Evaluation of StateEvaluation of State- ---Resolved Resolved … · 2013-07-24 · D. Wünderlich CRP Meeting, Vienna, 3.-5.7.2013 4 CR model for atomic hydrogen: Different excitation

Evaluation of StateEvaluation of StateEvaluation of StateEvaluation of State----Resolved Resolved Resolved Resolved

Reaction Reaction Reaction Reaction Probabilities applied in Probabilities applied in Probabilities applied in Probabilities applied in

Collisional Collisional Collisional Collisional RadiativeRadiativeRadiativeRadiative Models for H, HModels for H, HModels for H, HModels for H, H2222 and and and and HeHeHeHe

D. D. D. D. WünderlichWünderlichWünderlichWünderlich and U. and U. and U. and U. FantzFantzFantzFantz

CRP Meeting, Vienna, 3.-5.7.2013D. Wünderlich 1

Atomic and molecular data in CR models:Principle of CR models

Population models

• Predict population densities in dependence of plasma parameters (Te, ne, ground state densities)

• Main field of application: plasma diagnostics

• Low temperature, low pressure plasmas⇒ collisional radiative models

Collisional radiative models

• Several excited states of the considered atom/molecule

• Balance all relevant exciting and de-exciting reactions

⇒ Needed: extensive data base with reaction probabilities

⇒ Drastically increased complexity for molecules (electronic, vibrational and rotational excitation)

Error bar of model results directly correlates with the quality of the used input data

Critical evaluation of the available data using the flexible solver Yacora


Atomic and Molecular Data in CR Models:Outline of the talk

• CR models for light atoms (He and H)

• CR model for H2 and the used input data


CR model for helium:Input and main results

19 20 21 22 23 2410-10

10-9

10-8

10-7

10-6

10-5

10-4

31D

33D

31P33P

31S33S

21P23P

21S23S

n p/(g

p⋅n0)

Excitation energy [eV]

Yacora

Experiment

CR model for excited states up to n=4

• Cross sections from Ralchenko

• Optical thickness

Experimental benchmark

• Microwave driven ECR plasma experiment

• Te and ne from Langmuir probe

• Measured population densities:

� nn=2: white light absorption spectroscopy� nn=3: optical emission spectroscopy

Excellent agreement of CR model results with measured population densities

Y. Ralchenko et al, ADNDT 94, 2008, 603

��


CR model for atomic hydrogen:Different excitation channels

Excitation of atomic hydrogen…

Huge number of free parameters⇒ Evaluation needs a lot of time and experience

npH

H+ H3+

H2

H-

recombinationdissociative

recombination

directexcitation

mutual neutralization

dissociativeexcitation

dissociativerecombination

H2+

…in ionizing… …and recombining plasmas

npH

H+ H3+

H2

H-


recombination

directexcitation




H2+

npH

H+ H3+

H2

H-


recombination

directexcitation




H2+

12.0 12.5 13.0 13.510-9

10-8

10-7

n=3

n=4

n=5

n=6

n=7

Measurement

Yacoramodified input

Hε

Hδ

Hγ

Hβ

ECR discharge0.5 Pa, 10%H

2 in 5%Ar/He

n p/(g

p⋅n0)

Ethr

[eV]

ne = 2×1017 m-3, T

e= 4.5 eV

Hα

Yacoraoriginal input


CR model for atomic hydrogen:Cross sections for direct excitation

0 20 40 60 80 10010-23

10-22

10-21

10-20

1→7

1→6

1→5

1→4

1→3

σ [m

2 ]

Ee [eV]

1→2Data from Janev report

• Compilation of recent calculations and measurements

• Low energies (Ee<40 eV): discontinuitybetween cross sections for 1→5 and 1→6

� Reason: different primary data sources (R-Matrix, semi empirical modification of Born-Bethe)

� Solution: fit of rate coefficients

� Result: excellent agreement of measurement and model for ionizing plasma with known Te and ne

Benchmarked set of rate coefficients for direct excitation

��

R. Janev et al, JÜL-4105, Forschungszentrum Jülich, 2003D. Wünderlich et al, JQSRT 110, 2009, 62


CR model for atomic hydrogen:Dissociative recombination of molecular ions

0.1 1 1010-15

10-14

10-13

Janev 1987 Janev 2003

n=6

n=5

n=4

n=3

X [m

3 /s]

Te [eV]

Dissociativerecombination of H+

2

0.1 1 10 10010-23

10-22

10-21

10-20

10-19

10-18

Dissociativerecombination of H+

3

Production of H2 and H*

σ [m

2 ]

Ee [eV]

Total (Janev 2003)

Dissociative recombination of H2+

• Total cross section and branching ratio: Janev

• Extrapolation performed

� For low (Ee<0.5 eV) and high electron energies (Ee>10 eV)

� For high (v>5) vibrational excitation in H2+

Dissociative recombination of H3+

• Total cross section: Janev

• Two reaction channels:

• Branching ratio: Storage ring (Datz)

• 2nd channel: quantum state distribution?Kulander et al: only n=1 and n=2 for low Ee

H�� → H�H�H

H�� → H � H*

R. Janev et al, JÜL-4105, Forschungszentrum Jülich, 2003


CR model for atomic hydrogen:Benchmark at a magnetized plasma expansion

Magnetic field

H2

40 cm0 cm 20 cmHigh pressureplasma source

Low pressureexpansion chamber

Magnetized plasma expansion at TU/e:

• Cascaded arc, Pinput=6.8 kW

• Axial magnetic field (14 mT, generated by Helmholtz coils)

• Psource=104 Pa, Pvessel≈8 Pa ⇒ supersonic plasma expansion

• Pressure of plasma jet approaches background pressure after ≈20 cm

⇒ Shock front and transition red plasma → blue plasma

Investigate red and blue plasmausing Yacora for H based on most recent cross sections



Input: population densities and plasma

parameters

• nn=1: TALIF

• nn=2: absorption spectroscopy (TDLAS)

• nn≥3: emission spectroscopy

• Electron temperature:

� Fulcher emission (red plasma)� Langmuir double probe (blue plasma)

• Electron density:

� Saha equation (red plasma)� Langmuir double probe (blue plasma)

Application of Abel inversion ⇒

0 10 20 30 400.0

0.5

1.0

1.5

2.0

Te

[eV

]

Distance from nozzle [cm]

1016

1017

1018

1019

1020

1021

ne [m

-3]

0 10 20 30 40109

1010

1011

1012

1013

1014

1015

1016

1017

n=9n=8

n=7n=6

n=5n=4

n=3

n p/g p

[m-3]

Distance from nozzle [cm]

n=2z=13 cm

Overpopulationof n=5 and n=6

z=13 cm z=25 cm

Locally resolved plasma parameters

z=25 cm



1 2 3 4 5 6 7 8 9 101010

1011

1012

1013

1014

Yacora

H H+

H2

H+

2

H−

H+

3

n p/gp (

m-3)

Principal quantum number

z=13 cm, red plasma

Experiment

1 2 3 4 5 6 7 8 9 10109

1010

1011

1012

1013

1014

1015

H+

H+

2

H−

H+

3

n p/g p

(m-3)

Principal quantum number

z=25 cm, blue plasma

Yacora

Experiment

Compare experiment with model for red and

blue plasma

• Excellent agreement

• Correct prediction of overpopulation of n=4,5 and 6

Mutual Neutralization of H2+ and H−:

• Two reaction channels:

Cross sections from Janev and Eerden, respectively.CR model ⇒ Mixture of both channels

Influence of H3+

• Needs to be considered in order to fulfill quasi neutrality

H� � � H� → H

∗ �H

H� � � H� → H � H∗

��


CR model for atomic hydrogen:Benchmark at a tandem type negative hydrogen ion source

Investigate ionizing and recombining plasma using Yacora for H

Negative ion source prototype for

ITER NBI at IPP Garching

• Plasma generation in driver (PRF≤100 kW per driver)

• Reduce Te: magnetic filter field

• Reduce co-extracted electrons:bias voltage (plasma grid against source walls and bias plate)

• Conversion of atoms andpositive ions at caesiated surface of plasma grid


CR model for atomic hydrogen:Benchmark at a tandem type negative hydrogen ion source

Ionizing plasma in the Driver

• Good agreement of model with OES

• Te and ne agree reasonably well with Langmuir probe results

• Relevant excitation channels:Direct excitation and dissociative excitation

Recombining plasma in the

expansion region

• In some cases no fit of model to measurements possible at all

12.0 12.5 13.0 13.5 14.01020

1021

1022

1023

Te=12.1 eV, n

e=1.3⋅1018 m-3

PHF

=70 kW, pfill

=0.8 Pa

Driver plasma

Calculation

H2 Fulcher

Hδ

Hγ

Hβ

Em

issi

on [p

h/(m

-3s)

]

Excitation energy [eV]

Hα

MeasurementFrom H

From H2

8 10 12 14 16 18 201017

1018

1019

Driver plasma

PHF

=70 kW, pfill

=0.8 Pa

Te [eV]

n e [m-3]

-1,360

-0,2800

0,8000

1,610

Minimum:T

e=12.1 eV, n

e=1.3⋅1018 m-3

Deviation of

measurement

and calculation

Influence of gradients in the plasma parameters (caused by magnetic filter?)

New IPP test facility ELISE: combine OES with tomography for obtaining

locally resolved emission

��


Atomic and Molecular Data in CR Models:Outline of the talk

• CR models for light atoms (He and H)

• CR model for H2 and the used input data


Reaction probabilities for molecular hydrogen:CR model for H2

Large number of excited states

• Electronic excitation

0

2

4

6

8

10

12

14

16

18

20

...

n=3

n=1

n=2

v=1v=2

.

.

.

v=0

H

H2

+

H+

n=3

n=2

n=1

H2

Triplet systemSinglet system

j3∆gi3Π

gd3Π

uJ1

∆gI1Π

gD1

Πu

C1Π

u c3Π

u

E [e

V] a3

Σ+

g

b3Σ

+

u

X1Σ

+

g

EF1Σ

+

g

B1Σ

+

u

GK1Σ

+

gB'1Σ+

u

HH1Σ

+

ge3

Σ+

u

g3Σ

+

g h3Σ

+

g





• Vibrational excitation

0

2

4

6

8

10

12

14

16

18

20

...

n=3

n=1

n=2

v=1v=2

.

.

.

v=0

H

H2

+

H+

n=3

n=2

n=1

H2


j3∆gi3Π

gd3Π

uJ1

∆gI1Π

gD1

Πu

C1Π

u c3Π

u

E [e

V] a3

Σ+

g

b3Σ

+

u

X1Σ

+

g

EF1Σ

+

g

B1Σ

+

u

GK1Σ

+

gB'1Σ+

u

HH1Σ

+

ge3

Σ+

u

g3Σ

+

g h3Σ

+

g

13

14

15

16

17

v=12v=11v=10v=9v=8v=7v=6v=5

v=4

v=3

v=2

v=1

d3Π

u

E [e

V]

v=0

...

13.8

14.0

14.2

14.4

J=7

J=6

J=5

J=4J=3J=2J=1

d3Π

u(v=0)

E [e

V]

J=0





• Vibrational excitation

• Rotational excitation

Needed:

Probabilities for all reactions interconnecting all excited states

13

14

15

16

17

v=12v=11v=10v=9v=8v=7v=6v=5

v=4

v=3

v=2

v=1

d3Π

u

E [e

V]

v=0

...

0

2

4

6

8

10

12

14

16

18

20

...

n=3

n=1

n=2

v=1v=2

.

.

.

v=0

H

H2

+

H+

n=3

n=2

n=1

H2


j3∆gi3Π

gd3Π

uJ1

∆gI1Π

gD1

Πu

C1Π

u c3Π

u

E [e

V] a3

Σ+

g

b3Σ

+

u

X1Σ

+

g

EF1Σ

+

g

B1Σ

+

u

GK1Σ

+

gB'1Σ+

u

HH1Σ

+

ge3

Σ+

u

g3Σ

+

g h3Σ

+

g


Reaction probabilities for molecular hydrogen:Cross sections for electron collision excitation

Literature:

• Only few vibrationally or rotationally resolved data

• Excitation from the ground state:

� Contradictions between cross sections from different data sources

� Most excited states of n=2 and n=3:too few reliable data

� States of n>3: no reliable data

• Excitation between excited states:

� Almost no reliable data

• Two „data sets“ up to n=3

� Miles (1972, semi empiric)� Janev (2003, summary of recent

measurements and calculations)

10 20 30 40 50 60 70 80 9010010-23

10-22

10-21

10-20

Recommendation Janev 2003 Recommendation Miles 1972 Khakoo 1986 (Measurement) Chung 1975 (Calculation) Chung 1978 (Calculation) Lee 1982 (Calculation) Lima 1988 (Calculation)

σ [m

2 ]

Ee [eV]

Excitation X1Σ

+

g→c3

Πu

More reliable data for optically allowed transitions (e.g. impact

parameter method) than for forbidden transitions



10 20 30 40 50 60 70 80 9010010-23

10-22

10-21

10-20

Recommendation Janev 2003 Recommendation Miles 1972 Khakoo 1986 (Measurement) Shemansky 1985 (Measurement) Arrighini 1980 (Calculation) Celiberto 1999 (Calculation)

σ [m

2 ]

Ee [eV]

Excitation X1Σ

+

g→C1

Πu



Literature:













10 20 30 40 50 60 70 80 9010010-26

10-25

10-24

10-23

Recommendation Miles 1972

σ [m

2 ]

Ee [eV]

Excitation X1Σ

+

g→h3

Σ+

g



Literature:












Reaction probabilities for molecular hydrogen:Compare available cross sections

Use Janev or Miles. Excitation to states with n>3?

1 2 3 4 5 6 7 8 9 10 2010-20

10-19

10-18

10-17

10-16

10-15

Principal quantum number n

Excitation of singlet states

Rat

e co

effic

ient

[m3 /s

]

Miles

Rate coefficients at Te=3 eV

Janev

1 2 3 4 5 6 7 8 9 10 2010-20

10-19

10-18

10-17

10-16

10-15


Excitation of triplet states

Rat

e co

effic

ient

[m3 /s

]

Miles


Janev




• Scaling used in the Sawada CR model (based on H-like He)

1 2 3 4 5 6 7 8 9 10 2010-20

10-19

10-18

10-17

10-16

10-15


Sawada


Rat

e co

effic

ient

[m3 /s

]

Miles


Janev

1 2 3 4 5 6 7 8 9 10 2010-20

10-19

10-18

10-17

10-16

10-15


Sawada


Rat

e co

effic

ient

[m3 /s

]

Miles


Janev





• Gryzinski method

1 2 3 4 5 6 7 8 9 10 2010-20

10-19

10-18

10-17

10-16

10-15

Gryzinski


Sawada


Rat

e co

effic

ient

[m3 /s

]

Miles


Janev

1 2 3 4 5 6 7 8 9 10 2010-20

10-19

10-18

10-17

10-16

10-15

Gryzinski


Sawada


Rat

e co

effic

ient

[m3 /s

]

Miles


Janev



1 2 3 4 5 6 7 8 9 10 2010-20

10-19

10-18

10-17

10-16

10-15

Janevextrapol. Miles

extrapol.

Gryzinski


Sawada


Rat

e co

effic

ient

[m3 /s

]

Miles


Janev

1 2 3 4 5 6 7 8 9 10 2010-20

10-19

10-18

10-17

10-16

10-15

Milesextrapol.

Janevextrapol.

Gryzinski


Sawada


Rat

e co

effic

ient

[m3 /s

]

Miles


Janev



• Gryzinski method

• Extrapolation based on formulae suggested by Janev[2]:

� � → ��

�

� ��

��∙ � � → �� → ��

��

�

� ��

��∙ � � → ��


Reaction probabilities for molecular hydrogen:Benchmark available cross sections

Compare CR model results with experiment

• Calculations based on Miles or Sawada

• Higher excited states (n>3): Janev scaling

1 2 3 4 510-10

10-9

10-8

10-7

10-6

Strong quenching

Weak quenching

Weak quenching

Strong quenching

n(d3 Π

u)/n(

H2)

Te [eV]

Measurements

Hydrogen Deuterium Hydrogen

Miles

Janev

d3Π

u

1 2 3 4 510-11

10-10

10-9

10-8

10-7

Measurements

Hydrogen Deuterium Hydrogen

Janev

n(I1 Π

g)/n(

H2)

Te [eV]

MilesI1Π

g

Better agreement between model and experiment for the (outdated

and semiempiric) Miles data

CR models on Miles and Janev data

• Differences in population densities directly mapped onto diagnostics results

⇒ Model almost not usable for diagnostics in its current status

Perform – as far as possible – calculations on the missing reaction probabilities


Reaction probabilities for molecular hydrogen:Benchmark available cross sections

Needed:

New or extended cross section data base for H2:• Complete• Consistent• Including vibrational (and rotational) levels

0.2 1 10 200.0

0.2

0.4

0.6

0.8

1.0

Miles

Janev

Helicon plasma source100% H

2, 250 W

n(H

)/n(

H2)

Pressure [Pa]


Reaction probabilities for molecular hydrogen:Franck Condon factors and Einstein coefficients

Prepare extension of cross section database

Collect and prepare eigenvalues of electronic wave functions (=potential energy curves)

⇒ Vibrational eigenvalues

⇒ Vibrational wave functions

⇒ Franck Condon Factors

… for H2 and H2+ (and its isotopomeres)

v

v‘ q 0 1 2 3 40 4.76E-01 3.17E-01 1.36E-01 4.82E-02 1.54E-021 3.75E-01 2.73E-02 2.07E-01 1.96E-01 1.12E-012 1.26E-01 3.32E-01 2.93E-02 5.59E-02 1.51E-013 2.10E-02 2.53E-01 1.75E-01 1.15E-01 6.82E-044 1.56E-03 6.44E-02 3.22E-01 5.91E-02 1.49E-01...

0 1 2 3 4 5 6 7 8 9

0.0

0.2

0.4

0.6

0

24

68

FC

F

v' (H

+2(X

2 Σ+

g))

v (B 1Σ +

u )

0 2 4 6 8

12.0

14.0

16.0

18.0

20.0

B1Σ

+

u

H+

2(X2

Σ+

g)

Pot

entia

l ene

rgy

[eV

]

Internuclear distance [Å]


Reaction probabilities for molecular hydrogen:Franck Condon factors and Einstein coefficients

Prepare extension of cross section database

Collect and prepare eigenvalues of electronic wave functions (=potential energy curves)

⇒ Vibrational eigenvalues

⇒ Vibrational wave functions

⇒ Franck Condon Factors

… for H2 and H2+ (and its isotopomeres)

Collect and prepare dipole transition matrix elements

⇒ Einstein coefficients

v‘‘

v‘ q 0 1 2 3 40 2.41E+07 1.66E+06 9.27E+03 7.75E-02 5.62E-021 1.53E+06 2.07E+07 3.26E+06 2.97E+04 2.82E+002 1.07E+05 2.84E+06 1.74E+07 4.80E+06 6.23E+043 8.40E+03 3.19E+05 3.89E+06 1.43E+07 6.24E+064 5.87E+02 3.64E+04 6.22E+05 4.64E+06 1.15E+07...

0 1 2 3 4 5 6 7 8 9

0.0

5.0x106

1.0x107

1.5x107

2.0x107

2.5x107

02

46

8

Av'

v'' [s

-1]

v'(d

3 Π u)

v''(a 3Σ +

g )

0 1 2-4

-3

-2

-1

0

1

v'=3→v''=3

Ψ*M

elΨ

'

U. Fantz, ADNDT 92, 2006, 853D. Wünderlich, ADNDT 97, 2011, 152


Reaction probabilities for molecular hydrogen:New cross sections for ionization

0 1 2 3 4 50.0

5.0x104

1.0x105

1.5x105

2.0x105

2.5x105

3.0x105

H2(X1

Σ+

g)

H+

2(2

Σ+

g)

H+

2(2

Σ+

u)

E [c

m-1]

Internuclear distance [Å]

�

�

�

Literature: virtually no data for ionization of

excited states in H2

Test case for cross section calculations based on the Gryzinski method. Two possible reaction channels:

Non-dissociative

Dissociative

Needed for calculation of cross sections:

Franck Condon factors ��

and…

H ��, �� → H� 2"#

�, �� 2��

H ��, �� → H� 2"#

�, $�� 2�� → H � H� � 2��

H ��, �� → H� 2"%

�, $�� 2�� → H � H� � 2��

D. Wünderlich, Chem. Phys. 390, 2011, 75



10-9

10-8

10-7

10-6

10-5 v'=0

v=3

v=1

1.4x105 1.6x105 1.8x105

10-9

10-8

10-7

10-6

10-5

v'=2

FC

D [1

/cm

-1]

1.4x105 1.6x105 1.8x105

H2(X1

Σ+

g(v'))→H+

2(X2

Σ+

g)

∆E [cm-1]

Present calculation δ-function approximation

10-9

10-8

10-7

10-6

10-5 v'=0

v'=3

H2(X1

Σ+

g(v'))→H+

2(2

Σ+

u)

v'=1

2x105 3x105 4x105

10-9

10-8

10-7

10-6

10-5 v'=2

FC

D [1

/cm

-1]

2x105 3x105 4x105

∆E [cm-1]

Present calculation δ-function approximation

Franck Condon densities &'��(�(��

for

transitions H2↔H2+

Most publications: δ-function-approximation:

More appropriate calculation based on wave functions from TraDiMo:

Full set of FCD for H2 and H2+

*��+��

d$�� d-��

./0

d/ 121345��

.+��0

�6

7��

121345��

.+��0

d$′′

*��+��

d$�� 2

9

2:

$�� ; $<=>>��

7��

/ 7��

/ d/

d$′′




10 100 100010-23

10-22

10-21

10-20

Dissociative Crowe 1973 via 2Σ

+

g

Crowe 1973 via 2Σ

+

u

Celiberto 1990 via 2Σ+

g

Celiberto 1990 via 2Σ+

u

Straub 1996 total

Via 2Σ

+

u

Via 2Σ

+

g

σ [m

2 ]

Ee [eV]

Total

10 100 100010-22

10-21

10-20

10-19

Non dissociative Rapp 1965 Adamcyk 1966 Crowe 1973 Straub 1996 Celiberto 1990

σ [m

2 ]

Ee [eV]

H2(X1): Comparison with existing data

(experimental and theoretical)

• Perfect agreement for non dissociative process

• Dissociative ionization:

� Very good agreement with experiment� Previous calculations:

simplified theoretical framework


��

��

10-21

10-20

10-19

v=17v=14

v=11

v=8v=5

v=3

v=2v=1

v=0

H2(c3

Πu)

10-22

10-21

10-20

v=11

v=14v=17

Non-dissociative

Dissociative via 2Σ+

g

Dissociative via 2Σ+

u

1 10 100 1000

10-22

10-21

10-20

v=17

v=3v=2v=1

v=0

v=14v=11

v=8v=5

σ [m

2 ]

Ee [eV]



Construct set of ionization cross sections

for H2

• First five non repulsive electronic states:

� Vibrational sublevels considered� All dissociative and non-dissociative

channels



Most accurate existing set of theoretical ionization cross sections for H2

0.1 1 10 100 100010-21

10-20

10-19

10-18

10-17

n=1

n=10n=9

n=8n=7

n=6n=5 n=4

n=3

σ [m

2 ]

Ee [eV]

n=2

Singlet system

1 10 10010-13

10-12

10-11

10-10

Sawada CR model New data

X [m

3 /s]

Te [eV]

n=10n=9n=8

n=7n=6

n=5

n=4

Construct set of ionization cross sections

for H2

• First five non repulsive electronic states:

� Vibrational sublevels considered� All dissociative and non-dissociative

channels

• Electronically excited states with n>2:

� Gryzinski formula� Vibrational sublevels neglected� Disagreement with data previously used

in models


Reaction probabilities for molecular hydrogen:Apply Gryzinski method for collisional excitation?

Semiempiric methods not appropriate for molecular excitation.

Needed: new, complete and comprehensive set of quantum mechanical calculations

Gryzinski calculations for excitation of H2

• Original Gryzinski integral (not the simplified GBB formulation)

• Benchmark by comparison with σsuggested by Janev

� Highly variable agreement � Situation worse for forbidden transitions

(e.g. excitation into triplet system)� Allowed transitions:

impact parameter as alternative. But: high relevance of triplet levels (OES)

20 40 60 80 100

10-22

10-21

10-20

Factor 1.4Shape OK

Absolute value OKShape not X1

→B'1

σ [m

2 ]

Ee [eV]

X1→B1

Excitation from ground state into Σ+

u states...

20 40 60 80 10010-22

10-21

10-20

Factor 2.3Shape OK

Excitation from ground state into Πu states...

X1→D1

X1→C1

σ [m

2 ]

Ee [eV]

Absolute value OKShape not


Reaction probabilities for molecular hydrogen:Extension of the model to deuterium

0.0

0.2

0.4

0.6

0.8

1.0

H2

D2

H2

z=9 14 19

Te [e

V]

Ele

ctro

n de

nsity

[1018

m-3]

PRF

=40 kW 70 kW 70 kWWithout Cs With Cs

D2

H2

D2

H2

D2

PRF

=40 kW

0.0

0.2

0.4

0.6

0.8

1.0

n(H)/n(H

2 )

02468

10

H2

D2

z=9 cm

Evaluation of available data

• Only few vibrationally resolved data available for H2 and D2

(main exception: impact parameter calculations for optically allowed transitions)

• CR model for D2 urgently needed (example: isotope effect in dissociation and electron extraction in negative ion sources)

• Interim solution: vibrational splitting of data by Janev(or Miles?) by means of Gryzinski method

• Long-term solution:

Comprehensive set of cross sections for both isotopes


Atomic and molecular data in CR models:Conclusions and outlook

State resolved reaction probabilities for CR models

• Flexible solver Yacora: models for H, H2, He, …

• Error bar of results is correlated with the quality of the used input data:

� He: excellent quality of input data for models

� H: very good results of model possibleNegative ion source for ITER NBI: observed issues explainable by gradients of plasma parameters?

� H2: Existing data basis not sufficientFirst steps towards an improved data set have been done

Outlook

• Increased modeling efforts for Deuterium

• Rotational excitation (neglected up to now)

��

More efforts needed, especially based on sophisticated quantum mechanical calculations

Documents

Evaluation of StateEvaluation of State- ---Resolved Resolved … · 2013-07-24 · D. Wünderlich CRP Meeting, Vienna, 3.-5.7.2013 4 CR model for atomic hydrogen: Different excitation