AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |
Back to Blog
Alpha particles1/31/2024 One of the quantities used for this purpose is the linear energy transfer ( LET also referred to as L). Several investigators have used various other quantities to characterize the results of this spreading process. The stopping power is one indication of that density, but it is not a complete measure: Some of the energy lost by the particle is transferred to secondary radiations, electrons and photons, that penetrate to distances from the particle track. The energy lost by a charged particle produces damage of various kinds in the material with an effectiveness that depends on how densely the energy it loses is spread in the material. As a consequence, the damage (for example, caused by ionization, excitation, chemical alteration, and biological damage) is generally about that much higher along the alpha-particle tracks. 6 (Beta particles, the other common kind of charged particle emitted in radioactive decay, are electrons.) Note that for the energies shown, the stopping powers of the alpha particles are 2 to 3 orders of magnitude larger than those of the electrons. For comparison, the stopping power of electrons is also shown in Figure I-1. 1, 14 Figure I-1 shows the stopping power of alpha particles in soft tissues of unit density. The experimental and theoretical determinations of the alpha-particle stopping powers are in good agreement. The mass stopping power ( S/ρ) is the quotient of the stopping power by the density of the material. The stopping power ( S) of a charged particle of specified energy is its average energy loss per unit distance along its path. The actual rates of energy loss are close to the average rate. The differences in the energy losses are small, however. Alpha particles of the same energy lose different energies when they go equal distances because of randomness in the number and in the kinds of interactions with the material. At very low energies (less than 1 eV) they acquire two electrons and become atoms of helium gas in thermal equilibrium with the material. As alpha particles go through a material, they interact with the material's molecules, losing a little energy in each interaction.
0 Comments
Read More
Leave a Reply. |