Diagnosis of a High Harmonic Beam Using

1
Kansas State University Department of Physics
Diagnosis of a High Harmonic Beam Using COLTRIMS
Predrag Ranitovic
April 2005
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
4
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
5
Experimental Setup
6

High Harmonic Generation
7

High Harmonic Generation
8

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
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
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
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
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
T357.4/B ns
18
Momentum Imaging
P
y
P a.u.
P a.u.
x
z
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 energies
P
x
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