((Radiation )) This is the last sheet for Dr. Madi s lectures & its number is ((22)). This sheet contains (Slides and recording).. So I did my best to let you not refer to slides. First of all, there is tow type of radiation (in the Electromagnetic Spectrum): Ionizing RadiationNon-ionizing radiation - X rays Ultraviolet (in majority ) - Alpha beta gamma,visible -Cosmic raysinfrared (tow type : near(short)&far(long )) microwaves radio& TV power transmission Sticky Note: * Cosmic Rays: come from solar light. * Visible light between wavelengths (400-700 Nm) أيهمدغيم *Infrared (IR) used in militaryfor ; targets & taking night photos. * Power Transition ; used in big electric stations which are responsible for pumping the electricity. #Power Transition are 60 cycles per second with a wave length of 1 to 2 million meters.# (Sources of Radiation ): 1) Ultraviolet light 2) Visible light 3) Infrared radiation 4) Microwaves 5) Radio & TV 6) Power transmission ** Occupational Radiation ( we have to measure the amount and the distribution of the lights in the work place for safety ) (Measured in candles or lumens) To end up with: too high or too tow level of light indeed make too harm to our eyes. (Glare) is to have high level of lights right to your eyes which makes you not able to see for a while.
## We going to discussing three main types of rays (UV,IR, Microwaves ): 1)) UV it originate from the Sun light Most harmful UV is absorbed by the atmosphere depends on altitude Electric arc weldingcan damage the eye (cornea) or make skin cancer High ultraviolet kills bacterial and other infectious agents High dose causes - sun burn increased risk of skin cancer 2)) IR Energy between 750 nm to 0.3 cm, it is The energy of heat Heat is the transfer of energy Can damage cornea, iris, retina and lens of the eye (glass workers glass blower s cataract ) 3)) Microwaves /long wave opposite to its name / * define: microwaves are radio waves with wavelength (1nm-1m ) Produced by molecular vibration in solid bodies or crystals * Uses: a) in the communication /swishing on your lovely mobile (for that it needs huge supporting units so expensive ) b) for cooking c) transmission with satellites (by huge towers to collect and pumping out ) Compare between IR & Microwaves: IR u can feel it, like (heater ) with Microwaves you can t feel it like (microwave machine ) * Hazards of microwaves it isn t sensitively by human so it can hurt a lot of workers in their job without even feel that. It has high ability to get inside your body then start to damage it. Electrical Power researches show that :those who have leukemia are the closer for the high power and radiation resources Generally the research for radiation is not easy due to the need for high level &concentration of Rays to do studies. (Ionization Defined :radiation capable for producing ions when interacting with matter) tricky question : HOW we can stop Radiation??? α (by peace of paper even though it can make huge damage but in certain space -) Β (peace of wood can stop it,because it s wavelength =1.3 cm ) γ (Hard way to stop it. By concrete ) Lead has the ability for stop radiation (so we use lead in hospital or any ware we can t use concrete) ** so the nuclear mines it s need to be protected from releasing the radiation By concrete.
(Alpha Particles) Two neutrons and two protons,charge of +2, Emitted from nucleus of radioactive atoms Transfer energy in very short distances (10 cm in air) Shielded by paper or layer of skin Primary hazard from internal exposure //Alpha emitters can accumulate in tissue (bone, kidney, liver, lung, spleen) causing local damage//how?? the body start to take Alpha particles in small amount then accumulate by time in specific part in your body (we take Alpha particles from Canned foodor junk food or whatever was ) # we use the Geiger Counter to measure the radiation # (Beta Particles) Small electrically charged particles similar to electrons,charge of -1, Ejected from nuclei of radioactive atoms, Emitted with various kinetic energies + it cause skin burns or be an internal hazard of ingested && we can find α and β in large amounts in meats && (Gamma Rays ) Electromagnetic photons or radiation (identical to x-rays except for source) Emitted from nucleus of radioactive atoms spontaneous emission ((Radiation old Units)) 1- ) Exposure X (joul/kg)(related to energy)---called ----Roentgen 2- ) Absorbed Dose Gray (Gy):(amount of energy absorbed) ----called --- Rad /Radiation absorbed dose/ 3- ) Equivalent Dose Sievert (Sv): (makes different sources of radiation equivalent)-----called -----Red /Radiation equivalent man /.which use in measure the amount of damage caused by radiation. ** Standards (how people get radiated) There is tow way to exposure to the radiation ((occupational exposure & General public exposure )) occupational exposure :The Max amount of radiation(in work) 100msv/5 year..so 20msv / year, but it s not necessary to get that amount every year (i.e. some years get 30 other years get 20..ect )but the total must be 100 msv / year General exposure (which is the exposure in the normal life ).the Max exposure is 3msv/year ##Ionized radiation differs by many factors :(2 of them ) 2)) Highest : 1)) position : more high where is the large ionized rays more radiation come from the sun to earth?? but after 1000 it become hazard. The equator of earth,, because the concentration of radiation is the highest in The equator. After 1000 ft- you gain more cosmic rays than the earth radiation more than you need (imbalance state ) With high you gain from the cosmic rays to compensate what u lose from earth (good state ) (1000) ft Earth level
((Dose- Response Tissue)) ( Examples of tissue Sensitivity ) ( Dose Response Issues) (Half Life ) Rate of decay of radioisotope How long it takes to lose half their strength ((Reducing Exposure)) HOW we can reduce the radiation exposure?? Time: Reduce the spent near the source of radiation. Distance : Increase the distance from the source of radiation. Hurry readingabout (X- Rays ):/the Dr didn t mention them in this lecture/ = Overlap with gamma-rays,electromagnetic photons or radiation = Produced from orbiting electrons or free electrons usually machine produced = Produced when electrons strike a target material inside and x- ray tube = Emitted with various energies &wavelengths,highly penetrating extensive shielding required, External radiation Shielding :Place shielding material between you and the source of radiation. (which mean type of radiation and the sources of it, in mines, companies and factories ) Last words: We must use our biggest ambitions and dreams to harvest the best achievement and successful ( AYHAM DEGHAIM ) The majority of final exam focus in this material which from sheet (13-22) there is small proportion of Med-term s material required in the Final also. Dr. Madi