All exercise Short Questions of Thermonuclear Reactions of book Nuclear Physics for BS/MSc Physics students.
What is the principle of fusion?
In fusion reaction, two nuclei merge to form a single heavier nucleus. This process releases energy because the total mass of the resulting single nucleus is less than the mass of the two original nuclei. The leftover mass becomes energy.
What is an example of fusion reaction?
Fusion joins atomic nuclei together. The element formed has more neutrons or more protons then that of the starting material. For example hydrogen and hydrogen can fuse to form helium.
Why is it called fusion?
The noun fusion is comes from the Latin word funder, meaning melt, so fusion is the act of melting things together. In science, fusion is the process of merging atoms together to create energy. Fusion is also used as an adjective.
Write another example of fusion?
If we consider the fusion of two deuterons to produce an alpha particle according to the equation
H2+H2 He4, we get the Q value of the reaction as
Q=Ba-2Bd =4fBa-2× (2fBd)
Q= 28.3-2×2.225=23.84Mev
What is nuclear fusion?
The process in which two light nuclei combine to form a single heavier one while releasing massive amounts of energy.
What is the region of very stable nuclei?
The maximum B.E per nucleon occurs at A=56. The shaded region is called region of very stable nuclei.
What is a repulsive and attractive nuclear?
The electric repulsive force between the portions is huge, but attractive nuclear force is even stronger and keeps the nucleus from bursting apart.
Why is it hard to start a fusion reaction?
Without the electron, atom has a positive charge and repel. This means that you have super high atomic energies to get these things to have nuclear fusion. High energy particles are the problem. Then fusion is difficult and fission is relatively simple.
What is the main application of fusion?
The main application for fusion is in making electricity. Nuclear fusion can provide a safe clean energy source for future generation with several advantages over current fission reaction.
What is abundant fuel supply?
The main fuel is used in nuclear fusion are deuterium and tritium, both heavy isotopes of hydrogen. Deuterium constitutes a tiny fraction of natural hydrogen, only 0.0153%, and can be extracted inexpensively from seawater. Tritium can be made from lithium, which is also abundant in nature.
Write difference between safe and clean fusion?
Safe
The amount of fuel used for fusion is small compared to fission reactor. This is so that uncontrolled releases of energy do not occur. Most fusion reactor makes less radiation than the natural background radiation we live within our daily life.
Clean
No combustion occur in nuclear power (fusion or fission) so there is no air pollution.
What does nuclear waste means?
Radioactive by- products resulting from fusion, fission, refinement, or processing of radioactive materials. This includes all solid and liquid radioactive wastes. This does not include the processing and storage facilities for such waste.
How can we reduce nuclear waste?
The most widely favored solution is deep geological disposal. The focus is on how and where is constructing such facilities. Used fuel that is not intended for direct disposal may instead be reprocessed in order to recycle the uranium and plutonium it contains.
What are examples of nuclear waste?
The various types of nuclear waste include uranium tailing, transuranic (TRU) waste, low level waste, intermediate-level waste, high-level waste and spent fuel rods.
How does nuclear waste affect humans?
Exposure to very high levels of radiation, such as being close to an atomic blast, can cause acute health effects such as skin burn and acute radiation syndrome (“radiation sickness”). It can also result in long term health effects such as cancer and cardiovascular disease.
Can nuclear waste recycled?
Yes, nuclear waste is recyclable.
Which temperature is required for nuclear fusion?
Extremely high temperatures are required for a nuclear fusion reaction to occur.
What is the temperature inside the sun and star?
The temperature inside the sun and stars is 108—109k.
Define thermonuclear fusion?
Fusion reactions taking place at such high temperature is called thermonuclear fusion.
What is Liberate energy?
It is an energy company that specializes in providing solar energy, renewable energy and alternative energy.
What is a real life example of fusion?
In nuclear fusion, atoms are fused or combine together to create energy. The sun is one of the best examples of nuclear fusion. Inside the sun, hydrogen nuclei fuse together to form helium, creating heat energy that warms the earth.
What do you know about R.Atkinson and F.Houtermans first suggestion?
R. Atkinson and F.Houtermans (1928) were the first suggest that the successive capture of four protons by some light nuclei to produce an alpha particle might be the processes which would releases energy at reasonable rates for sun to continue burning for such long time.
What is the most common reaction cycle?
Proton-proton cycle and carbon-nitrogen cycle
What is proton-proton cycle?
The proton- proton cycle is also called proton- proton chain or proton- proton reaction, chain of thermonuclear reactions that is the chief source of the energy radiated by sun and other cool main-sequence star.
Why proton-proton cycle is very slow?
This is the rate-limiting reaction and is extremely slow due to it being initiated by the weak nuclear force. The average proton in the core of sun waits 9 billion years before it successfully fuses with another proton.
Who can propose the carbon cycle?
In hotter star, the energy output is mainly from the carbon cycle which was proposed by H.A Bethe (1939)
Who is H.A Bethe?
Hans Albrecht Bethe was a German-American theoretical physicist who made major contributions to nuclear physics, astrophysics, quantum electrodynamics, and solid state physics and he won Nobel Prize (1967) in physics for his work on the theory of stellar nucleosynthesis.
What did Hans Bethe discover?
In 1938, Hans Bethe proved the fusion produces the enormous energy emitted by star. He proposed two different process, both of which result is in hydrogen nuclei fusing with helium nuclei.
What is the purpose of thermonuclear fusion?
Thermonuclear is the process that occurs when two atoms combine to make a larger atom, creating a whole lot of energy.
What are the immense pressure and a temperature of force atomic nuclei to fuse and liberate energy?
The immense pressure and a temperature of 16 million degree C force atomic nuclei to fuse and liberate energy.
How million tons of matter is converted into sunlight every second?
About four million metric tons of matter is converted into sunlight every second.
What is plasma state?
Matter in the ionized state is called plasma state, a sort of second gaseous state. The mixture is electrically neutral. The matter contained in stars and galaxies in largely in the plasma state.
Who discovered plasma?
In 1879 Sir William Crookes.
What is the critical size in nuclear physics?
The critical size is the minimum size of a nuclear reactor core or nuclear weapon that can be made for a specific geometrical arrangement and material composition.
What is critical temperature in physics?
Critical temperature (the maximum temperature at which a gas can be liquefied by pressure) range from 5.2k, for helium, to temperature too high to measure.
Why fusion reactions are difficult to maintain?
Without electrons, atoms have a positive charge and repel. This means that you have to super high atomic energies to get these things to have nuclear fusion. High energy particles are problem.
What factors make fusion reaction difficult?
It has been particularly difficult to obtain high energy plasma densities, temperature, and energy confinement time simultaneously.
What is magic bottle method?
Bottle magic, better known as impossible bottles, the art of placing decks of cards and other objects into ordinary glass bottles through the neck.
What is pinch effect?
The construction of a plasma through which a large electric current is flowing, caused by attractive force of the current own magnetic field.
What do you mean by plasma instability?
Plasma instability is a region where turbulence occurs due to changes in the characteristics of plasma. (Example. temperature, density, electric field, magnetic fields)
Can plasma be stabilized?
In many cases, plasma can be treated as a fluid and its stability analyzed with magneto hydrodynamics (MHD). (MHD) theory is the simplest representation of plasma, so MHD stability is a necessity for stable devices to be used for nuclear fusion, specifically magnetic fusion energy.
Write the three main problems have to solve by modern research?
To find a way of heating a plasma to T ≥ 2×108K.
To device methods of controlling and isolating the hot plasma for adequate time.
To design a practical fusion reactor to produce electricity density and economically.
Who is J.D Lawson?
John David Lawson FRS was British engineer and physicist.
What is the work of J.D Lawson?
He is particularly remembered for Lawson criterion, a general measure of a system that defines the conditions needed for fusion reactor to achieve net power. Formulated in 1955, it was first publish in 1957, in some criteria for power producing thermonuclear reactor.
What are Lawson criteria?
The Lawson criterion is a figure of merit used in nuclear fusion research. It compares the rate of energy being generated by fusion reactions within the fusion fuel to the rate of energy losses to the environment. When the rate of production is higher than the rate of loss, the system will produce net energy.
What is energy confinement time?
The energy confinement time measures the rate at which the confined plasma loses energy to its environment. According to the Lawson criterion for ignition, the minimum energy confinement time for optimal D-T fusion is somewhat order 1 second while the temperature is approximately 15Kev.
What is required minimum value of the individual plasma parameters?
T= 1-2 ×108K
N = 2-3×1020sec/m3
tc= 0.5 -1.0sec
What do you mean by plasma confinement?
Plasma confinement refers to the containment of plasma by various forces at the extreme conditions necessary for thermonuclear fusion reactions.
What type of plasma is confinement?
Two type of plasma confinement have been reported, namely, magnetic and spatial confinement for enhancing the emission from laser-produced plasma.
How does plasma confinement reactor work?
The magnetic confinement concept employs a giant magnetic field to confine the movement of deuterium-tritium plasma.
What is meant by magnetic confinement?
The magnetic confinement concept employs a giant magnetic field to confine the movement of deuterium-tritium plasma.
What is magnetic mirror?
A magnetic mirror is a static magnetic field that, within a localized region, has a shape such that approaching charged particles are repelled back along their path of approach.
Can mirror be magnetic?
A magnetic mirror therefore produces a very strong electric filed at the mirror surface, enabling maximum absorption of the electromagnetic wave energy and paving the way for exciting new application said Brenner.
What is meant by magnetic bottle?
A magnetic field for confining plasma for experiments in nuclear fusion.
What is mirror machine?
The magnetic mirror is used for confinement of plasma inside a fusion reactor. Such reactors called mirror machine.
The magnetic bottle consist how many coils?
The magnetic bottle consists of two parallel coils separated by a small distance.
How many rings in typical bottle and full mirror machine?
A typical bottle has just two rings while full mirror machine has many rings.
Why is it called inertial confinement?
The inertia of fuel keeps it from escaping hence the name inertial-confinement fusion (ICF). Of course the quantity of fuel has to be much smaller than that used in a bomb, so that energy released in each “explosion” will not destroy the surrounding environment.
Write any two main tokamaks components and function?
High power supplies are used to generate the magnetic field and plasma.
The contained in a vacuum vessel. The vacuum is maintained by external pumps. The plasma is creating by small puff of gas. The puff of gas is heated- heated by driving a current through it.
Tokamak stands for?
Toroidal Magnetic Chamber.
Who proposed the tokamaks system?
Tokamak system was first proposed by U.S.S.R Physicist in 1969.
What are the conditions for occurrence of fusion?
Fusion required temperatures of about 100 million Kelvin (approximately six times hotter than the sun core). At theses temperatures, hydrogen is plasma not a gas. Plasma is a high energy state of matter in which all the electrons are stripped from atoms and move freely.
Define thermonuclear fusion?
Fusion reaction taking place at such high temperature called thermonuclear fusion.
What are required factors for controlled fusion reaction?
Plasma physicist combines three parameters temperature, density and time.
Existence of life on earth is based on fusion reaction. justify
Today, we know that the sun, along with all other stars, is powered by a reaction called nuclear fusion. If nuclear fusion can be replicated on the earth, it could provide virtually limitless clean. Safe and affordable energy to meet the world’s energy demand.
Differentiate D-D and D-T reactions?
The two nuclear reactions now most commonly used for power production purposes are designated as DD and DT reaction. The former stands for deuterium-deuterium and involves the combination of two deuterium nuclei to form helium-3 nucleus and free neutron.
Why fusion reaction is more favorable than fission reaction?
The fusion reaction release more energy than fission.
Calculate the potential barrier for proton-proton fusion?
Why energy released in fusion reaction is greater than that of in fusion reaction?
Fusion occurs when two atoms slam together to form heavier atom, like when two hydrogen atoms fuse to form one helium atom. This is the same process that powers the sun and creates huge amounts of energy—several times greater than fission. It also doesn’t produce highly radioactive fission product.
Calculate the potential barrier for carbon- nitrogen fusion?
Define the ionized state of matter? Matter is the ionized state is called plasma state, a sort of second gaseous state. The mixture is electrically neutral. The matter contained in stars and galaxies is largely in the plasma state.
