Spectroscopic Research Projects on Heavy Elements at

NIST

Wolfgang L. Wiese

National Institute of Standards and Technology (NIST), USA

ParticipantsExperimental Research: J. Reader, G. Nave,

J. Gillaspy, M. Bridges,* W. Wiese*Theoretical Approaches: Ch. Froese-Fischer,*

Y. Ralchenko,*Y.-K. Kim , P. Stone*

Data Assessment and J. Reader, E. Saloman,* Compilations: J. Fuhr,* D. Kelleher,*

L. Podobedova,* A. Kramida,* W. Wiese*

Database Development: Y. Ralchenko,* A. Kramida*R. Ibacache

*indicates Contractors or Guest Researchers

Three On-going Spectroscopic Research Projects on Heavy Elements at NIST

1. An updated and expanded critical compilation of spectroscopic reference data for Fe I and Fe II, focusing on better transition probabilities.

2. Calculations of ionization and excitation cross-sections of neutral and singly ionized Mo and W with the Binary-Encounter-Bethe (BEB) model.

3. Experimental observations of the spectra of highly charged tungsten ions, in the range from W+35 to W+63, with an Electron Beam Ion Trap (EBIT) and their analysis.

.

Fe I

O’Brian 180 lifetimes and branching fractions

Blackwell absorption (based on one lifetime)

Fe I

Kock several lifetimes and branching fractions

Fe II

Fe II

Raassen = semi-empirical calculation

1988

2006

Fe I

19882006

Fe II

Electron-Impact Cross Section Database(http://physics.nist.gov/ionxsec)

M. A. Ali, K. K. Irikura, Y.-K. Kim, P. M. Stone

Already in the database:

1. Total ionization cross sections of neutral atoms and molecules, singly charged molecular ions (about 100)

2. Differential ionization cross sections of H, He, H2

3. Excitation cross sections of light atoms

New results to be added by summer, 2007:

4. Total ionization cross sections (direct + excitation-autoionization) of Mo, Mo+, W, W+ (joint work with KAERI, see graphs)—BEB model plus BE/E scaling of Born cross sections [Mo/Mo+ in Kwon, Rhee & Kim, Int. J. Mass Spectrometry, 245, 26 (2005)]

5. Excitation cross sections of H2 (see graphs)—BE scaling of Born cross sections

6. Ionization cross sections of Si, Ge, Sn, Pb, Cl, Br, I, Cl2, Br2, I2

A Major Spectroscopic Research Project on Heavy Elements at NIST

• Experimental observations of the spectra of highly charged tungsten ions, in the range from W+35 to W+63, with an Electron Beam Ion Trap (EBIT) and their theoretical analysis.

SPECTRUM OF W IN ORMAK

INTERPRETATION AS W XXX - W XXXV

ISLER, NEIDIGH, AND COWAN (1977)

Cu and Zn sequences to W

READER & LUTHER (1980)

1S0-1P1

1/2-3/2

1/2-1/2

The EBIT not only creates a highly charged ions, but can hold their center

of mass at rest.

EBIT size ~ 1 m

This overcomes the primary limitation of large HCI facilities for precision

spectroscopy.

To first order, the relative Doppler shift is

/ =v/c

The NIST Electron Beam Ion Trap (EBIT)

Ion production, trapping, and excitation

http://physics.nist.gov/ebit

EBIT on a table top

EBIT Internal View

107 K plasma

A simplified EBIT:

Intense Electron Beam (4,000 A/cm2)

Strong magnetic field (3 tesla)

Highly Charged Ions (up to Bi72+at NIST).

Creates (by electron impact ionization) Traps (by electric and magnetic fields) Excites (electron impact)

Ion cloud width ~ 150 m

2 cmUltrahigh vacuum (~10-10 torr)

J.D. Gillaspy, Phys. Scr. T71, 99 (1997).

NIST EBIT 0.1-33 keV e-beam energy

Q up to 72+ produced

Ne-like U82+ threshold: 10 keV (10 remaining electrons)

He-like U90+ threshold: 33 keV (2 remaining electrons)

• operates at 65 mK

• absorber: a foil of superconducting tin

• thermistor: neutron transmutation-doped

(NTD) germanium

Quantum Microcalorimeter

“Crystal-quality” resolution, wide bandwidth and 100% efficiency.

L-shell

K-shell

Ar

EUV SPECTROMETER AT NIST EBIT

BLAGOJEVIC, LE BIGOT, ET AL. (2005)

IONIZATION ENERGIES FOR W IN ALL STAGES

KRAMIDA & READER (2006)

Ion Seq.IE

103 cm–1

Unc.103 cm–1

IE eV

Unc. eV

Unc., %

Ref.

W0+ W 63.4277 0.0008 7.86403 0.00010 0.0013 CM96

W+ Ta 132.0 1.2 16.37 0.15 0.9 K04

W2+ Hf 209.9 3.6 26.0 0.4 1.7 TW

W3+ Lu 308.2 2.9 38.2 0.4 0.9 TW

W4+ Yb 416.1 2.7 51.6 0.3 0.6 TW

W5+ Tm 522.37 0.30 64.77 0.04 0.06 S79

W6+ Er 984.1 0.5 122.01 0.06 0.05 S75

W7+ Ho 1139 10 141.2 1.2 0.9 TW

W8+ Dy 1292 10 160.2 1.2 0.8 TW

W9+ Tb 1444 10 179.0 1.2 0.7 TW

W10+ Gd 1685 10 208.9 1.2 0.6 TW

W11+ Eu 1868 10 231.6 1.2 0.5 TW

W12+ Sm 2083 10 258.2 1.2 0.5 TW

W13+ Pm 2345 10 290.7 1.2 0.4 TW

W14+ Nd 2624 12 325.3 1.5 0.5 TW

W15+ Pr 2919 12 361.9 1.5 0.4 TW

W16+ Ce 3129 10 387.9 1.2 0.3 TW

W17+ La 3393 11 420.7 1.4 0.3 TW

W18+ Ba 3727 11 462.1 1.4 0.3 TW

W19+ Cs 4054 11 502.6 1.4 0.3 TW

W20+ Xe 4383 11 543.4 1.4 0.3 TW

W21+ I 4795 12 594.5 1.5 0.3 TW

W22+ Te 5167 12 640.7 1.5 0.2 TW

= THIS WORK

IONIZATION ENERGIES OF W IONS

ION SEQUENCE GROUND CONFIG

ENERGY(eV)

W40+ Se 4s24p4 1941

W41+ As 4s24p3 1995

W42+ Ge 4s24p2 2149

W43+ Ga 4s24p 2210

W44+ Zn 3d104s2 2354

W45+ Cu 3d104s 2414

W46+ Ni 3d10 4057

W47+ Co 3d9 4180

COMPILATIONS of W SPECTRA AND ENERGY LEVELS

KRAMIDA & SHIRAI (2006 & 2007)

W I & II (260 pages)

W III - LXXIV (~250 pages)

IE (eV)

Cowan

(1977)

IE (eV) - Exp

Kramida

(2006)

Transition WL(Å) Cowan

(1977)

WL(Å) -Obs Obs. Source

Zn-like 44+ 2354 2354.5(1.5) 4s2 1S0 - 4s4p 1P1 60.2 60.931(2) Livermore

4s2 1S0 - 4s4p 3P1 135.0 132.88(3) ASDEX/NIST

4s4p 3P1 - 4s4p 3P2 127.47 134.80(3) NIST

Cu-like 45+ 2415 2414.1(4) 4s 2S1/2 - 4p 2P3/2 61.2 62.336(2) Livermore

4s 2S1/2 - 4p 2P1/2 127.5 126.998 Seely - ISO

Ni-like 46+ 4055 4057(3) 3d10 1S0 - 3d94f 3D1 5.68 5.6900(3) Livermore

3d10 1S0 - 3d94f 1P1 5.87 5.8665(3) Livermore

3d10 1S0 - 3d94f 3P1 5.95

3d10 1S0 - 3d94p 3D1 6.75 6.779(3) Israel

3d10 1S0 - 3d94p 1P1 7.01 7.028(3) Israel

3d10 1S0 - 3d94p3P1 7.17 7.1733(3) Livermore

COWAN (1977) vs. OBSERVED

IE’s SEMI-EMPIRICAL - KRAMIDA & READER (2006)

CuCu

O

O

CuCu

Zn

GaGe

Zn Zn

Ge

Ge

Ga

BrBr

CR MODELING OF PLASMA OF W IN NIST EBIT -

RALCHENKO ET AL. (2007)

EXPERIMENT THEORY

CO

UN

TS

SPECTRUM OF W IN NIST EBIT AT 4228 eV RALCHENKO ET AL. (2007)

Cu

Ni UTA

Ni

Cu

CoNiZn

* = 2 or 3 rd order

+ = O or NCu

Ni UTA

Cu

4p

4f

5f6f

4s

X-RAY SPECTRUM OF W WITH MICROCALORIMETER ON NIST EBIT

3d10-3d9nl

RALCHENKO ET AL. (2006)

E2 LINES OF W IN NIST EBIT - RALCHENKO ET AL. (2006)

0

2

1

2

3d10

3d94s

3

7.610 Å

7.930 Å

M

E2

E2

L

4p

4f

5f6f

4s

X-RAY SPECTRUM OF W WITH MICROCALORIMETER ON NIST EBIT

3d10-3d9nl

RALCHENKO ET AL. (2006)

E2 AND M3 LINES OF W IN NIST EBIT

RALCHENKO ET AL. (2006)

0

2

1

2

3d10

3d94s

3

7.610 Å

7.930 Å0.009 Å

M

L

E2

E2M3

CALCULATED E2:M3 RATIOS

RALCHENKO J. Phys. B: At. Mol. Opt. Phys. 40 (2007) F175