1. Monochromator Improvements and Focusing Elke Jackson Research performed by Elke Jackson, Shannon Lunt, and Yenny Martinez With the support of Drs. Steven Turley and David Allred

2. Monochromator Overview vacuum Octagonal Chamber XUV Source Monochromator Chamber XUV Source  Hydrogen gas  High voltage  Plasma  XUV light  Slits  Vacuum

3. Octagonal Chamber

4. Pinhole Channeltron Photon Detector Stage θ 2θ2θ Pinhole selects beam Stage/Detector: θ/2θ Channeltron: Multiplier Tube

5. Chamber Entrance Beam Exit Beam First Order Diffractions To XUV Source To Octagonal Chamber Entrance SlitsExit Slits Specular Reflection

6. Reflective Diffraction Grating Grating Equation: mλ = d (sin α + sin β) Gmλ = (sin α + sin β) mλ = d cos K sin φ

7. Reflective Diffraction Grating Grating Alignment Mount new grating Outside alignment with laser Inside alignment with laser –Aligning the laser –Adjusting the grating Alignment with source New grating: 1200 lines per mm, twice that of the old grating Half the width of the old grating

8. Reflective Diffraction Grating Adjustments

9. Focusing Detector placement Detector placement Reduce slit width, keeping counts up Reduce slit width, keeping counts up 10 micron goal 10 micron goal Centered beam Centered beam Small entrance beam focuses to small exit beam Small entrance beam focuses to small exit beam Adjust monochromator settings to find beam through small slits Adjust monochromator settings to find beam through small slits Slit, adjustable width Centering beam

10. Focusing: Detector scans at given slit widths Curve shape does not change with slit size Beam centered in slits

11. Focusing: Wavelength scans at given lever arm micrometer settings Lever Arm Lever Arm Adjustment Micrometer Adjusting the lever arm micrometer moves the grating Maximize counts to the detector around wavelengths of greatest intensity by comparing wavelength scans at various micrometer settings

12. Focusing: Wavelength scans at given lever arm micrometer settings

14. Peaks of 16,000 counts (2 second intervals) Peaks of 16,000 counts (2 second intervals) Average standard deviation of 112 counts Average standard deviation of 112 countsNow: Wavelength scans, lever arm at < 2.25 Wavelength scans, lever arm at < 2.25 Similar optimization with cam micrometer Similar optimization with cam micrometer Place pinhole and locate beam Place pinhole and locate beam Bug fixes in computer program Bug fixes in computer program Stabilize source or determine its rise Stabilize source or determine its rise Write new standards of procedure to reflect changes Write new standards of procedure to reflect changes