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) / ]3 gi Bif / 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