ARRT Registry Exam Questions and Correct Answers

ARRT Registry Exam Questions and Correct Answers X-ray Properties -Packets of energy that travel in wave form -Highly penetrating -Form of electromagnetic radiation -Wide variety of wavelengths and energies -Travels in straight lines and at the speed of light -Can ionize matter and release small amounts of energy upon passing through matter -Very high frequencies and very short wavelengths 4 Requirements for x-ray production 1)Source of free Electrons 2)Acceleration of Electrons 3)Focusing of Electrons 4)Deceleration of Electrons Focusing Cup Surrounds the filament and maintains a concentrated stream of electrons from the filament to the target area on the anode Typically made of molybdenum or nickel Bremsstrahlung Radiation Projectile (high speed) electron interacts with the electrostatic charge of the target nucleus (tungsten cathode) 1)slows down 2)changes direction 3)loses some of its energy -The greater the direction change, the greater energy loss and the brem photon will possess more energy Characteristic Radiation Think Cascade Projectile (high speed) electron ejects an inner (K) shell electron and ionizes the atom. Other electrons move to fill the vacancy which results in the emission of a characteristic x-ray photon. Only the initial energy of the K-shell ejection results in diagnostically useful x-rays. The rest will be absorbed by filtration or contribute to skin dose Electromagnetic Energy Travels in wave form (wavelength) and has a certain frequency. X-radiation if one form of electromagnetic energy on the electromagnetic spectrum Photon Smallest bit of electromagnetic energy Particulate Radiation Other forms of radiation, such as beta and alpha, travel in particles Frequency The rate of rise and fall (oscillation) of the electromagnetic photon and is measured in Hertz (Hz) Wavelength The distance between two successive peaks of an electromagnetic photon