goddard was the name of jimmy neutrons dog.
goddard was the name of jimmy neutrons dog.
what is the name of jimmy neutrons dog?
goddard
Na
Na
after neutrons are produced, they need to be slowed down (decrease in kinetic energy), to the speed desired for imaging. this can take the form of some length of water, polyethylene, or graphite at room temperature to produce thermal neutrons. in the moderator the neutrons will collide with the nucleus of atoms and so slow down. eventually the speed of these neutrons will achieve some distribution based on the temperature (amount of kinetic energy) of the moderator. if higher energy neutrons are desired, a graphite moderator can be heated to produce neutrons of higher energy (termed epithermal neutrons). for lower energy neutrons, a cold moderator such as liquid deuterium (an isotope of hydrogen), can be used to produce low energy neutrons (cold neutron). if no or less moderator is present, high energy neutrons (termed fast neutrons), can be produced. the higher the temperature of the moderator, the higher the resulting kinetic energy of the neutrons is and the faster the neutrons will travel. generally, faster neutrons will be more penetrating, but some interesting deviations from this trend exist and can sometimes be utilized in neutron imaging. generally an imaging system is designed and set up to produce only a single energy of neutrons, with most imaging systems producing thermal or cold neutrons.
neutron imaging