1. Extreme Ultraviolet Radiation Spectrometer Design and Optimization
Shaun Pacheco
Mentors: Dr. Guillaume Laurent & Wei Cao

2. Research Project Goal 1: Improve the Resolution
Goal 2: Calibrate the Spectrometer
to find wavelengths
not intensity profile
Summarize talk here.

3. Diagram of Apparatus COLTRIMS Interferometer To XUV SpectrometerGC DM
0.5m FM M1 M4 M2 BS DS RM AF TM
High-Order Harmonic
COLTRIMS
Gas Jet
Magnetic Coils
Spectrometer
MCP
PSD
PSD
To XUV
Spectrometer
Interferometer
M1~M4: Plane mirror BS: Beam splitter RM: Recombination mirror MCP: Microchannel Plate
FM: Focusing mirror GS: Gas cell DS: Delay stage PSD: Positon Sensitive Detector
DM: Diverging mirror AF: Al filter TM: Toroidal Mirror

4. Diagram of Apparatus Diffraction Grating Spherical Mirror
Minus first and second order diffraction shown in the image
Phosphor
Plate
MCP

5. High Harmonic Generation
Where n is an odd integer, ω0 is the fundamental laser frequency,
"High-order Harmonic Generation." Swineburne4 Aug < >.

6. Energies Allowed in Experiment
Transmission
Argon
Highest Order cut-off determined by
E = 3.2Up + Ip
Ip is the ionization potential of the gas
Up is the mean kinetic energy of the electron
Highest energy seen is 51eV
Aluminum
Foil
Citation needed
Photon Energy (eV)
Aluminum Foil 200 nm thickness
Argon mTorr for 3 cm followed by 5 mTorr for 1 m
Tong. High-Order Harmonic Generation. <
Gullikson, Eric. "X-Ray Interactions With Matter." Lawrence Berkeley National Laboratory. N.p., n.d. Web. 4 Aug <henke.lbl.gov/optical_constants/>

7. Goal 1: Improving the Resolution
Phosphor Plate
New Placement
100s of nanonmeter size hole
Old placement
"Microchannel Plate Principles of Operation." HRC. Web. 4 Aug <hea- >.

8. Goal 1: Improving the Resolution
Microchannel Plate
4 mm
Phosphor plate
Old Gap
10 mm
1 kV per mm otherwise u’ll get a spark
Phosphor plate was moved from 10 mm away to 4 mm

9. Goal 1: Resolution improved
Show photoelectron spectrum
Theoretical limit
New Resolution
Old Resolution

10. Goal 2: Calibrating the Spectrum
Find distance of each spectral line from zero order
Integrate across the spectral lines to get intensities
d is the slit spacing
m is the diffraction order
θi is the incident angle
θd is the diffracted angle
Supplementary slide how determined thetai and b

11. Calibrated Spectrum Black Curve is the photoelectron spectrum
Blue Curve is the spectrum from the XUV spectrometer
Energy resolution is comparable to photoelectron spectrum
Count (arb. Units)
Photoelectron Energy (eV)

12. Results and Discussion
Blue Shift Can be Observed
Blue Curve – Low Intensity, no blue shift
Red Curve – Medium Intensity, blue shift
Yellow Curve – High Intensity, blue shift
Calibrate positions of peak, not intensity
Harmonics

13. Conclusion XUV spectrum is now comparable to photoelectron spectrum
Spectrometer good enough to observe small change in the harmonic wavelength
Improvements:
Calibrate the intensity profile of XUV spectrum

14. Work Cited
"High-order Harmonic Generation." Swineburne4 Aug < >
"Microchannel Plate Principles of Operation." HRC. 4 Aug <hea- >.
Gullikson, Eric. "X-Ray Interactions With Matter." Lawrence Berkeley National Laboratory. Web. 4 Aug <henke.lbl.gov/optical_constants>
Tong. High-Order Harmonic Generation. <

15. Questions?