I M P A UNIVERSITT GIESSEN www.uni-giessen.de/cms/iamp Stefan - - PowerPoint PPT Presentation

▶
i m p a
SMART_READER_LITE
LIVE PREVIEW

I M P A UNIVERSITT GIESSEN www.uni-giessen.de/cms/iamp Stefan - - PowerPoint PPT Presentation

Jan 17, 2024 471 likes •745 views

Electron-Ion Collisions in Heavy-Ion Storage-Rings Stefan Schippers Institut fr Atom- und Moleklphysik JUSTUS-LIEBIG- I M P A UNIVERSITT GIESSEN www.uni-giessen.de/cms/iamp Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May

slide-1
SLIDE 1

Institut für Atom- und Molekülphysik

JUSTUS-LIEBIG- UNIVERSITÄT GIESSEN

I M P A

www.uni-giessen.de/cms/iamp

Stefan Schippers

Electron-Ion Collisions in Heavy-Ion Storage-Rings

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 1

slide-2
SLIDE 2

Overview

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 2

  • Electron-ion collisions at storage rings
  • Atomic structure
  • Electron-ion collision spectroscopy
  • Nuclear and QED effects on atomic structure
  • Lifetimes of atomic levels (exotic decay modes)
  • Atomic collisions
  • Absolute cross sections (important for applications in

astrophysics and plasma physics)

  • Electron-ion recombination
  • Electron-impact ionization of ions
slide-3
SLIDE 3

Ion-Storage Rings

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 3

CSR @ MPIK ESR @ GSI/FAIR

from accelerator injection and extraction ion beam direction

electron cooler Electron target section

collision product detectors beam profile monitor (hor./vert.) ion current monitor Schottky pick-up collision product detectors 5m

TSR @ ISOLDE CRYRING @ GSI/FAIR

slide-4
SLIDE 4

2 4 6 8 300 400 500

Storage time (s) Count rate (s

  • 1)

Decay of Excited States

Simply wait until metastable ions have relaxed to their ground state.

  • S. Schippers et al.

PRL 98 (2007) 033001

2s2p 3P0 HFI decay

Be-like 47Ti18+

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 4

slide-5
SLIDE 5

Reactions

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 5

e- beam

collision experiments with dilute ensembles of particles tunable relative energy: sub meV to sub MeV cross sections on an absolute scale Reaction products

  • beams of high directionality
  • high particle energies in lab frame

charge-changing collisions electron-ion recombination electron-impact ionization of ions

100% detection efficiency

slide-6
SLIDE 6

1 m

Recombination of Ions in the CSR

electron cooler ion injection reaction products single-particle detector T =10 K p = 10-13 mbar

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 6

electrostatic storage rings provide access to low-charged heavy ions

slide-7
SLIDE 7

Single-Particle Detector

incident particle secondary electrons converter plate

Kaija Spruck, Claude Krantz et al.

~100% detection efficiency

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 7

adapted to cryogenic environment

slide-8
SLIDE 8

Dielectronic Recombination (DR)

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 8

Aq+ + e-  A(q-1)+ + photons

recombination of a q-fold charged ion with a free electron (time-inverse of photoionization)

 A**(q-1)+ 

intermediate resonance state

10 20 30 50 100 150

18 17 16 15 15 14 13 n=12 2p3/211l 2p1/213l n=14

Rate coefficient (10

  • 10 cm

3 s

  • 1)

Electron-ion collision energy (eV)

40 50 60 70 2 4 6 8

Ni

25+

n=30 2p1/2 series 19 2p3/2 series n=16

  • S. Schippers et al., PRA 62 (2000) 022708
slide-9
SLIDE 9

Strong Astrophysical Relevance

D.W. Savin, JPCS 88 (2007) 012071

  • S. Schippers, JPCS 388 (2012) 012010
  • A. Müller and S. Schippers,

in Atomic Processes in Basic and Applied Physics,

  • V. Shevelko and H. Tawara (eds.),

Springer Series on Atomic, Optical, and Plasma Physics 68 (2012) Chapter 2

Also many papers from CRYRING, e.g. Ali et al., A&A 557 (2013) A2 Orban et al., ApJ 721 (2010) 1603

absolute rate coeffcients

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 9

slide-10
SLIDE 10

Electron-Ion Collision Spectroscopy

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 10

  • M. Lestinsky et al.,

PRL 100 (2008) 033001

hyperfine splitting

TSR electron target with LN2-cooled photocathode uncertainty of resonance energies: 0.1 meV

DR of Li-like Sc18+

slide-11
SLIDE 11

Sensitivity to Nuclear Size

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 11

1.0 1.5 2.0 2.5

1 2 3 4

A=142 <r> = 4.914 fm A=150 <r> = 5.047 fm

Nd

56+ (1s 2 2p1/2 18lj )

j=5/2 j>5/2 j=3/2

Rate coefficient ( arb. units ) Electron-ion collision energy ( eV )

n = 

n = 18 2p1/2 2s1/2

...

j=1/2

  • C. Brandau, et al.,

PRL 100 (2008) 073201; see also R. Schuch et al. PRL 95 (2005) 183003

recombination of Li-like Nd57+ - two different isotopes

slide-12
SLIDE 12

ESR – CRYRING Comparison

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 12

courtesy of C. Brandau

higher resolving power  higher energy-precision

slide-13
SLIDE 13

Electron-Ion Recombination with In-Flight Produced Nuclei

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 13

  • C. Brandau, et al.,

HFI 196 (2010) 115

T1/2 = 6.7 h

slide-14
SLIDE 14

DR of Stochastically Cooled Ions @ ESR

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 14

The ion beam is cooled stochastically, the electron cooler is exclusively used as an electron target.

combiner- station

  • long. pick-up

transv. pick-up long. kicker transv. kicker electron cooler

20.6 20.8 21.0 21.2 21.4 21.6 2 4 6 8

KL3/2L3/2 KL1/2L3/2 KL1/2L1/2

experiment theory natural line width theory convoluted

Rate coefficient (arb. units) Electron-ion collision energy (keV)

KLL-DR of H-like Xe53+

  • C. Kozhuharov, C. Brandau et al.,

ICPEAC 2003

ESR storage ring, GSI Darmstadt

slide-15
SLIDE 15

KLL-DR of Hydrogen-like U91+

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 15

  • D. Bernhardt et al., PRA 83 (2011) 020701

up to 44% Breit

63.8 64.0 0.0 2.0 4.0 6.0 8.0 68.4 68.6 Electron-ion collision energy [keV] 72.8 73.0 73.2

Recombination rate coefficient [10-12 cm3 s-1] MCDF-calculations by

  • Z. Harman, T. Steih, W. Scheid et al.

Coulomb only Coulomb + Breit

experiment and theory independently

  • n absolute scales

experimental resolution close to natural linewidths

Electron-ion collision energy [keV]

0.0 1.0 2.0 3.0 4.0

KL1L1 KL1L2/3 KL2/3L2/3

slide-16
SLIDE 16

2 4 6 8 200 400 600 800 1000

Storage time (s) Recombination count rate (Hz)

Exotic Atomic Decay Modes

1 2

  • Recomb. rate coeff. (10
  • 9cm

3 s

  • 1)

A=48

0.70 0.75 0.80 0.85 0.90 1 2

A=47 Electron-ion collision energy (eV)

A=47 A=48

  • S. Schippers et al., PRL 98 (2007) 033001

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 16

hyperfine induced 2s2p 3P0  2s2 1S0 transition in 47Ti18+ A=48 A=47

𝝊𝐈𝐆𝐉 = 1.8(1) s

slide-17
SLIDE 17

E1M1 Two-Photon 2s2p 3P0  2s2 1S0 Decay

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 17

10 20 30 40 50 60 70 80 90 10

  • 1

10 10

1

10

2

10

3

10

4

10

5

10

6

10

7

10

8

10

9

10

10

10

11

month decade millennium second minute hour century year

Lifetime (s) Nuclear charge

E1M1

[Laughlin, PLA 75, 199 (1980)]

day

relativistic theory

  • F. Fratini, A. Surzhykov,
  • S. Fritzsche (preliminary)

nonrelativistic theory

theoretical predictions

slide-18
SLIDE 18

Exotic Recombination Pathways

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 18

slide-19
SLIDE 19

0.01 0.1 1 10 0.1 1 10 100

Rate coefficient (10

  • 8 cm

3 s

  • 1)

Electron-ion collision energy (eV)

TSR experiment radiative recombination

Recombination of W18+([Kr] 4d10 4f10)

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 19

DR theory (autostructure) statistical theory

factor of 300 difference

  • K. Spruck, N. R. Badnell, C. Krantz et al., in preparation
slide-20
SLIDE 20

Many-Electron Systems with High Level Densities

first 491 levels of Ce+

energies taken from the NIST atomic spectra data base

1 2 3 4 5 6

Level energy (eV)

4f (2F) 5d2 (3F) 4H7/2 ground state In principle, a Rydberg series of DR resonances is associated with the excitation of each level.

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 20

slide-21
SLIDE 21

Giant Atomic Resonances

80 90 100 110 120 130 140 150 160 20 40 60 free Xe atom[exp, West & Morton ADNDT 22 (1978) 103]

Cross section ( Mb ) Photon energy ( eV )

Photoionization of Xe(4d) shell

Time inverse process: Recombination via collective excitation of 10 4d electrons

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 21

slide-22
SLIDE 22

Plasmon Excitations in C60

+

  • S. Scully et al., PRL 94 (2005) 065503

20 30 40 50 60 70 50 60 70 80 90 100 200 300 400 500

experiment

C

+ 60 + h  C 2+ 60 + e

  • Photoionization cross section ( Mb )

Photon energy ( eV ) volume plasmon surface plasmon fit curve

10 20 30 40 50 60 70 80 200 400 600

C60

+ + h  C60 2+ + e

  • Photoionization cross section ( Mb )

Photon Energy ( eV )

Experiment Theory (LDA) Theory (TDLDA)

density functional theory Photoionization of ions at the ALS (Gießen-Reno-Berkeley-Dresden collaboration)

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 22

slide-23
SLIDE 23

Access to Super-Atom States

Feng et al., Science 320 (2008) 359

1 2 3 4 5 eV

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 23

slide-24
SLIDE 24

Beam lifetime of stored C60+ ions

58 keV C60+ t = 10.8 s Yield of neutral particles

  • P. Hvelplund, Proceedings

XVIII ICPEAC, Aarhus1993 AIP CP 295 (1993) p. 709

stored in ASTRID at room temperature will be two orders of magnitude longer in CSR

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 24

slide-25
SLIDE 25

Collaborators

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 25

Justus-Liebig-Universität Gießen:

  • D. Bernhardt, S. Böhm, J. Jacobi, S. Kieslich, H. Knopp, A. Müller, E. W. Schmidt, W. Shi, K. Spruck, D. Yu
  • N. Grün, W. Scheid, T. Steih

Max-Planck-Institut für Kernphysik Heidelberg:

  • A. Becker, M. Beutelspacher, M. Grieser, G. Gwinner, C. Krantz, D. A. Orlov, R. Repnow, M. Schnell, F. Sprenger,
  • A. Wolf, Z. Harmann, U. D. Jentschura, C. H. Keitel

Columbia Astrophysics Laboratory New York:

  • M. Hahn, D. Lukic, O. Novotný, D. W. Savin

Stockholm University:

  • H. Danared, N. Eklöw, E. Lindroth, R. Schuch, M. Tokman

GSI, Darmstadt:

  • K. Beckert, P. Beller, F. Bosch, D. Boutin, C. Brandau, C. Dimopoulou, B. Franzke, A. Gumberidze, H.-J. Kluge,

P.-M. Hillenbrandt, C. Kozhuharov, M. Lestinsky, Yu. A. Litvinov, P. H. Mokler, F. Nolden, R. Reuschl,

  • U. Spillmann, M. Steck, T. Stöhlker, D. F. A. Winters

and

  • N. R. Badnell (Glasgow), M. Bannister (Oak Ridge), F. J. Currell, B. O‘Rourke (Belfast), S. Fritzsche (Jena),
  • D. C. Griffin & D. M. Mitnik (Rollins College), R. A. Phaneuf (Reno), Z. Stachura (Krakow), A. S. Terekov (Novosibirsk),
  • A. N. Artemyev, Y. S. Kozhedub, V. M. Shabaev, I. I. Tupitsyn (St. Petersburg), R. Krücken (Munich)
slide-26
SLIDE 26

Summary

  • Dielectronic recombination
  • sensitive to nuclear charge and magnetic moment
  • sensitive to relativistic and QED effects
  • absolute cross sections important for astro- and plasma physics
  • New opportunities at new and relocated storage rings
  • high-resolution electron-ion collision spectroscopy
  • access to long atomic lifetimes
  • rare isotopes
  • low-charged ions (atoms, molecules, clusters)
  • exploration of exotic recombination path-ways

Stefan Schippers, FLAIR workshop, Heidelberg, 15-16 May 2014 26