cavitation. Sonoluminescence in

the laboratory can be made to be stable, so that a single bubble will expand and collapse

over and over again in a periodic fashion, emitting a burst of light each time it collapses.

For this to occur, a standing acoustic wave is set up within a liquid, and the bubble will sit

at a pressure anti-node of the standing wave. The frequencies of resonance depend on the

shape and size of the container in which the bubble is contained.

Some facts about sonoluminescence:

The light flashes from the bubbles are extremely short—between 35 and a few

hundred picoseconds long—with peak intensities of the order of 1–10 mW.

The bubbles are very small when they emit the light—about 1 micro meter in

diameter—depending on the ambient fluid (e.g., water) and the gas content of the

bubble (e.g., atmospheric air).

Single-bubble sonoluminescence pulses can have very stable periods and positions. In

fact, the frequency of light flashes can be more stable than the rated frequency

stability of the oscillator making the sound waves driving them. However, the stability

analyses of the bubble show that the bubble itself undergoes significant geometric

instabilities, due to, for example, the Bjerknes forces and Rayleigh–Taylor

instabilities.

The addition of a small amount of noble gas (such as helium, argon, or xenon) to the

gas in the bubble increases the intensity of the emitted light.

Spectral measurements have given bubble temperatures in the range

from 2300 K to 5100 K, the exact temperatures depending on experimental conditions

including the composition of the liquid and gas. Detection of very high bubble

12

temperatures by spectral methods is limited due to the opacity of liquids to short

wavelength light characteristic of very high temperatures.

Writing in Nature, chemists David J. Flannigan and Kenneth S. Suslick describe a method

of determining temperatures based on the formation of plasmas. Using argon bubbles

in sulfuric acid, their data show the presence of ionized molecular oxygen O2+, sulfur

monoxide, and atomic argon populating high-energy excited states, which confirms a

hypothesis that the bubbles have a hot plasma core. The ionization and excitation energy

of dioxygenyl cations, which they observed, is 18electronvolts. From this they conclude

the core temperatures reach at least 20,000 Kelvin.

2.1. RAYLEIGH- PLESSET EQUATION

The dynamics of the motion of the bubble is characterized to a first approximation by the

Rayleigh-Plesset equation (named after Lord Rayleigh and Milton Plesset).

This is an approximate equation that is derived from the incompressible Navier-Stokes

equations and describes the motion of the radius of the bubble R as a function of time t.

Here, μ is the viscosity, pthe pressure, and γ the surface tension. The over-dots represent

time derivatives. This equation, though approximate, has been shown to give good

estimates on the motion of the bubble under the acoustically driven field except during

the final stages of collapse. Both simulation and experimental measurement show that

during the critical final stages of collapse, the bubble wall velocity exceeds the speed of

sound of the gas inside the bubble. Thus a more detailed analysis of the bubble's motion is

needed beyond Rayleigh-Plesset to explore the additional energy focusing that an

internally formed shock wave might produce.

13

2.2. MECHANISMS OF THE PHENOMENON

The mechanism of the phenomenon of sonoluminescence remains

unsettled. Hypotheses include:hotspot, bremsstrahlungradiation,collision- induced raand

coronadischargesnonclassicallight, proton

tunneling,electrodynamic jets andfractoluminescent jets.

Fig. 2.1 From left to right: apparition of bubble, slow expansion, quick and

sudden contraction, emission of light

In 2002, M. Brenner, S. Hilgenfeldt, and D. Lohse published a 60-page review Single

bubble sonoluminescencethat contains a detailed explanation of the mechanism. An

important factor is that the bubble contains mainly inert noble gas such as argon or xenon

(air contains about 1% argon, and the amount dissolved in water is too great for

sonoluminescence to occur, the concentration must be reduced to 20–40% of its

equilibrium value) and varying amounts of water vapor. Chemical reactions

cause nitrogen and oxygen to be removed from the bubble after about one hundred

expansion-collapse cycles. The bubble will then begin to emit light "Evidence for Gas

Exchange in Single-Bubble Sonoluminescence". The light emission of highly compressed

noble gas is exploited technologically in the argon flash devices.

During bubble collapse, the inertia of the surrounding water causes high pressure and

high temperature, reaching around 10,000 kelvins in the interior of the bubble, causing

the ionization of a small fraction of the noble gas present. The amount ionized is small

enough for the bubble to remain transparent, allowing volume emission; surface emission

would produce more intense light of longer duration, dependent on wavelength,

14

contradicting experimental results. Electrons from ionized atoms interact mainly with

neutral atoms, causing thermal bremsstrahlung radiation. As the wave hits a low e nergy

trough, the pressure drops, allowing electrons to recombine with atoms and light emission

to cease due to this lack of free electrons. This makes for a 160-picosecond light pulse for

argon (even a small drop in temperature causes a large drop in ionization, due to the

large ionization energy relative to photon energy). This description is simplified from the

literature above, which details various steps of differing duration from 15 microseconds

(expansion) to 100 picoseconds (emission).

Computations based on the theory presented in the review produce radiation parameters

(intensity and duration time versus wavelength) that match experimental results with

errors no larger than expected due to some simplifications (e.g., assuming a uniform

temperature in the entire bubble), so it seems the phenomenon o f sonoluminescence is at

least roughly explained, although some details of the process remain obscure.

Any discussion of sonoluminescence must include a detailed analysis of metastability.

Sonoluminescence in this respect is what is physically termed a bounded phenomenon

meaning that the sonoluminescence exists in a bounded region of parameter space for the

bubble; a coupled magnetic field being one such parameter. The magnetic aspects of

sonoluminescence are very well documented.

2.3. QUANTUM EXPLANATIONS

An unusually exotic hypothesis of sonoluminescence, which has received much popular

attention, is the Casimir energy hypothesis suggested by noted physicist Julian

Schwinger and more thoroughly considered in a paper by Claudia Eberleinof

the University of Sussex. Eberlein's paper suggests that the light in sonoluminescence is

generated by the vacuum within the bubble in a process similar to Hawking radiation, the

radiation generated at the event horizon of black holes. According to this vacuum energy

explanation, since quantum theory holds that vacuum contains virtual particles, the

rapidly moving interface between water and gas converts virtual photons into real

photons. This is related to the Unruh effector the Casimir effect. If true,

sonoluminescence may be the first observable example of quantum vacuum radiation.

The argument has been made that sonoluminescence releases too large an amount of

energy and releases the energy on too short a time scale to be consistent with the vacuum

15

energy explanation, although other credible sources argue the vacuum energy explanation

might yet prove to be correct.

2.4. NUCLEAR REACTION

Some have argued that the Rayleigh-Plesset equation described above is unreliable for

predicting bubble temperatures and that actual temperatures in sonoluminescing systems

can be far higher than 20,000 kelvins. Some research claims to have measured

temperatures as high as 100,000 kelvins, and speculates temperatures could reach into the

millions of kelvins.Temperatures this high could cause thermonuclear fusion. This

possibility is sometimes referred to as bubble fusion and is likened to the implosion

design used in the fusion component of thermonuclear weapons.

On January 27, 2006, researchers at Rensselaer Polytechnic Institute claimed to have

produced fusion in sonoluminescence experiments.

Experiments in 2002 and 2005 by R. P. Taleyarkhan using deuterated acetone showed

measurements of tritium and neutron output consistent with fusion. However, the papers

were considered low quality and there were doubts cast by a report about the author's

scientific misconduct. This made the report lose credibility among the scientific

community.

2.5. BIOLOGICALSONOLUMINESCENCE

Pistol shrimpalso called snapping shrimp produce a type of sonoluminescence from a

collapsing bubble caused by quickly snapping a specialized claw. The light produced is of

lower intensity than the light produced by typical sonoluminescence and is not visible to

the naked eye. The light and heat produced may have no direct significance, as it is the

shockwave produced by the rapidly collapsing bubble which these shrimp use to stun or

kill prey. However, it is the first known instance of an animal producing light by this

effect and was whimsically dubbed "shrimpoluminescence" upon its discovery in 2001.It

has subsequently been discovered that another group of crustaceans, the mantis shrimp,

contains species whose club- like forelimbs can strike so quickly and with such force as to

induce sonoluminescent cavitation bubbles upon impact.

16

When a gas bubble in a liquid is excited by ultrasonic acoustic waves it can emit short

flashes of light suggestive of extreme temperatures inside the bubble. These flashes of

light known as sonoluminescence, occur as the bubble implode or cavitates. It is show

that chemical reactions occur during cavitations of a single, isolated bubble and yield of

photons, radicals and ions formed. That is gas bubbles in a liquid can convert sound

energy in to light.

Sonoluminescence also called single-bubble sonoluminescence involves a single gas

bubble that is trapped inside the flask by a pressure field. For this loud speakers are used

to create pressure waves and for bubbles naturally occurring gas bubbles are used. These

bubbles can not withstand the excitation pressures higher than about 170 kilopascals.

Pressures higher than about 170 kilopascals would always dislodge the bubble from its

stable position and disperse it in the liquid. A pressure at least ten times that pressure

level to implode the bubbles is necessary to trigger thermonuclear fusion. The idea of

sonofusion overcomes these limitations.

17

3. THE IDEA OF SONOFUSION

It is hard to imagine that mere sound waves can possibly produce in the bubbles, the

extreme temperatures and pressures created by the lasers or magnetic fields, which

themselves replicate the interior conditions of stars like our sun, where fusion occurs

steadily. Nevertheless, three years ago, researchers obtained strong evidence that such a

process now known as sonofusion is indeed possible.

Sonofusion is technically known as acoustic inertial confinement fusion. In this we have a

bubble cluster (rather than a single bubble) is significant since when the bubble cluster

implodes the pressure within the bubble cluster may be greatly intensified. The centre of

the gas bubble cluster shows a typical pressure distribution during the bubble cluster

implosion process. It can be seen that, due to converging shock waves within the bubble

cluster, there can be significant pressure intensification in the interior of the bubble

cluster. This large local liquid pressure (P>1000 bar) will strongly compress the interior

bubbles with in the cluster, leading to conditions suitable for thermonuclear fusion. More

over during the expansion phase of the bubble cluster dynamics, coalescence of some of

interior bubbles is expected, and this will lead to the implosion of fairly large interior

bubbles which produce more energetic implosions.

3.1. EXPERIMENTAL SETUP

A. BASIC REQUIREMENTS

a. Pyrex flask.

b. Deuterated acetone (C3D6O).

c. Vacuum pump.

d. Piezoelectric crystal.

18

FIG. 3.1. EXPERIMENTAL SETUP

19

e. Wave generator.

f. Amplifier.

g. Neutron generator.

h. Neutron and gamma ray detector.

i. Photomultiplier.

j. Microphone and speaker.

20

4. SONOFUSION

The apparatus consists of a cylindrical Pyrex glass flask 100 m.m. in high and 65m.m.in

diameter. A lead-zirconate-titanate ceramic piezoelectric crystal in the form of a ring is

attached to the flask’s outer surface. The piezoelectric ring works like the loud speakers

in a sonoluminescence experiment, although it creates much stronger pressure waves.

When a positive voltage is applied to the piezoelectric ring, it contracts; when the voltage

is removed, it expands to its original size.

The flask is then filled with commercially available deuterated acetone (C3D6O), in which

99.9 percent of the hydrogen atoms in the acetone molecules are deuterium (this isotope

of hydrogen has one proton and one neutron in its nucleus). The main reason to choose

deuterated acetone is that atoms of deuterium can undergo fusion much more easily than

ordinary hydrogen atoms. Also the deuterated fluid can withstand significant tension

(stretching) without forming unwanted bubbles. The substance is also relatively cheap,

easy to work with, and not particularly hazardous.

4.1. ACTION OF VACUUM PUMP

The naturally occurring gas bubbles cannot withstand high temperature and pressure. All

the naturally occurring gas bubbles dissolved in the liquid are removed virtually by

attaching a vacuum pump to the flask and acoustically agitating the liquid.

4.2. ACTION OF THE WAVE GENERATOR

To initiate the sonofusion process, we apply an oscillating voltage with a frequency of

about 20,000 hertz to the piezoelectric ring. The alternating contractions and expansions

of the ring-and there by of the flask-send concentric pressure waves through the liquid.

The waves interact, and after a whiler they set up.

an acoustic standing wave that resonates and concentrates a huge amount of sound

21

energy. This wave causes the region at the flask’s centre to oscillate between a maximum

(1500kpa) and a minimum pressure.(-1500kpa).

4.3. ACTION OF THE NEUTRON GENERATOR

Precisely when the pressure reaches its lowest point, a pulsed neutron generatoris fired.

This is a commercially available, baseball bat size device that sits next to the flask. The

generator emits high-energy neutrons at 14.1 mega electron volts in a burst that lasts

about six microseconds and that goes in all directions.

4.4. ACTION IN THE FLASK

Stage 1:

Fig.4.1. Stage1

Some neutrons go through the liquid, and some collide head on with the Carbon, oxygen

and deuterium atoms of the deuterated acetone molecules. The fast moving neutrons may

knock the atom’s nuclei out of their molecules as these nuclei recoil; they give up their

kinetic energy to the liquid molecules. This interaction between the nuclei and the

molecules create heat in regions a few nanometers in size that results in tiny bubbles of

deuterated acetone vapor. Computer simulations, suggest that this process generates

clusters of about 1000 bubbles, each with a radius of only tens of nanometers.

Stage 2:

22

Fig.4.2. Stage 2

By firing the neutron generator during the liquid’s low pressure phase, the bubbles

instantly swell -a process known as cavitation. In these swelling phases, the bubbles

balloon out 100,000 times from their nanometer dimensions to about one millimeter in

size. To grasp the magnitude of this growth, imagine that the initial bubbles are the size of

peas after growing by a factor of 100,000, each bubble would be big enough to contain

the EmpireStateBuilding.

Stage 3:

Then the pressure rapidly reverses, the liquid pushes the bubbles’ walls inward with

tremendous force, and they implode with great violence. The implosion creates spherical

shock waves with in the bubbles that travel inward at high speed and significantly

strengthen as they converge to their centers.

23

Fig.4.3. Stage 3

The result, in terms of energy, is extra ordinary. Hydrodynamic shock-waves create, in a

small region at the centre of the collapsing bubble, a peak pressure greater than 10 trillion

kPa. For comparison, atmospheric pressure at sea level is101.3 kPa. The peak temperature

in this tiny region soars above 100 million degree centigrade about 20.000 times that of

the sun’s surface.

These extreme conditions within the bubbles-especially in the bubbles at the centre of the

cluster, where the shock waves are more intense because of the surrounding implosions-

cause the deuterium nuclei to collide at high speed. These collisions are so violent that the

positively charged nuclei overcome their natural electrostatic repulsion and fuse.

The fusion process creates neutrons which we detect using a scintillator, a device in

which the radiation interacts with a liquid that gives off light pulses that can be measured.

This process is also accompanied by bursts of photons, which is detected with a

photomultiplier. And subsequently, after about 20 microseconds, a shock wave in the

liquid reaches the flask’s inner wall, resulting in an audible “pop”, which can be picked

up and amplified by a microphone and a speaker.

24

4.5. FUSION REACTIONS

Fig. 4.4.Fusion Reactions

Deuterium-Deuterium fusion has two probable outputs, helium and a 2.45-MeV neutron

or tritium and a proton.

25

4.6. IF TRITIUM IS PRODUCED

Fig.4.5.Reaction with tritium

The total neutron output would include not only the neutrons from deuterium-deuterium

fusion, but also neutrons from deuterium-tritium fusion, since the tritium produced in

sonofusion remains within the liquid and can fuse with deuterium atoms. Compared with

deuterium-deuterium fusion, deuterium-tritium fusion occurs 1000 times more easily and

produces more energetic neutrons increasing the neutron yield by about three orders of

magnitude.

26

4.7. SCHEMATIC OF SONOLUMINESCENE &

SONOFUSION PHENOMENON

Fig.4.6. Schematic of Sonofusion&Sonoluminescene phenomenon

27

4.8. SEQUENCE OF EVENTS DURING SONOFUSION

Fig.4.7. Sequence of Events during Sonofusion

28

4.9. THE EVOLUTION OF LIQUID PRESSURE WITH IN BUBBLE

CLUSTER

Fig.4.8 Evolution of liquid pressure with in Bubble cluster.

29

5. SEPARATION OF DEUTERIUM FROM ORDINARY

HYDROGEN (PROTIUM)

5.1. SEPARATION FROM ORDINARY HYDROGEN BY DIFFUSION PROCESS

Deuterium can be isolated from ordinary hydrogen by taking advantage of different rates

of diffusion of the two isotopes. Protium, which is lighter, diffuses more readily than

deuterium. The diffusion is carried out under reduced pressure. The lower the pressure,

the greater is the efficiency of the process.

The process of diffusion is carried out in series of porous diffusion units, known as Hertz

diffusion units. Each unit contains a porous membrane represented by dotted portion. As

mixture is led into the diffusion units under reduced pressure, say from left to right, with

the help of the mercury diffusion pumps P1, P2, P3. etc. The heavier component

(deuterium) diffuses less readily and keeps behind while the lighter component (protium)

diffusing at a faster move more and more to the right. The process is repeated several

times, till ultimately, deuterium collects in the reservoir L on the left. The efficiency of

the separation process can be increased by increasing the number of diffusing units.

Fig. 5.1. Process of Diffusion

30

5.2. SEPARATION FROM ORDINARY HYDROGEN BY FRACTIONAL DISTILLATION

Deuterium can be separated from ordinary hydrogen by careful fractional distillation of

liquid hydrogen. Heavy hydrogen boils at -249.5 degree C while protium boils at a lower

temperature of -282.5 degree C. Hence fraction distillation of liquid hydrogen can result

in enrichment of the last fraction in deuterium, can be used for recovery of deuterium by

the diffusion process described above.

5.3. SEPARATION FROM ORDINARY HYDROGEN BY ADSORPTION ON CHARCOAL

Protium is adsorbed more readily and more strongly on solid surfaces in general and on

charcoal surface in particular. Thus when a mixture of the two isotopes is led over

charcoal kept at liquid air temperature, most of the protium gets adsorbed while most of

the deuterium passes out unchanged.

5.4. SEPARATION FROM ORDINARY HYDROGEN BY CHEMICAL METHODS

The lighter isotope (protium) is more reactive than the heavier isotope (deuterium). Thus

when ordinary hydrogen is passed over red hot copper oxide, the lighter component is

consumed more than the heavier one.

31

6. OTHER APPROACHES OF FUSION REACTION

There are mainly two approaches on fusion reactions other than bubble power. They are

1. Laser Beam Technique.

2. Magnetic Confinement Fusion.

6.1. LASER BEAM TECHNIQUE

In this process extremely energetic laser beams converge on a tiny solid pellet of

deuterium-deuterium fuel. The result is a shock wave that propagates towards the centre

of the pellet and creates an enormous increase in temperature and density.

One of the drawbacks of this approach is the amount of power lasers required. This

technique’s main goal is not producing energy but rather producing thermonuclear

weapons.

6.2. MAGNETIC CONFINEMENT FUSION

It uses powerful magnetic fields to create immense heat and pressure in hydrogen plasma

contained in a large, toroidal device known as a tokamak. The fusion produces high

energy by neutrons that escape the plasma and hit a liquid filled blanket surrounding it.

The idea is to use the heat produced in the blanket to generate vapor to drive a turbine and

thus generate electricity.

It is very much difficult to hold the plasma in place while increasing temperature and

pressure. It is a very unstable process that has been proved difficult to control.

32

7. EVIDENCE TO SUPPORT TABLE TOP NUCLEAR

FUSION DEVICE

There are two kinds of evidence that deuterium is fusing. The first neutron emission

detected by the neutron scintillator. The device registers two clearly distinct bursts of

neutron that are about 30 microseconds apart. The first is at 14.1 MeV, from the pulsed

neutron generator; the second, how ever, is at 2.45 MeV. This is the exact energy level a

neutron produced in a deuterium-deuterium fusion reaction is expected to have. These

2.45MeV neutrons are detected at about the same time that the photomultiplier detects a

burst of light, indicating that both events take place during the implosion of the bubbles.

The researchers believe the new evidence shows that "sonofusion" generates nuclear

reactions by creating tiny bubbles that implode with tremendous force. Nuclear fusion

reactors have historically required large, multibillion-dollar machines, but sonofusion

devices might be built for a fraction of that cost.

"What we are doing, in effect, is producing nuclear emissions in a simple desktop

apparatus," said RusiTaleyarkhan, the principal investigator and a professor of nuclear

engineer at Purdue University. "That really is the magnitude of the discovery - the ability

to use simple mechanical force for the first time in history to initiate conditions

comparable to the interior of stars."

The technology might one day result in a new class of low-cost, compact detectors for

security applications that use neutrons to probe the contents of suitcases; devices for

research that use neutrons to analyze the molecular structures of mate rials; machines that

cheaply manufacture new synthetic materials and efficiently produce tritium, which is

used for numerous applications ranging from medical imaging to watch dials; and a new

technique to study various phenomena in cosmology, including the workings of neutron

stars and black holes.

Taleyarkhan led the research team while he was a full-time scientist at the Oak Ridge

National Laboratory, and he is now the Arden L. Bement Jr. Professor of Nuclear

Engineering at Purdue.

The new findings are being reported in a paper that will appear this month in the journal

Physical Review E, published by the American Physical Society. The paper was written

by Taleyarkhan; postdoctoral fellow J.S Cho at Oak Ridge Associated Universities; Colin

West, a retired scientist from Oak Ridge; Richard T. Lahey Jr., the Edward E. Hood

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Professor of Engineering at Rensselaer Polytechnic Institute (RPI); R.C. Nigmatulin, a

visiting scholar at RPI and president of the Russian Academy of Sciences' Bashkortonstan

branch; and Robert C. Block, active professor emeritus in the School of Engineering at

RPI and director of RPI's Gaerttner Linear Accelerator Laboratory.

The discovery was first reported in March 2002 in the journal Science.

Since then the researchers have acquired additional funding from the U.S. Defense

Advanced Research Projects Agency, purchased more precise instruments and equipment

to collect more accurate data, and successfully reproduced and improved upon the

original experiment, Taleyarkhan said.

"A fair amount of very substantial new work was conducted, "Taleyarkhan said. "And

also, this time around I made a conscious decision to involve as many individuals as

possible - top scientists and physicists from around the world and experts in neutron

science - to come to the lab and review our procedures and findings before we even

submitted the manuscript to a journal for its own independent peer review."

The device is a clear glass canister about the height of two coffee mugs stacked on top of

one another. Inside the canister is a liquid called deuterated acetone. The acetone contains

a form of hydrogen called deuterium, or heavy hydrogen, which contains one proton and

one neutron in its nucleus. Normal hydrogen contains only one proton in its nucleus.

The researchers expose the clear canister of liquid to pulses of neutrons every five

milliseconds, or thousandths of a second, causing tiny cavities to form. At the same time,

the liquid is bombarded with a specific frequency of ultrasound, which causes the cavities

to form into bubbles that are about 60 nanometers - or billionths of a meter - in diameter.

The bubbles then expand to a much larger size, about 6,000 microns, or millionths of a

meter - large enough to be seen with the unaided eye.

"The process is analogous to stretching a slingshot from Earth to the nearest star, our sun,

thereby building up a huge amount of energy when released," Taleyarkhan said.

Within nanoseconds these large bubbles contract with tremendous force, returning to

roughly their original size, and release flashes of light in a well-known phenomenon

known as sonoluminescence. Because the bubbles grow to such a relatively large size

before they implode, their contraction causes extreme temperatures and pressures

comparable to those found in the interiors of stars. Researches estimate that temperatures

inside the imploding bubbles reach 10 million degrees Celsius and pressures comparable

to 1,000 million earth atmospheres at sea level.

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At that point, deuterium atoms fuse together, the same way hydrogen atoms fuse in stars,

releasing neutrons and energy in the process. The process also releases a type of radiation

called gamma rays and a radioactive material called tritium, all of which have been

recorded and measured by the team. In future versions of the experiment, the tritium

produced might then be used as a fuel to drive energy-producing reactions in which it

fuses with deuterium.

Whereas conventional nuclear fission reactors produce waste products that take thousands

of years to decay, the waste products from fusion plants are short- lived, decaying to non-

dangerous levels in a decade or two. The desktop experiment is safe because, although the

reactions generate extremely high pressures and temperatures, those extreme conditions

exist only in small regions of the liquid in the container - within the collapsing bubbles.

One key to the process is the large difference between the original size of the bubbles and

their expanded size. Going from 60 nanometers to 6,000 microns is about 100,000 times

larger, compared to the bubbles usually formed in sonoluminescence, which grow only

about 10 times larger before they implode.

"This means you've got about a trillion times more energy potentially available for

compression of the bubbles than you do with conventional sonoluminescence,"

Taleyarkhan said. "When the light flashes are emitted, it's getting extremely hot, and if

your liquid has deuterium atoms compared to ordinary hydrogen atoms, the conditions are

hot enough to produce nuclear fusion."

The ultrasound switches on and off about 20,000 times a second as the liquid is being

bombarded by neutrons.

The researchers compared their results using normal acetone and deuterated acetone,

showing no evidence of fusion in the former.

Each five-millisecond pulse of neutrons is followed by a five-millisecond gap, during

which time the bubbles implode, release light and emit a surge of about 1 million

neutrons per second.

In the first experiments, with the less sophisticated equipment, the team was only able to

collect data during a small portion of the five-millisecond intervals between neutron

pulses. The new equipment enabled the researchers to see what was happening over the

entire course of the experiment.

The data clearly show surges in neutrons emitted in precise timing with the light flashes,

meaning the neutron emissions are produced by the collapsing bubbles responsible for the

flashes of light, Taleyarkhan said.

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"We see neutrons being emitted each time the bubble is imploding with sufficient

violence," Taleyarkhan said.

Fusion of deuterium atoms emits neutrons that fall within a specific energy range of 2.5

mega-electron volts or below, which was the level of energy seen in neutrons produced in

the experiment. The production of tritium also can only be attributed to fusion, and it was

never observed in any of the control experiments in which normal acetone was used, he

said.

Whereas data from the previous experiment had roughly a one in 100 chance of being

attributed to some phenomena other than nuclear fusion, the new, more precise results

represent more like a one in a trillion chance of being wrong, Taleyarkhan said.

"There is only one way to produce tritium - through nuclear processes," he said.

The results also agree with mathematical theory and modeling.

Future work will focus on studying ways to scale up the device, which is needed before it

could be used in practical applications, and creating portable devices that operate without

the need for the expensive equipment now used to bombard the canister with pulses of

neutrons.

"That takes it to the next level because then it's a standalone generator," Taleyarkhan said.

"These will be little nuclear reactors by themselves that are producing neutrons and

energy."

Such an advance could lead to the development of extremely accurate portable detectors

that use neutrons for a wide variety of applications.

"If you have a neutron source you can detect virtually anything because neutrons interact

with atomic nuclei in such a way that each material shows a clear-cut signature,"

Taleyarkhan said.

The technique also might be used to synthesize materials inexpensively.

"For example, carbon is turned into diamond using extreme heat and temperature over

many years," Taleyarkhan said. "You wouldn't have to wait years to convert carbon to

diamond. In chemistry, most reactions grow exponentially with temperature. Now we

might have a way to synthesize certain chemicals that were otherwise difficult to do

economically.

"Several applications in the field of medicine also appear feasible, such as tumor

treatment."

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Before such a system could be used as a new energy source, however, researchers must

reach beyond the "break-even" point, in which more energy is released from the reaction

than the amount of energy it takes to drive the reaction.

"We are not yet at break-even," Taleyarkhan said. "That would be the ultimate. I don't

know if it will ever happen, but we are hopeful that it will and don't see any clear reason

why not. In the future we will attempt to scale up this system and see how far we can go."

There is a second fusion “fingerprint” by measuring levels of another hydrogen isotope,

tritium, in the deuterated acetone. The reason is that deuterium-deuterium fusion is a

reaction with two possible outputs at almost equal probability. On possibility gives 2.45

MeV neutrone plus helium, and the other gives tritium plus a proton. Thus, the build-up

of tritium above the measured initial levels is an independent and strong, indication that

fusion has taken place, since tritium can not be produced with out a nuclear reaction.

The desktop experiment is safe because although the reactions generate extremely high

pressures and temperature those extreme conditions exist only in small regions of the

liquid in the container-within the collapsing bubbles.

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8. ADVANTAGES AND APPLICATIONS OF BUBBLE

POWER OVER OTHER APPROACHES

8.1. ADVANTAGES

1. It is self sustainable.

2. Easily controllable.

3. It consistently produces more energy than it consumes.

4. Low cost.

5. Easily available raw materials.

6. Environmental friendly.

8.2. APPLICATIONS

1) Thermonuclear fusion gives a new, safe, environmental friendly way to produce

electrical energy.

2) This technology also could result in a new class of low cost, compact detectors for

security applications. That use neutrons to probe the contents of suitcases.

3) Devices for research that use neutrons to analyze the molecular structure of materials.

4) Machines that cheaply manufacture new synthetic materials and efficiently produce

tritium, which is used for numerous applications ranging from medical imaging to

watch dials.

5) A new technique to study various phenomenons in cosmology, including the working

of neutron star and black holes.

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9. FUTURE DEVELOPMENTS

9.1. FULLY SELF SUSTAINED

To make the fusion reaction fully self-sustainingarranging the setup so it produces a

continuous neutron outputwithout requiring the external neutron generator. One of the

possible ways isto put two complete apparatusesside by side so that they would

exchange neutrons and drive eachother’s fusion reactions. Imagine two adjacent

sonofusion setupswith just one difference: when the liquid pressure is low in one,it is

high in the other. That is, their pressure oscillations are180 degrees out of phase.

Suppose hit the first apparatus with neutrons from the external neutron generator,

causing the bubblecluster to form inside the first flask. Then turn off theneutron

generator permanently. As the bubble cluster grows andthen implodes, it will give off

neutrons, some of which will hitthe neighboring flask. If all is right, the neutrons will

hit the secondflask at the exact moment when it is at the lowest pressure,so that it

creates a bubble cluster there. If the process repeats,get a self-sustaining chain reaction.

9.2. TO CREATE A FULL-SIZE ELECTRICITY PRODUCING NUCLEAR GENERATOR

A table top single apparatus yields about 400000 per second. The neutrons are an

important measure of the output of the process because they carry most of the energy

released in the fusion reaction. Yet that yield corresponds to a negligible fraction of a

watt of power.

For operating a few thousand mega watts of thermal power, in terms of neutron-per-

second, output of 10^22 neutrons per second needed. For this we will improve various

parameters of Sonofusion process, such as the size of the liquid flask, the size of the

bubbles before implosion and the pressure compressing the bubbles etc. then we

installed a liquid filled blanket system around the reactor. All those high-energy

neutrons would collide with it, raising its temperature. So that it heat could used to boil

a fluid to drive a turbine and thus generate electricity.

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10. CONCLUSION

With the steady growth of world population and with economic progress in developing

countries, average electricity consumption per person has increased significantly. There

fore seeking new sources of energy isn’t just important, it is necessary. So for mo re than

half a century, thermonuclear fusion has held out the promise of cheap clean and virtually

limitless energy. Unleashed through a fusion reactor of some sort, the energy from 1 gram

of deuterium, an isotope of hydrogen, would be equivalent to that produced by burning

7000 liters of gasoline. Deuterium is abundant in ocean water, and one cubic kilometer of

seawater could, in principle, supply all the world’s energy needs for several hundred

years.

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11. REFERENCES

a. Richard T. Lahey Jr., Rusi P. Taleyarkhan& Robert I. Nigmatulin, bubble power,

IEEE spectrum, page no: 30-35,may 2005.

b. Fuels and combustion, author Samir Sarkar.

c. Principles of Inorganic chemistry, authors – Puri, Sharma, Kalia.

d. www.purdue.edu

e. www.iter.org

f. www.washington.edu

g. www.rpi.edu