N6+ +H and O6+ +H charge exchange

Y. Wu, P. C. StancilUniversity of Georgia

H. P. Lieberman, R. J. BuenkerBergische Universitat Wuppertal�

D. R. Schultz, Y. Hui , C. C. HavenerOak Ridge National Laboratory

ADAS 16th, Auburn, 06-10-2011

Outline

Background Theoretical Methods Results Summary

Background Charge exchange: X-rays and/or EUV photons

observed in cometary and planetary atmosphere and from the heliosphere;

Oq+, Cq+, Neq+, Mgq+, Siq+, Nq+, Sq+,... X-ray/EUV: study the solar wind composition and its

variation; the interaction of the solar wind with comets and planetary atmosphere; the atmospheres in the Solar System etc.

Oq+ + H → O(q-1)+(nl) + H+

O(q-1)+(nl) → O(q-1)+(n’l’) + hν

Theoretical MethodsTheoretical Methods

N6+(1s) + H → N5+(1s nl)+ H+

O6+(1s2) + H → O5+(1s2 nl) + H+

MOCC (Molecular orbital close-coupling)

AOCC (Atomic orbital close-coupling) CTMC (Classical orbital Monte-Carlo)

Molecular orbital close-coupling

calculations (MOCC) Full quantum, molecular orbital close-coupling;

Low energy collision, ≤ a few keV amu-1;

[Aq+ + B] as a quasi-molecule (perturbed stationary-state

approximation) ;

The multi-reference single-and double-excitation

configuration interaction approach (MRDCI): potentials,

radial and rotational couplings.

6 12 18

-26

-25

-24

4 6 8 10 12-25.2

-24.8

n=5

n=3

Po

ten

tial e

ne

rgy

(a.u

.)

(a) Singlet adiabatic potentials

n=4

-25.2

-24.8n=4

(b) singlet

n=4

(c) triplet

Internuclear distance (a.u.)

Adiabatic Potential: N6+(1s) + H → N5+(1s nl)+ H+

Results

Radial coupling matrix elements: [NH] 6+

1.5 2.0 2.5

-80

-60

-40

-20

0

71-81

121+-131+111+-121+ 71+-81+

Internuclear distance (a.u.)

4 5 6 7 8 9-40

-30

-20

-10

0

10 101+-111+

81+-91+

121+-131+

131+-141+

141+-151+

151+-161+

91+-101+

Rad

ial c

oupl

ing

mat

rix e

lem

ents

(a.

u.)

101+-111+

Rotational coupling matrix elements : [NH] 6+

0

1

2

61+-21

71+-31

51+-21

61+-21

101+-61

91+-61

91+-5181+-41

5 10 15 20-4

-2

0

2

4

Internuclear distance (a.u.)

Rot

atio

nal c

oupl

ong

mat

rix e

lem

ents

(a.

u.)

141+-81

131+-81

131+-71

121+-71

5 10 15 20

161+-101151+-101 151+-91

141+-91

0 10 20 30 40

-61.0

-60.5

-60.0

-59.5

-59.0

n=3

n=4

n=5

(a) adiabatic potentials

5 10 15

-60.0

-59.5

-59.0

Pot

entia

l ene

rgy

(a.u

.)

n=4

(b)

Internuclear distance (a.u.)

Adiabatic Potential: O6+(1s2) + H → O5+(1s2 nl) + H+

Results

20 22 24

-59.65 5g

5f

5d

5p

5s

(a) n=5 channels

Incident

5 6 7 8 9

-59.76

-59.68

-59.60

4f

4d

4p

Incident

Pot

entia

l ene

rgy

(a.u

.)

4s

(b) n=4 channels

Internuclear distance (a.u.)

Radial coupling matrix elements: [OH] 6+

2 4 6 8 10

0.0

0.4

0.8

5 2 - 6 2

2 2 - 3 2

2 2 - 3 25 2+ -6 2+

3 2+ -4 2+

Internulcer distance (a.u.)

3 6 9

0

20

9 2+ -10 2+

9 2+ -10 2+

10 2+ -11 2+

10 2+ -11 2+

6 2+ -7 2+

Rad

ial c

oupl

ing

mat

rix e

lem

ents

(a.u

.)

Rotational coupling matrix elements: [OH] 6+

10 20 30 40

-1

0

1

2

3

Ro

tatio

na

l co

up

ling

ma

trix

ele

me

nts

(a

.u.)

Internuclear distance (a.u.)

4 2+-2 2 5 2+-3 2; 7 2+-4 2;

8 2+-5 2; 9 2+-6 2;

12 2+-7 2; 13 2+-7 2;

14 2+-10 2; 15 2+-10 2;

Basis set optimization highly charged ion:

A hybrid basis set:

i)The standard Dunning neutral atom basis: inner core

electrons;

ii)One-electron basis of hydrogen-like orbitals: highly

excited electron.

The latter basis was optimized to reproduce nearly

exactly the hydrogen-like Rydberg ion energies.

Results

Results

Asymptotic energy: [NH]6+ singlet states

Results

Asymptotic energy: [OH]6+

10-1 100 101 102 103 104 105

15

30

45

60

Cro

ss s

ect

ion

(1

0-16 cm

2)

New merged-beams measurement Measurement of Panov et al Measurement of Meyer et al QMOCC using optimized basis AOCC calculation CTMC calculation

Results

Total cross section: N6+(1s) + H → N5+(1s nl)+ H+

10-2 10-1 100 101 102 103 104 10510-2

10-1

100

101

n=3

n=5

n-s

olv

ed

cro

ss s

ectio

n (

10

-16 c

m2)

Energy (eV/u)

AOCC: n=2 n=3 n=4 n=5 n=6 n=7 n=8 n=9

CTMC n=2 n=3 n=4 n=5 n=6 n=7 n=8 n=9

QMOCC: n=3 n=4 n=5

n=4

n-resolved cross section : N6+(1s) + H → N5+(1s nl)+ H+

Results

Agree well for the dominant n=4 channels between MOCC, AOCC, CTMC

10-2 10-1 100 101 102 103 104 10510-2

10-1

100

101

Cro

ss s

ectio

n (

10

-16 c

m2)

Energy (eV/u)

QMOCC 4s 4p 4d 4fAOCC 4s 4p 4d 4f

MOCC AOCC

nl-resolved cross section: N6+(1s) + H → N5+(1s nl)+ H+

Results

10-1 100 101 102 103 104 105 106

0

10

20

30

40

50

MOCC with rot MOCC without rot Present AOCC Present CTMC ShipseyMOCC ShipseyCTMC Phaneuf1987 Janev1995

To

tal cro

ss s

ectio

n (

10

-16 c

m2)

Energy (eV/u)

Phaneuf1982 Crandall1979 Olson1975 Dijkkamp1985 Meyer1979

Results

1, Good agreement in the a large energy range ;

2,Strong effect of rotational couplings

Total cross section: O6+(1s2) + H → O5+(1s2 nl) + H+

100 101 102 103 104

10-3

10-2

10-1

100

101

100 101 102 103 104

10-1

100

101

without rot 5s 5p 5d 5f 5g

with rot 5s 5p 5d 5f 5g

Stat

e-se

lect

ive c

ross

sec

tion

(10

-16

cm

2 )

Energy (eV/u)

n=5 channels

n=4 channels

with rot 4s 4p 4d 4f

without rot 4s 4p 4d 4f

Effect s of rotational couplings:

10-1 100 101 102 103 104

101TCS without rotatioinal coupling

Stat

e-se

lect

ive

cros

s se

ctio

n (1

0-1

6 c

m2 )

Energy (eV/u)

TCS including rotatioinal coupling

(a) Total cross section; (b) State-selective cross section

Results

20 22 24

-59.655g

5f

5d

5p

5s

(a) n=5 channels

Incident

Rx

Ex

5 6 7 8 9

-59.76

-59.68

-59.60

Rx

Ex

4f

4d

4p

Incident

Pot

entia

l ene

rgy

(a.u

.)4s

(b) n=4 channels

Internuclear distance (a.u.)

Similar effect found in C4+/H, Al3+/H, Si2+/H, M Gargaudt,

et al, JPB

Compared O6+/H with N6+/H

10-1 100 101 102 103 1040

10

20

30

40

50

60

Cro

ss s

ectio

n (

10-16 c

m2 )

Energy (eV/u)

O6+/H-MOCC

O6+/H-Phaneuf 1982

O6+/H-Dijkkamp 1985

N6+/H-MOCC

N6+/H-new merged beam

O6+/HN6+/H

Results

1, Good agreement;

2, Core effect;

A recommended set of cross sections are

deduced based on the MOCC, AOCC, and

CTMC and experiment;

Aid in X-ray modeling studies;

Core effect of the highly charged ions;

Strong effects of the rotational couplings:

O6++H This work is partially supported by NASA grants NX09AV46G,

NNG09WF24I, and NNH07ZDA001N.

Summary

Thank you for your

attention !!!