chan doan plasma

8/6/2019 Chan Doan Plasma

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TRNG I HC KHOA HC T NHINTRNG I HC KHOA HC T NHINKHOA VT LKHOA VT L

B MN VT L NG DNGB MN VT L NG DNG

HVTH:HVTH:Nguyn ng KhoaNguyn ng KhoaL Th LaL Th LaL Ngc Thy TinL Ngc Thy TinTrn Th M HnhTrn Th M Hnh

Nguyn Thanh TNguyn Thanh T

GVHDGVHD:: PGS. TS. L Vn HiuPGS. TS. L Vn Hiu


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Ni bn c th tho lun:http://myyagy.com/mientay/

Dch ti liu trc tuyn min ph:http://mientayvn.com/dich_tieng_anh_chuyen_nghanh.html

D n dch hc liu m:http://mientayvn.com/OCW/MIT/Co.html

Lin h vi ngi qun l trang web:Yahoo: [email protected]: [email protected]


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4/110

LCH S PHT TRIN VL PLASMA

1845:t Plasma c pht biu vi ngha sinh vt hc

1923: Langmuirv Tonks gi cht kh

trng thi dn in l plasma


5/110

1667,nh bc hc Floreltre pht hin rangn la n c tnh dn in.

1698,tin sVolt ngi Anh pht hin hintng phng tia la in trong khng khkhi nghin cu s nhim in ca hphch

u th k XIX,gio s Ptro pht minhra h quang



6/110

Irving Langmuir (1881 -1957) l nhkhoa hc M u tin nghin cuv trng thi plasma, ngi ccoi l cha ca vt l plasma.

Nm 1920, Langmuir m t th nghimto ra khi cu pht sng c ctnh dng nh ging st hn.

Nm 1924, ng a ra khi nim nhit in t v pht minh ra phngphp chn on mt v nhit plasma bng u d in.



7/110

Nm 1940, HannesAlfvn chngminh rng mt loichuyn ng tp th

mi, gi l sng t-thy ng lc hc cth c sinh ratrong cc h plasma.

Cc sng ny ngmt vai tr quantrng xc nh tnhcht ca plasma.



8/110

KHI NIM PLASMA

Theo nh ngha ca Langmuir, plasma l mttp hp cc ht mang in v cc ht trungha phi tha mn:

1. iu kin gn trung ha:

2. Bn knh Debye phi nhiu ln nh hn kchthc ca min cha tp hp :

, ,0

e i e iZ n }

Dr L=


9/110

Mt s dng Plasma


10/110

TNG QUAN V CHN ON PLASMA

Chn on plasma l nghin cu cc hin tng vt l tintrin bn trong plasma, t suy ra cc tnh cht caplasma.

Phng php chn on plasma l cc phng php onhit , mt , thnh phn plasma.

Kh khn trong vic thit lp m hnh l thuyt

Phi tin hnh chn on bng nhiu phng php khcnhau trn cng mt i tng


11/110

V d chn on plasma trong tokamak


12/110


13/110

Chn onChn on Thng s plasmaThng s plasmau d langmuir Nhit plasma, nng , th plasma ..

Phn tch quang ph pht x nhit , nng , thnh phn plasma

Chn on chm ntron nhit ion

Giao thoa k viba nng electron

Quay phim tc cao hnh nh plasma

Tn x thomson Nng v nhit electron

Tn x chm laser

. ..

Cc phng php chn onCc phng php chn on


14/110

u d t

Tn xThomson

u dLangmuir

Phn tch quangph pht x

Giao thoa kMicrowaves

Phn tch nnglng ion

Quay phimtc cao

Sng v tuyn

Plasma

Cc phng php chn onCc phng php chn on


15/110

plasma

Voltage GeneratorV

I

wire

insulator

u d tnh in Langmuir


16/110

L mt si dy kimloi mnh hnh tr,bn ngoi c

bao bc bi chtcch in dc theochiu di, ch hmi nhn ca si

dy gi l u d.Kch thc u dvo c vi mm nvi cm.

Lp in miLp in mi

Thp khng gThp khng g

Cu to u d LangmuirCu to u d Langmuir

Si dy kim loiSi dy kim loi

mnh lm bngmnh lm bngTungsten hay Modylen,Tungsten hay Modylen,


17/110

iu chnh bin triu chnh bin tr U Uanodeanode--u du d thay ithay i I I

u du dthay ithay i

Ampe k v Vn k xcAmpe k v Vn k xcnh s ph thuc ca Inh s ph thuc ca Iu du dvo Uvo Uanodeanode--u du d Cc c trng ca plasma Cc c trng ca plasma

(n(nee, T, Tee))

S mc mch


18/110

S hnh thnh th ni v th plasma Khi a u d vo trong

plasma, xung quanh ud hnh thnh mn chntnh in, xung quanh ud hnh thnh mt intrng

in trng ny ngn ccelectron i n gn ud

Sau mt thi gian s xyra s cn bng, th khicn bng gi l th ni: Vf

Lc ny trong plasmacng cn bng v c thgi l th plasma: Vp


19/110

Tin hnh thay i th u d

Khi th u d V> Vp: cc ion dng n ud s b y tr li mi trng plasma ng thicc electron b ht vo u d,

Khi th u d V< Vp: th ngc li, cc iondng b ht vo u d trong khi ccelectron b y ra xa u d.

Khi th u d V = Vf khi dng tng cng quau d bng khng t

Vy dng qua u d c th l dng m hocdng dng l ty thuc vo hiu th plasma Vpvi u d V,


20/110

Mt dng electron n u d

1

2

0exp

2

pee

e e

e V Vm J n e

kT kT T !

01

2

e

i

i

kT J enM

!

Mt dng ion n u d

cng dng tng cng m u d thu c:cng dng tng cng m u d thu c:

e i I AJ AJ !


21/110

Cng dng in qua u dCng dng in qua u d

Trong :Trong :

A ltit din ca u dA ltit din ca u d

MMii: khi lng ion trongplasma: khi lng ion trongplasmamme:e: khi lng electronkhi lng electron

nno:o: nng electron hay ionnng electron hay ion

1

2

0

211 exp

2

pi

B

e e

e V VM I A en v

m kTT

!


22/110

ng c trng Voltng c trng Volt -- AmpereAmpere

Min A:Min A: Khi th u d ln hn th plasma V>Khi th u d ln hn th plasma V> VpVp: cc ion: cc iondng n u d s b y trli mi trng plasma ngdng n u d s b y trli mi trng plasma ngthi cc electron b ht vo u d, u d c th thay th chothi cc electron b ht vo u d, u d c th thay th choanode ht cc dng in tch.anode ht cc dng in tch.


23/110

ng c trng Voltng c trng Volt -- AmpereAmpere

1 1

2 2

0 0 81. exp2 4

p Pe ei e e

e e e

e V V

m kT I I A J An e eA nkT kT mT T

! ! !

Min B: Khi th u d V = Vp,

lc ny khng tn ti mn chin bao quanh u d.

B mt u d thu nhn dng ion velectron va chm vo n, nhngdng electron ln hn rt nhiudng ion nn n xp x bng:

1

2

0

81

4

e

p e

e

kT I I eA n

mT

} !


24/110

Min C: V < VMin C: V < Vpp, u d, u d

bt u y cc e v ht ccbt u y cc e v ht ccion dng v pha u d.ion dng v pha u d.Ch c cc e no c ngCh c cc e no c ngnng mi ti c u d.nng mi ti c u d.

!

e

i

pfe

m

M

VV

e

kT

T

2ln

2Nhit e:

in th

Th plasma Vp

Th ni Vf

Khi V=Vf

e

pf

e

i

k

evenI exp

21

2

10

2

1

0

T


25/110

Min D: V < VMin D: V < Vff , cc ion, cc iondng c chuyn ng ngudng c chuyn ng ngu

nhin xuyn qua vng mnnhin xuyn qua vng mnchn tnh in s b u dchn tnh in s b u dthu nhn, cng vi n lpthu nhn, cng vi n lpmn chn b mng i do thmn chn b mng i do th

ca u dca u d..

Nu V


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Xc nh cc c trng ca plasmaXc nh cc c trng ca plasmaNhit eNhit e

!

e

i

pfe

m

M

VV

e

kT

T2ln

2

Nng e hay ion dngNng e hay ion dng

2

1

02

!

e

e

pm

kTeAnI

T

2

10

2

!

e

e

p

m

kTeA

In

T

Vi Te xc nh trn,ta c th tnh c n0

Cng dng electronbo ha khi V=VP:


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U D PHT X(Emissive probe)

1. CU TRC


28/110

Da trn nguyn l c bn l: Nu th u dl dng so vi th plasma, cc electronpht ra vi nng lng thp b ht tr li ud. Trong trng hp ny dng u d lkhng thay i bi s pht x ra ccelectron. Nu th u d l m so vi th

plasma, cc electron pht x c th i voplasma.

U D PHT X

2. Hot ng.


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Nu u d c nung nng cho n khi pht x raelectron, dng u d tng cng, l mt hm cain th u d, c cho bi cng thc:

Dng pht x:

( )p p i em e I V I I I !

* 2 expem em

B

e I A A T

k T

[[

[

J !

Vi Aem l din tch pht x ,

A* l hng s Richardson,T l nhit ca u d

l cng thot in t b mt u d.[J

U D PHT X


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U D PHT X


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o th plasma vi u d pht x ngi ta

dng 2 phng php chnh:Phng php th unPhng php th ni

Phng php o:

U D PHT X


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Phng php th un: Nguyn tc caphng php ny lda trn vic xc nh

trc tip th plasmat ng c trngu d pht x. Thm ti xut hinim un trn ng

c trng ca u dpht x tng ngvi th plasma.

U D PHT X


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Phng php th ni Phng php ny bao gm vic o cc th ni ca ud cc dng nhit khc nhau. Khi dng nhit tng ln,th ni ca u d s dch chuyn (tng) cho n khi nt gi tr bo ha ng vi th plasma.

U D PHT X


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Vpr

Ipr

Idis

3

1 2

Vdis

300- 00

-30-30

mch in u d trong plasma

U D PHT X


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U D FARADAY

(F

araday probe)u d Faraday l mt dng c o mt dng inCc loi u d:


36/110

u d c hai b phn chnh:

* Vnh gp

* Vng bo v

U D FARADAY


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Vnh gp

Lm bng thp khng rc phun mt lp tungsten lmgim s pht x electron th cp t sbn ph ion

U D FARADAY


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Vng bo vDng che chnvnh gp khi cc

ion nng lngthp n t ngpha bn ngoivnh gp.

U D FARADAY


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Hot ng: Khi cc ion p vo b mt ca vnh gp,

cc electron cha trong phn kim loi ca

u d Faraday tun ra b mt u d trung ha cc ion tp trung trn b mt

Cc electron di chuyn to ra dng inu d, dng ny bng vi dng ion.

Mt dng c xc nh bi t s cadng ion v din tch ca vnh gp.

J= I/A

U D FARADAY


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Trong thc nghim: Ngi ta s dng vn k o in th u dV, sau mt dng s c tnh nh sau:

Vj =

Vi : R l in tr trong mchA l tit din u d

U D FARADAY


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U D FARADAY


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th th hin sph thuc ca mt dng vo v tr gc

U D FARADAY


43/110


44/110

I. Nguyn tc kch thch ph phttrong plasma

Plasma, khi b nung nng n nhit khcao th tr thnh ngun bc x rt mnh.Cc dng va chm khc nhau gia ccht trong plasma l nguyn nhn gy ras pht x tia nng lng, v chnh ngthi sinh ra ph pht x.


45/110

II. Cc qu trnh sinh ra cc phtx nng lng:

1. Bc x gin on

2. S bc x ti hp

3. S bc x hm


46/110

1. Bc x gin on:

Cc nguyn t v cc ion caplasma b kch thch s bc xphoton

Quang ph bc x ca chng

l nhng quang ph vch. Ph vch l ph pht x ca

cc nguyn t ha hc hunh thng nm trong vngph t 190-1000nm (vngUVVIS). Ch c mt vi nguynt kim hay kim loi kim mic mt s vch ph nm ngoivng ny.


47/110

2. S bc x ti hp:

S bc x ti hp sinh rakhi ion thu nhn in t.

S ti hp gia ion mv in t v vi ion

dng s lm gim ionm Trong qu trnh ti hp,

cc photon c bc xto ra quang ph lin tc.

Hnh nh ca ph mt tri


48/110

2. S bc x ti hp:

S ti hp l qu trnh nghch ca qutrnh ion ho.


49/110

3. S bc x hm:

Do s va chm gia cc in t vi ccion nng, in t b mt mt phn nnglng ca mnh, phn nng lng ny

pht x ra di dng lng t nh sng.Bc x sinh ra khi c s va chm cain t vi nguyn t hoc ion dngnng, gi l bc x hm.

Bc x hm s sinh ra quang ph lin tc


50/110

III. Mi quan h gia cng , nhit , mt httrong plasma:

Trong plasma, nguyn t (Ao) ca mt nguyn t c kch thch ttrng thi nng lng thp Eo, ln trng thi nng lng cao Amc biu din theo phng trnh:

Ao +XE = A* (a) Sau mt thi gian,nguyn t b kch thch A* tr v trng thi c

mc nng lng thp hn s pht x ra lng t nng lng:

A* = hv +Ao (b)


51/110

III. Mi quan h gia cng , nhit ,mt httrong plasma:

Nu gi Nm l s nguyn t ca nguyn t Ao b kch thch n trng thi nng lng cao Am,th theo quy lut Bolzamann ta c:

Nm= Na (gm/ g0) . exp ( -Emo/k T)


52/110

Nu gi Ia l cng ca vch ph do qu trnh kchthch ph ni trn sinh ra,ng vi mt nhit plasma

nht nh ,Ia ph thuc vo:

- S nguyn t Ao b kch thchln trng thi A*, (Nm).

- Thi gian tn ti ca nguyn tA* trng thi kch thch, (tm).

- Nng lng kch thch nguynt A t trng thi c bn ntrng thi kch thch, (Em = h).

- Xc sut chuyn mc canguyn t A t trng thi kchthch nng lng Am v trngthi ban u nng lng Eo,(Amo).

Ia = f. (1/tm). Amo .Em. Nm I a = f. (l/t m) . A m0 .Na (gm/ g0).

h. exp ( -Emo/k T)


53/110

ivimt loinguyn tv trong mt nhit plasma nht nh thcc yu t Amo, go, gm, Cm, hv l nhng hngs.

Ia ch ph thuc vo Na

Ia =k Na

Vi: k = f. (l/tm) . A m0 (gm/ g0) h. exp ( -Emo/k T)

Nh vy i vi quangph nguyn t, ng vi nhit nht nh caplasma, ta tm c cng caph, ta c th tm c mt cc nguyn t trongplasma (Na).


54/110

Kho st nhit vt en:

Ngi ta to ra vt en bng cch dng mt bnh C c c mt lthng nh, bn trong bi en bng m hng, (c th coi l vten),bc x khi i qua l hng bn trong bnh, phn x nhiu ln lintip bn trong bnh, do hu ht nng lng bc x u b hp th.Din tch l hng va l b mt hp th, va l b mt bc x.

- Vt en l nhng vt hp th honton bc x chiu x chiu ti, ivi mi di sng v i vi migc ti.- Thc t khng c vt en tuyt i.


55/110

ng ctrng ph pht xca vt en:

Bc x pht ra bi mt vt gm nhiu n sc,nng lng pht ra ng vi mi n sc khng

bng nhau v c c trng bi h s chinng lng n sc E.

ng cong biu din s bin thin ca Etheo bc sng c gi l ng c trng

ph pht x ca vt.


56/110

Ta xc nh c c trng ph pht xca vt en bng th nghim:

A

C

ng cong biu din s bin thin ca ch trn in k G theo disng ca bc x ra bi vt en A chnh l ng cong biu din s bin thinca E theo hay chnh l ng c trngphpht x ca vt en.


57/110

Bng cch thay i nhit cu vt en,ta v cnhiu c trng ng vi nhiu nhit khc nhau

Nhn xt:

+Nhn xt ng c trngtrn,ta thy E cc i ngvi mt di sng

m + Nng sutpht x ton

phn Rtng rt nhanh theonhit T ca vt en

+ Nhit ca vt en cng

cao th tr s ca m cngtin v pha di sngngn.


58/110

Nhit bc x ca vtthc:

Rl nng sutpht x ton phn

Vi cc vt en, nng sutpht x ton phnR

vtun theo nh lutBolzamann:

Rv = T4

Vi cc vtthc (khng en) th nng sutpht x ton phn R < R

vVy: R < T4


59/110

- t R= b*T 4 , vi b l en ca vt,ph thuc votnh cht v nhit ca vt ( b


60/110

ng dng: Ho k quang hc:

Ho k dng o cc nhit cao: nhit ca mt vt nung , nhit ca l luynkim.


61/110

Chm bc x pht ra t ngun A ( ng vai tr l vt en nhca s ca mtl luyn kim), hi t vo mt a nh K bngbc bi en. chi ca nh A trn a K bng chi cangun A. Nhit ca a K c o bng mt cp nhit inv mt in k G c nhy ln. Nhit ny t l vi

chi ca nh A, do t l vi chi ca vt en A. Bngmt bng o mu nhit c sn,ta suy ra nhit ca A

bng cch c s ch ca in k G Nu A khng phi vt en th nhit c ch l nhit bc

x T ca vt.

Nhit thc ca A l T vi T c tnh theo biu thc


62/110

B phn tch nng lng

dng bn cong Lphng phpphn tch nnglng ion dng khiph k.

Cho bitthng tin v hmphn bnng lng v hmphn b khilng ca cc ion t khiplasma


63/110

NGUYN TCCHUN ON

Trong plasma, mt s cc iondng c gia tc,vt ra khimin bao plasma v i vo mtkhu nh, n cp bn cong t

song song vi nhau

Cc ion ny chuyn ng trongin trng gia 2 bn cong

Ch c cc ion chuyn ng theong cong chnh gia 2 bn congi qua khe thot n detector


64/110

XCNH NNG LNG ION in trng gia 2 bn cong tc dng lc ln cc ion lm chng chuyn ng

theo qu o cong,lc ny lc in trng ng vai tr lc hng tm:

in trng xuyn tm Ergia 2 bn cong c bn knh cong trung bnh Rxp x bng in trng gia 2 bn t song song cch nhau mt khong d, v

hiu in th gia 2 bn t 2VA

Nng lng Joule ca cc ion c khi lng M, vn tc vi

Th pt (1),(2) vo (3),ta c:

(eV) : Nng lng ion vi in th DC p vo 2 bncong


65/110

T l vi: in th p vo cc bn cong

Dng hnh hc ca cc bn cong


66/110

KHI PH K L dng c tch cc ht cht b ion ha theo khi

lng ca chng , hot dng da trn tc dng ca intrng hoc ttrng ln chm ion bay trong khnggian

Bungion ha

B phntch

Iondetector

Khiph

H thngx l d

liu

Bungchn

khng


67/110

B PHN TCH

CC LOI B PHN TCH B phn tch t: c phn gii ln nhng cng knh B phn tch t cc: c phn gii ln,cu trc gn nh B phn tch theo thi gian bay: c cu trc gn nh nhng phn gii thp B phn tch cng hng ion cyclotron: khng c s dngph bin

L b phnphn ly cc ion c khi lng khc nhau thnh

tng phn da vo s lm chch hng ca cc ion so vi quo ban u ca chng khi i vo in,t trng ty theo t sm/z (mass/charge). im mu cht ca kthutl: phn gii tt,php o khilng chnh xc, nhy


68/110

B PHN TCH TCC

Cu to: gm c 4trc,c t song song tng imt. Hai trc i nhau dccung cp in th +(U+V cost), hai trc i nhau cn li

c cung cp in th -(U+Vcos t)+(U+Vcost)

-(U+Vcost)

U:in th mt chiuV: in th xoay chiu

B PHN TCH T CC


69/110

Hot ng:Tc dng ca in th gia cc tr lm thay i qu o cacc ion vo ng ng chnh gia ca 4tr. S iu chnh

dng AC va DC ch cho cc ion c cng t s m/z ndetectorti mtthi im, cn nhng ion khc c a vqu o ban u. Ph khi lng nhn c l do s iukhin qu o ca cc ion bng cch thay i in ptrncc tr. C 2 cch thay i in p: thay i , cn U,V l

khng i hoc thay i U,V sao cho U/V =const

B PHN TCH TCC


70/110

mass scanning modeU/V = const

m1m3m4 m2

m3

m1

m4

m2

single mass transmission modeU,V= const,thay i

m2 m2 m2 m2m3

m1

m4

m2

T CC C KH NNG THAY I CH TRUYN


71/110

PHP O TRC TIP HM PHN B NNG LNGKHNG DNG B PHN TCH


72/110

PHP O HM PHN B NNG LNG DNG BPHN TCH TCC


73/110

GIAO THOA K VIBA(MICROWAVE INTERFEROMETRY)


74/110

GII THIU CHUNG

Tc dng

o mt electron ca dng plasma pht sng.

u im:Khng lm xo trn, v gy ra nhng hiu ng khng ng k trn plasma

Nguyn tc:

Nguyn tc hot ng da vo s thay i pha ca chm sng viba khi ni qua ct plasma. S thay i pha t l vi tch phn mt dc theong dn chm tia.

S thay i pha c xc nh da vo giao thoa k


75/110

PHNG PHP

Bc x c lm chm li khi qua mi trng plasma (c ch skhc x ln hn 1 ).So snh pha ca bc x c lm chm nyvi pha ca bc x khi khng qua plasma..Xc nh lch phaca hai bc x ny , t xc nh c mt ca electron ctrong plasma.

Microwave

PLASMA

mixer DDC


76/110

C S L THUYT

Quan h gia pha o c (rad) v phn thc ca ch s khc x ccho bi:

0

21

L

x dxT

QP

( !

Ch s khc x chunca giao thoa k

Ch s khc x cang plasma

L: qung ng truyn ca sng viba trong plasma (m)


77/110

Khi tn s va chm nh hn tn s ca sng viba, ta c phn thc cach s khc x trong plasma khng nhim t l:

Trong : : mt electron (electron/m3)

: mt gii hn (mt ct) (electron/m3)

( )e

n x

cn

C S L THUYT

2

2

0

22

0

( ).

.1 1 1

.

.

e

p ee

cw c

e

n x e

n xmx

n e n

m

[ I[

I

! ! !

2

2

0

.

.e

p

e

n e

m[ I!

2

2

0

.

.c

e

n e[ I!

2

02

e wc

mn

eI[! electrons/m3.


78/110

Trong hu ht plasma phng in pht sng: ne (x)


79/110

Mt trung bnh ca electron trong plasma c nh ngha

0

1L

e en n x dx

L! (1. 6)

Thay 1.6 vo 1.5 ta c:

e

c

Ln

cn

TRJ! (1. 7)

0

2

4c

e

cn c mn

L Le

T I RJ J

T R! ( ! ( (1. 8)

C S L THUYT


80/110

XC NH LCH PHA

Dng giao thoa k Michelson xc nh lch pha

- khcphc vic tn hiu quaplasma hailn ngi ta dng giaothoa k Mach-Zehnder

( qua mi trngplasma 1 ln)

microwave


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Dng giao thoa k Mach Zehnder

plasma

Tn hiu ch qua plasma 1 ln

microwave


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Giao thoa k Mach-Zehnder


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0

2

4c

e

cn c m

nL Le

T I RJ JT R! ( ! (

m : khi lng electron: tn s ca bc x viba

L : qung ng truyn ca sng viba trong plasma.

: hng s in mi

: tn s ca sng viba

e : ln in tch electron

R

0I

w[


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Cng dng : quan st hnh nh plasma

-Thi gian xy ra s phng in xung trong cht kh ch bng mt phntriu ca giy. V vy cn thit phi c s chp nh v quay phim cc nhanh ghili hnh nh ca plasma.

- Hin nay ngnh vt l thc nghim c trang b nhng bung chiuphim v my quay phim cc nhanh c th ghi c 10 000 000 bc nh trong mtgiy.

- Phng php chp nh nhanh v quay phim cc nhanh mang li

nhng kt qu tt p trong nghin cu nhng qu trnh tin trin nhanh. V dnh s phng in xung, tia la in v chp.

PHNG PHP QUAY PHIM TC CAO


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HNH NH QUAN ST PLASMA


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Mt s phng php chn on khc

S dng u d t

Dng sng v tuyn

Tn x Thomson

Tn x Rayleigh, tn x RamanPhng php LIF-Laser Induced Fluorescence


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Cu to: u d t trng l

mt vng dy rt nhng knh ch vo

khong 1mm Vng dy c gi

vng u ng phng

in nh bng thchanh.

u d t


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Nguyn tc hot ng:u d c a vo trong

plasmaS bin thin t trng trongvng dy lm in p hai u cau d thay iMt my dao ng k ghi li s

thay i in p.Da vo s thay i in p tabit c s phn b t trngtrong plasma


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Vai tr

Cho bit c s phn b cng t trng trong ngphng inKhi bit s phn b t trng, ta c th thit lp s phn bdng in trong plasma.

Nhc imu d b bc hi, lm xut hin nhng tp cht trong plasma.


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Chn on Plasma tngin ly bng sng v tuyn

Tng in ly (ionosphere)


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Tng in ly l tng trn cng ca kh quyn do tcdng ca Mt Tri b ion ha

Plasma tng in ly c 3 loi ht: trung ha, ion velectron.


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Tn s plasma

ne: nng electronM: khi lng electron

e: in tch electron

S lan truyn sng in t trong plasmaNu tn s sng in t ffp sng truyn qua plasmaSng v tuyn c tn s thp nn b phn x bi tngin ly do chn on plasma ca tng in lyngi ta thng dng sng v tuyn

S phn x c dng chiu cao


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S phn x c dng chiu caov nng ca tng in ly

Tng in ly gm nhiu lp, khi tn s sng ln hn th n bphn x lp cao hn v ngc li

Pht tn hiu sng v tuyn c tng s xc nh ln tng inly v thu lai tn hiu phn x ta c th xc nh c nng plasma

Lower frequency Higher frequency

Gii thiu mt s php chn on


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Gii thiu mt s php chn onMt my pht sng v tuyn s pht sng ln tng in lyMt my thu s thu nhn tn hiu phn xTn hiu thu c s c x l di dng phDi y l mt v d minh ha

th gm 2 trc, trc tn s v trc nng lng


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Nng

Nng ca vngplasma t l vi tngnng lng phn xtr v

th trn gy ra bivng c nng plasma cao,

th di tng ngvi vng c nng thp

Nhi i


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Nhit ion

Vn tc ca ion t l vi rngca tn hiu,

iu ny gy ra bi hiu ngm rng vch ph Doppler

Nhit Ion c th c tnht vn tc v khi lng can theo cng thc

Cool Ions

Hot Ions

m v2 = 3 k T

m khi lng ionv vn tc ion

k hng s Boltzmann (1.38 * 10-23 J/K)

T nhit ion (K

)

Nhit El t


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Nhit Electron

Nhit electrons thng cao hn nhit ion

Lin h gia nhit ca chng tng ng vi linh gia nh ph v ch lm trn th

Cool electrons Hot electrons

T Th


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Tn x Thomson l tn x ca photon nhsng vi cc electron t do trong plasma

Da vo s photon b tn x ta bit c

nng electron c trong plasma. Bphn thu (detector) s ghi nhn s photonb tn x v x l cho hnh nh ph.

m rng ca ph theo hiu ngdopper cho bit vn tc ca electron t suy ra nhit ca electron

Tn x Thomson

S chn on


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S chn on

B tr th nghim tn x Thomson ti phng


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B tr th nghim tn x Thomson ti phngth nghim Polydiagnostic (H lan)

T R l i h R


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Tn x Rayleigh ltn x ca photon nh sng vi cc htnng (ion, nguyn t) trong plasma

Tn x raman: phn t cng lm tn x photon nh nguyn t,tuy nhin i vi phn tphi xt n nng lng quay haydao ng, v vy ph tn x c nhiu nh

Cch tin hnh chn on tng t nh tn x Thomson,trnc sph thu c ta xc nh c nhit v nng ccht nng

Tn x Rayleigh v Raman

Ph tn x Raman v Rayleigh


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Ph tn x Raman v Rayleigh

Phng php LIF Laser Induced Fluorescence


109/110

fiber bundle

power meter

collection optics

Plasma

beam dump

Detector

Diode or Dye Laser

Phng php LIF - Laser Induced Fluorescence

Sdngngun sng laser kch thch cc nguyn t cc mcnng lng, mt s nguyn tnhnnng lng chuyn ln ccmc kch thch cao hn v sau bc x nh sng hunh quang vimt s bc sngnht nhBc x hunh quang thu c nhmt detector v x l bng mytnh, da trn ph thu c ta xc nh c nng htNgun laser thng dng l laser mu (330-900 nm) hoc laser Nd-

YAG laser (~380-900 nm)


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chan doan plasma

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