放射物理學英文版完整版課件

1、 Diagnostic radiology放射診斷學 Radiotherapy放射療法 Radiobiology放射生物學 Nuclear medicine 核醫(yī)療學 CT scanner; CT掃描X-ray machine;愛克斯光機DR;C-arms;PET;Performance Evaluation Test 性能鑒定試驗radiological imaging放射影像學CT SCANNERPETtraditional methods to kill tumors治療腫瘤的傳統(tǒng)方法clinical physicist;臨床物理學家，醫(yī)學物理師TPS;Technical Problem

2、 Summary 技術問題摘要the interaction between the radioactive particles and the cells在放射性的粒子和細胞之間的交互作用research work to make the radiology more advantageous for human研究工作讓 X 光線學變得更有利于人類ECT, 電休克治療 SPECT;單光子發(fā)射計算機化斷層顯像very popular abroad;bright future; Quantities and units量和單位(physical quantity)=(numerical val

3、ue)*(some unit) International system of units (SI)單位的國際系統(tǒng) Fundamental Units基本的單位Q: review the fundamental units?masslengthtimecurrent1.massmKilogram (kg )2.lengthl meter (m)3.time4.currenttI second (s) ampere (A) Derived units導出單位 velocity 速度ratio 比率of the increment增長 of distance to timeacceleration

4、 加速度 ratio of the change of velocity to timeforce (newton)力（牛頓）related to acceleration defined 界定by Newtons law of motion 運動定律運動定律 Derived units導出單位 work or energy (joule焦耳 )W=F*lpower (watt),功率rate of doing workfrequency 頻率(hertz赫茲) number of oscillation per unit time單位時間振動次數(shù)Example 1-1. A young sc

5、ientist of mass 75 kg at the Ontario Cancer Institute, in a foolish trial of endurance, ran from the basement to the seventh floor (height 25.8 m) in 23.6 s（在（在 23.6 秒中從地下室秒中從地下室跑到七樓（高度跑到七樓（高度 25.8 m） .Calculate the work done and the power developed . In Toronto the acceleration due to gravity is 9.

6、8 ms-2 .課本P4 Electrical units電單位電單位 charge (coulomb)電荷電荷(庫侖庫侖)1 coulomb = 1 C = 1 ampere second = 1 A s potential difference (volt)位差位差,電勢差電勢差(伏特伏特) Potential difference = Electrical circuits電路電路 circuitthroughgsinpaseargchcircuitelectricalindoneworkWork done = Q V = I t V JvoltCenergyofunitaeV19191

7、0602. 1110602. 1)(1 Electrical units capacity（電容）（電容）: ability to store charge resistance（電阻）（電阻）VCvoltcoulombFfarad/111111/11111VAAVamperevoltohmExample 1-2 . A potential of 12 volts placed across a heating coil暖管暖管 produces a current of 1.5 amperes. Find the resistance （電阻）（電阻）of the coil, the cha

8、rge which passes through the coil in 1.0 min, the energy dissipated（消耗的能量）（消耗的能量）, and power 功率developed. Example 1-3. A current of 2.5 10-6A flows into a 20.0 10-6 F condenser電容器電容器 for 20 seconds. Find the potential （電勢差電勢差）to which the condenser is charged. Radiation units輻射單位輻射單位 absorbed dose吸收

9、劑量吸收劑量 energy deposited吸收吸收 by ionizing （電（電離）離）radiation per unit mass of material 1 Gy = 100rads = 1J/kgexposure 曝光曝光 the charge（電荷電荷 ）liberated（釋放）（釋放） by ionizing radiation ( output of an X ray generator發(fā)生器發(fā)生器) per unit mass of air 1 roentgen （倫琴）（倫琴）= 2.58*10-4 C kg -1 Radiation units activity

10、活性活性 the number of disintegration（裂變）（裂變） per unit time of a radioactive isotope （放射性同位素）（放射性同位素） unit: becquerel 貝可勒爾貝可勒爾(放射性強度放射性強度單位單位, 每秒有一個原子衰變每秒有一個原子衰變) 1Bq = 1s-1 1Ci = 3.70*1010 Bq The physics of radiology（X 光線學光線學的物理學的物理學 Fundamental units基本的單位 Derived units導出單位 Units used in radioactive fi

11、eld（放（放射領域）射領域） Matter is composed by atoms物質由原物質由原子組成子組成 Structure of Atomsnucleus(原子原子)核核-radius半徑半徑 10-14melectrons clouds-radii 半徑半徑10-10m Atomic number原子序數(shù)原子序數(shù): Z number of electrons chemical properties化學特性化學特性 Constitution結構，構造結構，構造 protons (質子質子) neutrons(中子中子)Q: How to know the structure of

12、the nucleus?Q: Properties of protons and neutrons: charge and mass mass number(原子原子)質量數(shù)質量數(shù): A protons + neutrons neutrons = A-Znucleon核子核子 Isotope同位素同位素 definition(定義定義): Atoms composed of nuclei 原子核原子核(nucleus的復數(shù)形的復數(shù)形)with the same number of protons (質子質子)but different number of neutrons(中子中子) are

13、called isotopes. stable 穩(wěn)定的穩(wěn)定的or unstable ; disintegration（裂變）（裂變） and radioactive;（ 放射性的）放射性的） Carbon 碳碳 mass number 原子序數(shù)原子序數(shù)12 represented by A【mass number(原子原子)質量質量數(shù)數(shù)】 Notation for atomic species原子種類的標記法原子種類的標記法 subscripts（下標下標）-Z and superscripts（上標）（上標）-AIsotope of Hydrogen氫氫, Helium氦氦, Cobalt鈷

14、鈷(符符號為號為Co), H11H21H13Hydrogen（氫）氫氫氫氫Z = 1111012123StableStableRadioactiveProton(質子質子)Deuteron（氘核HydrogenDeuterium（氘Tritium（三重氫H11H13H12Helium氦氦Z = 232He42He52He62He82He222221234634568StableStableRadioactiveRadioactiveRadioactiveAlpha（） pproton 1.007277, +1 The proton is the nucleus of the hydrogen

15、atom. The hydrogen atom consists of 1 proton in the nucleus and 1 external（外部的）（外部的） electron. The mass of the neutral atom （中性（中性原子）原子）is 1.007277 +0.000548 = 1.007825 mass units. The proton is one of the fundamental building blocks of all nuclei. Beams（束（束, 柱）柱） of protons are being used in radiot

16、herapy.（放射療法）（放射療法） nneutron 1.008665, 0 The neutron(中子中子) is the other fundamental building block of all nuclei. Neutrons have nearly the same mass as protons. Since the neutrons is an uncharged particle （不帶電粒子）（不帶電粒子）it is hard to stop and difficult to detect（查（查明，發(fā)現(xiàn)，發(fā)覺明，發(fā)現(xiàn)，發(fā)覺. ）Beams of neutrons

17、are being used in radiotherapy. e- - 0.000548, -1The electron has a very small mass compared with the proton. Electrons abound in nature. Every atom contains electrons outside the nucleus. The electron is easily detected. It is sometimes called a negatron（陰電子（陰電子 ）or beta particle（粒子）粒子） and represe

18、nted by e, e- or -.Beams of high energy electrons are extensively（廣泛地）（廣泛地） used in radiotherapy. e+ + 0.000548, +1The positron（正電子）（正電子） has the same mass as an electron but carries a positive charge. Positrons exist in nature only while they are in motion（在運（在運轉中轉中;處于興奮狀態(tài)）處于興奮狀態(tài)）. A slowly moving

19、or stationary(靜止的靜止的) positron quickly combines with an electron to form a burst (爆炸爆炸, 爆裂爆裂)of radiation in the form of （用（用的形式）的形式）two gamma rays（射射線）線） (see below). Positrons are represented by e+, or + and referred to as beta plus particles They are used in nuclear medicine（核醫(yī)療學）（核醫(yī)療學）. Hv , 0,

20、0Strictly speaking, the photon （光子）（光子）is not a particle, but a bundle一捆一捆 of energy which travels at the speed of light (3108ms-1). In many interactions（相互作用）（相互作用） it acts much like a particle. Photons are referred to almost interchangeably（可替換地）（可替換地） as quanta 量子量子(quantum的復數(shù)形式的復數(shù)形式)or gamma ray

21、s and are represented symbolically（象征性地）（象征性地） by h or . Beams of photons account for the major part of external beam （外粒子束（外粒子束;外束）外束）radiotherapy（放射療法）（放射療法）. neutrino 中微子e , 0The neutrino （中微子）（中微子）is a very small particle with practically （幾乎）（幾乎）no mass and no charge. For this reason, it has be

22、en very difficult to detect experimentally（根據實驗地）（根據實驗地）. Its interaction （相互作用）（相互作用） with protons to form neutrons and positrons according to the reaction（反應）（反應）e+ p n + +has been observed. The neutrino was introduced originally from theoretical （假設的，（假設的，理論的）理論的）considerations to help explain be

23、ta decay（衰變）（衰變）. Mu mesons（介子）（介子） , + , - , 207m0 ,+1 or -1 Mu mesons may be either positively or negatively charged （帶負電荷的）（帶負電荷的）and have a mass 207 times the mass of the electron. They are produced indirectly（間接地）（間接地） by the interaction of very high energy particles with matter（物質（物質,物體）物體）. T

24、he particles are unstable and decay spontaneously （自發(fā)地（自發(fā)地衰變）衰變）into electrons and neutrinos（中微子 according to the reactions+ e+ + 2- e- + 2The mean life（平均壽命）（平均壽命） of the particles is 2.1510-6 sec.Pi mesons （介子）（介子） , + 273 m0 +1 - 273 m0 -1 0 265 m0 0Pi mesons may have a positive a negative charge

25、 or may be neutral（中性的）（中性的）. They are produced by the bombardment （炮擊；轟炸）（炮擊；轟炸）of matter with high energy protons or photons. The charged mesons decay into mu mesons and neutrinos（中微子）（中微子） according to + + + - - + with a mean life of 2.510-8 s. The neutral 0 meson decays（衰變）（衰變） into 2 photons0 h

26、1 + h2with a mean life of 10-15 seconds. Beams of negative mesons are being used in radiotherapy（放射療法）（放射療法）. pproton 1.007277, +1 nneutron 1.008665, 0 e- - 0.000548, -1 e+ + 0.000548, +1 H 0, 0 e , 0 Mu mesons 207m0 ,+1 or -1 Pi mesons 273m0 ,+1 or -1 265m0 0 Arrangement of planetary electrons 行星式電

27、子outside the nucleus The outermost orbit最外層軌道 Chemical properties and valence(化合)價 repeat inert gas惰性氣體 : He, Ne, alkaline elements堿性元素: lithium鋰, sodium鈉,Optical radiation 光輻射and X radiationGamma ray（伽馬射線,射線）伽馬射線,射線 Quantum (量子)or Photon（光子） bundle of energy 能量束 Energy of a PhotonhE hEJmJmpmmsJschh

28、E141226183410989.110101089.19101031063.6For a diagnostic （診斷的）X-ray Generator（發(fā)生器）, wavelength （波長）10pm, 1 photon:Important equation方程式, 等式 hE Wavelength （波長） and energy pmkeVE1240Quantum nature and continuous radiation連續(xù)輻射 keVeVeVJE1241024. 11060. 110989. 110989. 15191414Frequency(Hz)頻率Wavelength波長

29、PhotonEnergyProperties特性特性1.01053.01010103 km0.01 m413 peV124 eV Radio waves（無線電波） ranging（排列） from long waves through the broadcast band（廣播波段;廣播頻帶, to short waves and to ultra（極端的） short waves in radar（雷達）. These waves are produced by electrical oscillations（振蕩） and detected（發(fā)現(xiàn); 發(fā)覺, 查明） by electron

30、ic equipment. They will pass through nonconducting layers （不傳導層）of materials but are reflected（反射） by electrical conductors.（導電體;電導線）Frequency(Hz)WavelengthPhotonEnergyProperties特性特性3.0 01 10 012123.03.010101414100 m1 m12.4 meV1.24 eVInfrared radiations（紅外輻（紅外輻射）射）. These are produced by molecular v

31、ibration（分子振動）（分子振動） and the excitation 激發(fā)激發(fā)(過程過程)of the outer electrons of the atom. They are generated（產生）（產生） by heat in stores（堆積物）（堆積物）, radiators（散熱器）（散熱器）, et cetera（及其他（及其他,等等）等等）, and can be detected by heat devices（裝置（裝置, 設備）設備） and films（薄層，膠（薄層，膠卷）卷）. Most solid materials are opaque （不透明

32、的）（不透明的）to infrared radiations.Frequency(Hz)WavelengthPhotonEnergyProperties4.3 31 10 014147.57.510101414700 nm400 nm1.77 eV3.1 eV Visible light （可見光）（可見光）ranging from red through yellow, green and blue to violet紫紫. Produced by the excitation of the outer electrons of an atom. Generated（產生）（產生） in l

33、amps and in gas tubes（導（導氣管）氣管） by electrical discharge（釋放，（釋放，排放出的物體）排放出的物體）. Detected by films, by photoelectric cells（光電管）（光電管）, and by the eye. Transmitted（傳播傳播）by materials such as glass. Frequency(Hz)WavelengthPhotonEnergyProperties7.5 5101014143.03.010101616400 nm10 nm3.1 eV124 eV Ultraviolet

34、 light（紫外輻射（紫外輻射;紫外光）紫外光）. Produced by the excitation of outer electrons in the atom. Detected by films, Geiger counters蓋格計數(shù)器蓋格計數(shù)器（用于測量放射性）（用于測量放射性）, and ionization chambers（電離（電離室）室）. Produces erythematic（紅斑）（紅斑） of the skin; kills bacteria （細菌）（細菌）and is an agent（原動力（原動力, 動因動因; 作用劑）作用劑） in the pro

35、duction of vitamin D.Frequency(Hz)WavelengthPhotonEnergyProperties3.0 0101016163.03.01010181810 nm100 pm124 eV12.4 keVSoft x rays. Produced by the excitation of the inner electrons （內層電子）（內層電子）of an atom. Detected by films, Geiger counters, and ionization chambers. Have the ability to penetrate（穿過）（

36、穿過） very thin layers of material. Of little value in radiology （放射學（放射學,輻射學）輻射學）because of their limited power of penetration.穿透能力穿透能力3.0 0101018183.03.010101919100 pm10 pm12.4 keV124 keVDiagnostic x rays and superficial （表表面面(上上)的的）therapy（治療，（治療，療法療法）.Frequency(Hz)WavelengthPhotonEnergyProperties3

37、.0 0101019193.03.01010202010 pm1 pm124 keV1.24 MeVDeep therapy（深部療法）（深部療法） x rays and gamma rays from radium decay products（鐳衰變產（鐳衰變產物）物）.3.0 010102121100 fm12.4 MeVRadiation from a small betatron（電子感應加（電子感應加速器）速器） or linear accelerator（直線加速器）（直線加速器）.3.0 01010222210 fm124 MeVRadiation from a large l

38、inear accelerator.3.0 0101023231 fm1.24 GeVProduced in the operation of large proton synchrotrons （同步加速器）（同步加速器）or linear accelerators（直線加速器）（直線加速器）.Frequency(Hz)WavelengthPhotonEnergyProperties1.01053.010103 km0.01 m413 peV124 eVRadio waves ranging from long waves through the broadcast band, to sho

39、rt waves and to ultra short waves in radar. These waves are produced by electrical oscillations and detected by electronic equipment. They will pass through nonconducting layers of materials but are reflected by electrical conductors.3.010123.01014100 m1 m12.4 meV1.24 eVInfrared radiations. These ar

40、e produced by molecular vibration and the excitation of the outer electrons of the atom. They are generated by heat in stores, radiators, et cetera, and can be detected by heat devices and films. Most solid materials are opaque to infrared radiations.4.310147.51014700 nm400 nm1.77 eV3.1 eVVisible li

41、ght ranging from red through yellow, green and blue to violet. Produced by the excitation of the outer electrons of an atom. Generated in lamps and in gas tubes by electrical discharge. Detected by films, by photoelectric cells, and by the eye. Transmitted bymaterials such as glass. 7.510143.0101640

42、0 nm10 nm3.1 eV124 eVUltraviolet light. Produced by the excitation of outer electrons in the atom. Detected by films, Geiger counters, and ionization chambers. Produces erythematic of the skin; kills bacteria and is an agent in the production of vitamin D.3.010163.0101810 nm100 pm124 eV12.4 keVSoft

43、x rays. Produced by the excitation of the inner electrons of an atom. Detected by films, Geiger counters, and ionization chambers. Have the ability to penetrate very thin layers of material. Of little value in radiology because of their limited power of penetration.3.010183.01019100 pm10 pm12.4 keV1

44、24 keVDiagnostic x rays and superficial therapy.3.010193.0102010 pm1 pm124 keV1.24 MeVDeep therapy x rays and gamma rays from radium decay products.3.01021100 fm12.4 MeVRadiation from a small betatron or linear accelerator.3.0102210 fm124 MeVRadiation from a large linear accelerator.3.010231 fm1.24

45、GeVProduced in the operation of large proton synchrotrons or linear accelerators. Binding energy結合能結合能 K radiation, BE: 70000ev L radiation, BE: 11000ev M radiation, BE: 2500evAtoms原子原子The Nucleus原子核原子核Elemental Particles基本粒子基本粒子Extranuclear Structures核外結構核外結構Atomic Energy Levels原子能級原子能級Nuclear Ener

46、gy Levels核能級核能級Electromagnetic Radiation電磁輻射電磁輻射Quantum Nature of RadiationThe Electromagnetic Spectrum電磁波頻譜Radiation of Energy from an Atom 原子的原子的能量輻射能量輻射 Einsteins theory E = m c2 C代表光速)101 .sin(511. 010602.1087.811087.81)10kg(2.9989.10913151522281eqguMeVMeVJsmEEnergy corresponding to one electron

47、能量相當于1 kg m2S-2 = 1 joule JvoltCenergyofunitaeV191910602. 1110602. 1)(1Because:mass of one carbon atom = g23231099268. 110022045. 612.000gMeVMeVJsmkgE5 .931106022. 1104925. 1104925. 1)10998. 2(121099268. 1131010222826Example 1-7. Calculate the energy equivalent(能當量能當量) of 1 atomic mass unit (amu). A

48、vogadros number(阿伏伽德羅數(shù)阿伏伽德羅數(shù) )= 6.022045 1023 carbon has a mass number【(原子原子)質量數(shù)質量數(shù)】 of 12, it contains 12 amuHence, the conversion （ 轉化）轉化）of 1 amu to energy MeVmasselectron511. 0 1MeVamu5 .9311220/1cvmm202.cmmcEKm0 , the rest mass靜止質量靜止質量 1/10 the velocity of light , increase in mass of 0.5% 98% o

49、f light (v/c0.98), 5 times of the rest massKineticEnergy（動能）ElectronsProtonsTotalEnergy(MeV兆電子伏)VelocityRelative toVel. of LightMassRelative toRest Mass（靜止質量）VelocityRelative toVel. of LightMassRelative toRest Mass10 keV100 keV200 keV500 keV1 MeV2 MeV5 MeV10 MeV20 MeV50 MeV100 MeV 0.521 0.1950 1.020

50、 0.611 0.5483 1.196 0.711 0.6954 1.392 1.011 0.8629 1.979 1.511 0.9411 2.957 2.511 0.9791 4.916 5.511 0.9957 10.79 10.511 0.998817 20.58 20.511 0.999689 40.16 50.511 0.999949 99.01 100.511 0.999987 192.31 0.0046 1.0000 0.0147 1.0001 0.0208 1.0002 0.0326 1.0005 0.0465 1.0011 0.0657 1.002 0.1026 1.005

51、3 0.1451 1.0107 0.2033 1.0213 0.3141 1.0533 0.4283 1.1066 the rate of change of a function（函數(shù)）（函數(shù)） is proportional （比例的（比例的, 成比例的）成比例的）to the function. If a quantity changes by a certain factor （一個特（一個特定的因素）定的因素）in a given interval of time（時間時間間隔）間隔）, then there will be exponential behavior if in an

52、y other equal interval of time （相等時間間隔）（相等時間間隔）it changes by the same factor 相同的因素相同的因素 the growth of money in a bank account銀行存款銀行存款, the growth of populations, the growth of cells, the decay（衰變）（衰變） of radioactive isotopes（放射性同位素）（放射性同位素） the killing of cells by radiation, the attenuation （變細；變薄變細

53、；變薄;減弱）減弱）of x ray beams Occurred（發(fā)生）（發(fā)生） while:EXPONENTIAL DECAY（指數(shù)式衰減）（指數(shù)式衰減） OF A RADIOACTIVEISOTOPEHALF-LIFE（半衰期）（半衰期）on the average, after the half-life, half the radioactive atoms（放射性原子）（放射性原子） will disintegrate（破裂分裂）（破裂分裂）. In the next half-life, one-half of the remaining （剩下的）（剩下的）atoms will

54、 decay. For example, a source of radioactive gold (198Au) with a half-life of 2.69 days, , started with 100106 atoms, after 2.69 days there would be 50 106 remaining, after 5.38 days 25 106, after 8.07 days 12.5 106. EXPONENTIAL DECAY OF A RADIOACTIVEISOTOPEHALF-LIFEEXPONENTIAL DECAY OF A RADIOACTIV

55、EISOTOPEHALF-LIFEhhttttNNN/0/022Mathematical relation數(shù)學關系:substituting t = th , 2th, 3th. （取代取代）The number, N, after these times is N0 /2, N0 /4, N0 /8 EXPONENTIAL DECAY OF A RADIOACTIVEISOTOPEHALF-LIFEExample 1-8. Calculate the number of atoms of 198Au (th = 2.69 days) after 7 days if initially （開始

56、（開始,最初）最初）there were 108 atoms present. We now determine（測定） with a calculator（計算器） that 22.606.06 atoms 60. 269. 27htt781065. 106. 6/10 N e0.693 = 2.00 N = N0(2)-t/th = N0(e0.693) -t/th = N0e -0.693t/th Decay time (in units of half-lives) = N = -Nt , provided（只有（只有才）才） t 1 dN = - N dt N = N0e-t ht0

57、.693 hhattt44. 1693.1N = + Nt its solution leads to N = N0et and = dt0.693N = - ND N = N0e-D = N0e-D/D0Graphs showing exponential growth of cells and exponential killing（指數(shù)式消滅） of cells. N = -Nx N = N0e-x hxu0.693 , the linear attenuation coefficient線性衰減系數(shù)線性衰減系數(shù) the solution is :is called the half-v

58、alue thickness（半吸收厚度;半值層;強度減半厚度）, or half-value layer hxProcess(過程過程, 進程進程)Variable(變數(shù)變數(shù))Constant ofProportionality(常數(shù)常數(shù)比例比例)Useful RelationsUsualEquation(方程式方程式, 等式等式)Radioactivedecay ofatoms, Ntime, ttransformationconstant,（變形（變形常數(shù)）常數(shù)）mean life,th = 1/half-lifeth = 0.693/Growth of investment（投資投資）

59、，Vtime, tinterest rate,r（利率）（利率）doubling time（倍增時間）（倍增時間）,td = 0.693/rGrowth of pop. ofcells, Ntime, tgrowth constant（常（常數(shù)）數(shù)）, doubling time,td = 0.693/Killing ofcells, N, byradiationdose, D（劑量）（劑量）killing constant, mean lethaldose,D0 = 1/dose to kill50%, Dh = 0.693D0Attenuation（變細；變薄變細；變薄;減弱）減弱）of

60、a beam ofphotons, Nthickness, x（厚（厚度）度）attenuationcoefficient, （變薄（變薄系數(shù)）系數(shù)）mean freepath, 1/half-value layerxh = 0.693/teNN0treVV0teNN0 teNN0 0/0DDeNN Mass and energy Mass and velocity Exponential behaviorQ: How to produce X radiation?Substance(物質，物物質，物) bombarded (轟擊轟擊)by high speed electronsX-ray