| 1 | <html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>4.2. Material</title><link rel="stylesheet" href="../xml/XSLCustomizationLayer/G4HTMLStylesheet.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.71.1"><link rel="start" href="index.html" title="Geant4 User's Guide for Application Developers"><link rel="up" href="ch04.html" title="Chapter 4. Detector Definition and Response"><link rel="prev" href="ch04.html" title="Chapter 4. Detector Definition and Response"><link rel="next" href="ch04s03.html" title="4.3. Electromagnetic Field"><script language="JavaScript">
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| 2 | function remote_win(fName)
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| 3 | {
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| 4 | var url = "AllResources/Detector/geometry.src/" + fName;
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| 5 | RemoteWin=window.open(url,"","resizable=no,toolbar=0,location=0,directories=0,status=0,menubar=0,scrollbars=0,copyhistory=0,width=520,height=520")
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| 6 | RemoteWin.creator=self
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| 7 | }
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| 8 | </script></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">4.2.
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| 9 | Material
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| 10 | </th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ch04.html"><img src="AllResources/IconsGIF/prev.gif" alt="Prev"></a> </td><th width="60%" align="center">Chapter 4.
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| 11 | Detector Definition and Response
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| 12 | </th><td width="20%" align="right"> <a accesskey="n" href="ch04s03.html"><img src="AllResources/IconsGIF/next.gif" alt="Next"></a></td></tr></table><hr></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="sect.Mate"></a>4.2.
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| 13 | Material
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| 14 | </h2></div></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="sect.Mate.GenCons"></a>4.2.1.
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| 15 | General considerations
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| 16 | </h3></div></div></div><p>
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| 17 | In nature, materials (chemical compounds, mixtures) are made of
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| 18 | elements, and elements are made of isotopes. Geant4 has three main
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| 19 | classes designed to reflect this organization. Each of these
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| 20 | classes has a table, which is a static data member, used to keep
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| 21 | track of the instances of the respective classes created.
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| 22 |
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| 23 | </p><div class="variablelist"><p class="title"><b></b></p><dl><dt><span class="term">
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| 24 | <span class="emphasis"><em>G4Isotope</em></span>
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| 25 | </span></dt><dd><p>
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| 26 | This class describes the properties of atoms: atomic number,
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| 27 | number of nucleons, mass per mole, etc.
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| 28 | </p></dd><dt><span class="term">
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| 29 | <span class="emphasis"><em>G4Element</em></span>
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| 30 | </span></dt><dd><p>
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| 31 | This class describes the properties of elements: effective
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| 32 | atomic number, effective number of nucleons, effective mass per
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| 33 | mole, number of isotopes, shell energy, and quantities like cross
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| 34 | section per atom, etc.
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| 35 | </p></dd><dt><span class="term">
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| 36 | <span class="emphasis"><em>G4Material</em></span>
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| 37 | </span></dt><dd><p>
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| 38 | This class describes the macroscopic properties of matter:
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| 39 | density, state, temperature, pressure, and macroscopic quantities
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| 40 | like radiation length, mean free path, dE/dx, etc.
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| 41 | </p></dd></dl></div><p>
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| 42 | </p><p>
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| 43 | Only the <span class="emphasis"><em>G4Material</em></span> class is visible to the rest of the
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| 44 | toolkit and used by the tracking, the geometry and the physics. It
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| 45 | contains all the information relevant to its constituent elements
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| 46 | and isotopes, while at the same time hiding their implementation
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| 47 | details.
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| 48 | </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="sect.Mate.Intro"></a>4.2.2.
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| 49 | Introduction to the Classes
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| 50 | </h3></div></div></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="sect.Mate.Intro.Iso"></a>4.2.2.1.
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| 51 | G4Isotope
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| 52 | </h4></div></div></div><p>
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| 53 | A <span class="emphasis"><em>G4Isotope</em></span> object has a name, atomic number, number of
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| 54 | nucleons, mass per mole, and an index in the table. The constructor
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| 55 | automatically stores "this" isotope in the isotopes table, which
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| 56 | will assign it an index number.
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| 57 | </p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="sect.Mate.Intro.Ele"></a>4.2.2.2.
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| 58 | G4Element
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| 59 | </h4></div></div></div><p>
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| 60 | A <span class="emphasis"><em>G4Element</em></span> object has a name, symbol, effective atomic
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| 61 | number, effective number of nucleons, effective mass of a mole, an
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| 62 | index in the elements table, the number of isotopes, a vector of
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| 63 | pointers to such isotopes, and a vector of relative abundances
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| 64 | referring to such isotopes (where relative abundance means the
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| 65 | number of atoms per volume). In addition, the class has methods to
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| 66 | add, one by one, the isotopes which are to form the element.
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| 67 | </p><p>
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| 68 | A <span class="emphasis"><em>G4Element</em></span> object can be constructed by directly
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| 69 | providing the effective atomic number, effective number of
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| 70 | nucleons, and effective mass of a mole, if the user explicitly
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| 71 | wants to do so. Alternatively, a <span class="emphasis"><em>G4Element</em></span> object can be
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| 72 | constructed by declaring the number of isotopes of which it will be
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| 73 | composed. The constructor will "new" a vector of pointers to
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| 74 | <span class="emphasis"><em>G4Isotopes</em></span> and a vector of doubles to store their relative
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| 75 | abundances. Finally, the method to add an isotope must be invoked
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| 76 | for each of the desired (pre-existing) isotope objects, providing
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| 77 | their addresses and relative abundances. At the last isotope entry,
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| 78 | the system will automatically compute the effective atomic number,
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| 79 | effective number of nucleons and effective mass of a mole, and will
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| 80 | store "this" element in the elements table.
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| 81 | </p><p>
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| 82 | A few quantities, with physical meaning or not, which are
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| 83 | constant in a given element, are computed and stored here as
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| 84 | "derived data members".
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| 85 | </p><p>
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| 86 | Using the internal Geant4 database, a <span class="emphasis"><em>G4Element</em></span> can be accessed
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| 87 | by atomic number or by atomic symbol ("Al", "Fe", "Pb"...). In that
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| 88 | case <span class="emphasis"><em>G4Element</em></span> will be found from the list of existing elements or
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| 89 | will be constructed using data from the Geant4 database, which is
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| 90 | derived from the
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| 91 | <a href="http://physics.nist.gov/PhysRefData/Compositions/index.html" target="_top">NIST database
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| 92 | of elements and isotope compositions</a>.
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| 93 | Thus, the natural isotope composition can be built by default.
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| 94 | The same element
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| 95 | can be created as using the NIST database with the
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| 96 | natural composition of isotopes
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| 97 | and from scratch in user code with user defined isotope composition.
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| 98 | </p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="sect.Mate.Intro.Mate"></a>4.2.2.3.
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| 99 | G4Material
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| 100 | </h4></div></div></div><p>
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| 101 | A <span class="emphasis"><em>G4Material</em></span> object has a name, density, physical state,
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| 102 | temperature and pressure (by default the standard conditions), the
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| 103 | number of elements and a vector of pointers to such elements, a
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| 104 | vector of the fraction of mass for each element, a vector of the
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| 105 | atoms (or molecules) numbers of each element, and an index in the
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| 106 | materials table. In addition, the class has methods to add, one by
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| 107 | one, the elements which will comprise the material.
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| 108 | </p><p>
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| 109 | A <span class="emphasis"><em>G4Material</em></span> object can be constructed by directly
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| 110 | providing the resulting effective numbers, if the user explicitly
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| 111 | wants to do so (an underlying element will be created with these
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| 112 | numbers). Alternatively, a <span class="emphasis"><em>G4Material</em></span> object can be
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| 113 | constructed by declaring the number of elements of which it will be
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| 114 | composed. The constructor will "new" a vector of pointers to
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| 115 | <span class="emphasis"><em>G4Element</em></span> and a vector of doubles to store their fraction of
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| 116 | mass. Finally, the method to add an element must be invoked for
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| 117 | each of the desired (pre-existing) element objects, providing their
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| 118 | addresses and mass fractions. At the last element entry, the system
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| 119 | will automatically compute the vector of the number of atoms of
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| 120 | each element per volume, the total number of electrons per volume,
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| 121 | and will store "this" material in the materials table. In the same
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| 122 | way, a material can be constructed as a mixture of other materials
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| 123 | and elements.
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| 124 | </p><p>
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| 125 | It should be noted that if the user provides the number of atoms
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| 126 | (or molecules) for each element comprising the chemical compound,
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| 127 | the system automatically computes the mass fraction. A few
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| 128 | quantities, with physical meaning or not, which are constant in a
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| 129 | given material, are computed and stored here as "derived data
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| 130 | members".
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| 131 | </p><p>
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| 132 | Some materials are included in the internal Geant4 database,
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| 133 | which were derived from the
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| 134 | <a href="http://physics.nist.gov/PhysRefData/Star/Text/method.html" target="_top">NIST database
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| 135 | of material properties</a>.
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| 136 | Additionally a number of materials friquently used in HEP is
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| 137 | included in the database. Materials are interrogated or constructed
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| 138 | by their <span class="emphasis"><em>names</em></span> (<a href="apas08.html" title="8.
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| 139 | Geant4 Material Database
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| 140 | ">Section 8</a>).
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| 141 | There are UI commands for the material category, which provide
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| 142 | an interactive access to the database. If material is created
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| 143 | using the NIST database by it will
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| 144 | consist by default of elements with the natural composition of isotopes.
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| 145 | </p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="sect.Mate.Intro.Fin"></a>4.2.2.4.
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| 146 | Final Considerations
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| 147 | </h4></div></div></div><p>
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| 148 | The classes will automatically decide
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| 149 | if the total of the mass fractions is correct, and perform the
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| 150 | necessary checks. The main reason why a fixed index is kept as a
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| 151 | data member is that many cross section and energy tables will be
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| 152 | built in the physics processes "by rows of materials (or elements,
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| 153 | or even isotopes)". The tracking gives the physics process the
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| 154 | address of a material object (the material of the current volume).
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| 155 | If the material has an index according to which the cross section
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| 156 | table has been built, then direct access is available when a number
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| 157 | in such a table must be accessed. We get directly to the correct
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| 158 | row, and the energy of the particle will tell us the column.
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| 159 | Without such an index, every access to the cross section or energy
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| 160 | tables would imply a search to get to the correct material's row.
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| 161 | More details will be given in the section on processes.
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| 162 | </p><p>
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| 163 | Isotopes, elements and materials must be instantiated dynamically
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| 164 | in the user application; they are automatically registered in
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| 165 | internal stores and the system takes care to free the memory
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| 166 | allocated at the end of the job.
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| 167 | </p></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="sect.Mate.Recep"></a>4.2.3.
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| 168 | Recipes for Building Elements and Materials
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| 169 | </h3></div></div></div><p>
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| 170 | <a href="ch04s02.html#programlist_Mate_1" title="Example 4.10.
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| 171 | A program which illustrates the different ways to define materials.
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| 172 | ">Example 4.10</a> illustrates the different ways to define
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| 173 | materials.
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| 174 | </p><div class="example"><a name="programlist_Mate_1"></a><p class="title"><b>Example 4.10.
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| 175 | A program which illustrates the different ways to define materials.
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| 176 | </b></p><div class="example-contents"><pre class="programlisting">
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| 177 | #include "G4Isotope.hh"
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| 178 | #include "G4Element.hh"
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| 179 | #include "G4Material.hh"
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| 180 | #include "G4UnitsTable.hh"
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| 181 |
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| 182 | int main() {
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| 183 | G4String name, symbol; // a=mass of a mole;
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| 184 | G4double a, z, density; // z=mean number of protons;
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| 185 | G4int iz, n; // iz=nb of protons in an isotope;
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| 186 | // n=nb of nucleons in an isotope;
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| 187 | G4int ncomponents, natoms;
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| 188 | G4double abundance, fractionmass;
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| 189 | G4double temperature, pressure;
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| 190 |
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| 191 | G4UnitDefinition::BuildUnitsTable();
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| 192 |
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| 193 | // define Elements
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| 194 | a = 1.01*g/mole;
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| 195 | G4Element* elH = new G4Element(name="Hydrogen",symbol="H" , z= 1., a);
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| 196 |
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| 197 | a = 12.01*g/mole;
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| 198 | G4Element* elC = new G4Element(name="Carbon" ,symbol="C" , z= 6., a);
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| 199 |
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| 200 | a = 14.01*g/mole;
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| 201 | G4Element* elN = new G4Element(name="Nitrogen",symbol="N" , z= 7., a);
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| 202 |
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| 203 | a = 16.00*g/mole;
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| 204 | G4Element* elO = new G4Element(name="Oxygen" ,symbol="O" , z= 8., a);
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| 205 |
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| 206 | a = 28.09*g/mole;
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| 207 | G4Element* elSi = new G4Element(name="Silicon", symbol="Si", z=14., a);
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| 208 |
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| 209 | a = 55.85*g/mole;
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| 210 | G4Element* elFe = new G4Element(name="Iron" ,symbol="Fe", z=26., a);
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| 211 |
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| 212 | a = 183.84*g/mole;
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| 213 | G4Element* elW = new G4Element(name="Tungsten" ,symbol="W", z=74., a);
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| 214 |
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| 215 | a = 207.20*g/mole;
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| 216 | G4Element* elPb = new G4Element(name="Lead" ,symbol="Pb", z=82., a);
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| 217 |
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| 218 | // define an Element from isotopes, by relative abundance
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| 219 | G4Isotope* U5 = new G4Isotope(name="U235", iz=92, n=235, a=235.01*g/mole);
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| 220 | G4Isotope* U8 = new G4Isotope(name="U238", iz=92, n=238, a=238.03*g/mole);
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| 221 |
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| 222 | G4Element* elU = new G4Element(name="enriched Uranium", symbol="U", ncomponents=2);
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| 223 | elU->AddIsotope(U5, abundance= 90.*perCent);
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| 224 | elU->AddIsotope(U8, abundance= 10.*perCent);
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| 225 |
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| 226 | cout << *(G4Isotope::GetIsotopeTable()) << endl;
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| 227 | cout << *(G4Element::GetElementTable()) << endl;
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| 228 | </pre></div></div><br class="example-break"><div class="informalexample"><pre class="programlisting">
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| 229 | // define simple materials
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| 230 | density = 2.700*g/cm3;
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| 231 | a = 26.98*g/mole;
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| 232 | G4Material* Al = new G4Material(name="Aluminum", z=13., a, density);
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| 233 |
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| 234 | density = 1.390*g/cm3;
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| 235 | a = 39.95*g/mole;
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| 236 | vG4Material* lAr = new G4Material(name="liquidArgon", z=18., a, density);
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| 237 |
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| 238 | density = 8.960*g/cm3;
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| 239 | a = 63.55*g/mole;
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| 240 | G4Material* Cu = new G4Material(name="Copper" , z=29., a, density);
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| 241 |
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| 242 | // define a material from elements. case 1: chemical molecule
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| 243 | density = 1.000*g/cm3;
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| 244 | G4Material* H2O = new G4Material(name="Water", density, ncomponents=2);
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| 245 | H2O->AddElement(elH, natoms=2);
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| 246 | H2O->AddElement(elO, natoms=1);
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| 247 |
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| 248 | density = 1.032*g/cm3;
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| 249 | G4Material* Sci = new G4Material(name="Scintillator", density, ncomponents=2);
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| 250 | Sci->AddElement(elC, natoms=9);
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| 251 | Sci->AddElement(elH, natoms=10);
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| 252 |
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| 253 | density = 2.200*g/cm3;
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| 254 | G4Material* SiO2 = new G4Material(name="quartz", density, ncomponents=2);
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| 255 | SiO2->AddElement(elSi, natoms=1);
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| 256 | SiO2->AddElement(elO , natoms=2);
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| 257 |
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| 258 | density = 8.280*g/cm3;
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| 259 | G4Material* PbWO4= new G4Material(name="PbWO4", density, ncomponents=3);
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| 260 | PbWO4->AddElement(elO , natoms=4);
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| 261 | PbWO4->AddElement(elW , natoms=1);
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| 262 | PbWO4->AddElement(elPb, natoms=1);
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| 263 |
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| 264 | // define a material from elements. case 2: mixture by fractional mass
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| 265 | density = 1.290*mg/cm3;
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| 266 | G4Material* Air = new G4Material(name="Air " , density, ncomponents=2);
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| 267 | Air->AddElement(elN, fractionmass=0.7);
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| 268 | Air->AddElement(elO, fractionmass=0.3);
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| 269 |
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| 270 | // define a material from elements and/or others materials (mixture of mixtures)
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| 271 | density = 0.200*g/cm3;
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| 272 | G4Material* Aerog = new G4Material(name="Aerogel", density, ncomponents=3);
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| 273 | Aerog->AddMaterial(SiO2, fractionmass=62.5*perCent);
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| 274 | Aerog->AddMaterial(H2O , fractionmass=37.4*perCent);
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| 275 | Aerog->AddElement (elC , fractionmass= 0.1*perCent);
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| 276 | </pre></div><div class="informalexample"><pre class="programlisting">
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| 277 | // examples of gas in non STP conditions
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| 278 | density = 27.*mg/cm3;
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| 279 | pressure = 50.*atmosphere;
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| 280 | temperature = 325.*kelvin;
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| 281 | G4Material* CO2 = new G4Material(name="Carbonic gas", density, ncomponents=2,
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| 282 | kStateGas,temperature,pressure);
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| 283 | CO2->AddElement(elC, natoms=1);
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| 284 | CO2->AddElement(elO, natoms=2);
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| 285 |
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| 286 | density = 0.3*mg/cm3;
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| 287 | pressure = 2.*atmosphere;
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| 288 | temperature = 500.*kelvin;
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| 289 | G4Material* steam = new G4Material(name="Water steam ", density, ncomponents=1,
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| 290 | kStateGas,temperature,pressure);
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| 291 | steam->AddMaterial(H2O, fractionmass=1.);
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| 292 |
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| 293 | // What about vacuum ? Vacuum is an ordinary gas with very low density
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| 294 | density = universe_mean_density; //from PhysicalConstants.h
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| 295 | pressure = 1.e-19*pascal;
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| 296 | temperature = 0.1*kelvin;
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| 297 | new G4Material(name="Galactic", z=1., a=1.01*g/mole, density,
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| 298 | kStateGas,temperature,pressure);
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| 299 |
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| 300 | density = 1.e-5*g/cm3;
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| 301 | pressure = 2.e-2*bar;
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| 302 | temperature = STP_Temperature; //from PhysicalConstants.h
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| 303 | G4Material* beam = new G4Material(name="Beam ", density, ncomponents=1,
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| 304 | kStateGas,temperature,pressure);
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| 305 | beam->AddMaterial(Air, fractionmass=1.);
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| 306 |
|
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| 307 | // print the table of materials
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| 308 | G4cout << *(G4Material::GetMaterialTable()) << endl;
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| 309 |
|
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| 310 | return EXIT_SUCCESS;
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| 311 | }
|
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| 312 | </pre></div><p>
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| 313 | As can be seen in the later examples, a material has a state:
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| 314 | solid (the default), liquid, or gas. The constructor checks the
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| 315 | density and automatically sets the state to gas below a given
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| 316 | threshold (10 mg/cm3).
|
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| 317 | </p><p>
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| 318 | In the case of a gas, one may specify the temperature and
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| 319 | pressure. The defaults are STP conditions defined in
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| 320 | <code class="literal">PhysicalConstants.hh</code>.
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| 321 | </p><p>
|
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| 322 | An element must have the number of nucleons >= number of
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| 323 | protons >= 1.
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| 324 | </p><p>
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| 325 | A material must have non-zero values of density, temperature and
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| 326 | pressure.
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| 327 | </p><p>
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| 328 | Materials can also be defined using the internal Geant4
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| 329 | database. <a href="ch04s02.html#programlist_Mate_2" title="Example 4.11.
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| 330 | A program which shows how to define materials from the internal database.
|
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| 331 | ">Example 4.11</a> illustrates
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| 332 | how to do this for the same materials used in
|
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| 333 | <a href="ch04s02.html#programlist_Mate_1" title="Example 4.10.
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|---|
| 334 | A program which illustrates the different ways to define materials.
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|---|
| 335 | ">Example 4.10</a>.
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|---|
| 336 | There are also UI commands which allow the database to be accessed.
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| 337 | <span class="emphasis"><em>The list of currently avalable material names</em></span>
|
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| 338 | (<a href="apas08.html" title="8.
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| 339 | Geant4 Material Database
|
|---|
| 340 | ">Section 8</a>) is extended permanetly.
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|---|
| 341 | </p><div class="example"><a name="programlist_Mate_2"></a><p class="title"><b>Example 4.11.
|
|---|
| 342 | A program which shows how to define materials from the internal database.
|
|---|
| 343 | </b></p><div class="example-contents"><pre class="programlisting">
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| 344 | #include "globals.hh"
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| 345 | #include "G4Material.hh"
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|---|
| 346 | #include "G4NistManager.hh"
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|---|
| 347 |
|
|---|
| 348 | int main() {
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| 349 | G4NistManager* man = G4NistManager::Instance();
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|---|
| 350 | man->SetVerbose(1);
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| 351 |
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| 352 | // define elements
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|---|
| 353 | G4Element* C = man->FindOrBuildElement("C");
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|---|
| 354 | G4Element* Pb = man->FindOrBuildMaterial("Pb");
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|---|
| 355 |
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|---|
| 356 | // define pure NIST materials
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|---|
| 357 | G4Material* Al = man->FindOrBuildMaterial("G4_Al");
|
|---|
| 358 | G4Material* Cu = man->FindOrBuildMaterial("G4_Cu");
|
|---|
| 359 |
|
|---|
| 360 | // define NIST materials
|
|---|
| 361 | G4Material* H2O = man->FindOrBuildMaterial("G4_WATER");
|
|---|
| 362 | G4Material* Sci = man->FindOrBuildMaterial("G4_PLASTIC_SC_VINYLTOLUENE");
|
|---|
| 363 | G4Material* SiO2 = man->FindOrBuildMaterial("G4_SILICON_DIOXIDE");
|
|---|
| 364 | G4Material* Air = man->FindOrBuildMaterial("G4_AIR");
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|---|
| 365 |
|
|---|
| 366 | // HEP materials
|
|---|
| 367 | G4Material* PbWO4 = man->FindOrBuildMaterial("G4_PbWO4");
|
|---|
| 368 | G4Material* lAr = man->FindOrBuildMaterial("G4_lAr");
|
|---|
| 369 | G4Material* vac = man->FindOrBuildMaterial("G4_Galactic");
|
|---|
| 370 |
|
|---|
| 371 | // define gas material at non STP conditions (T = 120K, P=0.5atm)
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|---|
| 372 | G4Material* coldAr = man->ConstructNewGasdMaterial("ColdAr","G4_Ar",120.*kelvin,0.5*atmosphere);
|
|---|
| 373 |
|
|---|
| 374 | // print the table of materials
|
|---|
| 375 | G4cout << *(G4Material::GetMaterialTable()) << endl;
|
|---|
| 376 |
|
|---|
| 377 | return EXIT_SUCCESS;
|
|---|
| 378 | }
|
|---|
| 379 | </pre></div></div><br class="example-break"></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="sect.Mate.Tables"></a>4.2.4.
|
|---|
| 380 | The Tables
|
|---|
| 381 | </h3></div></div></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="sect.Mate.Tables.PrintCons"></a>4.2.4.1.
|
|---|
| 382 | Print a constituent
|
|---|
| 383 | </h4></div></div></div><p>
|
|---|
| 384 | The following shows how to print a constituent:
|
|---|
| 385 |
|
|---|
| 386 | </p><div class="informalexample"><pre class="programlisting">
|
|---|
| 387 | G4cout << elU << endl;
|
|---|
| 388 | G4cout << Air << endl;
|
|---|
| 389 | </pre></div><p>
|
|---|
| 390 | </p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="sect.Mate.Tables.PrintTab"></a>4.2.4.2.
|
|---|
| 391 | Print the table of materials
|
|---|
| 392 | </h4></div></div></div><p>
|
|---|
| 393 | The following shows how to print the table of materials:
|
|---|
| 394 |
|
|---|
| 395 | </p><div class="informalexample"><pre class="programlisting">
|
|---|
| 396 | G4cout << *(G4Material::GetMaterialTable()) << endl;
|
|---|
| 397 | </pre></div><p>
|
|---|
| 398 | </p></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ch04.html"><img src="AllResources/IconsGIF/prev.gif" alt="Prev"></a> </td><td width="20%" align="center"><a accesskey="u" href="ch04.html"><img src="AllResources/IconsGIF/up.gif" alt="Up"></a></td><td width="40%" align="right"> <a accesskey="n" href="ch04s03.html"><img src="AllResources/IconsGIF/next.gif" alt="Next"></a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 4.
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|---|
| 399 | Detector Definition and Response
|
|---|
| 400 | </td><td width="20%" align="center"><a accesskey="h" href="index.html"><img src="AllResources/IconsGIF/home.gif" alt="Home"></a></td><td width="40%" align="right" valign="top"> 4.3.
|
|---|
| 401 | Electromagnetic Field
|
|---|
| 402 | </td></tr></table></div></body></html>
|
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