放射防护学课件：Chapter 1 Nuclear Physical Basis of Radiation Protection

1、Radiation Protection(Radiological protection )放射防护学IntroductionCourse description:-Radiation Protection is an important part of preventative medicine. -Based on harmful effect of radiation on the population, this subject is mainly focused on：-investigating the relationship between radiation and huma

2、n life as well as human activity; -formulating the rules, approaches, evaluation and managements for the radiation safety; -improving the conditions of radiological environment; -preventing and reducing radiation damage; -medically preparing and responding to the emergency events of radiation. -The

3、purpose of this subject would be to make radiation better in the service to people.-Mastering the basic theories, knowledge, skills and laws for radiation protection; -Understanding the basic knowledge of nuclear physics and biology; knowing the basic requirements for medically preparing and respond

4、ing to the emergency events of radiation; -Training the ability in performing the practical activities related to radiation.Course Objective Chapter 1: Introduction to Radiation Protection and Nuclear Physical Basis of Radiation Protection Chapter 2: Radiation Biology Chapter 3: Radiation Exposure O

5、ccurring in Human Life Chapter 4: The Standards of Radiation ProtectionChapter 5: The Protection against External Radiation ExposureChapter 6: The Protection against Internal ExposureChapter 7: Medical Radiation ProtectionChapter 8: Radiation Protection Supervision and Occupational Health Surveillan

6、ceMain Contents Schematic of the electromagnetic spectrum (Hall and Giaccia, 2006).Ionizing Radiation：quantum energy12eV，Ionization to matters (organism) with severe injury； Such as X-Ray、-Ray, particles 、 particles、cosmic，Electromagnetic Radiation (电磁辐射）Non-ionizing Radiation：quantum energy 12eV ，N

7、o ionization to matters ；Such as UV light, infrared, visible light, laserIonizing RadiationNon-Ionizing Radiation12eVThe properties of electromagnetic waves：wavelength, frequency, propagation velocity, radiation energyRadiation can be classified as either ionizing or non-ionizing according to whethe

8、r it ionizes or does not ionize ordinary chemical matter. non-ionizing Radiation （非电离辐射）refers to any type of electromagnetic radiation that does not carry enough energy （less than 12ev） per quantum to ionize atoms or moleculesthat is, to completely remove an electron from an atom or molecule. Ioniz

9、ing Radiation（电离辐射）is radiation composed of particles that individually carry enough kinetic energy （more than 12ev）to liberate an electron from an atom or molecule, ionizing it.Classification of Radiation Colorless, odorless, invisible, intangible, strong penetrating Ionizing Radiation2007 ISO radi

10、oactivity danger symbol. The red background is intended to convey urgent danger, and the sign is intended to be used in long-term radioactive waste depositories, which might survive into a distant future where other danger symbols may be forgotten or misinterpreted Ionizing radiation hazard symbol 1

11、895_German physicist Wilhelm Roentgen discovered and named X-rays. While experimenting with high voltages applied to an evacuated tube on 8 November 1895, he noticed a fluorescence on a nearby plate of coated glass. He realized that he had produced a previously unknown invisible light, or ray. He al

12、so found that the new ray would pass through most substances casting shadows of solid objects on pieces of film. He named the new ray X-ray, because in mathematics X is used to indicated the unknown quantityThe history of the development of radiation 1896_Franch Physicist, Antoine Henri Becquerel (贝

13、克勒尔, Bq ) discovered radioactivity from uranium(铀), 1903-Nobel Prize in Physics One of the minerals Becquerel worked with was a uranium compound. The experiment normally consisted of wrapping some photographic film in light proof paper, placing a piece of fluorescent uranium on top of the film, and

14、leaving them in the sun. One day, after preparing the experiment, it was too cloudy to expose his samples to direct sunlight, so he stored the uranium compound and the film in a drawer. A couple of days later, he decided to develop this film anyway, and discovered an image of the uranium sample on t

15、he film. Becquerel questioned what would have caused this. He knew he had wrapped the film tightly in light proof paper, so the image was not due to stray light. In addition, he noticed that only the film that was in the drawer with the uranium compound had an image on it. Becquerel concluded that t

16、he uranium compound gave off something invisible that could penetrate heavy paper and affect photographic film. Becquerel continued to test many samples of compounds and determined that the source of the invisible something was the element uranium. This invisible something was named radiation, and i

17、t was determined that an element that gives off radiation is a radioactive element.1898-Marie curie and Pierre Curie theory of radioactivity (a term that she coined): decay law and half-life of radioactive elementstechniques for isolating radioactive isotopes , and the discovery of two elements, pol

18、onium(钋)and radium(镭).Marie Curie，French-Polish physicist and chemist, famous for her pioneering research on radioactivity. She was the first woman to win a Nobel Prize, the only woman to win in two fields, and the only person to win in multiple sciences. She was also the first female professor at t

19、he University of Paris, and in 1995 became the first woman to be entombed on her own merits in the Panthon in Paris.Curie died in 1934 due to aplastic anemia brought on by exposure to radiation Under her guidance, the first time people used radioisotopes for cancer treatment Radiation Harm to human：

20、-mountain sickness- in 20th century -Misuse -Abuse-Marie curie and her daughter _aplastic anemia-Nuclear accident or Nuclear disaster -the contaminations of radioactive materialsKazakhstan: 1949-1989 (470 nuclear tests); The history of development of radiation protection1902-concept about “Radiation

21、 danger line”(放射线危险界限)1913-suggestions about radiation protection, and related its guide was issued in Roentgen association conference in Germany.1925-1st international radiology conference, and “international commission on radiation units and measurements，ICRU” （国际辐射单位与测量委员会）was established1928-2nd

22、 international radiology conference, ICXRP (international commission on X-Ray and Radium protection,国际X射线和镭防护委员会) was established 1942-Radiological protection was formally formed following the establishment of nuclear reactor，the rise of the nuclear industry and application of the atomic bomb；After

23、second world war, the development of radiation protection was promoted rapidly.1950-ICXRP was renamed as “international commission on radiological protection” (ICRP, “国际放射防护委员会” ). -the publications issued by ICRP are the guidance document in the field of ionizing radiation-the important base to mak

24、e the regulations of radiation and instructions of radiological protection for all countries in the world.The history of development of radiation protectionInternational Organization and Research Agency: IAEA (International Atomic Energy Agency)UNSCEAR（United Nations Scientific Committee on the Effe

25、cts of Atomic Radiation ）ICNIRP（International Commission on Non-Ionizing Radiation Protection ）ABCC-RERF（Atomic Bomb Casualty CommissionRadiation Effects Research Foundation ）WHO（World health organization）*1954年10月：在广西富钟县黄羌坪花山区采集到中国第一块铀矿石，毛泽东主席称“这是决定命运的”。*1955年1月15日：在周恩来总理的周密安排下，由毛泽东主席亲自主持召开了共和国历史上有

26、特殊意义的中共中央书记处扩大会议，作出了我国研制核武器的重大战略决策，随后开创了“两弹”的伟大事业。*“596工程”：1959年6月20日苏共撕毁援助协议，中央决定自力更生研发核武器。建立了三个基地：核原料装料生产基地（甘肃）；核武器研制基地（青海）；核武器试验基地（新疆）Radiation development in China*1964年10月14日，我国成功地爆炸了第一颗原子弹，揭开了我国核武器试验的历史华章。*19641996年的33年间，我国共进行了45次核试验：包括大气层核试验23次（其中进行动物效应医学研究20次）和地下核试验22次，*习近平主席于2013年海牙核安全峰会上提出

27、：“发展和安全并重，确保核安全为前提发展核事业”。*经过几代人不懈的努力，我国原子能、放射事业取得了举世瞩目的成就。Radiation development in China一、放射防护基本标准(The Basic Standards of Radiation Protection)1. The standards of first generation1960年2月，国务院批准 卫生部和国家科委发布 放射性工作卫生防护暂行规定 电离辐射的最大容许量标准 放射性同位素工作的卫生防护细则 放射性工作人员的健康检查须知1964年1月，卫生部、国家科委发布试行放射性同位素工作卫生防护管理办法2.

28、The standards of second generation放射防护规定 （GBJ 874）放射性同位素工作卫生防护管理办法19790401实行3. The standards of third generation 放射卫生防护基本标准 （GB 4792 84） 辐射防护规定 （GB 8703 88） 放射性同位素与射线装置放射防护例 （国务院第 44 号令） 4. The standards of fourth generation电离辐射防护与辐射源安全基本标准 （GB 18871 2002） 200210 08由国家质监总局发布 2003 04 01实施二、放射卫生法规 (Th

29、e regulation of radiation)The First Stage（1956-1989）*1956年国家将同位素应用研究列入十二年科技发展规划。 *1960年国务院放射性工作卫生防护暂行规定，是我国第一部放射卫生防护法规。国务院所属部委参考国际上放射卫生防护管理的措施和经验，相继制定并发布了有关同位素管理、工作人员管理、医疗照射管理、食品卫生管理及核工业卫生管理的若干单项法规。*1987年国务院发出关于加强放射性同位素和射线装置放射防护管理工作的通知。Radiation development in China The Second Stage（1989-2001）*1989年

30、国务院发布放射性同位素与射线装置放射防护条例监督部门进行放射卫生监督的主要依据。*1989-1999年期间根据条例陆续制定和修订了20多项部门规章和规范，形成了较为完善的法规体系。卫生部令（10个）第3号 放射防护监督员管理规定 第9号 非医用加速器放射卫生管理办法 第12号 辐照加工装置卫生防护管理规定 第25号 核设施放射卫生防护管理规定第34号 医用X射线诊断卫生防护及影像质量保证管理规定 第38号 核事故医学应急管理规定第40号 放射治疗卫生防护与质量保证管理规定第43号 大型医用设备配置与应用管理暂行办法第47号 辐照食品卫生管理办法第52号 放射工作人员健康管理规定规范性文件（10

31、个）关于调整和加强卫生系统放射性污染监测工作的意见油（气）田非密封型放射源测井放射卫生管理办法 电离辐射计量检定员管理规定核设施正常运行和事故期间公众受照剂量监测与评价规范核事故医学应急准备与响应安全导则含放射性物质消费品卫生防护管理规定建设项目放射防护评价报告书格式和内容放射事故管理规定X-射线计算机体层摄影装置（CT）等大型医用设备配置与应用管理实施细则 X-射线计算机体层摄影装置（CT）应用质量检测与评审规范The Third Stage（2001-2004）*（1）国务院关于全面推进依法行政的决定， （2）卫生监督体制改革 （3）满足加入WTO的需要 *2001年发布放射工作卫生管理办

32、法、放射事故管理办法和放射防护器材与含放射性产品卫生管理办法*2002年和2003年发布职业病防治法配套规章。 现行法律、法规（5部）国家主席令第60号 职业病防治法国家主席令第6号 放射性污染防治法国务院令第44号 放射性同位素与射线装置放射防护条例国务院令第124号 核电厂核事故应急管理条例国务院令第376号 突发公共卫生事件应急条例现行卫生部令(12个）第52号 放射工作人员健康管理规定第16号 放射事故管理规定第17号 放射工作卫生防护管理办法第18号 放射防护器材与含放射性产品管理办法第25号 核设施放射卫生防护管理规定 第43号 大型医用设备配置与应用管理暂行办法 第20号 国家职

33、业卫生标准管理办法第21号 职业病危害项目申报管理办法第22号 建设项目职业病危害分类管理办法第23号 职业健康监护管理办法第24号 职业病诊断与鉴定管理办法第31号 职业卫生技术服务机构管理办法The frame about the regulation system of radiation in China职业病防治法放射性同位素与射线装置放射防护条例部门规章放射性污染防治法等相关法律突发公共卫生事件应急条例等相关法规核电厂核事故应急管理条例Chapter 1 Nuclear Physical Basis of Radiation ProtectionAtomic StructureMo

34、lecule (分子）Atom (原子）-atomic nucleus（原子核） proton（质子） neutron（中子） nucleon（核子）-electron（核外电子） energy level（能级）Ionization (电离)e-e-原子核KLenergy level (能级)ground state (基态)excited state (激发态)excitation (激发）Ion pair(离子对）ionization(电离)ionizing radiation(电离辐射)MN质子+中子e-特征X射线 symbols for elements (原子符号)53I78131

35、Examples:131I or I-131AXZElement(元素符号, the atom with the same mass# 质子数相同的一类原子，)Mass number (质量数=p#+n#)Atomic number (原子序数, 质子数即核电荷数)Atomic #=nuclear charge #=Proton# =extranuclear electrons# neutron number（中子数，A-Z）NRadionuclide and Nuclear Reaction nuclide （核素）：A nuclide (from nucleus) is an atomic

36、 species characterized by the specific constitution of its nucleus, i.e., by its number of protons Z, its number of neutrons N, and its nuclear energy state. ZXN isotope （同位素）：Isotopes are variants of a particular chemical element such that, while all isotopes of a given element share the same numbe

37、r of protons in each atom, they differ in neutron numbers. For example：1H、2H、3Hisomer（同质异能素）：isomers are molecules with the same molecular formula but different chemical structures and nuclear energy state. For example: 99mTc、99Tcstable nuclide（稳定核素）：Stable nuclides are atomic species that are not r

38、adioactive - that is, they do not spontaneously undergo radioactive decay. When such nuclides are referred to in relation to specific elements, they are usually termed stable isotopes. radioactive nuclide （ radionuclide,不稳定核素, 放射性同位素）：which is an atom with an unstable nucleus, characterized by exces

39、s energy available to be imparted either to a newly created radiation particle within the nucleus or via internal conversion. During this process, the radionuclide is said to undergo radioactive decay, resulting in the emission of gamma ray(s) and/or subatomic particles such as alpha or beta particl

40、es. These emissions constitute ionizing radiation. Radionuclides occur naturally, or can be produced artificially The nucleus of the smallest atom - the hydrogen atom, contains one proton only. But those of the larger atoms contain many protons and neutrons. A uranium-238 nucleus contains 92 protons

41、 and 146 neutrons.The nucleus of most atoms is stable, but some nuclei, in particular those larger ones, are unstable.Stability of Atomic Nucleus radioactive nuclide-nuclear reactionNuclear reaction：nuclear reaction is semantically considered to be the process in which two nuclei, or else a nucleus

42、of an atom and a subatomic particle (such as a proton, neutron, or high energy electron) from outside the atom, collide to produce one or more nuclides that are different from the nuclide(s) that began the process. Thus, a nuclear reaction must cause a transformation of at least one nuclide to anoth

43、er. Application:-generate the artificial radioactive nuclide; nuclear fission -obtain nuclear energy. Notable types: fission （裂变）and fusion (聚变) Neutron-induced nuclear fission reactions a very heavy nucleus, spontaneously or after absorbing additional light particles (usually neutrons), splits into

44、 two or sometimes three pieces. This is an induced nuclear reaction. Fusion reactions(聚变反应) two light nuclei join to form a heavier one, with additional particles (usually protons or neutrons) thrown off to conserve momentum Radioactivity theory ： Nuclear Decay and its law nuclear decay（ Radioactive

45、 decay，放射性核衰变）As an unstable atom tries to reach a stable form, energy and matter are released from the nucleus. This spontaneous change in the nucleus is called radioactive decay. U-238 (A) U-234 (B)+ He-4 A: parent, B: daughterThe type of decay: decay ： decay：- decay、+ decay、electron capture radia

46、tion (or ray)：Discovery of alpha decay （衰变）, decay and radiation Alpha particles were first described in the investigations of radioactivity by Ernest Rutherford in 1899, and by 1907 they were identified as He2+ ions. alpha decay （衰变）It is a type of radioactive decay in which an atomic nucleus emits

47、 an alpha particle and thereby transforms (or decays) into an atom with a mass number 4 less and atomic number 2 less. Such as： U-235alpha decay : internal exposurealpha decay （衰变）Rn-2225.4%94.6%Ra-2261600yExcited stateground stateHarm of alpha rayExternal exposure:external alpha radiation is Not ha

48、rmful since alpha particles are effectively shielded by a few centimeters of air, a piece of paper, or the thin layer of dead skin cells that make up the epidermis. Internal exposure:The substances emitting alpha particles are ingested, inhaled, injected or introduced through the skin, which can cau

49、se internal exposure and result in serious harm to body. Beta decay ( decay) is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted from an atomic nucleus. Beta decay is a process which allows the atom to obtain the optimal ratio of protons and neutrons.Beta d

50、ecay is mediated by the weak force. There are two types: beta minus, beta plus and electron capture decay . In the case of beta decay that produces an electron emission, it is referred to as beta minus (), while in the case of a positron emission as beta plus (+).electron capture decay is included a

51、s a type of beta decay (and is referred to as inverse beta decay), because the basic process, mediated by the weak force is the same. However, no beta particle is emitted, but only an electron neutrino. Instead of beta-plus emission, an inner atomic electron is captured by a proton in the nucleus. c

52、haracteristics X-ray（标识X射线）eE auger electron- decayP-32(15)100% -S-32(16)14.28dayCs-1375.6%Ba-137-94.4%661.7keV+ and Electron Capture Decay (EC)F-18(9)+O-18(8)109.7minZn-65(30)Cu-65(29)+1.7%EC 49%EC, +49%Harm of Beta RayExternal exposure:beta particle with higher energy can penetrate several mm of s

53、uperficial tissue in human skin, so it can result in external exposure;Internal exposure:The range of beta particle is farther than alpha particle in the tissue. The tissue damage generated by beta particle is much less that alpha particleRange and Path for alpha and Beta particles radiation（ Gamma

54、radiation, also known as gamma rays , 辐射 ） and denoted by the Greek letter , refers to electromagnetic radiation of extremely high frequency and therefore high energy per photon. Gamma rays are ionizing radiation, and are thus biologically hazardous. They are classically produced by the decay from h

55、igh energy states of atomic nuclei (after alpha or beta decay), but are also created by other processes. e: internal conversion electron(内转换电子）eAm X AY+ ZZGamma radiation: External exposureHarm of Gamma RayExternal exposure:Gamma ray with farther range and higher penetration, it is very easy to resu

56、lt in external exposure;Internal exposure:Since gamma ray is very easy to penetrate body, the damage caused by internal exposure is less than alpha and beta particles .Harm from internal exposure ray ray radiationHarm from external exposure radiation ray rayThe property of common raysRayformmasschar

57、geRange in airRange in tissue He 4 +2 0.03m 0.05mm electron 1/1840 -1 or +1 3m 5mm photon 0 no X photon 0 no How to Protect Ourselves from Ionizing Radiation? 核衰变过程示意图发射性母核激发态子核基态子核How do generate an X-ray?To generate X-rays, we must have three things:-a source electrons, -a means of accelerating th

58、e electrons at high speeds, -a target materialto receive the impact of the electrons and interact with them.X-RayWhy do we need electrons to produce x-rays?X-rays are generated when free electrons give up some of their energy when they interact with the orbital electrons or nucleus of an atom. The e

59、nergy given up by the electron during this interaction appears as electromagnetic energy known as X-radiation. There are two different atomic processes that can produce x-ray photons：One is called Bremsstrahlungother is called K-shell emission. X-rays produced by Bremsstrahlung are the most useful f

60、or medical and industrial applications.X-Ray X-Ray generated by K-shell emissioncharacteristics X-ray（标识X射线）X-Ray generated by Bremsstrahlung（韧致辐射）X-Ray generated by BremsstrahlungThe Same points and Difference between X-rays and gamma-rays X-rays and gamma-rays can be characterized by frequency, wa