The electromagnetic radiation spectra of a homogeneous source wherein the relativistic electron acceleration on the langmuir waves leads to the formation of maxwelllike spectra with. Electromagnetic radiation models to understand how electromagnetic radiation is created, how it propagates through space, and how it interacts with other matter, it is useful to describe the processes using two different models. Biological effects of electromagnetic radiation engineering. Online textbook table of contents chapter contents introduction and overview interaction types photon interactions photoelectric compton coherent scatter pair production electron interactions electron range linear energy transfer positron interactions 1 of 30. Interaction of radiation with matter focuses on the physics of the interactions of ionizing radiation in living matter and the monte carlo simulation of radiation tracks. Much of our understanding of the physical properties of a material comes from its interaction with electromagnetic waves. For example, consider the hydrogen atom with its one proton, one neutron, and one electron. Electromagnetic radiation the nature of electromagnetic. The densitythickness is the same in each case, so the three slabs will. For example, when electromagnetic radiation is absorbed by matter. Chapter 2 provides the fundamentals of interaction mechanisms of electromagnetic radiation and matter. Interaction of radiation with matter mit opencourseware. Interaction of electromagnetic radiation with matter energy can occur in different forms e g chemical, electrical and thermal energy. At sufficiently high flux levels, various bands of electromagnetic radiation have been found to cause deleterious health effects in people.
M and speed v there is a maximum energy loss em to an electron given in the nonrelativistic. If the medium is transparent cherenkov radiation can be emitted above a certain threshold. In the nearfield region with d dimension of the source and r sourcesample. The waves are due to a disturbance at the airwater interface. In this section we will look at the electromagnetic spectrum and then go on to look at the structure of the atom. We want to describe the interaction of radiation with matter as a scattering process. A vacancy exists in an inner electron shell of an atom photoelectric effect, the energy liberated when this vacancy is filled, instead of emerging form the atom as fluorescent radiation, can be transferred to another electron of the atom, thereby ejecting the electron. Electromagnetic radiation the nature of electromagnetic radiation visible light is a complex phenomenon that is classically explained with a simple model based on propagating rays and wavefronts, a concept first proposed in the late 1600s by dutch physicist christiaan huygens. The ultimate fate of this energy depends on the context. Learn vocabulary, terms, and more with flashcards, games, and other study tools. In a series of our papers, we have proposed and studied in detail a new type of electromagnetic radiation that can be emitted by a massive neutrino with nonzero magnetic moment moving in background matter.
The masses of all the samples are the same but the densities are different. The diameter of a single proton has been measured to be about 1015 meters. Electromagnetic radiation can be classified into two types. Interaction of radiation with matter bose institute. Interaction of electromagnetic radiation with matter. The magnitude of the attenuation coefficient depends on the material of the. The coulomb interaction is longranged so the slowing down of the charged particles is most effective and is a continuous process. Interaction of radiation with matter crc press book. Electromagnetic radiation sometimes abbreviated emr is a ubiquitous phenomenon that takes the form of selfpropagating waves in a vacuum or in matter. It is quantized in that for a given frequency, its energy occurs as an integer times h, in which h is a fundamental constant of nature known as plancks constant. We have termed this radiation the spin light of neutrino s l. They have no charge and are therefore an indirectly ionizing particle.
Wave properties of electromagnetic radiation two options are available for analytical utility when an analyte interacts with a beam of electromagnetic radiation in an instrument 1. Electromagnetic radiation, however, has particlelike properties in addition to those associated with wave motion. Photons are particleswaves waveparticle duality without rest mass or electrical charge. Also visible light is electromagnetic radiation, but with much lower energies. The quantitative study of the interaction of electromagnetic radiation with matter can be done using a simple semiclassical model. In physics, electromagnetic radiation em radiation or emr refers to the waves or their quanta. In slaters model both, electromagnetic waves and photon particles were assigned physical existence in space, the waves, or photonwavefunctions, serving as. Thus radiation does not need matter to help it travel through the universe. As we assumed that the radiation is represented by plane waves and assuming for convenience they are contained in a cavity of edge l, the.
Interaction of matter and electromagnetic radiation. Interaction of radiation with matter perry sprawls, ph. But also subthreshold emission of electromagnetic radiation can occur, if discontinuities of the dielectric constant of the material are present transition radiation. Even people who are aware of this fact often ignore it, but once you know all of the adverse effects this type of radiation can have on your health, you start to pay more attention. Consider a 50kev xray photon undergoing a photoelectric interaction. Interaction of electromagnetic radiation and matter. For example, in air, radiation must expend an average energy of 33. A quantum of electromagnetic energy is called a photon. Interaction of matter and radiation absorption moleculeselectronic transitionsvibrational, rotational transitionsabsorption particlesscattering. Interactions of electromagnetic radiation with matter. Interaction of electromagnetic energy with vegetable food. At lower energies, they predominantly interact with matter.
What most people dont seem to realize, however, is that all of these electronic devices are known to emit waves of electromagnetic radiation emf. The initial interaction of the photon ionizes one atom. Electron and electromagnetic radiation generation and. There are many different forms of electromagnetic radiation, including visible, ultraviolet, and infrared light as well as microwaves, xrays, radio waves, and so on, all comprising the entire electromagnetic spectrum discussed in the next chapter. In this model the electromagnetic radiation is treated classically, while the energy levels are obtainedbysolvingthetimedependentschrodingerequation. Radiation the term radiation applies to the emission and propagation of energy through space or a material medium. A fast relativistic charged particle traversing matter loses energy in discrete amounts in. Spectroscopy is the study of the interaction of electromagnetic radiation with matter involving either absorption, emission, or scattering of radiation by the system under study. Starting with low frequency radio waves, the human body is quite transparent. Publishers pdf, also known as version of record includes final page. In the farfield radiation region, the measured electrodynamic property is averaged over a length scale in the order of the wavelength. Realistic model for radiationmatter interaction arxiv.
Gamma rays are electromagnetic radiation emitted as quanta photons of. It is well known that all matter is comprised of atoms. The pdf of energy loss for the particles described in fig. However, the really interesting thing about electromagnetic radiation is that we can see so little of it. Chernsimons cs systems interacting with electromagnetic radiation are described by a term f f. The way matter interacts with electromagnetic radiation gives a great deal of information about the electronic structure of atoms.
Interaction of radiation with matter nuclear power. But subatomically, matter is made up of mostly empty space. Afmcompatible nearfield scanning microwave microscope with. Chapter 2 interaction of xradiation with matter flashcards. Aug 28, 2011 in passing through matter, the intensity of the radiation is reduced attenuation, both because some radiation energy is taken up by material absorption and some is deflected from its original path to travel in a new direction scattering. Electromagnetic interactions of radiation in matter. Attenuation is the removal of photons from a beam of x. The way matter interacts with electromagnetic radiation gives. Interaction of radiation with matter ii 1 interaction of radiation with matter ii 2 attenuation of x and gamma rays. Radiation may be electromagnetic radiation particle radiation when radiation passes through matter it may interact with the material, transferring some or all of its energy to the atoms of that material. Ppt interaction of radiation with matter ii powerpoint. The interaction of electromagnetic waves or photons with matter may involve an exchange of momentum. The electromagnetic radiation of interest includes xrays emitted in the rearrangement of electron shells of atoms and gamma rays that are emitted from nucleus. I am aware of the fact that a comprehensive treatment of the different lightmatter interaction mechanisms alone would require several books as theyin deedcan be found for each different lightmatter interaction mechanism in literature.
In the preceding chapter it was shown that the radiation field interacts with matter via the current density term in the electromagnetic wave equation 2. Ionizing radiation, because though coulomb interaction with. Introduction to particle and radiation interaction with matter conference ndip 2011, lyon. Passage of particles through matter particle data group.
Radiation interaction with matter pdf patzak, lecture. It could be immediately reradiated and appear as scattered, reflected, or transmitted radiation. The different parts of the electromagnetic spectrum have very different effects upon interaction with matter. Clearly progressing from an elementary level to the state of the art, the text explores the classical physics of track descriptio. The cherenkov radiation is electromagnetic radiation emitted when a charged particle such as an electron moves through a dielectric medium faster than the phase velocity of light in that medium.
Interaction between penetrating radiation and matter when xrays or gamma rays are directed into an object, some of the photons interact with the particles of the matter and their energy can be absorbed or scattered. When electromagnetic radiation impinges on matter, it causes the charged particles to oscillate and gain energy. Jul 02, 2012 radiation the term radiation applies to the emission and propagation of energy through space or a material medium. We are interested in doing this because the interaction of radiation with matter is described by a driven and damped harmonic oscillator. For electronspositrons energy loss through electromagnetic radiation arising from scattering in the electric field of a nucleus bremsstrahlung also becomes. Interaction of radiation with matter stefano meroli cern.
Part four interactions of electromagnetic radiation and. All we earthlings can see is a very, very narrow part of the electromagnetic spectrum. The detection, characterization and effects of radiation are almost entirely. The interaction between electromagnetic waves and matter. We can monitor the changes that occur in the radiation after the interaction, or in this case, wave properties of the electromagnetic radiation is useful.
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