....
Nali o nalLib r ary oi Ca nadagi~a~~~a~~h:::;~~vision
'Olla wa, Can al;la K1AO N4
NOTIC E
'Bib lio tllequenalionaleduCanad a Oi rectiondLlcaialo·gage· Oivisiondes thesescanedrennes•
AVIS
Aep.~uclioninfOil-orin~~noflhi sfilmisgoverned bytheCan adianCopyriQht Acl ,R.S.C ,1970,c.c.30 Pleaseread.lhaauthorizalio~tormswhic haccompltfly
this 1Mesis.· . '
The qualityof1his microlicheis heavilydepende nl upon the qualityol lheoriginal 1hes is submilted formicrofilm- ing.E~eryet tentiesbeeo maceic ensurethehighest qu ality of,rep~oductjonpo.ssi,ble. .
I(pages a'emisslng,contaettbeliniversity wllich ,qrented tnedeqree,
: :
Laqualil~
de
cane micro lith ede,pend grafldemen\de la:::u~t ';:i~~~:~h:::u;:~':~::~;i~~t~~::~i~~'r~'~~s: ev:f6~
ducl ian.
S'iL[l:Ianq uedes pages,veuillel'~Ommuniquefavec runive<!ileqUI,~ ~6,!lere~~grade.,,' So~pages mayhavein d iSlinctprintespeciallyil L~qualited'i;"'pre ssi'on'ciecert~inesinigas1Hl~1 the.,ongmalpages were type dWllh'apoorlypewriler laiS.seradesire., surtoutsirespages origln alesont.'l~
ribbonor ifthe unive rsitysent us e poor pholocopy,• .dac t Ylographie,esaraidee.un.ub.al'UlsiJousil'u,niversitB
" ', -'. " '. " '(l:_
nousal llll parv enir~ nC ~ho\Ocopie demau...elsequ alilB,Previouslycopyrighted materials (jour,nalarticles. Les doc\j rnenls quilOnJdej.1lI'objetd'undroild'au-
~'published",,!lIs,elc .)eren~~filmed . . leur(artidesdere~lle,exerrenspubllh.etc.jpeso ntpas m:crOlilrds, ' .- .
La
.eprOd~ction, m~~e
parti eile,de ce.microliirn~~i. '
SDu rn iseareLoic,anadicnnesurIe droit,d'auleLlr,'SRC 1970, c.C-30: Veuillelprend.e.connalssancedes lor- mul.esd'aul0 risation'quiaccompagnenlceueeese..
THISDISSERTATION HASBEEN MICROFILMED
EXACTLY ASRECEIVED
/'lL-339131771
LATHESEA ETE MICROFILMEETELLEQUE
NOUSL'AVONS REYUE.
.'.;.
..
,{, " .
"
.:~\(l\i FRf(iu~~cy :~IPlOkAVE\P[CTRA OF14NII3
AHnCllRBONYl SUl PHIllEr/ #
.(
, b ,
:.:
. ,. .
.,. B~ksM~v~dyarand
Sinha.B:Sc.(Hons.i .
M.Sc.(Patna}..~
.:
.. .
.t
,"
~par~ntcf.Phys
tcs.
·MelOrl ~rrl.v~rsfty
or.NewfoundlandAU9u:st 1976. . ...
. Subllfttedinpartial.fulfil lalentof the,req~i ~~ntsfortile.de gree
o f
!-\aster:ofsctence'
·St.John's'
tJ .:
.~
. .. '." '.
'lel~foundl and
,.
',~'.
,"
;'W.1;~h' t~
,expre,ss mydeep"s ense0.(graU'tudeto my supervtser-,'Pr01es!l'~r,P.D.P,~lthfor'hisgu'c1ancean helpdur i ngthecourseof'
w ot1.: ' ,, :
~ , ' , ', - - , ,," " : . "
. .1 UIindebt e dto Ih".R ,ti p p i naCo su&gestillathe,ideaofshift ing
.
· thf re(~'e~~1~~_ reson,-n c:s_~~,~ 1n
the$Iuf~e . ·-
:,_.\ ;''~
. I
a~kllOlll~d~~ th::~'~
Of':thecomp~ ~ttO[1~l '~orlt done'~y
. D~.
'6:'Jleoers Ew-and""r .Paul'·G111a~
ofK'tC t4predfctthe.14NH]spect.rua.~
" .•' " . . 0\- \ '.
, ,,'~. ' Th~ffpanC~Al,~upport:1~~a,fonns0r.-t~~MelOOr}alUniversity'.
0'( Newf oundlandG.raduate ,Fellowshi pand:te a chinaas 5i stantshipis•
'''''',l1y "'n."~d.ed, . ' :: ..'\ :,: . _ ,
\.
-·i' .'
"J".
~ .'.'
,'H i
:
-,!~.:.
. ! ",
;:
v,
..
/ :.".:'.
: ,
·r
" A B5T RM:T
. '. Fifteen.
ne<~rou~~ '5t."t~'.i-n v~rSiO~) i,n~ o f
141fl3were~~~~rnd '
..If! _ at~O
eo__9.00C~ ac~u'ratelY ~aSU~d a~iJ .~5·s·~'~n:~~ 'th~
...elec~ri~ di Po~e' l'lOme"~
.:cOll1lutedfrom
th e
Starkshiftsis 1.472i0.002O~-whtdl
cot-resW!11withthevalue\1.4 75't-0.006 0repot t: dre centl yby FUjlQ
'S~~~i%U.
Co' etion;weT e•applied.tol· 3lndK•§lines.,. . . -
' . ' . . . ' . L . V '~ ;
.Ntne0_ 1rotat ionaltransitio nSof Call1ony1'Sl.!lphide ,~ .
i~chrdlng
oM,Fe~ pai;-'a~ o~" trl~~it ~ue" ~ qU~ dNlOle 1n~rictior: o~3S
.
~uc1~~'. ~~.re.~~~rved; ' ~c~ur~~l.Y'·rrwi~Su·~,d.~~~ i1~s~gne~.Th~ .re\~u've·el~(:t~IC· ·
d1'pole
~n'~
ofOCS1n tll~ {lnOor~nd
(0200)5tat~S
andthose of'18ots:·OlleS.;..'..oc3
3s
arid·oc~s·. ~n·~e. g~nd
:stilte'we~t c~'ted h·~ t:h'~ sta~ ~hi~
..
'.~}~tl·~e e.;~ci:~~·c ·dl~le ~n't.;
fP'f-o13~ andot~~ .are resPl;~tivelY
t••0051'·',. -
and 1.;0155.. :•. ' ,
.. ,
. c;
. (
.
38 IS
'1818
1\
20 21 22
?'
39 83
•• • •••••• 85
•••.•••• •:_.\81
••• •• • •" 88
s~:~~~1~~~c~~~~e.~h~f~Ul" .
',-';'" •.; •~
•••. •••".••'.. 22Identi fica t i on ofReflection Res onance-lines•• •". ;' •••. ?4'
i~~.f.~~~~et~~~R~s~n~,n~e;L~n~s .b: ;~Je~t~n~ . ~
••:_~ ~
' .'~ .
242;2d VoltageCalibrati onofStarkCell.••~••• •••"," , 26
2;2e Analysls.of. thelines.'.''.' ••.•••.• • 26
2.2f ~aJ'lbrati.onof:~eFrequencyMe ter•~".•• 27
'R~SUnSANDDISCUSSIONS .:' <". 14 .
;:~, " ·x:~ndR~i:i~o~~~e;~:~~i~~~;: ~~
,NH3• ••• _.•••~.
Carbonyl Sulphide••• • ••• ••••••••••••• 3.3 Surrrnaryof Results••• •••••• '••••••• '."••
.
1-t. , EX;~ERmENTAr A~PA~Ti;s
ANDTECHNI QuE ," ,'. i\:l:'Descl'i pUo naridnts cus et cnof Components-'.••'.",
t ~~ ~~~~:~eY 'f;ei~~~m;nt<';' : : ':,: , ::-: :' : ': ::-:
2.1c TheAbsqrp tfonCell.•',' ','':,•••~ . 2.1d VacuumSystem·,• • •'.; .•••'.'" • '.',' .'• 2.1e SignalHodulat;-orr.:".".
J.lt Detection"•••_.• ..2.1g·D~splay ;,0>.'.•••;
~sl:ract
'..••~ . , , ~ > : ' . , ." .;' ;...' : .. '; . '"~ . .
·::H..Acknowledgement s. .. .~ .'..' •...•..; .. :•••'.'\~.•• •••ii'i. 'List'of ,Tabl es';'.' . ••• .• "','.,'" •• •" .'.;".
< .'. '
~...., . .., " ,
~::t::F~9ures
.~' . : " . '
.-,.': ,, ":':.4 ; " :.; : ~. '. ' .,' . ~ ~ '-( ':. :
I;INTRODUCTIOtI.':;'.:'. ; • • •••:.• ,. '..,'.••.'
~
;" ~i~C~;~:r~I~,~R~ : .~ :: ~: ,:.:
:,-:-,:::'.':. : :.;::.:':. :.::. : ' :1.2 Some Pote nt ialFunct ions'of the Two' FQ1.d
Inver sion Bar.rier•.•.:.,: ••••.•• '••'•• ;'..','. .~
, ~}~;~~~o~fl~~.~~~~ ~~,~~~~:~ti~!1 .- >'-. ', ..'. ,~' . , ; ',. ..
,Illve n,f on Spectrumof·Ammo nf a•.';'.•• •••.'~.;•'. :,' "
1.5 Selecti on~ules :,,";'.•'•••:••••••".•••'.~.',', '• '1.6 Stark·.Effec t s• • ••,•.•--'•.• .•.• •••." •.•••'.' •.••; 7
i:~. ~~;~;~~~~~ . i~~;;~tt~n~·i~~;, ~~~~i~o~~~p~~~c~·~~~tu;
:::':',;'l~
1;'8 FermiResonance••';.•'.,.~,•••'.••.-.'~. .•• •• ••• 10
.42 .43
..: r-
44 3.1Lo';"freqllenc'y,'i:h"O~d ~~ate ·lnversi·~.n Li;~~ '~f·. ~,4NH3 {S.~
to1U:GHz)S~ark
shiftseethe(13. ,3lin·version '~in~;f ~~~3 .~.
J.3.,S'ta r k',
~hif.ts
"of'the'( 1~~,5)'~nvers~·~.n
:~in~',:
of,~.4.fflIJ
.•." .-.', : ,, " ,. ' "" ,..' , . --. ', ii' ,
S-tark lIhi f t s ofthe0,..1Rotat ional-Li neof 0 CS'': . 3. 4,0:;','~.,·~ tat ion~I' T~II~sition5'of~.arbonYl'SUrphidc.... .,3•.
~,~t~~ ·,Sh~.ft ~·Of t~e. O.,+.~ flo~a~on~{ ~,!,nCOf
OCSjnth~.{OO O)Sta t e . Stirk'sh:i::ft, S
.(,f,,~lie, O;,~I '~O~llt~on~1 ii~e,
'of"~CS
.'-"··TABLE
in'
~h'~,
{OOO)'S~;te"
.,',.,",:>' . ' :"
3.9
s~~rk
-shj,ft'~'~f :,~~~,
0...;1Ro~aii~nal
LineDf'~33~
in th e(0 00)"State (Lo wercompooen t)
··3. JO
:!';ta~'k S~ifi:.~·~f the','O~ i Rotat1on~i i.i~e
ofOCi3~
in. the,'(0 0 0)St:~ te}Middlec:omPonc":7},••
3~11'Starkshif ts of'the D +1Rotatiol).al Line 0(,OC3.3S .in'the (0 0 0) State (Upperc:onfpooent ) .• ••'.. . .
' :3. 12'.~~ark '~hift5 ~f .
the 0""' },:Rot_a~iona,l.
Line Qf oc34s
inth e(OOO)St a te ••
3.1.3 'St8~~
shift's'Q~' th~
0...l'Rotat~~~Bi Li~';'of :
18cesin the (OOO) Sta te'.;. . •••,. ••. .•• 3.14,Dip ol emoment s'oftJteIs ot opi c Specfc s oIC~~bonrl.
" Sulphid eindiffer~tYi b rat iona lState~.•
't. : .
4S
. .46
46
.46.
'•.47;
51 29
• ;••• • • •.•• ••.•.30., .,,-0
'LI ST OF FfGpRES
/. I.
i
Viewof
ihe'end~ of
the'septum-,•• va~uum.~ystem •••••~~'••..::~,' " ' ,,; '
'.
Starkshiftsof,the 0'':;', 1r~tatiOllalHne'o f
013CSin,th"OOO)
state . '. " .". . . ':' .. '. . ~'
535").; ,hift'. 'f '~'
o-,";'" '00'''''''
ofoc3~s
1"-th,e,(000)s'ta te,(l,fMer'COlllPonentl'','.'...:,'.~.
54 -Sta~.shifts.,ot:,the0...1r\ltati onal l ine.ofqc33\,n~. (O~) ""',;mddl' ,om
P,' '''' ')•• •••••••••• c.o~letC'~~s.en'bl,yo.f.-th~.X4.24C?,5t~1~d~tect~r._••• •'••;.. 31 (l:oCkdia9r~mofStar~modul a t i on mtcrwave./~~ctro~e:r ~l
....'~ ':' : ~._~) '
'..: :.'•",', '"Complete1)1ockdiagramofthe Stark lIl~ dUl ated
.mf;crowav~spec'trcneter-et ecron te gear •~•-, ';.'
ca;l1bratfOncu·rve:f.or
th~' ~,st~i'n~s ,~aUge. " 4. ,.>
...:••••_, Ca,librationcur ve forthe St ar kfie l d '.'.'••• •'•• •• •'t ..' . . . •
Ch!,rtshO\llUigtherotat1onalitine.serccture.' " " - o~,the inv~rs1onspecr um of ,ffil3• • •• • ',.•,'•• • • •'."
~l~art: stiOW1~9
the,d1st~fbut1.on of :,K-;I lfn~s .~f
"NH3,,•",""".,,~"-" •••• •• "":..~•','.~•'•• •• •
St~,rk ",Shifts of ~fie ~U.3J · inve~sion nee
of14NH's'"'s ta rk
sh1f~~" o~
the(1.4.~) , i~version 'li~'e
of14~1:s
•" ••~
•t • " . .,
Stark shiftsof the0-+1 i'otatforia-lline of
.0Ciinthe(000 )state."~:..,,',".•"': ','•~...~••
Stark shifts,
0t
~h e ,0-+1r,otati~al'lineof..OC~In-the (10 0) state."," ••r,,•• • "•• .',' :~•
~2~r~ns~~:t10260)h;ta~,~~~a~i~n;~ .l~n~ ,~:~ ',' ..
s, ';," 52No~al
.mOdes..ofVibra.t ior;'ofF,e
;1:4NH3lIo1~ecule;
," ••~
,,,..) '. 15.Pot ent1!!1~u rvefor ~IH3" ,.... '" :"••~.-.'."• •• 16.
Ener-gy'leveldiagramfor,invers1on.:.SpJt tt1ngs of . 17,. d;'fferen't
1r.o'~es ~'6~ V1bra~10n ~f 14~1l3' "
••'...:':"~'
.• -.'. 17Ab~orpti oll Cel 1,",',;•.~•••• •.-: ;••'••", '.'..,.2~
..
FIGURE1.'1 1.2 1. 3
2.1 ).1~
2.2"
2.;3 2-.4
2.5
2",6 2:7 -2.8
2. '
3.1 3.2 3.]-
~3 ,\4
3.5
3.6
'3. 7
72 70 71 68"
ss ,:.'
3.29
'." '!"'" , ." , ,': " , ' ':
St ;;1;,'jS.hifts.of ee.c,-+~.rota,tional lin.~of ~' . ,DC Sn~he,~?~9)sta~e.(~PR,e.~ c~neri~) :.•;••" ':.:• '$t;~k ~hf ftSof.t~;,8.~I!.rotati~alline.of" , "
DC.S,1n-t he(OOO) ;ta.,~f;'" • ~.:'•_••'_"••.••• • Stark',shifts
of
~he0...-1'l'ot at ion:l l ineof:180CS"i'nthe(000)sta t e:,;~'...'• ••••-; •.:•• ••'
~~i~h:~:r~~~\~~~:S~~fii~6 ;~~;~~, t~e~s~~7 . lin,~~',.~fl:~~f
Groiin'dstate
,,(l~ "2) i nv'e~~.o.n l1ne:'~f" 14NH;: ' ~ ..- :' .".",'.', ••
.Hain:,and
sta~ linc's~he 'gro"una'
sta teJl~ .~):inyersioll
li ne,Of.14NH3';••••,'..."
~
•••"•,.",' ','.'::'"•• • •', ,'Gr~u,nds'ta te'(15~,~)'inversi onlineOf"14NH3•.• •••~•• •• •
.Grolin d
st~.~ (15~5l 'i,nverS10n , l1~~ cif
,14NH3,.;.'•• '• •~, '< . ~ ', 6~
Gro~nd
s'te t ett6.5l ,friv,ers1o~ ~ine'~f'
14mf3,• ••,.'.v. • . . •
64Grotin~
state:(16':,6)'invers;'~n" li iie
of'14NH~
'•• ••~roun~
s-tete (16~
7)·tnve~10n l ~
lie.of,14NK3• ".'':•••'~
,',••_Gr oundsta t~'(17.9)tnverstcnline,of.~4NH3~ ~';',
~round s~~te, (17. 10l f,nv'e~i ~n
l,ine'of14"~3, .: ~, ' :
•'••Ground
st~te
(17.n i
tnvers tcn line~f)4rlH3
•GrO~nd .s~at~·(1B .}l)
inVers.ionl1 ne ofl~1I3 ~
· G.rO,u~d~tate ~,~lf:. 12)
tnverstonline0.(1:\113•Groun,~ state(l~~13l i n~e~fon ,'line ~f14N1I3 ~
Ground'st~te {i.B~14J 1~verslon ~ine OfI4~~3
.::',','•••.~
•••Mafn·and St ark"11nesof'ithe0'+ 1-rota t-\onal tr,ansi ti onof~cs.i nthe ground.state.r :',.
3.28
" ~~:~s~~~0~t~7ogj,~~ s. t(l~B';;~!.~~~~'t:o~a~ . ;
FIGURE
..,
-.3 .'
3.10
3.11
3,12
I
3.13 3.14,3.15.
3'.16 ,3;17 '3.18 3.19 3.2.0 3.2 1
·3. 2.Z 3.23 3.24 3'.25 3. 26 3.27
.... .
f'..L-.
.j.
18
j ..
3.30 f.al n arid
S~ark 1fn~s--of \h e
o ..f.r.oudona!; ...
iransit!on~of 01.~S
inti.; 9~ltf\d sta~ ~~ : "" .-.'~ ·i·.~_ ..': ,:,~ .
113.3 1 M;a~n'.llndSu.rkliDoS.of th.e-0"'1ro uti.ona.t ... trl nsHtonof
cic
33S.~nth..9l"Ou~dstate.~;" ••"... . FIGUREt...
. .
.3~J2 MainandStar kHn~s'ofthe0"1rotation a l .
trln5ft1~-D" OCJJs · 1~·.~~~roun ~
.s.ta.te.•'.' .~
:."::':-,'~, . 3 .33 i;~~s~:~o~t:;k~~~;;~',:f z 90 :~t:~~tt~O~a.l ... ~ ..;; :., "
"
" 3.34:::;~~~:~~~;·~\i:'f~t:: :';::~~~.:', .. .: ..
3:35'.I'Ialri'ands~i-~
'lines;-
ofth~.
~"'1_rot~tl.on.'l·tn'.'5~tton_9f:~Bocstn.the
ground,
state", ._ ..81
82
i...·.·.·..\··..
':
..
~\
., 0
~.
../ ...:'l
c.\
I.J
-l·
IIf
o·.,
..
,' ..
",_ :
.1I~a~S~ ,.~f.
·t h.e1p.~e~!Ih~
a,nd~ichrie89
o'f,_~.~8 :ectrum . ·<ll=~n.1a
,'"hasp1ayed 8,ma j orrole1nthe develop,",n t;of'lIlic rQ\1lIve-s pect ro s c.opy., z e
h~ -P~~!·.i~a -l.~~e nUl:lb'~r Of,e~~U; D~8
..';~ble :i~~~s O~-,,~ith t9t~y
both.~xpe:illlen~a1':'techni'l~~~theory . ,_
the .1.nvesUgationofrottit1onal·R..:U.a~:aridiat>pe~ti~of llIIlIlOn::l;':
.has'
s~~ ~~at'
't h i s~o~e6u~e ha"PYJ:"am~da'l
ed-uc-ture~i~~'
th e1:ti.tr~qerf
,a t o,"/
. \
..
. .' . . .· . ":1t~O~gh~~hinVe,E'll10n~~;etrum·is,wel l.r,Ud~eJo i~f.z:e,q~enc.il.es a~?ve,12~~z•.and,S~~il\lIea SUI~~n~8:eon~~u:.d~:to-72~~.~~,~.}'e~
thereremainhundred s-oflineabelow,the'la 8 ~fre quency,lind's o me abO'v'e
. . . . . '. ,
.
.re..which have:'~otbeen ()baerve4.mostprobab ly,bec.! " s e of theirlow
ab8~~Ptio~8'D Th~8'
's:L"tua t'i o n;bec:..:m.e"~ ~pp:~r~n't
'an:ex:.,;.in~i FiS'.·;- .e ~ ...
wbi~h ,~ioi;.
't hli~req~e~c.~~s p,f~~'ieted·b~ ·-8.Il"_~mPiric:al .~~l"lllUl_a·~fint
.:in.tr~d~e~d~~ c~ta'1n';
,:md'_8hOW~ : the. apP·rox:lmit~'-~f~;<iuenc.l~.~
'ofa',c.Q1\11t~~u~e"Df~:in.ll.&1wl:tl,,,,,e.ab8~:ipu~a- '8h_o~lddecrease'a~'t~ freqll~n~y deereai:e;,or
th~ im~"ubr ~o~en~ qu~~WIl. ' n~ber' ~
'·incre a ses••' ,. . ..,.{"h~b ,h~.,. ;r~ th~ri;:. ·.Hch ;';11>•• ~,iOO:d in:h1• .. .
.-
~h~p_~~r ;' eo~e~~~d '~i.t:h ~he ',~neYrll~1~
,Of''~ht' '8llI1!l~i8 ;n'~l~~~i~."~
~ ~c:n~~al ·pot~nriall ba~rier~', ~:t'
rioneot- th~
. :aliff:i.den~l~, a'~~'\lrate: "
'.
'~ the:l.~', ~'r~dictlona .t~be r~a1~Y uBeftii '~ mierjw~~~ spe~~:rOBCOPy~ . ~h'"eU
"' ilea6Ur~erl~;' are";~adllY ~a4~
't oac~'~'ra~ies
,ofi!.'f~~ illind~ectths o~a .:
; "'.' ,'.' ,';,.-",: ,';': ', "". '-," ". : '. '-, i
~he.ories,are~nabl.e'to ind,icllte.t h e,qll8lltum .nUlllbe r s ofo~llervedl:111e~
ii~, 6im~le' eOlllpar is~ :of--'t~e ' ~b~e~ed ,'frequencie/!l'';''1th th~l~ ·~;~dlet~~~'.
'.- ',' - . - " . ,, : ., . , : . ' ' :- ' J.- : .'. '
·For~ple.the,freque.iide·~p,r~dlcte~by"t h ethe.or y ofSpi~lto~_'St~e' a,n'd:Papousekforthe1:h if,S'
,w:Li:~' J ,";' .-7.·'di'ff~~ f~·OlII. t.he ~,~,serv~~
,fi: e quenci'e B:,'-,'-'\.- '."'"
-:. " " " ,:
" :,:-".:. ...
" ~·by.amou nts r an g ing frOill51to10% of/theob8 erv~dfre'lllency, ..milespacing,
., "
-2 -
~:
.
'\
.;
" .not.use f;u la~_thMem1.ero~a.vefi:-equ.~:,c ies,be l ,:,'" 12. gH:;>;,bu t,later
~~~ifi~at~o~a ~~'
the,proc~~"re
•.-su*:~s·
th at. bySChnabel' .!!. ~'
-' ar e.u-sefulfor 11.nl',l d entif teat i on in, th'1srang e. Ro_v er,withou t
, , " ;, , '
,'"
. .lJIeasur ",lIIentssueh as t;.hese, thereis.no cr11:i qu eeither of' such the o rie s ,
or
~r'emplrical·a~~,:~;;'1in
..tiori.s.'r . :' ''' ."'On'e~undred!;;-;I~i"'eie';nfair ly','str'onginver8iori'li~es
of
) ~l 'i~ ~heg;oun~:j~~~~~'h~v~
'Le en'repJ~~ed ~ 'th~ NB~ .mon~~l"~Ph,
• " , ', . " ," ,I"
70 ,VolUlll.l'-I-V: Thea bl'ol,u t eint ens i t i e sof the se,linesare-10-'=- 'o r
·~r~a~e·r:" .:
By.r.Il1.';.1.n~;' t~
..temp~rs'tur~
of th'"ga~ '
thehighrot~t:i.onal
<'·- lev e1-...'ean bepop~lai:ed.,i.nd~h":"rhe co";paratively..';;cakel"linescan
.
,' , .,'." . ",
-,..
'.'. .
al~obe observed. The obj ec t,Ofthe,pre.sen r1!Ork, b,"0·ob lle rVe,.8li ll1li;D.
. " , , ,~:~~~~"~~::~:~:::. : :': ., ~::~~:::.~;~:::~E:~.:::::b~~:: '<."h~
~
- .
• _(mo r e Unea...ith'thepl'esentappsr; tus ,:-b:causein~t..lca ses the 1n1;errsi~ywa~,beloW' the.1imIt.of2'~'10- em- 1• • •
.
" "A1'thoug h,theground's t a t '; .arrcngc st;'; o t a U oria l-
rc .... i>,
trand-of.'diff~tent,iso t op 1<>,8P~~ie:s,ofthem~iectlleind.iff~re(ll:' ~ibrat~o:'ai
... . , ( " " .', '. " e . , ' , '
•-"s t ate s bi:'i ng. de t e]:min ed.'~or'thisre a s on,whileusingth e (00 0) 0....1OCS lin e'fOr
~~11bratf:';n 'purpoB~s.
i t·ap.p ea re d "",,11toob s erve-;:OIJIe'ofrbe ,'1::10;;.! in e
o.~,~Oc~ ,hSS~
b;'e?' u~ed'~D~~:~bie i:~~?~~ce' e~~,el'~en'~11 '~~tt~ii~
•../ •" ,CozII'iniand l'ola ce o an dpt:herst25) )',the re Is H,t t le'ref e r e n c e,inthe .'
~.~iit~·ratur~·~· theweak~r ·~ompo~ents' ·~~h~ .~l' iot,"~~~~J. t~ans~~i~s
'i><;
'a.r.~s7<'gour.,.o fo;the5,.v.ibrat.iona~ 'state,scirot~~r.iso~?p.icspe~iea~f '\,~ ca i-bO.n?,!aulph:de-.Als o',,t~ereisnO"n fer~~e.to-th~ diPO-l~.m~mm.rll, "
:-~:---~:-:~~:;':;~~~"e~ ' t~:~-~;:~;;;;~fm):-;:-(3~~, _~e~;;~~
du'ced,a tthe l~st'moinent,ilnd.aren.ol;1.nthe ,regu:L~rnume rica l,seq~enc:e.'.
.
;, .. ' - , . - :.
.'~.
.
re
the
pot'~U~l~nera.Y-isplotted.~'• •func.~ionofthed~tllnc:e. ofthe 1I":.tOllofn.
tb.Il..-plane ~aCU",,, or't'IIt'f ;no sh e n.18Ff.8:.1.2i.:.
~bt~~ed. ~e~. ·is ~~~ le1"
ofh~ight ~1
bet"';'eo.t.hee....f~_f,P~u"L~1l8:: '
.".-fu
nlt.t.os:e nat~ ca~. tunnel thJ;~~h.,.the pot~t1a~.bu~.~;r .~d.
Bojlrlvert.th emole<::ul. r"pyra mid . The-effect i vemagnitude0[,thepoten tialbarrterto
In.!'HJ leach:"lb~anQllalleV1e:
(v+ )andC(v-). Th..epU tt.in g of b
~t!,r .he.igh~ V I' bee~~a ~ero
'UI'theharrieT becc.eai.D.f1al~e. Bee.uu ,tb..l-.11at .1b ratl Dl1.allewel'1.
oal....;. -.,..etdc.
tha _~ower'~-i.er of ue~ ,.·tt ·o t 5U!>-le~ela u" ~~etrlc:
...
an~
theuPPel:fa.nt.l-.;-e-t.rl~
to,1nvenl _ • .;...~raAa1t.i~ b:~_
'r "'"- ...b-leve1~of'th.•,'~.,lbra Uon.ust a r t.'iacalled.tnve....t.on. The invers i on• fre qUenc y~D
be.tu;r:har"el<p1liu'~ bY~C~~1d.~~t1_
o!thepr~·peJ;
poteatW. " ",
. .
' ".- ; ' .... Va ri ou spoten·tilllfunct1.ousfo r'th.l11trog en.atOlllas.t.tCoes
•through th e
·~l.n~
oft~. h~1?"ogen atO!ll~ h~.,e beett~
su'u uted bydlff',.rent authoTs,wi th'anss.\ll1Iptionth at the inver.iotiDOU""isaSl!lo<:. iil t e dwi t h.toll.,"'v"2
. :bim~ ing'~od~
of, . "'''''i~
.andthat"th~. invenion':'~~b;·",;,"'~an
befOr1ll.ulat...~
in teI1JlS of.a8ine1epar tic l e . "",v inaul1deJ;th. lllfluenc",of.twofol d
. " . .
potentia.!. but nstr-in ",dtoastng l e·co.:.ordinat",:
".
. . . ..-
Nu_ rous·the o r et icalpa"peu ded tna:wit h1Dv a nloaspUt t ing dlr f col
-, :'
1D:bo~1i"
thefo~
of th..pot eD.U al~~ctiOlls
us ed:~lld
..op prox f.ni mUI_d...wt:'1 :::
. ' . .
-.-- - --
. j .
- --
so'lvfng'theS"hr5d1nger'seqUat i on: Thus, DennisonBndUh lenbeck(2) treated tbe
dou~le JDinilllu~
po t e n t ia l prob:elllthroUgh ·~.K. B
.. _apPt'O:dmati;'ns~or. the
ground aswel1-as~exci tedv:1bratio;'"lstat,,: Theagree mept"f or't he.
". . ,. '
, ",
groun ds~a-tewasYel'}'-g~odandit-"'as to~thin20%for fhefirstexClt"d
.
"
a n dND3''''ith t he'pot""tialf"nction
.
.-, .wea:.e K.aandbareconotantii'~,.:andy.isproportional,to x;:The\I.K.II ••
. , "
.
" _..1IU'!thod..~used fo~the solutionof'~ SChr&li,;gez::' sequa t i on..Thisgive~
res~t8 ~ic:Jl
. ,compa~lIbl,~'
iiiacc-"~a~\ith ' t~os~
" "M:i~ni~g'
s'pot';ntt~l'.
Butthe~a1tlescalcu lated for,t he firste~ i te ~.,~ ta te ' arenotsatisfactory.
• CostailJ- andSuth e rlan d (5),h a ve~~eda potentialfun c ti on..hichill
. .
. ..'..- \
. '. -
moreobviously and-d i r e c tly ;relatedto the UlOleo:;ularIlOtionina B1mple"'ay·.
V(x)..-C'..e"lI z.("*)+1)f;ech4{~j
..
~e~ ~' ~IJ' ~d p·'~re :,,_on;;'tants. Th~
variablexisth~,
di stance.of~~"
i ~~atOm
frOlllthe.'plane~ftheH-ai:o='; n.i
energy lev:ldifferen~ell
obtaiile1,: by hlmaTf'ingo"d agreement Wl!hexperiment~llYobseTV~dyaluesfo;"tIH3~ ~'ApprO':d~te barrl~r height~ ';~r 'Nil3
an d,ND3obtaine~ t~reby
';"r",2~;~ ·;~~l
and2~6B'c ",-1respe c t ively, ~
Nt'Yt on and.Thomas:(4.'chos e a differentpo~.entia.lf~n.~t'ion
V-tkr'Hly)2_+t'k~
(A,n
2•-.where Ara~d_Mareo:;ha nges in theb.;Ii.d length~nd'bOnda'ng b respe~tively;
'and krand.k'~:ar..th eco r r e.spondin gfo r c e
~"
.
S..al~nBnd.Ibern.( 6) uSeda pote nUa lofthefoh
whe r ea,b, c-a " d,~a'rethe'potential"coMtanu'andq isth enor=l
::' ,
. '
' . . "-.~OOrditl,?-'teofmoti o n. Th~agreell"ntbei:we~60the caicul tl t ed'.s ndobserVed v..lu~~·forthe,en".rgyle ve lsof IDt3 an d ND3isfarb,ettlfi,'thanpr e vi ously
.. -
.Ds.:tbu rgandPr~pin.{"7l.usedtheone ':"di lllens io nalpotettiial
, v(:x)....':'(R2_11:2) 2 /8&2;
· -. ' .:
..~wh er e2Ris'th~distancebetwe~nthe~lIliniJl\a-of the
tw
poten tia lwella,Vi bratio n - I nve r aion Interaction
All t.he.
th,;oretl~~ pa~ers
.;Liste'd"above'~ave
aimedat'p r e d'i c t l n g. ' . . '. .. ,
. ) . -
.. ..·th~-dependen~,:,o f the1?-ve rsion:spl i ttirigon-theqUant ulIInumb~r02asso ciate dwith·
. -~", . .
the"'2U1Q.de'lnwhiehth epyrami d,height changealIlOstdrast"iFslly. 'The rela t ive
-auece~a
oftheon~i:me~'ional trl!latment" c~mf!fl from ~h~
fa ct'rha t~:a
•
v2.~ormai
.mode',:lS,~runarll~
:,'invol~ed i~
-.·inVeTll~on.
Butother'l'lo1:m.J~d~~
ofv1bratioli.. als oaffE' et.t~einvers i onconsiderably . Thiswaa{intre a.118ed byWee ks'!.!
!l',
(9,) .•Th'ey
us~d"po t entia l~~ergy'o;:onsisUngofa~doublemnill-lJIll
po t';nU al:l~"o~vi~~ the · 1n"~~Blon-c()Ord~n~·te.
plu sthe
p':'ten Ualo f asys te m'o ff~ve' ~~O~l~d ~~~JJ.lators
represen ting-~he
re lllainl ng'Uve.
. .
v1hrati~ar,de gree s'offre edom.
I
L
The. aU!Ill:\a t'ion ;ls ' c;iver-theremai n i n g five'vib;r aUonal .wdes andqi;l~,th~
'apprllpr~~te v~brational , co\~dinate.
The'formo~ 'the -p'oten'~~al ~~~
by~~e~\s
" , - .'.. -- , ' . ' \
V~(Toy:.-2F.(."O~(r)+2Gcos (-~) Jot-
v.(x)..2 (1!
+
G)1rt.<
\xl
<OCft.
" F~ ';nd. .
LUO' OO.{Lhn,nn'
Lh;two min'''': n:nu~ ~\;U: (~) .- fe.F au'.G
are assllJDed to
.
bemi l d'f unc ti on!} oithe. ::re mai n;ln gvib:ra~ionalcoo rdina tes, and can be'exp J:esae d in aTa ylo r,se r ie sfo'-r'~m:allV1.bnlti on al amp·1!tude.The
C~irent av~llable'
data'on't heinv~'~sio~::"s~~itt1n8"i~
Illml 3·( 10 ) ar esunnaris~din
Tabl ei;l.'~
..~~e~~< le~~~' ~i'at,:a~'f~'~
\ov'"l Yi n g.v i.b ; a u onil•'is8ho~1~Fig',.10 3 . "'._~.
"
""
.'V.spirkQ.!:!& (11)have also'developedanef f e ctive.inversion. rotat'ion
Handlt~ni~~'
to des cribe thecent.:r1~u~~~·cj::i.·~~"oJ:t.i:0i1
an d'Coriolis; . . - . , .
int~ractlonsinth~,gro~nd a~dexcited,v1~r~tiOn-inV~:r6iOna't ates of'aIDIll\>nia. but tha t_doe s not wor kwe l l inthe Ililc row ayeregion.,
1.4 EffectsofRotationon theIn ve rs ion Spectt'UmofAmmonia.
. . " Q
.
..'The fac tth at· themolecu l eia rotating causesth~'pur e inversion"'!
•spect:ru...to be'
i1pli~ i'~to
-a ,large .nUIIll:!erofli nes ;.eachli~~ cor~esp~:i.ng .
"Withagiv~ll'J.Ksta t e ofa s)'DIlllet i ictop.llIOl e.; U1e.•,Jisth~'q~antumml~be'~
symmetryaxiS. . .
~~ro t.~t1onalst i u ct u:re wasf11"st r,e solvedby~leanyand
t.>:.~~::~~_2~:::_~~_~~:~:~~~::_~~::~:~~_~: '
Shengss,
& (13.>.. They~'"l't'essed
.In thepaper.byWeek s.!.t~....was qiven..a~
I
~:a.~p[int~.:theobs.eiVedfrequencies in.t h..e,fo:r:m
, ' :
.
.:rhb fits'th~low,Jaod K''::~iueg'~'ettertha n thehigh.
(.1+1) K2.+eK'++~••
/
-,~,\,
'. - ' ,
.
v..v~ell:p [AJ(J+'i)
4:
B \1;2 + CJ2.(J + l)2+D,J(J+l)i',+EK4 ] This:f.o:mul~·i!llWll,YS9i:e'" v'po s1t1ve-,con tr~yto,Shen9 '" f.o>:mU la.t1l1,BHts ,:,-l i:li~e's'in't~eground.state,:w1t h,J,~16t.o ~ith~~.1.3"M!b:exe e p,t· ' .for thelineswi.'tli__K' '':-"3n. whe r e'n-.1.2..3;.'~••
Scnnabel!.i .& (15) ex tende d Cost.a in's,fo~~auptohigherpo;..e"a
si: ~:':: :::u:::~;:;,:::'o:::'~: ::: ::,:':;:: ::::::v::::"iml ~::-
cJ ;be 'an;oma~~ us
de;;iation s'ofl\"3lines· frO~,,:the
..ab6,~e, f~muiae ,
l
'-'ha veb,' on ••pi",.,'
byN"':onandtenrueon(l~)0'<h"~•• , ,of'P,~""ing.'.L. \
{"f.l~ l...-
3le v e ls'byaVibra.~o?-r~ta.tioni~te~ac tion .. The yde rive.da1
'0';'' '''0< '" do"bl.~
SP,',itting,Of,1,<,1..3.1~W~1 ,
••• :','' ' '., ...~ Av..(_l )J nJ(J + 1).(J( J :1).-2},[~(J+1)-
61-
. ", "
\onere.a :wa sca lle da'rotatiori';'vibra.t1on'con"tan t, butit:15:re.a.llyafunction
·)of.1(.1H ): ' \. . ., ' .
Sel~c tion'Rules.
~en.~n ele1~ri~fieldh,app~ied·,toa'polargas,i,t.in~t~~aet~vi~h '.th a elec tt:'ic dipo le,caus inga apUttit\gofth erot a tio nal energ yl"e18.~
.'
e
tlJ"O +'- -
.
-
, ' ..
'Thellele et i onrules'forpure-invers i on.tra~ullit1ons"ina.a ~t~ie top1D01eculeere
" ' ". .- , + .'The .,fe'e t rie',dipol eIlIOmen t,can_be.re'present~d,byavecto~~
~osemagnitude,isme~suredbyth~di~tdbutlonof'chargeinth''-,inole~le iihd the
distance"be'~~en th~ c~~tre~ <Of~h.e
chB3ges'.,I.e •:H(1 ) . ,.t . E
nie
'firs~ ordet'pe;tutbll.~iOn 'e~·~l:"gie~" aJ:e,obtaiJl~d
from,an~~rsge"~f
thepertu~~st'i~'n
te rm"H(l), -'iri
the:'Hamiltontau""'"'.
int er act ion-energy 11'1 exp r<ls s ed11.&
, : , > . (. , .. )
'\:Y. .
I "whi chrCJ!ul tsin"th ..s:,l'"l a r a n cl!
.~f
finestnu;:tureoft~~~"-
rotationallevel speCtrum. 'Ibisiskno..nasS.t ar k ..ffeet.,_:. . t , ["", ' ,' . " ~ : r.
"Ih~~'~
"1is~t.~~ eha~ge
on th"e.it,h)l-~;~icl'e ~d-ti, ',~-S
-t he~ctbr 'dista~cl!'" ~.;
,-theithpa.rticle fromt'h~originofacoo~inate,_lIy.tel\fiXed-inth~.mo,leele. ·' nie's"uuinaU op.,is"a ve ;-
all t~e
nuclei'~'nd the ele~tr?nB ' in
theii.:.~~~";le'.:
-,", . ,' ,,' 1j , : " .-'':
If-thestllr kef{~ct perturbatio~lsconsiderably'''"'',:l~eT:t~an,th e. ',_
~_., .~.
Lev e L., . .• •; ._ _ • • ••_ • •j -
be - • •~.~- .
the-St al:k spl itt i ngs . The pel:tutbaUonte rtii
trC.
1\ s theinteraction ener gy", _iIe:tw~en ~he"~1~ctr1~ ~ie.ld t a~~ ~he lD;)lecU.l'~rdi~b~
...'.lD;)Clen tt.
.ovel-"the"unperturbed s tute.)Le.;"
" '"
Thetrsnil i d o ns iilVolvinginveJ's19J.lobey thes ele cU.l:lnrule
A.J..0, ..lI.K-.0, .lI.M_
o,
r::"i0'.
'.' .. ;"'h~re .~ is the .qu}!b~u;"
nUl:lbel:,pert fli.nin g't~
thep~jection
of.3inth e E~diTectlon-. TheSt.al:k,ef~e'ct'~fth ein v er s i ondou bii ngot'am1llOnill.repr e,s ent Pasp e cial eue e inthesenseth attho!dipole-.noment'of'~~n1..a'
is
.onl~ ~'seIll17erm:"neo.t'~
.b e c a.us e',o~
th e.1n~r~l~~ .sPl1;t~~g:· H~nc~.
i.t d6esno t·show' th efirs t'oroer ,S t arkeff~ct'. The second o;de r Stark shift
o f
&llmlOtiia
· is
g1v!"it.b y
'(I n. '-'; 'A~'-0.50 65u2E2Vq
whe re"'. l s·; nMHz,\I
i~ D!lb;e ~n'1t~;' ~nd ~
,in~o1ts
perClll.llec~use
theE2." .:. ....,. '. ".'... ..
' . . '." .
contributions:to ener gyaredege ner a tei.n±E. only.1+ 17"esolv&.b l e Stark 1ine:"-re s ul t,. 'Al l I e veis
for
}I.01,0aredoubly_ciegenera~ein .iM•.The ..'.'l1l,ee;:c-p l:eaaion~o~theStark'shif~for o-rrota.tiO?al·tra~i~i';'ns ofOCS ls ,g :lve n'b y'{27)
. Av:':.'0.1351·Il'-f?
ve
:Fo r
t.hh .
transi t i on ther eison lyone.Stark'c ompone n t .whose~ntegr~ted
.<~t.ensitYr
equal sthatoLt~e ~r=.l.li~e~
Thisis,~~ advlI.~.ta.ge
in't~~
. ., lIl~asuremel1tfof'the'di p oleandqUadrup ole tll:0mentsoftb eca:r:bonylsU1!hlde molecule.
,
.
. 'fu,tatibnalSp e ctT8of.Line ar'p~lyatOl'l\ioMOle ='ies
"Hi.le~~~e8 w1.th
..pe.r~~n~t ei~'~'t,r1/d1Po le, ~ents' ~ive 7o~atlonai
spe ctra,IlJId'fot,the se th e sel e 'et l a n.ru l eis4.1" i.1.'
- 10 -
~
. .. .BVI'the'effe'ctiv~'r o t a tiona l. par;ametel:for thevib r,!-t;i o n a l stat'f!v,,is
.
.
giv enby
BV=Be":
.~~i(Vi+ 'f)
",whereBe1s_the rotationalCO<lsta n tCor equilibr i.u.aconficurllcion. The"
. I . " ,. ." .
l':Il)Wllat l o n extends over all-vibr at ions...ith- thedegene rateonesin c l ud ed
~ " " . .
:,on l Y~rice:.,Vi.b } h,"~::,ratiOn~lq~n t~nUIllber a~d,dil~:pt;~'."'.d~gr~e
0:,degeneracy.-fo~thei IiiOdro fvib r a tion. For,alIon.,~egenQrat9L-.ode
\..
In apolyaro;'lemolecule'
~t'
IDayhappenth at two vibrational~ . ' . .
.d~".,i~'~~ a .',dOUbl Y
""?"?"
modedi:~_ .2' .e~c . 'D~isr_he,-c-entr-!~(\lgal,?i~tor:t~on"cons t~~t fortheVibrati"nal,~tatl!.V. 0.1isa small
const~nr
wh t e,li..~asur~s ~~e
correctioniIi Bfo.f
tha t·rood'e." .".
'l\1.8 Fen:>l R';'sonano:'.e·
.
levelsbelongingto'different'v~brati~ns(or combinationsof vibrat10'u.') may have nearly the's~m~, e~ergy.that is, may'beaCd<l~ntlY'.d.e8enerat~.
(I' Th~pe:rturbationfunci::1c,ln
.w
ishereeS$~nti.allygi;"enby the:anhaim.onic eereeinthepot,:".nti al ,",ner~••whi l e.1/1~an dIjIID_a;etheeu r c'appro~i-~ , .-'.
.
m<t:tioneigenfunetio~~.of the._twovi b ra tio n allevelsthat pcrturb ....
s,ch
·'(2)
"
I' . .
\ -u- . ' . f
SinceV1. tot allylIJm1etr c;VidvilllI-zeroWlle&s.0aDd~o
. ' \ . • 11 i
au oftbe~_spec-i.e . ~l .e.•of tll eSA~lI; -t.ry'!;type).
,tI~
tJ:le
relionanc e~.fair ly~oaei~:-:-KAl t wt eofthe~h:U·t.··cao =beob't:alnecl.c~r41n8to tbef1rst-ord~rpert~rb.t.1oqtheory"fro,.
. ' \
. .
) t.hesecular deterad_nt • • .. . .
\ ' / E : ' ." V,. . ., '.:
• \ W
n i ~~,E""0."
• I. . . . . ' . .
where.,Enand,,~:1.are.the:,;,nperturbeden~r~VIl .
The~~eparatlo;".of·:the·_pert.urb~~levels 1.a,g1~e~,by
\ -.Ai".. ~ ·~.4t~D~n2H\ ! . .
w here
1!5~"E: -\E£'b th.·~~~r~t:io~ .~etve~"' , ~e ~~rtul:~ed i~~;_.
· .: .. '"Hos tlo f.
th~ pd~~
ot OCS'tevetswhtch~rtrub each oth~~ ~~
·
t~o~e ~~t.b qua~,t.-~'n~ete .(v~.~/LIJ·~~)' ';'~ ~l:~·.v:~"!" lr.~. ·~~) : -
'SuCha.~rof bvell:'willbed~s~I\.~ ~ecrby BUbacri p t.~and.1.
respectively_
•an d(0,2° , 0).
"', '.- . . .
TheHut.~lrrif Per~rb:tD&:.l~l~.:tD·OCSare (l.00.0)
(4)
whereW12 h.tt,eiD~era~t1oDenusyan 4k·u •coostant~oragiven'· ."..
mol ee ule. Thepertur be d wavefunc:U=. a ra.lx~reof the~per
etur b e d wave func:t l on san elare81ve4~:.,
· ' ·0 .'0 . ; "' 0
'h-.~1-~1jI2 'h..b"'l +ah.
whe re· [[62
;
z !j!J2!'2i
t u)",i~1 62 + '~ ~ur211
,.
(5)
.... _ ----_.-
:~
. ... .
-.1..-
~,1 2-
(7) (6) b..
~[fl'l~'
+i.r~1'21,21~ -,,6)
,l:i. ' 2[112
'+
41!J12f2]1i .
Th'eactu~lBvaiue~"ofthe in.teract.,i"-g·l.:.ve15·1lJ:'~givenby
'ar e'sh own t.oAc~-.
. ... .
.
""
Uripe":i:u,~b~d
'vnue:of'02 is~O~~d
frora'th e~.e~a\-~tion
betw cent.he:
ro'tation~l
'i ev'el8of8tat~s
·(OOO) and(OJ.~',
O).Thefl:'eq ue n c y" ".' '0 " " ,'" " '.. "', ':- ' ,, '... ,'. ,
shift of the~(020)levelduetoFermiresc aaacemaybeobtained,froJ\l
. ,: . ' ,
'. " ,
the
kaci~
value of02", '.P'~
un.pertu:be'd valueofellJDaybe d.eterldned~lnc~the fr e quen c y change of the'(lOo)state'VlllSr.·be equal'andopp~s1.r.e .
tc:'~that ~f ' (02·~O) . .~e~ frOll1e~u8"tlon ~!l at,a~d b(~~n. ., ~lc~a~ed
~ndWitobtaineduS'1~ge'iilat.~on(~)•.
1.9
Quai'lrupol~~terattion'b'Y
a" ~:L~g1e
Coupling'Nucieu~
.'u
.e , ~yst~'
captai ns a'~u~diuPol~';cle
..s.'.:~~,:",~lnterac'~1'~D cif
th~~qUadriipole,7iththe'n~er~al ~ectrona,~UPI~,tOg~~';t~~,~;the~UCle~r~spin
1. rd
ther?ta~io~al an~u1Br~ment~'!'j'to.f~~ar~;ultantF.
'wheret.hequantumnumberFtakesoneottheva l ues
F -:r+'l~: , ":'J+ J. :_·~~ '. •• lJ~';' I! ~ ~
Fr01ll quantummechanica~cons i d er a t i o ns, thefirst--orderquadn>po~e
, ./
-13-
. . . - .
8?d Y(J.-I',F)a~ib.e~9~erfunct ion..
~4,C( C+1).-,I(1+l) ..J(J+l).
Y(J.
?
F) ....?(2J-l )(tJ+3)1.'21-'1). , '
SJ,6orp~1onspe.:.tra.ar e
lU"+1, IJF,"0,, 11. AI- O.
~e -Totati~al'~~rc~uC~Cics'~ertu~~ed by :qU~d.ruP;;l~· ~~upi1ng:~re_ 81ve~
by
.' ',v. . .
vo;-~ (~qQ)
-(Y( J +l,','l ,"!."' ) -Y(J:,I;~, F)J Wher~
-\10'isth~ ~npe'rturbed rot,itio~a1
.fz-equency,~~d
'PIco~r~3~ndS
.eo.the
low~'r'6 tat~re la t 1?e~the rotat1onai l~vel:w1thout hyperl'~e i '!.
,/
J,llvel
vi' vi V3.9. ~ V.,..9.lt Boo:'
- Bn+
0
o'
,~'? -0.005054O'
O' 35.81 -(I.1S17,: 0°
"0° 284.56 ,'-0.5 350
J o'
O' 512.,02 -0 . 3041'
·0 "
0',' "-:'0.35 '-0.00360:
"0 r ,.~ -+<1.0486 " "0 '0°'
~
0.99 :.:.0.0120
z
-'0°,
, 0 :4 3
:-'1
·
~.: ..
-.'.:'1(;-
EXPERIMENTAL APPARA'l1lSAND TECHNIQUE
2.1,tlescri~tionand Discussion ofComponents
Aa1cr~wavlispect rc ee ter ees~nt1ally con5i~tsof ) l) II ...om:~of..', 1llO~~chromad.cradfadonwithproperfreq'u~nCy-rang".(2)~fteq,;ency...o·nitor.·
.-; " ~
'"
,.- ::- "
(3)an absorption cell,eo n ta ialn g the gasunder 1nve.stigat1on. (4) a
" :,' -".
';detecto r ','-and (5)a de n c'e for _spectral presentation . In this sectiona brief~escr1llt~onof these componenu wi l lbe&iwm~,
2.-1a Sources
The microwave,t"ad!at i on sourcesemployed herevere twoWa t ki n ll-
.'.Joh n s o,n,Ba c kwar d-llaveOScihators.· ""'d<;"lY.1'2020-2 an d Y.1 2019-1.
~ti.q_~~e x
and,.1 band s're sp ective ly.The .1,b andha~frequen cy,'r"n~e:f:.ro;',~~Q'-
to
e.c~~''' ;;d.the-x,bandr'from.
S.O
to'1?-. 4,cne;'Th~
powe'r'outp;tf~m
-t he s e o9d i la t o r sis
50 to lOOJ:lW.These.
!;l.W. O"sc illatorswere',wunted, in tb!!Hewlett-P,ack.ard. S",~~pOsct1l~tO:••eaet esse A.-Tbefre~ueocy~veepWaSe~~tro.l1~dby.,:varyi:ag the electrodevolt~~ - <lf.the B.W.O.. tub!!by
.
mean$ of' a50K~ teri.',t ...rnpotent~omete'r,~onner.~~d·t~.ther;~f,t.of,a4',to'24~~tsD._C.,~t~'r.It waSpos sibleto obtain
a
widevariety'ofsl ow sweeprat~';_bY,v a T?"lll g the~~ivi:,~.~~lt;'~e.
ofth~
motoro~ .
by adj;"';tiDg~f
-e.the-swe epOS~ll~~t~f~~
2.1b FreguencyMeasuremen~
...-.- ' . .
.Aportionof_t h e microwave po.wer~u.~put',rromt.he'~.W',Osc1llator15 coup1ed_'outto the frequeI\cy",~as,ur~~gden"e,by_.1--0So~
a
10 <l:b-direct:ional~up1~r.
.
The frequency'
is
measured on a Hewlett-Packard'El e c t ro n i c"Counter~H:.Idel52~St .,
-1 9,..
I
_~ equ ipp ed with'tl,";' 11C~lett-rtlcka ~d!r~qllcn~y 'con~e;i:.cr.(3to12.~.~.GiI7:)"
Mndel 525 5A;
'011. ," v::,::::,:::::::,':o:": : :::::':: :::::":::7':t50"'i'~
.a.ae TheAbao r p t i on Cells
The,ab's o r pt i o nc~li swer e m",.,d c~f ten~footpi('c" ,. ofS.~band.' w<'\v,,&uideofinte.r!ordir.llinH~o ns2.840".x1. 3 40",'wit k ,,'ce nt r al'fla t ' pl ot"
. . ' "
. ""•.
, 's1xequid is t "n tpill ar sof ins"l"ting matc J"t. 3l . Con n e ,c'tionte. th eStark
" ', ' ...; .
electrodeis eade by a
, "
brassrodthro u gh..
ah ermetic seal' " in the,. side _ai loI.
l th",ccll;wll1c hrc rm na t l?si~'ascr~wth r e a de d int o'th.e.pl at" ; '.ByJmunting
cut-off.~_r~q,:,endlsfor'the dOllllnantTE~o,~~defor,~he's;J,".and'xband wa ve gu i d e s are 2.078,GHo:;4.'.301GHz,a n d 6.S'!!,"-GIl',~e9pect1vely.o.
. ! .
It1s COllU:lon practic,eto useoversizedguide.such as S'b and
, , ' ,
gu~de.for the.. ain ab\,orpt i on ce l ltoav o i dsaJ~ ra~1rigthe",ole.culea
w~~h
excessivers diation,'{al,Soto avoid,exces~i:'le
,guidelosse~
.;the.ea s e where,t h efi:~que~ciesexceed20 gH,Z). qu,O~ing'fr01llWal t e r Gordy.
"Sincethere":~eno~ouple.r".T-section s,'slots.etc.'in theab s or pt i on
ce~l
..i t~s
possibl";'t~use ove,~sized g~id~ with~ut ~~C1.ting
un ...te d. "
-~ ..
' . ,, . 'mode s. •'••••• •Here !'otDukewe have us e d S-:bandguide'(3"x11.:1" )ve r ll;
effectively for absorption'cellsin'the region: from 3 to
5
mm wave':'lerigth•• ••••••Inother're ion sovers izedcellsarc,de s i r ab l eto avoidsaturating t.he mol eculeR:.. Uh ra, at:1on.'~(29)
guide swithhorns,'or tap e red sec eIens ofguide,and th:1s'hn sbeenthe
.' ", ",
~rai:ticein micro ...ave spectroscopyformany years: In th e'case ment:1oned by \.IalteJ::Sordy the ratio ofthe~-band";i~thtothat~fth;.a.easmID ban dgui d e wouldhave be"n2.'S4"/o.ll"",'25.8.WU,,'inthislabora'tory
t~e;~t'iO ,-1a.on~y 2'.S~">O. 90~ ~
3:i 6.ye~.Gor~y !It~t~d:that
the;'had '..~o .
morethnn'theus ual't r oubl e.with ref lect ions",
The~ic.ro..ave,po~rp~ssea:a8showninFig. ,2:S.t hrOUGh a directional'coupler.a variable atten us tor••series 'ofta p"r e d lIIst,chlllg, wavel\U:~desectiona,'and,then.int~the'absorption'ceU:.-' whi chh'oidsa1nIl~1l
sa~pleofth~gas. Theat t cnu~t.or "c,antro,l,the amount-of.lDic or wa v e,power allowed to pa....t.h r ough the absorptioncell.'an dalso at tenuatE! theun'fante~
.
~reflected ~:ves gener'~t'~d
chieflys'tthe endsoft~e'
'S tar kelect r o de'8n~ ~t
,t he w:indo"'!I.Thedir ect ional coupler placeddirect ~y,af terth e source does
.
- ' ."~otpr ovi d eany appreciableattenuation betwe en sourceandde t e ctor.,but
, . '. .
..
p:ovldes,1%oofthe,lIlkrowave.'poWer.ee thefre'luenc~;"eter'forfr"qu~ne.y~ea~u:";'ent.
7' . -,."...
1
I
.;20 •-
', .,
'.
,,,,., .Tb~u1b _re.ure~t1 y ~onoe~ tedto I~lc:>.I"'"17It~'byan ,:",t1e t
throughthei~broa d11d_fl!,IbOU~·.";"~.thirdalong thei rl~&th."tbeva cuUlll
.y.t~,
(Fig. 2,.2)~Onsisted .
of';'~u.ber ~f &t"p-e:OCIt~:
and.::01d't rl Ps G.'- .
-21- •Shoal~lodu1ation
. .
.' . . ' " , .. . 'I
,I fan electric.fi" l disIIppl,i e dtoepolar,;I\Ol "cu le its absorption fr eq uen ci e s are shifted.be,causeofth e StarkeU"c!=. I f.atsoee:instantthe B.W. 08ci11a'tol:;frequency'co~ncideswiththat of ani:tbsorpt ionline.andII .pe riodi c
e~c,;'t~iC
'fi'Cldisap~l.;ed.
'th e n'the re w11,1'beeac:orresPo~diltg
t-,i.:J qvadation inth e powerdetected bythecryst a l ,.si nceth~.Star... co mponents ofthc ' lin e are sh iftednlaUve tothe ,source.freque ncy,',n..e,swi t ch in g c n n bedoneelectronically'IIi:radiofre q'ue n cy.andthe' re su lti ngIIOdulationof .
the·..J:ci:owav c"
po;"er abso~hed
b;thegas~a~ th~~
be'de;cct~d
bJ:'aradi~;
~ec~~y"<tu~edto th,;,modu1a ting frcqu..ncy , Thi si~the'pri.n~,ip~eof;the
~tarkI:IOdu latio nspectromet er'in t roduced by,Hughes.and Wi1l ialllS(18).
i~
adii tion~'o' 1ncreasing sensiti~ity
bya.vOid~ng
aov frequency.-2';' -
2.1 f ~
," ~e'o ,:,tp u t from'th e ab.8orp tion ce'11"':Os detecte d'byH~,,!lc tt-Pack~td Cryst41Detec tori Mod-"1
X 42 4
or'J42II,~ (ne~...tive'bl"sed).,. Theout pu tofthe Cryst,al'det".,c to rwas'f~d.into.apreampl ifier. , a~dthentoarecei~er-t~ed . tolOOKIlO:(both"IIl!ln~factu~ed ~
,'Ind~strial
ColllponEmt $. ' .Incorpo~ated) .
The'cryst al- its e lfcon~iB tsofa
smaIl'
pieceof,~se;":i.conducto~lIIate r~al~i'"con tactwith a·fine',t. unqsten"'hisker:~
Sucha syste mbeha ves.8Sa rect i fier'fo rcur r ent.at ercreee vefreq uen ci e s.
. ,"
. ' .
ThecrYat~l",:i~.~unted'ona holder wh o s eoutet~ng,iBin.'cont~c twithth e waveguidewal1s.'Th.einnerco~lluctor.towhich,the tungst e n "h isker is .
cio~rieete:d. lea~s , ~cross
th'ewaveguide :.an.d';0ac ts~8
't he.a.:. tennac~ ,
col lectin gmicrow averad ia tion ;
a~d the
rec t ified'o~tput
signalpaeeea'to the" , . ..
, '.
cosJ<ial'll-.N.C .'-connectOl: . 'l:'heasse1llp~Yof~beX4 24Acrys t aldete ct ori8 showninFig~2,.3.
F'ar.the'display
'~f
t.he, ou t p utsi q rialfr01llthe 100 KJlz'recei ve reit.hera_lIewiett-J'aCk~rd
7035A: X -Y
recorderOr.a110 0B·stripc;ha"C'~ ~-"';';rd'erw~~
use d.'E'o r !:he.pr e lim1nar y,s e " r ch'of'th e a!:lSQrptioil'l1n es the'x-yreco r d e r ~
"nd .~or
the· fi~~l analY~'is· Ofgth~ ,
lin:'stJ:1e. ,jtrip:"~art
r<.K:Or der·was uead, The'.ro~PM' " "'k « " ' ';'
of"0,' o<Ow...'POCt<"~'Ph
'"'h~,~ i, Fi,.i ,,: . ~
Exp e rime n ta lTechnique
Searchof Line s
. , . .
Theabfi'orpt lim ceil
an~
the'glassW3re ~re ~~llY,
evacu at ed'.toa'
pressureof0.002 tor r."In fa c t"t J:le
'p~~ng
out·ope ra t'ton.,;:asc~nti~~'d " io~
- 23-
by,i n tenn it t e nt 'h eat' iugof telie g"ide
lob
'ensur e t'tia t'the
ab~or·~t:i.on
'cel l'a Dd the, re~t
ofehe vacuoe syste41wereeo";-"lete l y·
f~ee fr~ "ny
trae",'of abs o rbedgas es'."Fu'r t h",r.,'th'~
abso r ption·cel1'wa s'
flushe~'
s" ve r al'~imes ~'ith ·~'9.99%· 1~NH~ gnS
sup p lied byMa'thes on- , " '•• ' '.';" " '.,f'
?fcanadaLtd.,by lettingin'the,gas,t h r o.ughtheinlet.:~aehflush wa.sf~l1~wedby:~v~c.u.atl..ono~,tl:e•.vacuu~system. 'nli~,p:o~sswas,~~ated
;sElve ral
t , '"
to,ens ur~th~tve r yl\tt.~".in'th'.,abs orpti onC:e~~:;andel1"91 8sS,w".r.es•.
•'<. •Finally, a freshsampl e of
.c:>: .
·ammoniagas,~roD1the~o t t1ewa sintrodu ced1.nrotli'e..bsor ptioncell until,the,pre~SU,J;elJ'oseup tO,ltor r. Then,ebeexceee-or\t~e g~,Swas remove d'froQ thecel. ).bypWllp 1.ilg'i t out,andeooU,n g,in thetrap untilthepressurew;;'n i downto the'o p t m_ .l ev el .'i.e... to 0.01torr:
Usingthe fo=ulagivenbySc1mabel~ ~",(l5)" ., an emp iri c al sp ec t l1Jlll
wa~ gm;;~r~ted'.:· ·~h~.- l~tens·ltJ.?S
ofth~sel.ineoi.
a't"lOOOC..fere also calculated.'Af te r'ra1.a i.tg'the
't_peratur~
of'"thE!" .'gu i deto'
ab~u~ 900~,
"s earclif~r
tho,se Jin e s""'hose" ,t~~i-er:i~l-inte~lt~"S '
;. w~r~'
of the.orderof2
xiO.,.'JClII-l.wa s IIl6.deon a~~ow-6w~e~
cha.rtrecorder.
Th~ ,telllPe~at~rl! '~;"~d no~'
beu~se~ furth"r,~s
thesea ls io the absorp~iond",1.1sta r te' dle ak 1.n9 at hi gher tcmpcr;;, tur:e s.., ,
_.24~·
i:21>
'I <h ,n t :l.r"iea t i o n'< i
ReflectionRes ona nce- Line s'I~ iden't~fY_
thereso~a~ce-li,;es-~~'th1n"
thesUi. d'..;;th e abllorp -. ' tion ce.n.washi<ftilY .evacuated with'inte~itt...nthe at i ng ,80,<1.8to
leave .litt le' ~r~e';'- Of
'I "NH]'~al!l
'i nthe~ae,,~';' 6YSi:~. n:" outPllt:~~ltllgli:
,. . '-": . ' ," , ' . ,' ," '
ofthe-cr yst alwss.d,feectl)' fed to theX-Yr~"'td er.IlDdagainasweep
was'taken
at
thestep sof 100 MIIzfot the,f requ<me y range4.0to'12: 4G!j..%. asdonepr ev io usly with thega~in'the,c.e lla.-Many!~~nl'.9.ti!,3ppeac,ed
w1.th ;d~inl$hed ht_~n91;Y, · 'Th~~e
we re ,I'O~
S,lblYr·f,e,r,,~~~ance 1~e.9
withinthe gu:1.de. As3.lurt her,check. on the nature ofthe originat.
~h~8e
l1nea,.the~pec~~nt ~a8'repeated
afterra:l.81ngth~ yt"p~rature
'.of't heg~ideby'.sODto.f!'ODC. ,Thes'e lincs appearedaiai n, but wer e ,"disPlaCed
~~
-the IDwerf.requency"liideby·...n_a"';~~t. wh~Ch
depende don :....'the,thenaa~expaaetcnof t,heguid e. As expla;inedbe lo w,thi sf~eql'ency;';'.
shifLduetotemper atur e- VlIrlationl11 the: characteristicasso ch t e d' ,'With the
r~sonance 11~';-~
onl y._·':1n.'th iS,~'nn~r~ :
th e.~es,~na~~""liries)~_.'
..lt J.l;nth~gui dewer,:,'u~igUoufl1yldentlf.tedaod_el:lJdna ted fro mthe .lis t~or.f ur t he rin~e8t.1&a.tion.
2.2cShif~i!ll!.the Re90nanceUtl<!SbyH~St1~g'th~Guide_
one.of,themOB~ser10-'"pr o bl e.osinlIlic~ave specttnscopyi~th a t
,
ofdist:lngu1sh1.~~abso rp t io n dueto th e~t:rialunde r ",tudy!r01lltheunwaii~ed r'e sonance s setu~witw.nthewsv~gui4e'~Y8tem.itself."'Sl',ch's tllUding ";sves
ad~e. f~~IIl·~e·fleetio.nS
bee-en~i1ght':dis~nt.u'uit'14:
inthe ~sveiui~e
_2~._
l'<>-i:t kul"Tl Y at
tl", ~oUPl~ne .
.j o.int s.'windo ws, .et c,_ Tlws<:'resonancesoverlap;andobs c u r etl,' 1! Sta rl<1.1.0 1'$
as
",J,J.'ho ,o,on.:::k:::o:",:h:o:;·:~:;::::d.:: ::~l::d:'iP:s.:;:;d Of, ~vio,
'«,,,noy,
to'iVOO:: li ' '<~ ,
where.v..;vclo c ity o f'.theJd.CrOl'll,e sinthe.gI11dQ~ ~~
'·<i. ""' ,,n, i~te~er.
~..:l c n g t h oft'hecabs o rpt.Io
Hh e n the.
~s~iption
ee 1 1is.h=t~d
its,length1nc re'as c's ttl\ .
' ,. .. Lt,'' ' '
Le I
+een,
l!.T"":inerc...eein crnpp--ra ture,
of~ resi:allt!lecb" tu r J:neofthe Sta r k.lfne~caus<!d hy.these'
-:
:inthe'd e S i pl"o fthe',S.t.a r k m>dulation
; ,
' .
cell,,t he distancebetwe e, l.'-thesap Ill..and.th eW3US of,t he guidemay not re...,:inUnchang<!dthroughoutit sle n gt h ,cauging'a vat"btion :intheelect r i c
" ""'d'" ;h,""""q"" "'"'';i.'''."" ''' ,.,."i~
. '', <h, ko,",.d"
".,' ,f"the, Held strength. ~Th~'a"cj~l:~'valu~of th"f'~,e1d~Yhe,~btilined'b)' .calibratio n~:i,th.isub~tanc.·e,whos e dipolc. .~nt:'i~,lr.no,ro acc"~:'telY .'For
v"lt:(\'E~·.cal:ibrat:ionofthe.guide'i1e~e ,carbonoXY$~lph:i<1e(160'I}C 32 5 )"as
~ :::~'::f:~:b::Z,;' . ::,:h: . :7:::::::i:::::': ';,Z, ;:: :: :::':::::d
fOtd~ffcre;;t>"Ql ~agesaridIi;"clcc"td~'f.ic li:l;'s tIl:llg t l,·(voits/ ~~),;,a&
_,-,_~~~'!~!L~rOl\l' ~f~~'"
, " ' ..,
r. ~ ~ ~~1
, " ' ,
, , '-",,---
Av~S ta'ikshiftintm"andu~-().714 9D.
vOlt..etc~ r~ading
V'an dthee11!~tr'iCf~'i<l~'stre~&~~ E~ ,~i/l ";asd"';'~' fO~~both
. " " " ,' : " ,
""" ,
.th';guid es. n,ecal:ib ration-curves1"~e rep~duce,~ln.F:i g : 2;7:
the
r"so1U~ion' o~
Starklines,the b"-~put-'freque~cY-Vildati~
wasi(jnt:rol~'~d :~y,
a'50 k,:olilll~en~tu:rn ~o'tC'.ntio~ter, ':~~owi;;" ~tiven
bY"O''4 ~ 24
VOltS.,'D.c ." mo-torv~
awO~.,te.a~ ..
Ily~ee~in g
,t~e,'·dt:i..vi~~.~l~agC'., at?(1.
volto"2~d .
mal.ntai"ill!:·, Af,at'~oo ~1; .'n~8\;eCp~ate,0£·0.1eec.z 101Hz:permi n ut eW~9 obtain~d.crysta lcurrent,whichIss190'a measureof,th ss1g1l41strength,vee
'k~Pt ~t
120~a··. ·
Thebandwidt h~f,
the 100 Kl12:reCei~er
1188'selectedto.',". 'The ,display
.
,of,the output.
signal.fron.,the100
KHz· re,c e!ve r,)-lasmade onthell t rip chartre~order ; ,
the'paper spe e d bemg''i" " .
lIlaint~lnedat 0.2in ch per mi n u t e. Thev£,ltage'Scaleu~al1ychosen ,was 250mV.f ull scal edef lection•
.2.2f Cali.b rat i onof the'F reque ncy- Me ter
U~~ng t~,,~r~~dstate()+lrotatlolla1tranSi.t~nalheq}L~nc:y ofOCS
,,~,~,",t~~~!i~~uencY
'sta nda r d.'t he::lIPfr(!,quencY-IlI~ter
.sa s, c,ai~br~t~d:
·Th(-~verilg~·'reault.of,th e'96 samp'leawas,12162 . 970Mitz~ !h.etheoreti<;=al
~ . " ~~l'~e
18'12162.984MIll':whi chla:cal culatedu~ing Co~t~inIB val~e
of'36488;8128MHz for theJ •2+3 linesof'oes and the Laildho1t-Borna te1n
' "
, -
, '.
v~iue fo~'
D of 1,.3i'x'10 -3~z.
::Thewetgh;edaverag~'f~~ ~he r8t~o, O;~8 th';'or~~ical' f~~quenc)'and t~~ obaervcd
frequency:ls1..00000ll, Th~
·corre ctiontotheObae~e;d'frequeilci~81s+0,014MHl':~,which isless thslI th e r.II',B.
err6~
'of:to.02 isMHz.Hcn~
in'the'p re aen:t'work no'cor r e c tio ns. "', ,' : . ' .-
.
~~re,applie d,tothe~requeuCy-:lliete~readi~gs.' X,~willbeno.ted'th aton~y ooestandardfrequencyi s lIet!ded,beca";sethi s !ssufficiollt·to calibrat~'
·the
~~stalintJ:af"~equenCY-lI\8tar,'1tIofrequene:Y:eearota~~ona;l'~~:e -~s_given.,by,the'formula,''.
v·=2 B (J+l l~4 D{J+ll, ,'
- . .
,." " ,Whe r,e'Jisth6.:-otationalqU,anturlnumberof the lowerstate . Cbviously ,.' f';lrthe0_1 tran"'ition •