FAST-ION-BEAM ATOMIC SPECTROSCOPY

1. FAST-ION-BEAM ATOMIC SPECTROSCOPY Toledo Heavy Ion Accelerator (THIA) Laboratory

2. PROPERTIES OF FREE ATOMS • Have discrete orbital energies (level structure) • Undergo radiative transitions (wavelengths) • Transitions have natural linewidths (lifetimes) • Decay has branched exit channels (intensities) • Levels have population amplitudes (coherence) • Orbitals have magnetic moments (g-factors) A free atom can be characterized by its energy levels, oscillator strengths, population amplitudes, and g-factors. (The oscillator strengths are the spring constants that characterize its distortions)

3. PROPERTIES OF ATOMS IN ARBITRARY ENVIRONMENTS (ALL KNOWN MATTER) • 1.The same as those of the free atom, except the eigenstates are different. • 2. Eigenstates of a free atom comprise a complete basis set. • An atom in an arbitrary environment can be described as a coherent superposition of amplitudes of the free atom, if its energy levels and spring constants are known. (For example, electric polarizabilities, indices of refraction, virial coefficients, scattering cross sections, etc, are all sums of oscillator strengths multiplied by appropriate powers of energy factors.)

4. 700 Li+ beam (v=4.4 mm/ns) incident on a thin (3 g/cm2) carbon foil. The blue light is H-like 4f-5g in Li2+ (4500Å, =3 ns, x=1.3 cm). The green light is He-like 2s 3S-2p 3P in Li+ (5485Å, =44 ns, x=19 cm).

5. McMaster Hall Room 1019

6. slowest ions exiting foil < v < speed of light shortest resolvable length < vt < longest non-divergent path

7. Multiplexed Simultaneous PSD Efficient detection of a range of ’s Allowed & forbidden transitions are manifest Time-dep: beam fluctuations cancel in ratios; line profiles reveal blends; bkgds obtained between lines; ANDC possible in real time

8. 2-E1 decay of 1s2s 1S0 in He-like Br - (bkgd: M1 decay of 1s2s 3S1 ) Spike: Random M1+M1. Ridges: Random M1+Continuum Diagonal island: Real E1+E1

9. Differential Quantum Beat Measurements

11. Spectrometer Refocussing Eliminate blending

12. ANDC Method Eliminate Cascading

13. Adjusted Normalization of Decay Curves

15. 1951 King Gustav IV Adolf Professor Bengt Edlén

16. ISOELECTRONIC SYSTEMATIZATION Line Strength Factor: Sifmi mf  i | r/ao | f 2 Deduced from measured data: Sif = [ if(Å) / 1265.38]3giBif / i(ns) Parametrized: Z2Sif SH + b/(Z-C) ; SH = 3n2 (n2-1) gi / 4

19. Cancellation

20. Singlet-Triplet Mixing nsnp levels RES INT

21. Mixing Angles

22. Alkaline-earthlike sequences

25. Ca II Branching fractions: VIS, IR, UV, VUV calibrations needed

26. Determination of branching fractions: Requires intensity calibration of detection apparatus as a function of wavelength Standard lamps: continuum radiation fixed in laboratory beam light Doppler shifted Line standards available in Visible, but not UV Need in-beam ions with known intensity ratios

27. Si sequence

29. S II : (Å) 907, 911, 913 1053, 1056 1167, 1173

30. Differential Lifetime Measurements

33. MCDHF Calculations

34. 8-1/2 =0.3535

35. 5670