XDAP2004-TokXra-11/15 16/28/2015 6:53 AM K.B. Fournier, M. Finkenthal 1, M.J. May, M. Mattioli 2, S.B. Hansen and W.H Goldstein Lawrence Livermore National

04/18/23 22:02

XDAP2004-TokXra-11/15 1

K.B. Fournier, M. Finkenthal1, M.J. May, M. Mattioli2, S.B. Hansen and W.H Goldstein Lawrence Livermore National Laboratory

presented at theX-ray Diagnostics for Astrophysical Plasmas Workshop,

Cambridge, MA, 15-17 November 2004

Work performed under the auspices of the United States Department of Energy by the University of California Lawrence Livermore National Laboratory under contract number W-7405-ENG-48.

Application of Laboratory Experiments and Atomic Physics Modeling to Astrophysical Observations

1 Permanent Address: The Johns Hopkins University, Baltimore, MD 21218, USA2 Permanent Address: Consorzio RFX, Corso Stati Uniti 4, Padova, I-35127, Italy

04/18/23 22:02


Introduction - Motivations

• X-rays from 60 eV to 8 keV probe conditions in everything from the local

ISM to the farthest cosmic objects…• Each spectral band, and the corresponding types of ions (M-shell, L-shell

and K-shell) that emit in that band have their unique challenges:

- absorption and extinction

- differing excitation mechanisms (resonances, cascades, photopumping, …)

- computational challenges for complex atomic structure (ie. accuracy!)

• Spectral resolution and effective areas are continuously improving and increasing

for x-ray telescopes• Line blends must be quantified at a new level of precision (requires complete AND

accurate data sets) as interesting, informative weak lines come out of the noise• This is our emphasis in on going laboratory investigations: in particular,

we are starting a new multi-year program to get high-resolution composite

spectra in the 10 - 200Å range.

Nov 02 - 3.5mm defocus, converg. -> 540 um beam waist at center -> 860 um overlap region

June 03 - 5.5 to 14.2 mm defocus, converg. -> 700 - 2120 um beam waist at center -> 940 um overlap region

Nov 02 - I_total = 7.8x10^15 W/cm^2 (39*2.E14)

June 03 - I_total = 2.3x10^15 W/cm^2 (4 beam groups)

TS in Nov 02 - 2w beam pointed at edge of bag -> T_e ~ 1.6keV

TS in June 03 - 4w beam pointed at center of bag -> Te ~ 3.5keV (0.5 - 0.8ns), 2keV (1.25 - 1.3ns)



Nov 02 - I_total = 7.8x10^15 W/cm^2 (39*2.E14)




04/18/23 22:02


Introduction - Our goals

• Our emphasis is on furthering laboratory investigations: in particular, we

are starting a new multi-year program to get high-resolution composite

spectra in the 10 - 200Å range.

• We will get high resolution composite spectra in the 10-200Å (10-40Å)

range.• We will resolve blending problems by sophisticated atomic structure

calculations and • We plan to interpret the brightness of individual lines in terms of

measured electron temperatures and densities.



Nov 02 - I_total = 7.8x10^15 W/cm^2 (39*2.E14)






Nov 02 - I_total = 7.8x10^15 W/cm^2 (39*2.E14)




04/18/23 22:02


Introduction - Important processes in x-ray astrophysics

• Ionization• Electron/proton collisions• Photoionization• Innershell ionization

• Excitation/De-excitation• Electron/proton collisions• Photoexcitation• Radiative decay/cascades



Nov 02 - I_total = 7.8x10^15 W/cm^2 (39*2.E14)






Nov 02 - I_total = 7.8x10^15 W/cm^2 (39*2.E14)




•Recombination• Dielectronic• Radiative• Charge exchange• 3-body

• Laboratory observations have the capabilities to • catolog lines and study/deconvolve line blends

• benchmark Ne and Te diagnostic lines and ratios

• look at ionization-equilibria emisison spectra• look at non-thermal effects

04/18/23 22:02


Vacuum vessel

Position control coil

Primary coil

Tokamaks are important tools for MFE research and laboratory astrophysics

ASDEX Upgrade in Da light Tokamak magnetic geometry

Image from http://www.ipp.mpg.de/ipp/ipp.eng.html

Bp

Ip

BT

R

a

BZ

Primary current

Torriodal fieldcoil

04/18/23 22:02


Tokamaks around the world offer a range of sizes and parameters for experiments



Nov 02 - I_total = 7.8x10^15 W/cm^2 (39*2.E14)






Nov 02 - I_total = 7.8x10^15 W/cm^2 (39*2.E14)




JET

AUG

FTU

Alcator C-Mod

Photograph courtesy of EFDS-JET

AUG

04/18/23 22:02


-1

0

1

2

3

4

0.60 0.70 0.80 0.90 1.0 1.1 1.2 1.3major radius (m)

Te (keV)

Ne (m-3)

0 100

2 1019

4 1019

6 1019

8 1019

1 1020

0.0 0.20 0.40 0.60 0.80 1.0 1.2 1.4 1.6time (s)

Te (keV)N

e (m-3)

Electron temperature and density profiles and histories for a typical FTU discharge

Temperature and density histories Temperature and density profiles

Te (keV

)de

nsity

(cm

-3)

Impurity injections can be made during stationary condition

time (s) major radius (m)

Accurate to 10% Accurate to 10%

04/18/23 22:02


Observed L-shell lines serve as local density diagnostics in stellar coronae

90 100 110 120 130 140

wavelength (Å)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

90 100 110 120 130 140

wavelength (Å)

simulation at log(Te)=7.0

Pre-injection background signal subtracted from data

K.B. Fournier, et al., ApJ 561, 1144 (2001)

Fe L-shell n=0 spectra (absolute units) HULLAC simulation at resolution

04/18/23 22:02


0.0

0.1

0.2

0.3

0.4

0.5

0.6

1012 1013 1014

FeXIX 91.01/108.37FeXIX 91.01/(108.37+120.00)Stratton et al. 1984 91.01/108.37FTU, present work 91.01/108.37FTU, present work 91.01/(108.37+120.00)

electron density (cm-3)

44i Boo - EUVE

PLT results from Stratton, ApJ, 279, L31 1984

FTU results

FeXIX ratios indicate high density in the inflowing material in 44i Boo

Resolving spectral blends will improve significance of the agreement

44i Boo data - N. Brickhouse and A. Dupree, ApJ 502,918 (1998)

K.B. Fournier, et al., ApJ 561, 1144 (2001)

04/18/23 22:02


Thermal plasmas can be used to study Fe K-shell ionization balance and spectral line strengths

Data courtesy of M. Leigheb, http://efrw01.frascati.enea.it/Documents/TaskForcesFTU/Spectroscopy/CEAENEA

Fe K-shell lines will be discussed at length by others at this meeting(from titles alone): Palmeri, Beiersdorfer, Liedahl, Jacobs, Rozanska

Bent crystal spectrometer:Spectral resolution ≥ 10000time resolution = 140 ms possible to select among eight different wavelength ranges

Ti = 12.8MKTe = 25.5MKnH:nHe:nLi ::0.02:1.0:0.6

04/18/23 22:02


Atomic data are tested by studies of high-n Rydberg series under controlled conditions

Ar16+ high-n x-ray lines and satellites for three satellite groups in Ar15+

J. Rice, et al., NJP 1, 19.1-19.27 (1999)

04/18/23 22:02


Precise fits to spectral lines are possible with complete data sets

Observed Ar16+ 1-4 spectrum plus blends

Ar16+ satellites to Ly: 1s2s 1S0 - 2p3s 1P1 and 1s2p 1P1 - 2p3p 1D2

Ar16+ intercombination line: 1s2 1S0 - 1s4p 3P1

Ar15+ W5 satellite lines: 1s22p J - 1s2p5p J’

J. Rice, et al., NJP 1, 19.1-19.27 (1999)

Blends within an element’s spectra are handled with high-resolution (and nicely with an EBIT), blends between different elements are handled by time-resolved, controlled injections

04/18/23 22:02


Electron temperature during rampdown is essentially gradient free over large volume

0.0 100

4.0 102

8.0 102

1.2 103

1.6 103

2.0 103

10.00 15.00 20.00 25.00 30.00

minor radius (cm)

Steady state temperature profile

ramp-down temperature profile

M.J. May, et al., Nucl. Fusion 42, 1299 (2002)

log(Te(K))=5.9

04/18/23 22:02


0.00.20.40.60.81.0

4 5 6 7 8 9

ion fraction

log(Te K)

FeXVIIFeXVIFeXVIII

4 5 6 7 8 9

FeIXFeVIIIFeX

Ionization equilibrium calculations are essential for interpreting spectroscopic data

Calculations must include multi-step processes (EA and DR)

M. Arnaud and J. Raymond, ApJ, 398, 394 (1992)

Ion

frac

tion

04/18/23 22:02


0.0

0.2

0.4

0.6

0.8

1.0

170.0 175.0 180.0 185.0 190.0 195.0 200.0 205.0

wavelength (Å)

Fe XXIV

0.0

0.2

0.4

0.6

0.8

1.0

160.0 170.0 180.0 190.0 200.0 210.0

wavelength (Å)

0.0

0.2

0.4

0.6

0.8

1.0

0.0

0.2

0.4

0.6

0.8

1.0

Measured M-shell iron spectrum is a sensitive thermometer

Log(Te)=5.9

Log(Te)=6.0

Log(Te)=6.1

• Ramp-down plasma temperature profile is measured to be nearly single valued• Ionization equilibration times are 10’s of s, much faster than changes in plasma conditions• Measured volume-averaged temp <Te> = 7530 eV (log(Te)=5.94).

K.B. Fournier, et al., ApJ 550, L117 (2001)

04/18/23 22:02


Measured iron M-shell CSD and best simulation using updated atomic physics

0.00

0.05

0.10

0.15

0.20

0.25

0.30

6 7 8 9 10 11 12 13

experiment (#14623) FTU simulation

ion charge Feq+

Ca K Ar Cl S P Si Al

These observations confirm modeling codes used to compute emission measures

Possible inaccuracy in atomic data

K.B. Fournier, et al., ApJ 550, L117 (2001)

04/18/23 22:02


FeIX (171Å) is an important temperature diagnostic of the solar chromosphere

Image from http://umbra.nascom.nasa.gov/eit/eit_full_res.html 07Dec1999 19:00:15 SOHO - Extreme Ultraviolet Imaging Telescope

EIT SOHO image of the sun at 171Å

150.0 160.0 170.0 180.0 190.0 200.0 210.0 220.0

wavelength (Å)

FeIX (171Å)

no 3p 43d 2

FeIX (171Å)

with 3p 43d 2

FeXII (195Å)

Neglect of 3p43d2 in models leads to a 20% overestimate of the 171Å/195Å ratio

A-rate affected by CI

04/18/23 22:02


10-3

10-2

10-1

100

101

102

5.85 5.90 5.95 6.00 6.05 6.10 6.15 6.20 6.25

R(195.12Å/171.07Å)

Ratio w/out 3p43d2

R((195.12+195.14)/171)

log(Te)

Uncertainty in atomic data leads to a 3% uncertainty in Te from FeXII(195)/FeIX (171Å)

20% change in 171Å A-rate leads to only a 3 eV (out of ~100eV) uncertainty.

04/18/23 22:02


Recent CHIPS observations of FeIX M-shell emission indicate local ISM is out of equilibrium

ApJ Letter preprint at http://chips.ssl.berkeley.edu/AAS1.pdf

Solid- Charged particle backgroundDashed- “Canonical” local hot bubble model

FeIX 171Å

Recent work of Hurwitz, Sasseen and Sirk:

• Canonical models have the local cavity as filled (or partly filled) with a thermal (CIE) gas at 106 K.• Diffuse soft x-ray emission observations support this picture.• Substantial counts above the background in the bins covering FeX - FeXII should be seen.

• As a result, the EUV emitting gas must be at a temperature below 105.8 K; the reduced EM could be explained by depleted iron in a thermal plasma, or significant foreground absorption towards the source .

• The emission measure derived from the shown spectrum is an order of magnitude lower than inferred from the soft x-ray observations.

04/18/23 22:02


0.0

0.2

0.4

0.6

0.8

1.0

0.0

0.2

0.4

0.6

0.8

1.0

160.0 165.0 170.0 175.0 180.0 185.0 190.0 195.0

wavelength (Å)

M-shell simulations support CHIPS local ISM observations of log(Te)5.8 component

log(Te K) = 5.9

log(Te K) = 5.8

0.0

0.2

0.4

0.6

0.8

1.0

160.0 165.0 170.0 175.0 180.0 185.0 190.0 195.0

wavelength (Å)

log(Te K) = 5.7

04/18/23 22:02


Summary/Conclusions

• There exist many robust laboratory sources for producing astrophysically relevant data: EBITs, tokamaks, Z-pinches…• Control and knowledge of plasma parameters, independently of the measured spectra, is essential to benchmarking atomic data.• Flexibility in elements studied, and in plasma conditions, requires a diverse diagnostic suite, i.e., high-energy x-ray crystal spectrometers, grating-based spectrometers, calorimeters, etc.• Observations of complex ions, especially with limited spectral resolution, must be augmented with sophisticated spectral calculations.

• This means accurate atomic data, particularly to assess blends (levels), and to get excitation physics right (resonances). • Complete sets of atomic data (for CI, cascades, line catalog, etc.)• Models that account for all relevant processes (e.g., proton excitation, photo-excitation, charge exchange reactions)

• Progress is being made on all these fronts, driven by exciting new opportunities for x-ray observations of the near and distant universe.

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Extra slides

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The tokamak is an axi-symmetric vessel containing the fusion plasma while thermonuclear reactions take place



Nov 02 - I_total = 7.8x10^15 W/cm^2 (39*2.E14)






Nov 02 - I_total = 7.8x10^15 W/cm^2 (39*2.E14)




Ev

Ev x BB�

B�

�

Ro R

R

a

—B

r�

_

+

0

( ) The Plasma thermal Pressure is Balanced by Magnetic Forces

Toroidal Coordinatesr = radial direction = poloidal direction = toroidal direction

A toroidal current creates a poloidal magnetic field. A (larger) toroidal magnetic field is created by external coils. The net magnetic field lines spiral around the plasma.

10–27

10–28

10–29

10–30

10–31

10–321 10 100

Deuteron energy (keV)

Cross Sections For Nuclear ReactionsInvolving Hydrogen Isotopes and He3

The preferred reaction is 1D2 + 1T2 Æ 2He4 + 0n1

3.5 MeV 14.1 MeV

–D T

–D D

–D He3

1000

04/18/23 22:02


Cross section of a tokamak showing magnetic flux surfaces and regions of interest in the plasma



Nov 02 - I_total = 7.8x10^15 W/cm^2 (39*2.E14)






Nov 02 - I_total = 7.8x10^15 W/cm^2 (39*2.E14)




Target

Wall

LCFS(Separatrix)

Scrape-offlayer

Mainplasma

• Plasma-wall interactions take place in the scrape-off layer

• Plasma inside the LCFS is confined

• The majority of heating (Ohmic and auxillary) takes place on the axis

• The plasma is either shaped by an external limiter (not shown) or exhaused into a divertor strike plate

Alcator C-Mod in cross section

04/18/23 22:02


Measurements of radiative power losses and spectroscopy test NLTE models and contribute to the design of MFE facilities



Nov 02 - I_total = 7.8x10^15 W/cm^2 (39*2.E14)






Nov 02 - I_total = 7.8x10^15 W/cm^2 (39*2.E14)



TS in June 03 - 4w beam pointed at center of bag -> Te ~ 3.5keV (0.5 - 0.8ns), 2keV (1.25 - 1.3ns) devil-gnol fo ecruos deziretcarahc lleW •

snoi Z-hgih gniniatnoc samsalp

fo stnemerusaem tnednepednI •ytisned dna erutarepmet

noituloser-hgih dna cirtemoloB • yltcerid stnemerusaem ypocsortceps

noitaticxe dna ecnalab noitazinoi tcelfersessecorp

sledoM lartcepS rof debtseT

lairetam Z-hgih fo stnenopmoc lacitirC •Fe, Mo, Au) ,.g.e(

eroc amsalp erutarepmet

nac )rK ,rA( seitirupmi fo noitcudortnI •gnidaol taeh lortnoc ot desu eb

stneiciffeoc gnilooc evitaidar rof sledoM •eerga ton od

EFM rof ecnacifingiS

04/18/23 22:02


Tokamak plasmas provide unique capabilities in terms of range of parameters and elements

• Controlled plasma (fueling, shaping, current profile, etc.)

• Well diagnosed conditions (105 ≤ Te(K) ≤ 108, 1012 ≤ Ne(cm-3) ≤ 1015) are known independently of impurity spectroscopy

• Controlled injections of any element

04/18/23 22:02


10-2

10-1

100

800.0 1600 2400 3200 4000 4800 5600

( )electron temperature eV

HULLAC

Safronova

K-shell diagnostic line ratios can be benchmarked in thermal plasmas

Ca injection in Alcator C-Mod

Data from J.E. Rice, MIT, see J. Rice, et al., Phys. Plasmas 7, 1825 (2000)

R(Te ) =a DR

CEX(Te)=

F1(Te)F2 ( j, f )CEX(Te)

DR to CX rate coefficients for Ca

The usual (j+k)/W ratio used to diagnose Te is compromised here by blending of Z and j

blend with j

04/18/23 22:02


High-resolution and good detection gives access to other diagnostic line ratios

Ca injection in Alcator C-Mod

Electron temperatures during solar flares are drived by looking at the n=3 to W line ratio, also observed in Alcator C-Mod spectra

Yohkoh blue shifted flare spectrum

T. Kato, et al., ApJ 492,822 (1998)

J. Rice, et al., Phys. Plasmas 7, 1825 (2000)

Te(MK)=19.1

Ti (MK)=16.2

04/18/23 22:02


FeIX line emission is sensitive to population flux from highly excited configurations

Including 3p43d2 in the FeIX model results in a ≥ 50% enhancement of the 3D1 - 1S / 1P - 1S ratio

3P

3F

3D

1D1D

1P

405 - 584 kK

3p53d

3s3p63d

3D

1D

726 - 750 kK

830 -1200 kK

3p43d2

3s3p53d2

1146 -1500 kK

3s23p6

3p54s 982 -1000 kK

3p54d1219 - 1250 kK

3p54p1067 -1140 kK

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.10

1010 1011 1012 1013 1014 1015

electron density (cm -3)

Atomic model including 3p 43d 2

Atomic model without doubly excited configurations

FeIX Ratio (217Å/171Å)Some configurations in FeIX

111 levels

D.A. Liedah., Atomic Data Needs for X-ray Astronomy, NASA/CP-2000-209968

04/18/23 22:02


The universe is x-ray active

04/18/23 22:02


The success of thermonuclear-fusion experiments depends critically on the energy available to colliding particles

10–27

10–28

10–29

10–30

10–31

10–321 10 100

Deuteron energy (keV)

Cross Sections For Nuclear ReactionsInvolving Hydrogen Isotopes and He3

The preferred reaction is 1D2 + 1T2 Æ 2He4 + 0n1

3.5 MeV 14.1 MeV

–D T

–D D

–D He3

1000

04/18/23 22:02


T. Kato, et al., ApJ 492, 822 (1998)

K-shell Fe spectrum from recombination phase of a solar flare

04/18/23 22:02


Non-thermal plasma effects can be studied with appropriate heating schemes

Calculations with the FAC code of M.F. Gu and SCRAM S.B. Hansen and A.S. Shlyaptseva, PRE 70, 036402 (2004).

Hot electrons broaden charge-state distributions and enhance inner-shell lines

04/18/23 22:02


Fe L-shell at PLT (and EBIT) - Beiersdorfer/brown

04/18/23 22:02


Fe L-shell from CXO observation (Behar)

04/18/23 22:02


Background subtracted M-shell iron data from a current ramp-down injection in FTU

160.0 170.0 180.0 190.0 200.0 210.0

wavelength (Å)

t=1.567 s

160.0 170.0 180.0 190.0 200.0 210.0

wavelength (Å)

t=1.590 s

160.0 170.0 180.0 190.0 200.0 210.0

wavelength (Å)

t=1.601 s

160.0 170.0 180.0 190.0 200.0 210.0

wavelength (Å)

t=1.613 s

160.0 170.0 180.0 190.0 200.0 210.0

wavelength (Å)

t=1.625 s

160.0 170.0 180.0 190.0 200.0 210.0

wavelength (Å)

t=1.636 s

We see the evolution of the iron charge state distribution during the injection

M-shell M-shell L-shell

M-shell L-shell

M-shell L-shell