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Kansas State University Department of Physics. Diagnosis of a High Harmonic Beam Using COLTRIMS. Predrag Ranitovi ć. April 2005. Outline. 1. Motivation. Time resolved photoelectron spectroscopy. Development of an apparatus for performing pump-probe experiments.
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Kansas State University Department of Physics Diagnosis of a High Harmonic Beam Using COLTRIMS Predrag Ranitović April 2005
Outline 1. Motivation Time resolved photoelectron spectroscopy 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. Development of an apparatus for performing pump-probe experiments
Outline 1. Motivation 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
Spectrometer Aluminum filter High Harmonic Generation gas cell f=30 cm Experimental Setup
+ High Harmonic Generation
+ 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,
High Harmonic Generation Aluminum absorber
High Harmonic Generation Spectrometer Aluminum filter
COLTRIMS – Momentum Imaging Technique Mono energetic electron with the momentum along the spectrometer electric field
+ Ar time of flight and detector image y [mm/2] t [ns] x [mm/2]
Electron time of flight and detector image B = 12 Gauss y [mm/2] t [ns] x [mm/2]
Electron time of flight and detector image Electron time of flight and detector image B = 8 Gauss y [mm/2] t [ns] x [mm/2]
Electron time of flight and detector image Electron time of flight and detector image B = 6 Gauss y [mm/2] t [ns] x [mm/2]
The Wiggles r [mm/2] r [m] t [ns] t [s] T=357.4/B [ns]
Momentum Imaging P y P [a.u.] P [a.u.] x z
Momentum Imaging B = 6 Gauss P P x y P [a.u.] P [a.u.] z z
Momentum Imaging B = 8 Gauss P x P [a.u.] t [ns] z
Photoelectron energies = E [eV]
Photoelectron energies P x P [a.u.] z E [eV]
Summary and Outlook X-ray Angular Divergence Photon flux Harmonic Orders
+ + 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
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
Photoelectron energy (eV) Those five peaks correspond to 13th, 15th, 17th, 19th and 21st harmonic in a field free arrangement