1. Diagnosis of a High Harmonic Beam Using
Kansas State University
Department of Physics
Diagnosis of a High Harmonic Beam Using
COLTRIMS
April 2005
Predrag Ranitović

2. Outline 1. Motivation Time resolved photoelectron spectroscopy
Development of an apparatus for performing pump-probe experiments

3. Development of an apparatus for performing pump-probe experiments
Generation and Characterization of a High Harmonic Beam 1.
Pump and Probe Arrangement using Visible-Pump and an x-ray as a probe pulse 2.

4. Outline 1. Motivation 2. Summary and Outlook
Time resolved photoelectron spectroscopy
Development of an apparatus for performing pump-probe experiments
Development of an apparatus for performing pump-probe experiments
Generation and Characterization of a High Harmonic Beam
2. Summary and Outlook

5. Experimental Setup Spectrometer f=30 cm Aluminum filter High Harmonic
Generation gas cell
f=30 cm

6. +
High Harmonic Generation

7. +
High Harmonic Generation

8. High Harmonic Generation+
High Harmonic Generation
Gas Tube
Argon gas as a harmonic generation medium
Harmonics’ intensity varies with the lasers’ focusing point
Al filter
Aluminum absorber
 = 800 nm
  40 fs,

9. High Harmonic Generation
Aluminum absorber

10. High Harmonic Generation
Spectrometer
Aluminum filter

11. COLTRIMS

12. COLTRIMS – Momentum Imaging Technique
Mono energetic electron with the momentum along the spectrometer electric field

13. Ar time of flight and detector image+
Ar time of flight and detector image
y [mm/2]
t [ns]
x [mm/2]

14. Electron time of flight and detector image
B = 12 Gauss
y [mm/2]
t [ns]
x [mm/2]

15. Electron time of flight and detector image
B = 8 Gauss
y [mm/2]
t [ns]
x [mm/2]

16. Electron time of flight and detector image
B = 6 Gauss
y [mm/2]
t [ns]
x [mm/2]

17. The Wiggles
r [mm/2]
r [m]
t [ns]
t [s]
T=357.4/B [ns]

18. Momentum Imaging P y
P [a.u.]
P [a.u.] z x

19. Momentum Imaging
B = 6 Gauss P P x y
P [a.u.]
P [a.u.] z z

20. Momentum Imaging
B = 8 Gauss P x
P [a.u.]
t [ns] z

21. Photoelectron energies=
E [eV]

22. Photoelectron energiesx
P [a.u.] z
E [eV]

23. Summary and Outlook X-ray Angular Divergence Photon flux
Harmonic Orders

24. The Wiggles

25. Old Data

26. + +
Ar time of flight and detector image
Ar time of flight and detector image
This is a E  40 V/cm run, the recoil detector is still 22 cm from the interaction region

27. Electron time of flight and detector image
This is a E = 2.4 V/cm and B = 10 Gauss run, the electron detector is 5.3 cm from the interaction region

28. Photoelectron energy (eV)
Those five peaks correspond to 13th, 15th, 17th, 19th and 21st harmonic in a field free arrangement