Outline
電漿科學的展望
Perspectives on Plasmas
宇宙中大部分的物質處於電漿狀態, 即原子解離成帶正電的
離子與帶負電的電子.
--- the fourth state of matter
電漿所產生的現象廣泛存在, 並造成許許多多有趣的現象. 然
而, 大部分的人對電漿的認識是電漿電視.
張存續
這個演講將引導大家從電磁學進入電漿科學. 我會介紹電漿
的物理特性, 主要的研究領域, 如雷射電漿, 太空與天文電漿,
熱核融合電漿、電漿粒子加速、微粒電漿等;
清華大學 物理系
並介紹電漿的應用, 如電漿材料處理, 電漿顯示器.
最後會簡介清華物理的電漿物理研究.
May 2, 2006
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Definition of Plasma
Plasma is a quasineutral gas of electrons, ions
and neutral particles which exhibits collective
behavior.
Because of collective behavior, a plasma does not
tend to conform to external influences; rather, it
often behaves as if it had a mind of its own.
Plasma Classifications
Generation of Plasma
electrons are accelerated by electric field and collide with
other particles to induce excitation and ionization.
Electron impact ionization:
e− + A → 2e− + A+
Electron impact excitation
e− + A → e− + A*
Meanwhile de-excitation and recombination also take place.
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核融合反應
天然的核融合爐：太陽
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Plasma Generation
(Ex: Electron Cyclotron Resonance)
海水
能量
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Maxwell’s Equations
Nonlinear Model for Gyrotron Oscillators
In terms of free charges and currents, Maxwell’s equations
read
∂B
∇ ⋅ D = ρf ∇ × E +
=0
∂t
∂D
∇⋅B = 0 ∇×H −
= Jf
∂t
The constitutive relations:
P = ε 0 χeE
1
µ0
B−M
−1
∆γj Wj = f (Eo2 ; ∆)
∑
γ o −1 j
L
0
G G
L − P⋅ E
dγ
dz
dz = ∫
0
Pz
dz
z Electron beam generates wave
Eo2 =
QIbVb
α
 Q Pb 
 η
α
nm


η = 
where


2
 
′ )
weighting factor Wj, and electron α nm = µπk a 2L5 1 −  n   J n2 (χ nm
2
5.464
2 ′ 2
)(1 − m )
′ ×)10 ω LE0χ
nm

P out = 8(χ nm
J
(
x
transit angle,
m
mn
 x

Q
D = ε 0 E + P = ε 0 (1 + χ e )E = ε E
H=
η=
where∆γ j = ∫
M = µ0 χ m H
So
z Wave modulates the
electron beam
sΩ  L

∆ = ω − k z vz − e 
γ  vz

⇒ B = µ0 (1 + χ m )H = µ H
2 4
and Q =
ωoW
mn
P
P outloss
= Pbη ( E 0 )
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國際核融合實驗反應爐: ITER
(International Thermonuclear
Experimental Reactor )
Research and Applications
合作國家： 歐盟、美、
俄、日、中、韓
造價：28億美元
預期完工日期：2015年
電漿溫度：攝氏1億度
預期產生功率：500 MW
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環境電漿
電漿氣化熔融
微粒電漿(Dusty Plasma)
電漿轉化
電漿清潔製程
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雷射電漿(Laser Plasma)
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雷射電漿(Laser Plasma)
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Plasma Display Panel (PDP)
High Frequency and Plasma Lab
by Prof. C.S. Kuo
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vane height tuner
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RF Capacitively Coupled Plasma
three stub tuner
power
head
2.45 GHz
surface wave cavity
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1
quartz plate
substrate
z=0
movable Langmuir probe
movable
substrate holder
RF power 13.56 MHz
coupler
differential
pumping
stepping
motor
bellows
pumping system
Fig.1
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RF Inductively Coupled Plasma
Microwave Plasma Source
Power source frequency=2.45 GHz
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Plasma etching processing
He plasma
Ar plasma
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Plasma Processing
High Frequency Electrodynamics Lab
Growth of diamond
Carbon nano tubes
(i) Nonstationary and Chaotic Behavior
of the Electron Cyclotron Maser
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Micro/mm-wave Sources Design & Fabrication
Significance of the ECM
Theoretical design
one photon
per excitation,
multiple-photon multiple photon
per electron,
per electron,
Computer simulation
large interaction large interaction interaction space
space
space
~ wavelength
↓
↓
Engineering drawing
↓
Precision machining
Brazing in vacuum
& RF furnace
Hot test
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Final system
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Gyro-monotron pulse shape and spectrogram
at different beam currents (I)
Gyrotron Experimental Setup
Magnetron
Injection Gun
Drift Region
for Magnetic Compression
Gyro-BWO
Circuit
(a) Stationary,
Ib=50mA
f=33.1467 GHz
∆f= 0 MHz
t (100 nS/div)
normal injection locking port
alternative injection locking ports
(30dB isolation from output port)
(to be discussed later)
(b) Nonstationary,
Ib=1300mA
(self-modulation)
(c) Nonstationary,
Ib=1600mA
(selfmodulation)
Collector
output port
TE10 ↔TE11
polarization converters
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Gyro-monotron pulse shape and spectrogram
at different beam currents (II)
(d) Nonstationary,
Ib=1700mA
(period
doubling)
∆f= 102.5 MHz
t (100 nS/div)
interaction section
MIG
f=33.3225 GHz
f=33.3867 GHz
∆f= 108.3 MHz
t (100 nS/div)
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Single-mode self-modulation --- stability
map
f=33.4008 GHz
∆f= 111.7 MHz
t (100 nS/div)
(e) Nonstationary,
Ib=1800mA
(period tripling)
f=33.4101 GHz
∆f= 116.7 MHz
t (100 nS/div)
(f) Nonstationary,
Ib=2000mA
(chaotic)
f=33.4175 GHz
t (100 nS/div)
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No correlation between onset current of nonstationary
oscillation and the calculated start-oscillation current of high
order axial modes.
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Multi-Mode Competition at Ib = 5 A
( PIC Simulation )
Evolution in time (B0 = 14.8 kG)
Time–frequency analysis
(using an 8-nsec Hann-type window)
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120
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r
Linea
growth
0
10
2
0
l=2
l=3
l=1
-2
)
10
-4
35
10
-6
10
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-8
10
0
20
40
60
80
Time (ns)
Linear
growth
„
(ii) Millimeter-Wave and THz Devices,
and Their Applications
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z
GH
y(
c
n
ue
req
Amplitude
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Mode
Single-mode
competition stationary
oscillation
High Frequency Electrodynamics Lab
-mode
Single ary
o
stati n on
ti
Mode n
oscilla
o
ti
ti
e
comp
80
80
60
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F
Power (kW)
200
40
20
32 0
e
Ti m
(ns)
The fast-growing, well-established l = 3 mode is subsequently
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suppressed by the later-starting, slower-growing l =1 mode.
TE11 Mode Converter
For Laser Cooling Experiment
Linearly and Circularly Polarized rf Fields
RHCP
HFSS simulation
Linear polarization
Circular polarization
Linear
LHCP
Field patterns directly visualize on thermal sensitive LCD
film.
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Terahertz Radiation and Device Physics
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Terahertz Radiation and Device Physics
Transmission (dB)
0
-2
4.1 GHz
-4
-6
measurement
simulation
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-10
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Frequency (GHz)
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T. H. Chang, C. F. Yu, and C. T. Fan, “Novel polarization controllable TE21 mode converter”, Rev. Sci. Instrum., 76, 074703 (2005).
C. F. Yu and T. H. Chang, ”High Performance Circular TE01 Mode Converter”, IEEE Trans. Microwave Theory Tech. 53,
No.12, 3794 (2005).
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International Cooperation on THz
High Frequency Electrodynamics Lab
(iii) Application of Micro/mm-Wave
Technology on Material Science
200 W, 300 GHz @ Far Infrared Region Research Center,
Fukui Univ., Japan.
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Quasi-optical applicator: Major challenges
Critical coupling
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Experimental setup for quasi-optical applicator
Resonant detecting
Ka-band driver
diagnostic circuit
Ka-band
source
QO applicator
Controller & Modulator
Field pattern
IR temperature sensor
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Quasi-optical cavity: BaTiO3 SEM results
Quasi-optical cavity: PZT SEM results
Source: EIA, Frequency~ 35 GHz (operating at TEM0,0,12 mode)
Quasi-optical Cavity: L~146-9 mm, R=140 mm, d=200 mm Q~11000
before
Source: EIA, Frequency~ 35 GHz (operating at TEM0,0,12 mode)
Quasi-optical Cavity: L~146-9 mm, R=140 mm, d=200 mm Q~11000
Necking effect observed on the surface
after
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Low-temperature processing of PZT thin films
using 2.45 GHz microwave annealing
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High Performance Ferroelectric Material
The microwave annealing of PZT thin film
- dielectric constant: 560
- dissipation factor: 0.025% of dielectric constant.
XRD results
The conventional annealing of PZT thin film
- dielectric constant : 345
- dissipation factor : 0.03% of dielectric constant.
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