Across
- 1. After absorbing the neutron the nucleus splits into two nuclei of lower Z as well as giving off additional neutrons
- 3. the amount of energy present per unit of time per unit of area perpendicular to the beam direction
- 4. Low mass nuclei combine to form one nucleusmass released since the mass of the product particles is less than the mass of reactants
- 6. the difference between the actual weight and the sum of the constituent parts. (Two words)
- 10. ____ dose describes the quantity of radiation for all types of ionizing radiation, including charged and uncharged particles, all materials, and all energies
- 13. A type of scatter when an electromagnetic wave, passes near an electron and causes it to oscillate and the oscillating electron then re-irradiates the energy at the same frequency, and wavelength, as the incident e.m. wave
- 15. The time required for either that activity or the number of radioactive atoms to decay to half the initial value (two words)
- 17. treatment criteria for the plan optimization are given by the planner and the computer will determine what the correct leaf sequence is needed is considered _____ planning
- 18. The law in which the voltage across the total circuit or any portion of the circuit is equal to the current times the resistance.
- 20. affects the low energy portion of the spectrum by absorbing the low energy photons and hardens the beam
- 21. This type of therapy treats in the 50 to 150kV range and treats to a depth of 5mm or less
- 22. the scattering of photons away from the original point source
- 24. atoms having nuclei with the same number of Neutrons but different number of protons
- 25. a single fraction treatment for intracranial lesions using a combination of a specialized immobilization and narrow multiple beams delivered through Non-coplanar isocentric arcs (acronym)
- 27. technique in which a nonuniform fluence is delivered to the patient from any given position of the treatment beam to optimize composite dose distribution (acronym)
- 29. Elementary particle with a positive electric charge equal to that of an electron and a mass approximately to that of a neutron. found within the nucleus of the atom
- 30. Electron interacts with atom and ejects an orbital electron an outer shell orbital wants to fill that vacancy and the excess energy is given off as this type of x-ray
- 33. "type of radiotherapy wave maximizes reflecting waves at both ends as to give rise to stationary waves by combining forward and reverse traveling waves.
- 34. ratio of dose at a depth in a phantom to dose in free space at the same distance (acronym)
- 37. Elementary particle with one negative charge that surrounds the positively charged nucleus and determines the chemical properties of the atom
- 41. A material that in some conditions behaves as a conductor but behaves like an insulator in other conditions
- 42. a type of phantom that uses materials to simulate body parts
- 43. A type of decay where the mass number is reduced by 4 and the atomic number is reduced by 2
- 46. Vacancy in orbital shell is filled by another electron and the transition energy is given off as characteristic x-ray (two words)
- 48. energy transferred from photons to electrons
- 49. type of radiotherapy wave that requires a terminating load to absorb the residual power at the end of the structure- to prevent backward reflecting wave
- 50. atoms having nuclei with the same number of Protons but different number of neutrons
Down
- 2. An insulator is any material that does not allow electron flow
- 5. same number of nucleons but different number of protons (different element)
- 7. the principle that energy absorbed in a medium from radiation appears ultimately as heat energy while a small amount may appear in the form of a chemical change
- 8. the region at the edge of a radiation beam over which the dose rate changes rapidly as a function of distance from the beam axis
- 9. measure of ionization produced in air by photons
- 11. uncharged elementary particle, with a mass slightly greater than that of a proton, that is found in the nucleus of every atom heavier than hydrogen
- 12. Radioactive decay accompanied by the ejection of a positive or negative electron from the nucleus
- 14. Thickness of a specified material that when introduced into the path of the beam, reduces the exposure rate by one half (acronym)
- 16. the incident particle does not have sufficient energy to eject an electron from the atom- so it raises the electrons to higher energy levels
- 19. "a dosimetry device used determine the optical density of the film which is a measure of the degree of blackening of the film
- 23. when an x-ray passes near an orbital electron of an atom and passes enough energy to the electron to remove it from the atom
- 24. same number of protons as well as neutrons- same elements but differ in the nuclear energy states… the last example has an isomer
- 25. this type of therapy treat 500 to 1000 kV and uses a transmission target
- 26. “Breaking” Radiation– electronic collision in which the electron passes near a nucleus and the columbic forces causing an ACCELERATION in which the electron MUST release energy
- 28. energy emitted and transferred through space
- 31. The Law in which the electrostatic force is directly proportional to the product of the electrostatic charges and inversely proportional to the SQUARE of the distance between them
- 32. "A law that states that the intensity of radiation at a location is inversely proportional to the square of its distance from the source of radiation. (two words)
- 35. the RATIO of the daughter activity to the parent activity remains constant over time.
- 36. component to the linac that includes pulse forming network and thyratron- high voltage pulses are flat topped DV pulses of few microseconds in duration. These pulses are delivered to either the magnetron or klystron and simultaneously to the electron gun
- 38. Electron produced outside the collection region, which enter the ion-collecting region, is equal to the electron produced inside the collection region , which deposit their energy outside the region. (acronym)
- 39. the energy of the electron orbit, but with the opposite sign./The energy required to dissociate a structure. (two words)
- 40. this type of therapy treats in the 200 to 400 kV with the 90% isodose line at a depth of 2cm
- 44. A conductor is a substance through which electrons flow easily
- 45. component to the linac that Produces microwaves of several microseconds duration and a rep rate of several hundred pulses per second and Has cathode and anode in which electrons are generated by heating a filament within the cathode
- 47. a dosimetric device of tissue equivalence used to predict dose distribution in an actual patient
- 51. percentage of the absorbed dose at any depth d to the absorbed dose at a fixed reference depth along central axis (acronym)