A brief history of discovery of structure of atoms - particles and rays, nuclear decays, radioactivity, X-ray production. For RADIATION ONCOLOGY students. Purely academic and non-commercial purpose.
Oral medicine and Radiology, Dentistry
Components of tube head.
Production of X-rays
Factors controlling the x-ray beam.
Collimation.
Inverse square law.
Stuart. C. White and Michael J. Pharoah
this is to present basic functional principles of high frequency x-ray generators. The emphasis is put on physical concepts that determine the engineering solutions to the problem of efficient generation and control of high voltage power required to drive the x-ray tube. The physics of magnetically coupled circuits is discussed first, as a background for the discussion of Study related to high-frequency power transformer design by X-ray Generator.
X- Ray physics- X-Ray Tube, Transformer, Generator and Rectifiers by kajalsra...DrKajalLimbad
X-Ray physics including x-ray tube, transformer, generator, and rectifiers. physics made an easy
Note: this ppt has many animations that may not be appreciated over here. Request original ppt at kajalsradiology@gmail.com
Oral medicine and Radiology, Dentistry
Components of tube head.
Production of X-rays
Factors controlling the x-ray beam.
Collimation.
Inverse square law.
Stuart. C. White and Michael J. Pharoah
this is to present basic functional principles of high frequency x-ray generators. The emphasis is put on physical concepts that determine the engineering solutions to the problem of efficient generation and control of high voltage power required to drive the x-ray tube. The physics of magnetically coupled circuits is discussed first, as a background for the discussion of Study related to high-frequency power transformer design by X-ray Generator.
X- Ray physics- X-Ray Tube, Transformer, Generator and Rectifiers by kajalsra...DrKajalLimbad
X-Ray physics including x-ray tube, transformer, generator, and rectifiers. physics made an easy
Note: this ppt has many animations that may not be appreciated over here. Request original ppt at kajalsradiology@gmail.com
Matter Structure & Chemical & Physical changes, properties, and processes.Ospina19
A brief introduction to matter structure and how chemical and physical changes affect its properties in the processes described before. For more science information follow this link, which will take you to our blog; http://biologyblogvermont7.weebly.com
Types of radiation
and
Interaction of radiation with matter
How different types of matter interacts with different media. Includes interaction of photon, neutron, proton, electron and alpha particles.
CONTENTS
INTRODUCTION
NEED FOR CYBER LAWS
CYBER LAWS IN INDIA
CYBER CRIMES
OFFENCES AND LAWS IN CYBER SPACE
CYBER LAWS AMENDMENTS
CONCLUSION
INTRODUCTION
What is Cyber Law?
Cyber Law is the lawgoverning cyber space.Cyber space is a very wideterm and includescomputers, networks,software, data storagedevices (such as hard disks,USB disks etc), theInternet, websites, emailsand even electronic devicessuch as cell phones, ATMmachines etc.
Cyber lawencompasses lawsrelating to
:
1. Cyber Crimes
2. Electronic and DigitalSignatures
3. Intellectual Property
4. Data Protection andPrivacy
NEED FOR CYBER LAWS
TACKLING CYBERCRIMES
INTELLECTUALPROPERTYRIGHTS ANDCOPYRIGHTSPROTECTION ACT
NEED FOR CYBER LAWS
1. Cyberspace is an
intangible
dimension that is impossible togovern and regulate usingconventional law.
2. Cyberspace has complete
disrespect for jurisdictionalboundaries
. A person in Indiacould break into a bank’selectronic vault hosted on acomputer in USA and transfermillions of Rupees to anotherbank in Switzerland, all withinminutes. All he would need is alaptop computer and a cellphone.
3. Cyberspace
handlesgigantic traffic volumesevery second
. Billions ofemails are crisscrossing theglobe even as we read this,millions of websites are beingaccessed every minute andbillions of dollars areelectronically transferredaround the world by banksevery day.
4. Cyberspace is
absolutelyopen to participation by all.
A ten year-old in Bhutan canhave a live chat session with aneight year-old in Bali withoutany regard for the distance orthe anonymity between them
ABOUT AUTHOR
Sumit Verma
Chitkara University
Undergraduate
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RADIOACTIVITY
Atomic theory
In chemistry and physics, the atomic theory explains how our understanding of the atom has changed over time. Atoms were once thought to be the smallest pieces of matter.
The first idea of the atom came from the Greek philosopher Democritus. A lot of the ideas in the modern theory came from John Dalton, a British chemist and physicist.
Democritus' atomic theory
3.1 Discovery of the X Ray and the Electron
3.2 Determination of Electron Charge
3.3 Line Spectra
3.4 Quantization
3.5 Blackbody Radiation
3.6 Photoelectric Effect
3.7 X-Ray Production
3.8 Compton Effect
3.9 Pair Production and Annihilation
Quantum Mechanics: Electrons, Transistors, & LASERS. Paul H. Carr
Quantum Mechanics, QM, has enabled new technologies that impact our daily lives. Yet, there have been at least 14 different QM interpretations in the last century. “If you think you understand QM, you don’t,” said Richard Feynman. Our macroscopic language is inadequate to describe the wave-particle duality of microscopic QM particles. Mathematics works better. This talk illuminated the production of the play Copenhagen, in which German physicist Werner Heisenberg, who directed the German attempt to make an atom bomb, visited Niels Bohr in Denmark during WWII.
4.1 The Atomic Models of Thomson and Rutherford
4.2 Rutherford Scattering
4.3 The Classic Atomic Model
4.4 The Bohr Model of the Hydrogen Atom
4.5 Successes and Failures of the Bohr Model
4.6 Characteristic X-Ray Spectra and Atomic Number
4.7 Atomic Excitation by Electrons
Nuclear physithese slides are related to the introduction of nuclear physics some contents is given which are related to the discovery of nucleus. The history of atoms etc
Structure of Atoms some basic concepts of atomic structure its history of modelling and also the present and accepted model including the quantum model of atomic structure.
Similar to Bikramjit radiation physics lecture1 (20)
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Eutylone crystal
Protonitazene (hydrochloride) CAS: 119276-01-6
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Samples will be sent for your evaluation!If you are interested in, please contact me, let's talk details.
We specializes in exporting high quality Research chemical, medical intermediate, Pharmaceutical chemicals and so on. Products are exported to USA, Canada, France, Korea, Japan,Russia, Southeast Asia and other countries.
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
The prostate is an exocrine gland of the male mammalian reproductive system
It is a walnut-sized gland that forms part of the male reproductive system and is located in front of the rectum and just below the urinary bladder
Function is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semen
A healthy human prostate measures (4cm-vertical, by 3cm-horizontal, 2cm ant-post ).
It surrounds the urethra just below the urinary bladder. It has anterior, median, posterior and two lateral lobes
It’s work is regulated by androgens which are responsible for male sex characteristics
Generalised disease of the prostate due to hormonal derangement which leads to non malignant enlargement of the gland (increase in the number of epithelial cells and stromal tissue)to cause compression of the urethra leading to symptoms (LUTS
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
4. A brief history of discovery of
atomic structure
• Discovery of cathode ray, X-ray
• Discovery of radioactive elements – natural
and artificial,
• Discovery of nucleus, atomic and fundamental
particles.
5. John Dalton (1803)
1. All elements are composed of
atoms, which are indivisible and
indestructible particles.
2. All atoms of the same element are
exactly alike; in particular, they all
have the same mass.
3. All atoms of different elements are
different; in particular, they have
different masses.
4. Compounds are formed by the
joining of atoms of two or more
elements. In any compound atoms
combined only in small whole-number
ratios, such as 1:1, 1:2, 2:1, 2:3, to
form compounds.
6. Cathode Ray
- Johann Hittorf & Eugen Goldstein (1869)
Cathode ray causing fluorescence on glass wall.
Shadow of fan is deviated when magnetic field is
applied.
7. Cathode ray
•Traveled in a straight line
•Their path could be "bent" by the influence of magnetic or electrical fields
•A metal plate in the path of the "cathode rays" acquired a negative charge
•Produce fluorescence
8. Wilhelm Roentgen (1895)
New type of ray that
1.Could pass unimpeded through
many objects
2.Were unaffected by magnetic or
electric fields
3.Produced an image on
photographic plates (i.e. they
interacted with silver emulsions
like visible light)
4.Produced fluorescence
5.Ionized a gas
9. X ray production
Vacuum
glass tube
Vacuum
glass tube
Cathode
made of
tungsten
filament
Cathode
made of
tungsten
filament
High voltage
(10V, 6A) for TI E
High voltage
(10V, 6A) for TI E
Thick
copper
rod
Thick
copper
rod
High Z,
High melting
point
High Z,
High melting
point
Cu: absorbs stray electrons,
W: absorbs stray XR
Cu: absorbs stray electrons,
W: absorbs stray XR
Coolidge tube
10. • Focal spot: Line focus (a
sinѲ)
• Heel effect
• Circuitry: step-up
transformer and rheostat
• Tube voltage measured by
sphere gap method.
• Efficiency= OE/IE,
• Output = exposure =
ionization produced,
depends on voltage.
11. • The probability of
bremsstrahlung emission is
proportional to the value of Z2
• Fluorescent yield: Probability to
produce characteristic X-rays.
• Typical anode currents,
depending on the examination
mode, are <10 mA in
fluoroscopy and 100 mA to
>1000 mA in single exposures.
• The typical range of tube
voltages is 40–150 kV for
general diagnostic radiology and
25–40 kV in mammography.
12. Properties of X-ray produced
Heterogeneous: The energy of the Bremsstrahlung photon depends on
• the attractive Coulomb forces and hence on the distance of the
electron from the nucleus.
• Energy of incident electrons
Self-filtration: X rays are not generated at the surface but within the
target, resulting in an attenuation of the X ray beam. This self-
filtration appears most prominent at the low energy end of the
spectrum. Additionally, characteristic radiation shows up if the
kinetic electron energy exceeds the binding energies. L radiation is
totally absorbed by a typical filtration of 2.5 mm Al. For tungsten
targets, the fraction of K radiation contributing to the total energy
fluence is less than 10% for a 150 kV tube voltage.
13. Contd..
• For mammography, other anode materials such as molybdenum (Z =
42) and rhodium (Z = 45) are frequently used. For such anodes, X ray
spectra show less contribution by bremsstrahlung but rather
dominant characteristic X rays of the anode materials. This allows a
more satisfactory optimization of image quality and patient dose. In
digital mammography, these advantages are less significant and
some manufacturers prefer tungsten anodes.
• Off focus radiation: Extrafocal radiation can contribute up to ~10% of
the primary X ray intensity. Sometimes, parts of the body are imaged
outside the collimated beam by off focus radiation. Off focus
radiation also increases patient dose. The best position for a
diaphragm to reduce off focus radiation is close to the focus.
14. Antonio Henri Becquerel (1896)
Radioactivity – radiation from nucleus
Photographic plate with potassium uranyl sulfate
crystals showed a dark spot even when stored in
dark.
15. JJ THOMSON (1897) – CRT
experiment: Discovery of electron
• Electron was discovered by J. J.
Thomson in 1897 when he was
studying the properties of cathode
ray.
• J. J. Thomson measured the charge-by-
mass-ratio (e/m) of cathode ray
particle using deflection in both
electric and magnetic field.
• em=−1.76×108em=−1.76×108 coul
omb per gram
• Thompson determined the charge to
mass ratio for the electron, but was not
able to determine the mass of the
electron.
17. In 1899, Rutherford had
discovered alpha and
beta "rays" from
uranium.
Now, today we know they are not rays,
they are particles; alpha is a nucleus
of helium and beta is an electron.
Ernest Rutherford (1899)
18. Albert Einstein (1905)
Nobel prize for work on photo-electric effect !!
• The laws of physics are the same for all
observers in uniform motion relative to
one another (principle of relativity),
• The speed of light in a vacuum is the
same for all observers, regardless of their
relative motion or of the motion of the
source of the light.
• E= mc2.
The faster an object moves, the
more massive it becomes. That means
that, in theory, no object can ever reach
100 percent of the speed of light because
its mass would become infinite.
• The general theory of relativity (1916):
acceleration distorts the shape of time
and space.
19. Ernest Rutherford (1908)
But why electrons do not radiate
energy to spiral into the nucleus?
Line spectra not explained
20. Ernest Rutherford (1908)
1. Almost all the incident alpha
particles go straight and are scarcely
scattered.
2. Only occasionally such a large-
angle scattering through an angle
greater than 90 degrees or near 180
degrees occurs.
3. The scattering rate depends on the
atomic weight of the target; the more
the atomic weight, the larger the
probability.
21. Concept of proton (in anode or
canal rays) – Goldstein (1908)
• The lightest
ones, formed
when there was
some hydrogen g
as in the tube,
were calculated
to be about 1840
times as massive
as an electron.Cathode: Perforated,
Potential difference: several thousands.
22. Niels Bohr (1913) - postulates
• Electrons can exist only in
orbits where angular
momentum = multiple of
Planck constant/2π
• No energy is gained or lost
when in this permissible orbits.
• Radiation is absorbed or
emitted when an electron
moves from one orbit to
another. And the energy
change E = E2 – E1
23. Niels Bohr (1913) – failed to explain
• Incorrect value for the ground state orbital
angular momentum.
• Dual nature of electron and the Heisenberg
Uncertainty Principle because it considers
electrons to have both a known radius and
orbit.
• No explanation of fine structure of spectra
-Existence of additional quantum numbers.
• Poor predictions regarding the spectra of
larger atoms.
• Does not explain fine structure and
hyperfine structure in spectral lines.
• No explanation for Zeeman Effect and Stark
Effect.
24. Arnold Somerfield
• He introduced the 2nd quantum
number (azimuthal quantum
number) and the 4th quantum
number (spin quantum
number). He also introduced
the fine-structure constant and
pioneered X-ray wave theory.
• Elliptical orbit
• Sub-shell s,p,d,f
• Modification of angular
momentum as given by Bohr.
25. Max Karl Ernst Ludwig Plank (1918)
• Worked on thermodynamics.
• Energy did not flow in a
steady continuum, but was
delivered in discrete packets
Planck later called quanta.
• Planck's constant (the
proportion of light's energy to
its wave frequency, or
approximately
h = 6.626 x 10-34
J-sec).
29. ‘GOD PARTICLES’ ARE
BOSONS
The “God particle” nickname actually arose when the book The
God Particle: If the Universe Is the Answer, What Is the Question?
by Leon Lederman was published.
30. • In 1924, Satyendra Nath Bose published an article titled
Max Planck's Law and Light Quantum Hypothesis. This
article was sent to Albert Einstein. Einstein appreciated it
so much that he himself translated it into German and
sent it for publication to a famous periodical in Germany
- 'Zeitschrift fur Physik'. The hypothesis received a great
attention and was highly appreciated by the scientists. It
became famous to the scientists as 'Bose-Einstein
Theory‘.
• A Bose–Einstein condensate (BEC) is a state of matter of
a dilute gas of bosons cooled to temperatures very close
to absolute zero (that is, very near 0 K or −273.15 °C).
Under such conditions, a large fraction of bosons occupy
the lowest quantum state, at which point macroscopic
quantum phenomena become apparent.
31. 89 years later....
• The Nobel Prize in Physics 2013 was awarded jointly to
François Englert and Peter W. Higgs "for the theoretical
discovery of a mechanism that contributes to our
understanding of the origin of mass of subatomic particles,
and which recently was confirmed through the discovery of
the predicted fundamental particle, by the ATLAS and CMS
experiments at CERN's Large Hadron Collider.
And now boson became ‘Higgs Boson’ !!!!!
32. Louis de Broglie (1925)
– Wave-particle duality
• Wave like properties: eg refraction,
• Particle like properties: eg momentum
• Uncertainty about position and
momentum of wave.
• E= hv = hc/λ
33. Erwin Schrödinger (1926)
-quantum mechanical model of the atom.
• By solving the Schrödinger equation
(Hψ = E ψ), we obtain a set of
mathematical equations, called wave
functions (ψ), which describe the
probability of finding electrons at
certain energy levels within an
atom..
34. Quantum number of electrons
QUANTUM NUMBERS OF ELECTRON VALUE SPECIFIES
Principal Quantum Number (n) n = 1, 2, 3, …, ∞ Energy of an electron and
the size of the orbital
Angular Momentum (Secondary,
Azimunthal) Quantum Number (l)
l = 0, ..., n-1. Divides the shells into subshells
(s,p,d,f)
Magnetic Quantum Number (ml) ml = -l, ..., 0, ..., +l. divides the subshell into
individual orbitals
Spin Quantum Number (ms) ms = +½ or -½. Specifies the orientation of the
spin axis of an electron.
• Atomic orbital describes a region of space in which there is a high
probability of finding the electron. Energy changes within an atom
are the result of an electron changing from a wave pattern with one
energy to a wave pattern with a different energy (usually
accompanied by the absorption or emission of a photon of light).
• Each electron in an atom is described by four different quantum
numbers. The first three (n, l, ml) specify the particular orbital of
interest, and the fourth (ms) specifies how many electrons can
occupy that orbital.
35. James Chadwick (1935)
Discovery of neutron
Schematic diagram for the
experiment that led to the
discovery of neutrons by
Chadwick.
4Be9
+2α4
[⟶ 6C13
] [⟶ 6C12
]+0n1
36. Wolfgang Pauli (1945)
Pauli exclusion principle, a quantum mechanical principle
No two electrons in the same
atom can have identical values
for all four of their quantum
numbers.
Two electrons in the same orbital
must have opposite spins.
37. Enrico fermi
• Built first nuclear reactor
• Postulated and named
neutrino,
• Described weak nuclear
force,
• He was present at the
Trinity test on 16 July 1945,
where he used his Fermi
method to estimate the
bomb's yield.
• Fermions are named after
him.
38.
39. Commonly used γ-emitters
ISOTOPE SOURCE HALF LIFE PRODUCT ENERGY HVL Pb
88Ra226
NATURAL 1622 yrs 82Pb206 0.83 MeV 16-20 mm
27Co60
27Co59
5.26 yrs 28Ni60 1.25 MeV 11 mm
55Cs137
92U235
30 yrs 56Ba137 0.66 MeV 6.5 mm
77Ir192
77Ir191
74 days 78Pt192 0.38 MeV 6 mm
46Pd103
46Pd102
17 days 45Rh103 0.021 MeV
53I125
54Xe124
60 days 52Te125 0.026 MeV 0.025 mm
53I131
52Te130
8 days 54Xe131 0.364 MeV
43Tc99m
42Mo98
6 hrs Tc99 0.14 MeV
PURE BETA
EMITTERS
ALPHA EMITTERS NEUTRON EMITTER POSITRON EMITTER
Y90
, Sr90
, P32
, Tl204
,
C14
, tritium (H3
)
Bi212
, Pb212
, Ac225,
Po210
, U238
Cf252
F18
, C11
, O15
, N13
40. • Difference between molecule, atom, radical, ion
• Size of atom: 10-10
m, nucleus: 10-15
m.
• Nucleus
• Atomic mass: Amu = 1
/12 of C12
= 1.66 X 10-27
kg = 931.5 MeV
(1 eV = 1.602 X 10-19
J)
• No of atoms per gram = NA/AW
• No of electrons per gram = NA*Z/AW
• Energy levels of
– Atoms
– Nucleus:
Mass defect = binding energy of nucleus
Alpha particle requires nearly 30 Mev to cross potential barrier of
nucleus.
– Electron: Potential energy = negative of binding energy.
41. Electron
• Unit negative charge:
1.602X 10-19
C
• Mass: 5.48 X 10-4
amu
• K,L,M shells: 2n2
• Proton:
• Mass: 1.00727 amu
42. Identify…
• Atomic number
• Mass number
• Isobar
• Isotope
• Isotone
• Isomer
• Radio-isotope
vs radio-nuclide
43. Fundamental particles
FERMION BOSON
Matter particles
12 in number
Types: 6 quarks + 6 leptons
Odd half-integer spin of
quantum units of ang mom.
Messenger particles
13 in number
Types: Photon, gluon, Weak force, gluon, gravitron
etc.
Integer spin (0,1,2)
46. Alpha decay
2 neutrons + 2 protons ejected as helium nucleus
• Most common type of decay,
• Seen in Z > 82
• Alpha particles are helium nuclei,
• Alpha particles have a typical kinetic energy of
5 MeV.
47. High n/p ratio - β-
decay
Neutron converts into proton along with beta ray emission
•Beta particles are emitted with a spectra of energy, from zero to
a maximum value.
•Average energy is 1/3 of maximum energy.
48. Low n/p ratio
Proton converts into neutron
Orbital electron capture (K capture)
With characteristic X-ray emission
(internal PE effect)
β+
decay
With
positron
emission
49. Other processes
• Internal conversion:
– Excess energy liberated
as γ → ejects orbital
electron → ‘hole’ →
characteristic x-ray
produced.
• Isomeric transition
– 99m
Tc → 99
Tc
51. Nuclear reactions
• α-p reaction
• α-n reaction
• Proton (p,γ; p,n; p,d; p,α reactions):
• Neutron bombardment (fast neutrons required if mass
difference is high):
– n-γ reaction (common)
– n-α reaction
– n-p reaction
• Deuteron (fast neutron stripped):
• Photo-disintegration
• Fission: High Z → low Z
• Fusion: Low Z → high Z
52. Remember..
• Activity = number of disintegrations per
second.
• Decay constant
• Half life
• Mean or average life = avg time before a
particle decays.
• 1 Ci = rate of decay of 1 gram radium = 3.7 X 1010
Bq
• 1 Bq = 1 dps
53. Activating nuclide in nuclear
reactor
• Chain reaction of fission -> Neutrons
generated -> bombarded to produce radio-
nuclide from non-radioactive nuclide.
54. Lecture 2
Next day
• Types of radiation.
• Interaction of radiation with matter.
Editor's Notes
Particle physics is the study of the basic elements of matter and the forcesacting among them. It aims to determine the fundamental laws that control themake-up of matter and the physical universe.
Quantum mechanics (QM -- also known asquantum physics, or quantum theory) is a branch of physics which deals with physical phenomena at nanoscopic scales where the action is on the order of the Planck constant. It departs from classical mechanics primarily at the quantum realm of atomic and subatomic length scales
Particle physics is the study of the basic elements of matter and the forcesacting among them. It aims to determine the fundamental laws that control themake-up of matter and the physical universe.
Quantum mechanics (QM -- also known asquantum physics, or quantum theory) is a branch of physics which deals with physical phenomena at nanoscopic scales where the action is on the order of the Planck constant. It departs from classical mechanics primarily at the quantum realm of atomic and subatomic length scales
1803 Dalton - the atom is a indivisible, indestructible, tiny ball
atom meaning &quot;indivisible&quot; in Greek
They were first observed in 1869 by German physicist Johann Hittorf, and were named in 1876 by Eugen Goldstein Kathodenstrahlen, or cathode rays.
Cathode rays and electrons
Electrical discharge through partially evacuated tubes produced radiation. This radiation originated from the negative electrode, known as the cathode (thus, these rays were termed cathode rays).
The &quot;rays&quot; traveled towards, or were attracted to the positive electrode (anode)
Not directly visible but could be detected by their ability to cause other materials to glow, or fluoresce
Traveled in a straight line
Their path could be &quot;bent&quot; by the influence of magnetic or electrical fields
A metal plate in the path of the &quot;cathode rays&quot; aquired a negative charge
The &quot;cathode rays&quot; produced by cathodes of different materials appeared to have the same properties
Henri Becquerel (1896) was studying materials which would emit light after being exposed to sunlight (i.e. phosphorescent materials). The discovery by Roentgen made Becquerel wonder if the phosphorescent materials might also emit x- rays. He discovered that uranium containing minerals produced x-ray radiation (i.e. high energy photons).
The electron is a subatomic particle, symbol e− or β−, with a negative elementary electric charge.[8]Electrons belong to the first generation of the leptonparticle family,[9] and are generally thought to beelementary particles because they have no known components or substructure.[1] The electron has amass that is approximately 1/1836 that of theproton.[10] Quantum mechanical properties of the electron include an intrinsic angular momentum (spin) of a half-integer value in units of ħ, which means that it is a fermion. Being fermions, no two electrons can occupy the same quantum state, in accordance with the Pauli exclusion principle.[9] Like all matter, electrons have properties of both particles and waves, and so can collide with other particles and can bediffracted like light. The wave properties of electronsare easier to observe with experiments than those of other particles like neutrons and protons because electrons have a lower mass and hence a higher De Broglie wavelength for typical energies.
Radium was discovered by Marie Sklodowska-Curie and her husband Pierre Curie on 21 December 1898, in a uraninitesample.[14] While studying the mineral earlier, the Curies removed uranium from it and found that the remaining material was still radioactive.
Einstein worked in a patent office in Bern, Switzerland, from 1902 through 1909 (during the time he published his landmark works). Even people who will be famous have day jobs.
He won the Nobel Prize for Physics in 1921. What for? His work on the photoelectric effect, which held that light be considered as consisting of particles called photons.
Rutherford&apos;s find came from a very strange experience. Everyone at that time imagined the atom as a &quot;plum pudding.&quot; That is, it was roughly the same consistency throughout, with negatively-charged electrons scattered about in it like raisins in a pudding. As part of an experiment with x-rays in 1909, Rutherford was shooting a beam of alpha particles (or alpha rays, emitted by the radioactive element radium) at a sheet of gold foil only 1/3000 of an inch thick, and tracing the particles&apos; paths. Most of the particles went right through the foil, which would be expected if the atoms in the gold were like a plum pudding. But every now and then, a particle bounced back as though it had hit something solid. After tracing many particles and examining the patterns, Rutherford deduced that the atom must have nearly all its mass, and positive charge, in a central nucleus about 10,000 times smaller than the atom itself. All of the negative charge was held in the electrons, which must orbit the dense nucleus like planets around the sun.
Ernest Rutherford studied alpha rays, beta rays and gamma rays, emitted by certain radioactive substances. He noticed that each behaved differently in response to an electric field:The b-rays were attracted to the anode
The a-rays were attracted to the cathode
The g-rays were not affected by the electric field
The a and b &quot;rays&quot; were composed of (charged) particles and the g-&quot;ray&quot; was high energy radiation (photons) similar to x-rays
b-particles are high speed electrons (charge = -1)
a-particles are the positively charged core of the helium atom (charge = +2)
Rutherford&apos;s find came from a very strange experience. Everyone at that time imagined the atom as a &quot;plum pudding.&quot; That is, it was roughly the same consistency throughout, with negatively-charged electrons scattered about in it like raisins in a pudding. As part of an experiment with x-rays in 1909, Rutherford was shooting a beam of alpha particles (or alpha rays, emitted by the radioactive element radium) at a sheet of gold foil only 1/3000 of an inch thick, and tracing the particles&apos; paths. Most of the particles went right through the foil, which would be expected if the atoms in the gold were like a plum pudding. But every now and then, a particle bounced back as though it had hit something solid. After tracing many particles and examining the patterns, Rutherford deduced that the atom must have nearly all its mass, and positive charge, in a central nucleus about 10,000 times smaller than the atom itself. All of the negative charge was held in the electrons, which must orbit the dense nucleus like planets around the sun.
Ernest Rutherford studied alpha rays, beta rays and gamma rays, emitted by certain radioactive substances. He noticed that each behaved differently in response to an electric field:The b-rays were attracted to the anode
The a-rays were attracted to the cathode
The g-rays were not affected by the electric field
The a and b &quot;rays&quot; were composed of (charged) particles and the g-&quot;ray&quot; was high energy radiation (photons) similar to x-rays
b-particles are high speed electrons (charge = -1)
a-particles are the positively charged core of the helium atom (charge = +2)
Goldstein used a gas discharge tube which had a perforated cathode. When a high electrical potential of several thousand volts is applied between the cathode and anode, faint luminous &quot;rays&quot; are seen extending from the holes in the back of the cathode. These rays are beams of particles moving in a direction opposite to the &quot;cathode rays,&quot; which are streams of electrons which move toward the anode. Goldstein called these positive rays Kanalstrahlen, &quot;channel rays&quot; or &quot;canal rays&quot;, because they were produced by the holes or channels in the cathode. In 1907 a study of how this &quot;ray&quot; was deflected in a magnetic field, revealed that the particles making up the ray were not all the same mass. The lightest ones, formed when there was some hydrogen gas in the tube, were calculated to be about 1840 times as massive as an electron. They were protons.
In 1911, Niels Bohr earned his PhD in Denmark with a dissertation on the electron theory of metals
In 1912 Bohr joined Rutherford. He realized that Rutherford&apos;s model wasn&apos;t quite right. By all rules of classical physics, it should be very unstable. For one thing, the orbiting electrons should give off energy and eventually spiral down into the nucleus, making the atom collapse. Or the electrons could be knocked out of position if a charged particle passed by. Bohr turned to Planck&apos;s quantum theory to explain the stability of most atoms. He found that the ratio of energy in electrons and the frequency of their orbits around the nucleus was equal to Planck&apos;s constant (the proportion of light&apos;s energy to its wave frequency, or approximately 6.626 x 10-23 ). Bohr suggested the revolutionary idea that electrons &quot;jump&quot; between energy levels (orbits) in a quantum fashion, that is, without ever existing in an in-between state. Thus when an atom absorbs or gives off energy (as in light or heat), the electron jumps to higher or lower orbits.
In 1911, Niels Bohr earned his PhD in Denmark with a dissertation on the electron theory of metals
In 1912 Bohr joined Rutherford. He realized that Rutherford&apos;s model wasn&apos;t quite right. By all rules of classical physics, it should be very unstable. For one thing, the orbiting electrons should give off energy and eventually spiral down into the nucleus, making the atom collapse. Or the electrons could be knocked out of position if a charged particle passed by. Bohr turned to Planck&apos;s quantum theory to explain the stability of most atoms. He found that the ratio of energy in electrons and the frequency of their orbits around the nucleus was equal to Planck&apos;s constant (the proportion of light&apos;s energy to its wave frequency, or approximately 6.626 x 10-23 ). Bohr suggested the revolutionary idea that electrons &quot;jump&quot; between energy levels (orbits) in a quantum fashion, that is, without ever existing in an in-between state. Thus when an atom absorbs or gives off energy (as in light or heat), the electron jumps to higher or lower orbits.
Bohr was able to calculate the radii as well energies of the stationary orbit around the nucleus in an atom and those calculated values were found to be in a good agreement with the experimental values. He also gave the Hydrogen ion spectrum. For these reasons, his theory was widely accepted throughout the world. But a few years later, the use of high resolving power spectroscopes revealed some very fine spectral lines which Bohr was not able to explain. So from this point only, Sommerfeld extended Bohr Theory and gave his postulates.
According to him, the stationary orbits in which electrons are revolving around the nucleus in the atom are not circular but elliptical in shape. It is due to the influence of the centrally located nucleus. The electron revolves in elliptical path with nucleus at one of its foci. So there will be a major and a minor axis of the path. He said that with the broadening of the orbit, the lengths of the two axis approach to equal value and ultimately become equal i.e. the path become circular. So we can say the circular path is just one special case elliptical path.
As electrons travel in elliptical path, it will have an angular momentum and this angular momentum must be quantized according to the quantum theory of radiations. Bohr gave that angular momentum as m=nh/2Ω but Sommerfeld used another integer k instead of n. k is an integer known as azimuthal quantum number.
In fact, when people refer to &quot;classical physics&quot; today, they mean &quot;before Planck.
Satyendra Nath Bose had his schooling from Hindu High School in Calcutta. He was a brilliant student. He passed the ISc in 1911 from the Presidency College, Calcutta securing the first position. Satyendra Nath Bose did his BSc in Mathematics from the Presidency College in 1913 and MSc in Mixed Mathematics in 1915 from the same college. He topped the university in BSc. and MSc. Exams. In 1916, the Calcutta University started M.Sc. classes in Modern Mathematics and Modern Physics. S.N. Bose started his career in 1916 as a Lecturer in Physics in Calcutta University. He served here from 1916 to 1921. He joined the newly established Dhaka University in 1921 as a Reader in the Department of Physics.
E= hv = hc/λ
But scientists soon realized that the atomic model offered by Rutherford is not complete. Various experiments showed that mass of the nucleus is approximately twice than the number of proton. What is the origin of this additional mass? Rutherford postulated the existence of some neutral particle having mass similar to proton but there was no direct experimental evidence.
1897 Thomson discovers the electron1911 Rutherford discovers the nucleus1932 Chadwick discovers the neutron
Radium is always radio-nuclide
The electron neutrino (a lepton) was first postulated in 1930 by Wolfgang Pauli to explain why the electrons in beta decay were not emitted with the full reaction energy of the nuclear transition. The apparent violation of conservation of energy and momentum was most easily avoided by postulating another particle.
Enrico Fermi called the particle a neutrino and developed a theory of beta decay based on it, but it was notexperimentally observed until 1956. This elusive particle, with no charge and almost no mass, could penetrate vast thicknesses of material without interaction. The mean free path of a neutrino in water would be on the order of 10x the distance from the Earth to the Sun.
The Octet Rule was formulated from the observation that atoms with eight valence electrons were especially stable (and common). A similar situation applies to nuclei regarding the number of neutron and proton numbers that generate stable (non-radioactive) isotopes. Thes &quot;magic numbers&quot; are natural occurrences in isotopes that are particularly stable. Table 1 list of numbers of protons and neutrons; isotopes that have these numbers occurring in either the proton or neutron are stable. In some cases there the isotopes can consist of magic numbers for both protons and neutrons; these would be called double magic numbers. The double numbers only occur for isotopes that are heavier, because the repulsion of the forces between the protons.