RT 102: Radiation Production and Characteristics PDF

**RT 102: RADIATION PRODUCTION AND CHARACTERISTICS** **PART I: DISCOVERY OF X-RAY** X-rays were not developed: they were discovered, and quite by accident. During the **1870s** and **1880s**, many university physics laboratories were investigating the conduction of **cathode rays**, or electrons,...

**RT 102: RADIATION PRODUCTION AND CHARACTERISTICS** **PART I: DISCOVERY OF X-RAY** X-rays were not developed: they were discovered, and quite by accident. During the **1870s** and **1880s**, many university physics laboratories were investigating the conduction of **cathode rays**, or electrons, through a large, partially evacuated glass tube known as a **crookes tube.** Sir **William Crookes** was an englishman from a humble background who was a self- taught genius. The tube that bears his name was the **forerunner of the modern fluorescent lamps** and **x-ray tubes.** There were many different types of Crookes Tubes: most of them were capable of producing x-rays. **Wilhelm Conrad Roentgen** was experimenting with a type of tube when he discovered x-rays. On **November 8, 1895**, Roentgen was working in his physics laboratory at **Wurzburg University** in **Germany**. He darkened his laboratory and completely enclosed his Crookes Tube with **black photographic paper** so he could better visualize the effects of cathode rays in the tube. A plate coated with **Barium Platinocyanide**, a **fluorescent material**, happened to be lying on a bench several meters from the Crookes tube. No visible light escaped from the Crookes tube because of the black paper that enclosed it, but Roentgen noted that the **Barium Platinocyanide glowed**. The intensity of the glow increased as the plate was brought closer to the tube consequently, there was little doubt about the origin of the stimulus of the glow. [This glow is called **fluorescence**.] Roentgen\'s immediate approach to investigating this \"**X-light**\" as he called it, was to interpose various materials-wood, aluminum, and his hand -between the Crookes tube and the fluorescing plate. The \"**X**\" for unknown! He feverishly continued these investigations for several weeks. Early in his experiment, he was astonished to see the **image** of the **bones** in his **own hands** on the screen, while the flesh was penetrated through by the X-rays. The field of Radiography was born when he placed his **wife\'s hand** in front of the screen and allowed the screen\'s fluorescent light to expose a photographic film for about **four minutes**. Along with **three other radiographs**, this image was **published two months later** in his paper, \"**On a New** **Kind of Rays**\", introducing the process of radiography to the world. Through his use of the scientific method, Roentgen found that X-rays: 1. Are highly penetrating, invisible rays which are a form of electromagnetic radiation. 2. Are electrically neutral and therefore not affected by either electric or magnetic fields. 3. Can be produced over a wide variety of energies and wavelengths. 4. Release very small amounts of heat upon passing through matter. 5. Travel a straight lines. 6. Travel at the speed of light. 3x10\*8 meters per second in a vacuum. 7. Can ionize matter. 8. Cause fluorescence of certain crystals. 9. Cannot be focused by a lense. 10. Affects photographic film. 11. Produce chemical and biological changes in matter through ionization and excitation. 12. Produce secondary and scatter radiation. **PART II: EARLY PIONEERS IN RADIOGRAPHY** **Wilhelm Conrad Roentgen** *March 27, 1845 -- February 10, 1923* - He was a German Mechanical Engineer and Physicist, who, on **8 November 1895**, produced and detected electromagnetic radiation in a wavelength range known **as X-rays** or **Roentgen Rays**, an achievement that earned him the inaugural **Nobel Prize** in **Physics** in **1901**. **Anna Bertha Ludwig** *April 22, 1839 - October 31, 1919* - **Wife** of **Wilhelm Conrad Roentgen,** the discoverer of X-rays, she was the **first person** to experience the x-ray on her body on **December 22, 1895.** **William Crookes** *June 17, 1832 - April 4, 1919* - He was a British **Chemist** and **Physicist** who attended the **Royal College of Chemistry**, now part of Imperial College London, and worked on **Spectroscopy**. He was a **pioneer** of **Vacuum Tubes**, inventing the **Crookes Tube** which was made in **1875**. **Michael Pupin** *October 9, 1854 - March 12, 1935* - He demonstrated the use of a **Radiographic Intensifying Screen** in **1996**, but only many years later did it receive adequate recognition and use. **NOTE:** Radiographs during Roentgen\'s time were made by exposing a glass plate with a layer of photographic emulsion coated on one side. **Charles Leonard** *September 16, 1822 August 27, 1918* - He found that by exposing **two glass X-ray plates** with the emulsion surfaces together, exposure time was **halved**, and the image was considerably **enhanced**. **NOTE**: The demonstration of double-emulsion radiography was conducted in **1904**, out double-emulsion film did not become commercially available until **1918**. **Thomas Edison** *February 11, 1847-October 18, 1931* - He developed the **Fluoroscope** in **1890**. He was an American **Inventor** and **Businessman**. - He developed many devices in fields such as **electric power generator, mass communication, sound recording,** and **motion pictures.** **Clarence Dally** *January 8, 1865-October 2, 1904* - He experienced a **severe X-ray burn** that eventually required **amputation** of **both arms**. He was an American Glassblower, noted as an assistant to **Thomas Edison** in his work on X- rays and as an early victim of **radiation dermatitis** and its **complications**. **NOTE**: Dally died on **1904** and is counted as the first X-ray fatality in the United States. **William Rollins** *June 19, 1852 - 1929* - **Before 20th century** Boston Dentist William Rollins used X-rays to image a **teeth** and found that **restricting the X-ray beam** with a sheet of lead and with a **hole** in a center, a **diaphragm** and inserting a leather or **aluminum filter** improved the diagnostic **quality of radiographs.** **NOTE**: This was the first application of collimation and filtration. Later recognized that these devices reduce the hazard associated with X-rays. **Homer Clyde Snook** *March 25, 1878 - September 23, 1942* - In **1907**, he introduced a **substitute high-voltage power supply**, an **interruptless transformer**. It was not until the introduction of **Coolidge Tube** that the S**nook Transformer** was widely adopted. **NOTE**: During Roentgen\'s time, only static generators were available. These units could provide currents of only few milliamperes and a voltage to 50 kVp. **William Coolidge** *October 23, 1873 - February 3, 1975* - In **1913**, he unveiled his **hot-cathode X-ray tube** to the medical community. It was immediately recognized as **far superior** to the Crookes tube. It was a vacuum tube that allowed **X-ray intensity** and **energy** to **be selected separately** and with **great accuracy**. X-ray tubes in use today are refinements of the Coolidge tube. **NOTE**: Radiology emerged as a medical specialty because of the Snook Transformer and the Coolidge X-ray tube **Gustav Bucky** *September 3, 1880 - February 19, 1963* - In **1913**, he invented the **stationary grid** (\"**glitterblende**\") 2 months later, he applied his second patent for a **moving grid.** **Hollis Potter** *February 16, 1880 - October 15, 1964* - In **1915**, he probably unaware of Bucky\'s patent because of WWI, he also invented a **moving grid**. To his credit, Potter recognized **Bucky\'s work**, and the **Potter-Bucky grid** was introduced in **1921**. **Bell Telephone Laboratories** *1946* - In **1946**, the **light amplifier tube** was demonstrated at **Bell Telephone Laboratories**. - This device was adapted for **fluoroscopy** by **1950** as an **image intensifier tube**. Today, image-intensified fluoroscopy is being **replaced** **by solid-state image receptors.** **PART III: DEVELOPMENT OF MODERN RADIOLOGY** **1895** - X-rays are discovered by **Wilhelm Conrad Roentgen** in **Germany**. The first image captured was of his **wife\'s hand**, showing its skeletal outline with a ring on one of her fingers. **1896** - X-ray applications are being used as early as January. Concurrently, French Physicist, **Antoine Henri Becquerel**, discovers **radioactivity**. **1900** - The **American Roentgen Society**, the **first American Radiology Organization**, is founded. **1901** - **Roentgen** receives the **first Nobel prize** in **Physics**. **1905** - **Einstein** introduces his **theory of relativity** and the famous equation E = mc^2^ **1907** - The **Snook interrupterless transformer** is introduced. **1913** - **Bohr** theorizes his **model of the atom**, featuring a **nucleus** and **planetary electrons.** - The **Coolidge Hot-Filament X-ray tube** is developed. **1914** - **Radiological equipment** is used in field **hospitals** during **World War I.** **1917** - The **Cellulose Nitrate Film Base** is widely adopted. **1918** - **George Eastman** introduces **film**, replacing radiographs made onto glass photographic plates. **1920** - Several investigators demonstrate the use of **Soluble Iodine** compounds as **Contrast Media.** - The **American Society** **of Radiologic Technologists** (ASRT) is founded. **1921** - The **Potter-Bucky Grid** is introduced. **1922** - **Compton** describes the **scattering of x-rays.** **1923** - **Cellulose Acetate** \"Safety\" **X-ray film** is introduced (Eastman Kodak). **1929** - The **rotating anode X-ray tube** is introduced. **1932** - **Blue tint** is added to **X-ray film** (DuPont). **1942** - The first **Automatic Film Processor** (Pako) is introduced. **1946** - **Nuclear Magnetic Resonance** (NMR) is discovered independently by American Physicists, **Coward Purcell** and **Felix Bloch.** **1955** - **Ian Donald**, a Scottish Physician, endeavors **ultrasound** in Gynecology, together with engineer **Tom Brown** he develops a **Portable Ultrasound Machine.** **1956** - **First Automatic Roller Transport Film Processing** (Eastman Kodak) is introduced. **1960** - **Polyester Base Film** is introduced (DuPont). **1963** - **Kuhl** and **Edwards** demonstrate **Single-Photon Emission Computed Tomography** (SPECT). **1965** - **Ninety-Second Rapid Processor** is introduced (Eastman Kodak). **1966** - **Diagnostic Ultrasonography** enters routine use. **1972** - **Single-Emulsion Film** and **One-Screen Mammography** become available (DuPont). **1973** - **Hounsfield** completes development of first **Computed Tomography** (CT) **Imaging System** (EMI). - **Damadian** and **Lauterbur** produce the first **Magnetic Resonance Image** (MRI). **1974** - **Rare Earth Radiographic Intensifying Screens** are introduced. **1979** - **The Nobel prize** in **Physiology** or **Medicine** is awarded to **Allan Cormack** and **Godfrey Hounsfield** for **CT**. **1980** - **MRI** scanners are **installed** in **Hospitals**. **1990** - **Ultrasound** becomes a routine procedure in **pregnancy** as a means of **monitoring** the **development** and **health** of the **Fetus**. **1991** - The **first Functional MRI** (fMRI) of the brain is conducted by **Belliveau Et Al.** **2000** - The **PET-CT Scanner**, attributed to **David Townsend** and **Ronald Nutt**, is named by **TIME Magazine** as the **Medical Invention of the Year.** **2003** - The **Nobel Prize** in **Physiology** or **Medicine** is awarded to **Paul Lauterbur** and **Sir Peter Mansfield** for MRI. **2012** - The **International Day of Radiology (IDoR)** is introduced. It is recognized on **November 8** annually. **2014** - The **University of Canterbury** was granted **\$12 Million** to build the **World's First Human Color X-ray Scanner.** **PART IV: THE CONCEPT OF ATOM AND THE BASIC FORCES IN NATURE** **What is PHYSICS?** - **Branch** of **science** concerned with the **nature, properties,** and **interaction** of **matter** and **energy.** **MATTER** - Anything that occupies **space** and has **mass.** **MASS** - The **quantity** of **matter** described by its **energy equivalence**. it is the amount of **matter** or **substance** that makes up an object; measured in **kilogram** (**kg**). WEIGHT A measure of **force acting on an object** with **mass**; measured in **pound** (**lb**.) **Wt** = MG **Weight** = Mass x Gravity = **Newton** (N) 4.5 N = 1 LB. **Earth**: 9.8 m/s^2^ **Moon**: 1.6 m/s^2^ **THE PHYSICAL STATE OF MATTER** - SOLID - LIQUID - GAS - PASMA - BOSE-EINSTEIN CONDENSATE **ENERGY** - "**Ability** to do **work**, which is the ability to **exert a force** causing **displacement** of an **object**." energy is just the **force that causes things to move**. - Energy is divided into two types: **Potential** and **Kinetic**. **UNITS OF ENERGY** - Joules - Electron-volt - Calorie - Ergs **JOULES** - Unit of work or energy in the **International System** of **Units** (SI). **ELECTRON-VOLT** - **Unit** of **energy** commonly used in **atomic and nuclear physics** **CALORIE** - A **measurement** of the **energy content** of **food.** **ERGS** - **Unit** of **energy** or **work** in the **centimetre-gram- second system** of **physical units** used in **physics.** **COMMON FORMS OF ENERGY** - **Kinetic Energy** - **Potential Energy** - **Mechanical Energy** - **Chemical Energy** - **Electrical Energy** - **Thermal/Heat Energy** - **Nuclear Energy** - **Electromagnetic Energy** **KINETIC ENERGY** - Kinetic energy is the **energy of motion**, observable as the **movement of an object** or **subatomic particle**. Every moving object and particle have kinetic energy. A person walking, a soaring baseball, a crumb falling from a table and a charged particle in an electric field are all examples of kinetic energy at work. **POTENTIAL ENERGY** - Potential energy, **stored energy** that depends upon the relative position of various parts of a system. A spring has more potential energy when it is compressed or stretched. A steel ball has more potential energy raised above the ground than it has after falling to Earth. - Energy **at rest**. **MECHANICAL ENERGY** - Mechanical energy is **the sum of potential energy** and **kinetic energy**. The principle of conservation of mechanical energy states that if an isolated system is subject only to conservative forces, then the mechanical energy is constant. **CHEMICAL ENERGY** - Energy **stored** in the **bonds of chemical compounds.** Chemical energy may be released during a **chemical reaction**, often in the form of heat; such reactions are called exothermic. Reactions that require an input of heat to proceed may store some of that energy as chemical energy in newly formed bonds. **ELECTRICAL ENERGY** - Electrical energy is **a type of kinetic energy caused by moving electric charges**. The amount of energy depends on the speed of the charges the faster they move, the more electrical energy they carry. **THERMAL ENERGY** - Thermal energy refers to the energy contained within a system that is **responsible for its temperature**. Heat is the flow of thermal energy. **NUCLEAR ENERGY** - Nuclear energy is a form of **energy released from the nucleus**, the core of atoms, made up of protons and neutrons. This source of energy can be produced in two ways: **Fission** -- when nuclei of atoms split into several parts. **Fusion** -- when nuclei fuse together. **ELECTROMAGNETIC ENERGY** - The type of energy that is **used** in an **x-ray imaging**. **Least familiar** form of energy but **most important** in **radiology**. - Electromagnetic radiation is a special kind of energy that travels in waves through space. It is like a wave of energy that can move without needing anything else to carry it, even in empty space. **TYPES OF ELECTROMAGNETIC RADIATION** **RADIO WAVES** - These are the waves that allow us to **listen to the radio.** They have **long wavelengths** and **low frequencies**. Radio waves are used for **broadcasting music, news**, and other **information**. **MICRO WAVES** - Microwaves have **shorter wavelengths** and **higher frequencies than radio waves**. They are used in **microwave ovens** to **cook** and **heat** food. They are also used for **communication**, such as **cell phones** and **WiFi**. **INFRARED RADIATION** - Infrared radiation is sometimes called \"**heat radiation**\" because we feel it as **warmth**. It has longer wavelengths than visible light. Infrared radiation is used in devices like **TV remote controls** and thermal cameras. **VISIBLE LIGHT** - This is the type of electromagnetic radiation that **allows us to see the world around us**. Visible light comes in different colors, like **red**, **orange**, **yellow**, **green**, **blue**, **indigo**, and **violet**. Each color has a different wavelength. **ULTRAVIOLET RADIATION** - UV radiation has shorter wavelengths and higher frequencies than visible light. It comes from the **sun** and is responsible for causing **sunburns**. We can\'t see UV radiation, but it can be **harmful** to our skin and **eyes**. **X-RAY RADIATION** - X-rays have even shorter wavelengths and higher frequencies than UV radiation. They can pass through our bodies and are used in **medical imaging**, like **X-ray machines**, to see our bones and organs. **GAMMA RADIATION** - Gamma rays have the shortest wavelengths and highest frequencies of all the radiations. They are produced during **nuclear reactions** and can be very **harmful**. Scientists use gamma rays to **treat cancer**. What is **FIELDS?** - **Numerical quantity** assigned to every point in **space that changes in time.** **COMMON TYPES OF FIELDS** - **Scalar Fields** - **Vector Fields** - **Tensor Fields** **FORCES** - Is an **influence** that can cause an **object to change its velocity.** - Any action that, when **unopposed**, will **change** the **motion** of an **object.** **FUNDAMENTAL FORCES OF NATURE** - **Gravitational Force** - **Weak Nuclear Force** - **Electromagnetic/Electrostatic Force** - **Strong Nuclear Force** **GRAVITATIONAL FORCE** - Is an **invisible pulling force between two objects.** The **strength** of the **gravitational force depends** on an **object.** **WEAK NUCLEAR FORCE** - The **force** that **allows protons to turn into neutrons** and **vice versa** through beta decay, acts inside of individual nucleons. **ELECTROSTATIC FORCE** - The **force of attraction between unlike charges or repulsion between like charges** is attributable to the electric field. **STRONG NUCLEAR FORCE** - This **force is strong enough** that is **overcomes** the **repulsive force/electrostatic force between two charge**. Allowing **two same charge to stick together**. What is **LAWS**? - Generalized **rules to explain a body of observations in the form of verbal** or **mathematical statement.** **EXAMPLES OF LAWS OF PHYSICS** - **Law of Universal Gravitational** - **Newton's Three Laws of Motions** - **Laws of Conservation of Energy** - **Laws of Conservation of Mass** - **Laws of Conservation of Mass & Energy** **LAW OF UNIVERSAL GRAVITATIONAL** - Is an **invisible pulling force between two objects.** The **strength** of gravitational force **depends on an object mass.** **NEWTON'S THREE LAWS OF MOTION** **Inertia** - A body will remain at rest or will continue to move with constant velocity in a straight line unless acted on by an external force. **Force** - The force (F) that acts on an object is equal to the mass (M) of the object multiplied by the acceleration (A) produced. **Action/Reaction** - For every action, there is an equal and opposite reaction. **LAW OF CONSERVATION OF ENERGY** - States that **energy** can **neither be created nor destroyed**. it only converted from one form of energy to another. - The **total amount of energy in a system remain constant,** even as that energy is transferred or converted. **LAW OF CONSERVATION OF MASS** - The principle that states that **matter** can be **neither created nor destroyed.** It **convert one form of matter into another.** - The **properties and mass of that matter remain constant,** even as that matter transform into different states of matter: Solid, Liquid, Gas. **LAW OF CONSERVATION OF MASS AND ENERGY** way definition