工业等离子体.pptx

《工业等离子体.pptx》由会员分享，可在线阅读，更多相关《工业等离子体.pptx（323页珍藏版）》请在得力文库 - 分享文档赚钱的网站上搜索。

1、会计学1工业等离子体工业等离子体Contentsn n1 Introduction1 Introduction 1.1 The social role of industrial plasma engineering1.1 The social role of industrial plasma engineering 1.2 Important definitions 1.2 Important definitions 1.3 Plasma physics regimes and issues 1.3 Plasma physics regimes and issuesn n2 Kinetic

2、 Theory of Gases2 Kinetic Theory of Gases 2.1 measurement of high vacuum2.1 measurement of high vacuum 2.2 particle distribution functions 2.2 particle distribution functions 2.3 particle collisions 2.3 particle collisionsn n3 Motion of Charges in Electric and Magnetic Fields3 Motion of Charges in E

3、lectric and Magnetic Fields 3.1 Charged particle motion in electric fields3.1 Charged particle motion in electric fields 3.2 Charged particle motion in magnetic fields 3.2 Charged particle motion in magnetic fields 3.3 3.3 Charged Charged particle particle motion motion in in steady steady electric

4、electric and and magnetic fieldsmagnetic fields第1页/共322页n n4 Characteristics of Plasma 4.1 Bulk properties of plasma 4.1 Bulk properties of plasma 4.2 Quasi-neutrality of plasma 4.2 Quasi-neutrality of plasma 4.3 Electrostatic Boltzmann equation 4.3 Electrostatic Boltzmann equation 4.4 Simple electr

5、ostatic plasma sheaths 4.4 Simple electrostatic plasma sheaths 4.5 Plasma frequency 4.5 Plasma frequencyn n5 Electron Sources and Beams 5.1Thermionic emission sources 5.1Thermionic emission sources 5.2 Photoelectric emission sources 5.2 Photoelectric emission sources 5.3 Field emission sources 5.3 F

6、ield emission sources 5.4 Hollow cathode sources 5.4 Hollow cathode sources 5.5 Secondary electron emission sources 5.5 Secondary electron emission sources 5.6 Sources and beams characteristics 5.6 Sources and beams characteristics 5.7 Charged particle beam transport 5.7 Charged particle beam transp

7、ort第2页/共322页n n6 Ion Sources and Beams6 Ion Sources and Beamsn n7 Dark Electrical Discharges in Gases7 Dark Electrical Discharges in Gases7.1 Background ionization 7.2 Saturation regime 7.3 Townsend discharge 7.4 Corona discharges 7.5 Corona sources 7.6 Electrical breakdown第3页/共322页8 DC Electrical A

8、rc Discharges in Gases8 DC Electrical Arc Discharges in Gases 8.1 8.1 Arc regime Arc regime 8.1.1 Voltage-Current Characteristic 8.1.1 Voltage-Current Characteristic 8.2Phenomenology of electrical arcs 8.2Phenomenology of electrical arcs 8.2.1 Classical Arc Nomenclature 8.2.1 Classical Arc Nomenclat

9、ure 8.3 Physical processes in electrical 8.3 Physical processes in electrical 8.3.1 Body forces on arcs 8.3.1 Body forces on arcs 8.3.2 Electrode Jet Formation 8.3.2 Electrode Jet Formation第4页/共322页n n9 9 Inductive Inductive RF RF Electrical Electrical Discharges Discharges in in GasesGases 9.1 Intr

10、oduction 9.2 Phenomenology of RF-plasma Interactions 9.3 Skin depth of plasma 9.4 Inductive plasma torch 9.5 Other methods of generating inductive plasmas第5页/共322页Chapter 1 Introduction1.1 The social role of industrial plasma engineering1.1 The social role of industrial plasma engineering The plasma

11、 engineering have an important role to promote The plasma engineering have an important role to promote the society development and increase the living standard of the society development and increase the living standard of the human beings due to it:the human beings due to it:May May resolve the pr

12、oblemresolve the problem of the energy sourcesof the energy sources for the for the society development society development May May have very high efficiency and effectivenesshave very high efficiency and effectiveness of energy of energy consumposition consumposition May May accomplish industrial p

13、rocessingaccomplish industrial processing without unwanted without unwanted byproducts or waste materialsbyproducts or waste materials第6页/共322页Discussed in details:Discussed in details:First,First,Plasmas offer two primary characteristics of Plasmas offer two primary characteristics of industrial in

14、terest:(1)industrial interest:(1)higher temperatures and energy higher temperatures and energy densitiesdensities than that achieved by chemical or other than that achieved by chemical or other means;(2)means;(2)energetic actives speciesenergetic actives species:ultraviolet or:ultraviolet or visible

15、 photons;charged particles,including visible photons;charged particles,including electrons,ions,and free radicals;and highly electrons,ions,and free radicals;and highly reactive neutral species,such as reactive atoms reactive neutral species,such as reactive atoms(O,F,etc),excited atomic states,and

16、reactive(O,F,etc),excited atomic states,and reactive molecular fragments such as monomers.molecular fragments such as monomers.第7页/共322页and as a result,Plasmas offer benefits over other industrial processing method,such more efficiently and cheaply,without producing large volumes of unwanted byprodu

17、cts or waste materials,with minimal pollution or production of toxic wastes.第8页/共322页Some applications listed below:Some applications listed below:1.1.More efficient energy utilizationMore efficient energy utilization a)Plasma lighting devices a)Plasma lighting devices b)Plasma chemistry b)Plasma ch

18、emistry c)Materials processing with thermal plasma c)Materials processing with thermal plasma 2.2.Accomplishing unique resultsAccomplishing unique results a)Electron,ion,and plasma sources a)Electron,ion,and plasma sources b)New materials from plasma chemistry b)New materials from plasma chemistry c

19、)c)Plasma Plasma etching etching and and deposition deposition for for microelectronicsmicroelectronics d)Materials processing with thermal plasma d)Materials processing with thermal plasma e)Communications using geophysical plasmas e)Communications using geophysical plasmas f)Space propulsion syste

20、ms f)Space propulsion systems g)surface modification of materials g)surface modification of materials第9页/共322页3.3.Production with minimum waste materialsProduction with minimum waste materials a)Plasma chemistrya)Plasma chemistry b)Plasma etching and deposition for microelectronics b)Plasma etching

21、and deposition for microelectronics c)Materials processing with thermal plasma c)Materials processing with thermal plasma d)Surface treatment of materials d)Surface treatment of materials e)Ion implantation of materials e)Ion implantation of materials4.Production with minimum toxic waste4.Production

22、 with minimum toxic waste a)Plasma chemistrya)Plasma chemistry b)Plasma etching and deposition for microelectronics b)Plasma etching and deposition for microelectronics c)Surface treatment of materials c)Surface treatment of materials d)Ion implantation of materials d)Ion implantation of materials第1

23、0页/共322页1.2 Important definitions The history of plasma may be recalled to 17th century and The history of plasma may be recalled to 17th century and the termthe term plasma plasma was introduced by Irving Langmuir in was introduced by Irving Langmuir in 1928.1928.Now plasma research including three

24、 branches:Now plasma research including three branches:Plasma physicsPlasma physics:concerned with the basic laws and physic processes concerned with the basic laws and physic processes which govern the behavior of plasma.which govern the behavior of plasma.magnetohydrodynamics(MHD)magnetohydrodynam

25、ics(MHD)Electrohydrodynamics(EHD)Electrohydrodynamics(EHD)Plasma chemistryPlasma chemistry:concerned with chemical reactions which occur in concerned with chemical reactions which occur in the presence of a plasma the presence of a plasma Plasma science and plasma engineeringPlasma science and plasm

26、a engineering:concerned with the application concerned with the application of plasma to devices or processesof plasma to devices or processes第11页/共322页1.3 Plasma physics regimes and issues1.3 Plasma physics regimes and issues 1 1 Density and temperatureDensity and temperature regimes regimes Temper

27、ature:1-20eV,1eV=11,605K Temperature:1-20eV,1eV=11,605K Density:10 Density:101212-10-102525electron/melectron/m3 3 2 2 Heterogenous interactionsHeterogenous interactions of plasma of plasma Plasma can interact with other states of matter individually,or with Plasma can interact with other states of

28、matter individually,or with combinatios of solids,liquids,and binatios of solids,liquids,and gases.Interacting with neutral gases,will result in dissociation,ionization and plasma Interacting with neutral gases,will result in dissociation,ionization and plasma chemical reaction,chemical reaction,Int

29、eracting directly with solid surface,usually associated with the etching Interacting directly with solid surface,usually associated with the etching processing or sputteringprocessing or sputtering 3 3 Approaches Approaches to the study of plasmas:to the study of plasmas:In the In the continuum appr

30、oachcontinuum approach,a plasma is treated as if it were a continuous,a plasma is treated as if it were a continuous fluid.fluid.A second major theoretical approach is to regard the plasma as a A second major theoretical approach is to regard the plasma as a collection collection of individual parti

31、clesof individual particles,and its collective behavior as the result of their motion.,and its collective behavior as the result of their motion.A third major approach is to regard the plasma as A third major approach is to regard the plasma as a black boxa black box with inputs and with inputs and

32、outputs.outputs.第12页/共322页The challenges of plasma physics:The challenges of plasma physics:Multi-body problemMulti-body problem;Another difficulty is that the Another difficulty is that the differential equationsdifferential equations which which describe the conservation of particles,momentum,and

33、describe the conservation of particles,momentum,and energy in plasmas are often nonlinear.energy in plasmas are often nonlinear.Plasma experimentsPlasma experiments are usually difficult to set up and are usually difficult to set up and interpret.Boundary condition;Multivariable problem.interpret.Bo

34、undary condition;Multivariable problem.Difficult to diagnoseDifficult to diagnose because of its high kinetic temperature because of its high kinetic temperature and high energy density:two probe methods:perturbing and high energy density:two probe methods:perturbing probe such as Langmuir probe and

35、 non-perturbing prob probe such as Langmuir probe and non-perturbing prob such spectrum analysissuch spectrum analysis第13页/共322页Homework:1.Please review the social role of the industrial plasma engineering.第14页/共322页 It It is is not not possible possible to to fully fully understand understand the t

36、he physical physical processes processes which which occur occur in in the the industrial industrial applications applications of of plasma plasma without without a a knowledge knowledge of of the the behavior behavior of of gases gases on on a a microscopic microscopic scale,scale,i.e.i.e.at at the

37、 the level level of of individual individual atoms,atoms,molecules,molecules,and and charged charged particles.particles.The The behavior behavior of of gases gases on on the the microscopic microscopic scale scale is is described described by by a a branch branch of of physics physics called called

38、 the the kinetic kinetic theory theory of of gasesgases,and and the the implications implications of of this this behavior behavior in in the the macroscopic macroscopic world world are treated by the subjected of are treated by the subjected of statistical mechanicsstatistical mechanics.2 Kinetic T

39、heory of Gases第15页/共322页2.1 measurement of high vacuum2.1 measurement of high vacuumn nIn the 19th century when the first quantitative measurements were made in when the first quantitative measurements were made in vacuum system,the degree of vacuum was measured vacuum system,the degree of vacuum wa

40、s measured with with mercury manometersmercury manometers which referred the which referred the pressure in the vacuum system to that of the pressure in the vacuum system to that of the atmosphere.Thus,the common unit of pressure was atmosphere.Thus,the common unit of pressure was the millimeter of

41、mercury(mm Hg),in which one the millimeter of mercury(mm Hg),in which one standard atmosphere(atm),at 0standard atmosphere(atm),at 0,was equal to 760,was equal to 760 mm Hg.mm Hg.第16页/共322页n nIn the mid 20In the mid 20th th century century An An international standards committees decided to change t

42、he name of the unit pressure from millimeters of mercury to the Torr,which is,at this time,the unit most frequently found in the North America literature of plasma science.The torr was named in honor of Evangelista Torricelli(1608-1647),an Italian physical known for his work on barometers.第17页/共322页

43、The usual applied situations of the unitsThe usual applied situations of the unitsn nAtmosphereAtmosphere:in industrial applications such as thermal:in industrial applications such as thermal plasma processing and magnetohydrodynamic power plasma processing and magnetohydrodynamic power generation,f

44、or these applications,the pressures are generation,for these applications,the pressures are usually at or slightly above 1 atmusually at or slightly above 1 atmn nMillitorr or micronMillitorr or micron:10:10-3-3 Torr or 10 Torr or 10-6-6 Torr,which is Torr,which is widely used in materials science a

45、nd microelectronic widely used in materials science and microelectronic plasma processing,because the used pressures in these plasma processing,because the used pressures in these applications are usually between 10applications are usually between 10-3-3 Torr and 10 Torr.Torr and 10 Torr.第18页/共322页S

46、I systemSI systemn nAfter After the the introduction introduction of of the the Torr,Torr,the the same same international international standards standards committee committee decided decided that that the the official official unit unit of of pressure pressure in in the the SI SI system system of o

47、f units units would would henceforward henceforward be be the the pascalpascal (symbol(symbol Pa),Pa),defined defined as as 1 1 Newton Newton per per square square meter meter(N/m(N/m2 2).).In In the the field field of of industrial industrial plasma plasma engineering,engineering,it it is is still

48、still common common practice practice to to quote quote the the vacuum vacuum pressure pressure in in Torr,Torr,with with an an increasing increasing tendency tendency to to cite cite the the neutral neutral particle densities,rather than background pressures.particle densities,rather than backgroun

49、d pressures.第19页/共322页The relationship of each unitsThe relationship of each unitsn n The conversion between the Pascal and the Torr is via the The conversion between the Pascal and the Torr is via the standard atmosphere which is defined as exactly equal to both 760 standard atmosphere which is def

50、ined as exactly equal to both 760 Torr and 1.01325 10Torr and 1.01325 105 5 Pa,given by Pa,given by n nThe pressure can be related to the number density in particles per The pressure can be related to the number density in particles per cubic meter by the perfect gas law,cubic meter by the perfect g