Continuous-

Wav

e Cav

ity

Rin

gdow

nStu

dy

of

the

14N

2+

Mei

nel

Sys

tem

2-1

Ban

d a

nd t

he

Firs

t Po

sitive

Ban

d S

yste

m o

f N

2*

Dep

artm

ents

of

Chem

istr

y an

d A

stro

nom

y, U

niv

ersi

ty o

f Illin

ois

at

Urb

ana-

Cham

pai

gn

ŧ Dep

artm

ent

of

Chem

istr

y, U

niv

ersi

ty o

f W

isco

nsi

n-M

adis

on

Susa

nna

L. W

idic

us

Wea

ver

Bogdan

Neg

ruM

ichae

l W

icze

rBrian

A.

Tom

Josh

ua

P. D

iGan

giŧ

Ben

jam

in J

. M

cCal

l

The

Mei

nel

Sys

tem

of

14N

2+

OSU

MolS

pec

Abst

ract

fro

m 1

951

IR A

uro

ralEm

issi

on B

ands

of

N2+

obse

rved

by

Mei

nel

in 1

950

Confe

rence

on A

uro

ralPh

ysic

sU

niv

ersi

ty o

f W

este

rn O

nta

rio,

1951

The

Mei

nel

(A2Π

u-X

2Σ g

+)

Sys

tem

of N

2+

20486

18972

17428

15854

14251

12617

10953

9260

7537

5783

4000

2187

343

-1530

5

18477

22529

24606

26715

28858

31032

13

16962

21015

23092

25201

27343

29518

12

15418

19471

21548

23657

25799

27974

11

13845

17897

19974

22083

24226

26400

10

12241

16294

18370

20480

22622

24797

9

10607

14660

16737

18846

20988

23163

8

8944

12967

15073

17183

19325

21500

7

7250

11303

13380

15489

17631

19806

6

5527

9580

11656

13766

15908

18083

5

3774

7827

9903

12013

14155

16329

4

1990

6043

8120

10229

12371

14546

3

177

4230

6306

8416

10558

12733

2

-1666

2387

4463

6572

8715

10889

1

-3540

513

2590

4699

6841

9016

0

64

32

10

ν''

ν'

Cal

cula

ted

Exp

erim

enta

l

Adap

ted

from

Tar

sita

no&

Oka

J. M

ol. S

pec.

219,

200

3.

10200 –

10600 c

m-1

dio

de

lase

r

Dal

by

and D

ougla

s firs

t ch

arac

terize

d

the

N2+

Mei

nel

syst

em in t

he

labor

ator

y in

1951

(Phys

. Rev

. 84).

The

Firs

t Po

sitive

Gro

up (

B3Π

g–

A3Σ g

+)

of N

2

19873

18489

17076

16612

14161

12660

11129

9668

7979

6361

4713

3037

1332

6

18607

17224

16811

14369

12896

11395

9862

8303

6714

5096

3448

1772

7

17370

15988

14575

13132

11670

10158

8627

7067

5477

3859

2212

5358

16163

14780

13307

11924

10462

8960

7419

5859

4270

2681

1004

9

21166

19873

18310

26927

16455

13963

12422

10862

9273

7654

6007

4331

2625

5

12

21105

11

19692

21041

10

18249

19599

20976

9

16777

18126

19504

20909

8

16274

16625

18002

19407

20840

7

14742

16093

16471

17876

19309

6

12184

13513

14911

16316

17749

5

10594

11944

13321

14727

16160

4

8976

10326

11703

13108

14540

3

7329

8678

10056

11461

12894

2

5652

7002

8379

9784

11217

1

3947

5297

6674

8079

9512

0

43

21

0ν'

'ν'

Cal

cula

ted

Exp

erim

enta

lA

dapt

ed fr

om D

ieke

& H

eath

Joh

ns H

opki

ns S

pec.

Rep

ort 1

7, 1

959

& R

oux

& M

icha

ud J

. Mol

. Spe

c.97

, 253

, 198

3.

Firs

t obse

rved

in t

he

visi

ble

by

Des

landre

sin

1902

(C.

R.

Soci

ety,

Par

is,

134)

10200 –

10600 c

m-1

dio

de

lase

r

The

A2Π

u-X

2Σ g

+Sys

tem

of

14N

2+

The

A2Π

ust

ate

dis

pla

ys

Λ-d

oublin

g a

nd H

und’s

case

a a

pplie

s.

The

X2Σ g

+st

ate

of N

2+

is

split

by

spin

-rota

tion

inte

ract

ion.

Hund’s

case

b a

pplie

s.

P, Q

, an

d R

-typ

e vi

bro

nic

tran

sitions

are

allo

wed

.2Σ g

+

F 1 F 1 F 1 F 2F 2F 24 3 2N

2.5

3.5

4.5

3.5

2.5J 1.5

- - + + - -

- +

+ -- +

+ -

- +

- +

+ -

- +

+ -+ -

4.5

3.5

2.5J 1.5

5.5

2.5

3.5

1.5

4.5

5.5J

2Π

3/2

(F1)

2Π

1/2

(F2)

R21 R

22Q

21 Q

22P

21 P

22

R11 R

12Q

11 Q

12P

11 P

12

The

B3Π

g–

A3Σ g

+Sys

tem

of N

2H

und’s

case

a

applie

s fo

r th

e B

3Π

ust

ate

at low

J,

and

an inte

rmed

iate

bet

wee

n H

und’s

case

s a

and b

ap

plie

s at

hig

h J

.

The

3Π

g s

tate

is

split

in

to 6

sub-s

tate

s

Hund’s

case

b

applie

s fo

r th

eA

3Σ g

+st

ate.

P, Q

, an

d R

-typ

e vi

bro

nic

tran

sitions

are

allo

wed

.3Σ g

+

3Π

0g

4 3 2N

J

1 0

3 5 4 2 4 3 1 3 2 0 2 1 0F 1F 3 F 1 F 2F 3 F 1 F 2F 3 F 1 F 2F 3 F 1 F 2

N

J

1

2f e

N

J

2

2f e

N

J

3

2f e

Q11 P11 R

11Q

12 P12 R

12Q13 P13 R

13

3Π

1g

3Π

2g

Q21 P21 R

21Q

22 P22 R

22Q23 P23 R

23Q

31 P31 R

31Q

32 P32 R

32Q33 P33 R

33

CW

Cav

ity

Rin

gdow

nSpec

trosc

opy

(cw

-CRD

S)

•A h

igh fin

esse

cav

ity

is

pla

ced a

round t

he

dis

char

ge.

•La

ser

light

is c

ouple

d into

th

e ca

vity

, w

hic

h is

cycl

ed

in a

nd o

ut

of re

sonan

ce.

•W

hen

the

cavi

ty is

on r

esonan

ce t

he

lase

r lig

ht

is

div

erte

d o

r sw

itch

ed o

ff.

•The

exponen

tial

dec

ay r

ate

is a

direc

t m

easu

rem

ent

of

abso

rption.

Exp

erim

enta

l Set

up

Spec

tral

Cal

ibra

tion

Mode

Hop

The

N2+

Spec

trum

0.0

3 c

m-1

α min

= 2

x 1

0-9

cm-1

31

00

V,

70

mA

N2/

Ar

dis

charg

e

N2*

vsN

2+

The

A2Π

u-X

2Σ g

+Sys

tem

of

14N

2+

14N

2+

Lin

e Ass

ignm

ents

Freq

uen

cies

cal

cula

ted fro

m M

iller

et

al.,

J.

Chem

. Phys

.80,

1984 a

nd F

erguso

n e

t al

., J

. M

ol. S

pec

.153,

1992.

Inte

nsi

ties

cal

cula

ted f

rom

Ear

ls,

Phys

. Rev

.48,

1935.

Spec

tral

Par

amet

ers

Det

erm

ined

for

the

14N

2+

2-1

vib

ronic

ban

d

5.1

8(1

9)

x 10

-34.8

7(2

7)

x 10

-3p

v

-3.3

7(6

) x

10

-4-3

.08(1

1)

x 10

-4q

v

-2.9

8(5

) x

10

-5-8

.0(1

1)

x 10

-5A

dv

-74.6

417(4

3)

-74.6

332(1

8)

Av

5.9

52(7

5)

x 10

-65.9

1(1

0)

x 10

-6D

v

1.6

97442(8

7)

1.6

97391(6

7)

Bv

10558.0

931(2

5)

10558.1

Tv

9.3

1(5

4)

x 10

-39.1

97(2

7)

x 10

-3γ

5.9

97(7

5)

x 10

-65.9

42(8

) x

10

-6D

v

1.9

03499(8

8)

1.9

03373(1

3)

Bv

Low

er S

tate

Upper

Sta

te

Fit

RM

S =

0.0

09 c

m-1

for

95 lin

es†H

o e

t al

., J

. M

ol. S

pec

.153,

1992

Ferg

uso

n e

t al

., J.

Mol. S

pec

.153,

1992

Our

Wor

k

Prev

ious

Stu

die

s†Pa

ram

eter

The

14N

2* P

roble

m

Freq

uen

cies

cal

cula

ted fro

m D

ieke

and H

eath

Johns

Hopki

ns

Spec

trosc

opic

Rep

ort

17,

1959.

Inte

nsi

ties

cal

cula

ted f

rom

Budo,

A.

Z.

fuer

Phys

.105,

1937;

Die

keand H

eath

Johns

Hopki

ns

Spec

trosc

opic

Rep

ort

17,

1959;

Bilo

iu,

Sun,

Har

vey,

& S

cim

eJ.

of

App.

Phys

.101,

2007.

Concl

usi

ons

and F

utu

re W

ork

•The

cw-C

RD

S s

pec

tra

of N

2+

and N

2*

from

10227 -

10590 c

m-1

hav

e bee

n a

cquired

.

•95 N

2+

lines

fro

m t

he

2-1

ban

d o

f th

e M

einel

syst

em

hav

e bee

n a

ssig

ned

and s

pec

tral

par

amet

ers

det

erm

ined

. M

ore

ass

ignm

ents

are

under

way

.

•≥

400 lin

es fro

m t

he

firs

t pos

itiv

e ban

d s

yste

m o

f N

2*

hav

e bee

n iden

tified

. F

inal

ass

ignm

ent

and

det

erm

inat

ion o

f sp

ectr

al p

aram

eter

s is

under

way

.

•Li

nes

fro

m t

he

3-2

ban

d o

f th

e N

2+

Mei

nel

syst

em m

aybe

obse

rvab

le.

Ack

now

ledgm

ents

Brian

Tom

NASA

Labora

tory

Ast

rophys

ics

The

McC

all G

roup

htt

p:/

/ast

roch

emis

try.

uiu

c.ed

u

Bogdan

Neg

ruFo

rmer

gro

up m

ember

s Jo

sh D

iGan

gi, B

rian

Poh

rte,

an

d M

atth

ew Z

wie

r

NSF

CH

EACS

Dre

yfus

UIU

C

Mic

hae

l W

icze

r

Christ

opher

G.

Tar

sita

no

for

the

N2+

spec

tral

fitting

routine