Sample Alignment Quick Reference: Difference between revisions

From CNM Wiki
Jump to navigation Jump to search
(Created page with "Back to X-Ray Microscopy '''1) Select x-ray energy:'''<br /> Calculate scattering angle of Si 111 for desired energy with Bragg law calculator (or approximate Theta ~ asin(1…")
 
No edit summary
Line 1: Line 1:
Back to [[X-Ray Microscopy]]
Back to [[Diffraction]]


'''1) Select x-ray energy:'''<br />
'''1) Verify optic alignment'''<br />
Calculate scattering angle of Si 111 for desired energy with Bragg law calculator (or approximate Theta ~ asin(1.977084/E keV) )  <br />
Perform [[CCD changeover]] to [[Coolsnap]] <br />
Drive DCM Theta to the correct Bragg angle for the desired energy, drive undulators approximately to this energy as well <br />
Drive focusing optic into beam, adjust OSAX and OSAY so outgoing focused beam is not clipped and remnant central parallel beam intensity is minimized<br />
Close NES slits to 0.1x0.1, adjust FOMX and FOMY to center optic on beam axis - outgoing wavefront clipped by slits should look symmetric around the edges<br />  


NOTES:<br />
NOTES:<br />
i) If DCM theta looks low for the current energy (~2-4 deg) you may need to re-set user offset (current calibrated theta offset = dial + 8.646deg) <br />
i) Central stop may be offset from the center of optic - do not simply put image of central stop in the center of the beam footprint<br />
ii) Approximate undulator offsets are ~ desired energy +0.1 keV <br />
 
'''2) Mount sample'''<br />
Perform [[CCD changeover]] to [[Coolsnap]] <br />
Drive focusing optic into beam, adjust OSAX and OSAY so outgoing focused beam is not clipped and remnant central parallel beam intensity is minimized<br />
Close NES slits to 0.1x0.1, adjust FOMX and FOMY to center optic on beam axis - outgoing wavefront clipped by slits should look symmetric around the edges<br />
 
NOTES:<br />
i) Central stop may be offset from the center of optic - do not simply put image of central stop in the center of the beam footprint<br />

Revision as of 14:45, September 8, 2010

Back to Diffraction

1) Verify optic alignment
Perform CCD changeover to Coolsnap
Drive focusing optic into beam, adjust OSAX and OSAY so outgoing focused beam is not clipped and remnant central parallel beam intensity is minimized
Close NES slits to 0.1x0.1, adjust FOMX and FOMY to center optic on beam axis - outgoing wavefront clipped by slits should look symmetric around the edges

NOTES:
i) Central stop may be offset from the center of optic - do not simply put image of central stop in the center of the beam footprint

2) Mount sample
Perform CCD changeover to Coolsnap
Drive focusing optic into beam, adjust OSAX and OSAY so outgoing focused beam is not clipped and remnant central parallel beam intensity is minimized
Close NES slits to 0.1x0.1, adjust FOMX and FOMY to center optic on beam axis - outgoing wavefront clipped by slits should look symmetric around the edges

NOTES:
i) Central stop may be offset from the center of optic - do not simply put image of central stop in the center of the beam footprint