Beamline Alignment Quick Reference: Difference between revisions
No edit summary |
No edit summary |
||
| Line 4: | Line 4: | ||
Calculate scattering angle of Si 111 for desired energy with Bragg law calculator (or approximate Theta ~ asin(1.977084/E keV) ) <br /> | Calculate scattering angle of Si 111 for desired energy with Bragg law calculator (or approximate Theta ~ asin(1.977084/E keV) ) <br /> | ||
Drive DCM Theta to the correct Bragg angle for the desired energy<br /> | Drive DCM Theta to the correct Bragg angle for the desired energy<br /> | ||
Drive undulators | Drive both undulators to the desired energy plus an approximate offset of +0.1keV<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) 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 /> | ||
ii) Approximate undulator offsets are ~ desired energy +0.1 keV <br /> | ii) Approximate undulator offsets are ~ desired energy +0.1 keV at ~8keV, +0.2keV at 12 keV <br /> | ||
| Line 25: | Line 25: | ||
| BDA || 2 ||| - | | BDA || 2 ||| - | ||
|} | |} | ||
Scan mirror piezo with a scan width of ~2V, ~ 21 points. <br /> | |||
Set mirror piezo to the maximum intensity.<br /> | |||
NOTES:<br /> | NOTES:<br /> | ||
i) mirror piezo feedback should be OFF <br /> | i) mirror piezo feedback should be OFF (MIR flag on main beamline screen)<br /> | ||
ii) CCD shutter should be set to "manual open"<br /> | ii) CCD azsol shutter should be set to "manual open" or removed from beam path<br /> | ||
<br /> | <br /> | ||
| Line 45: | Line 46: | ||
| BDA || 2 ||| - | | BDA || 2 ||| - | ||
|} | |} | ||
scan | Scan DCM Chi2 (roll) with a scan width of ~0.2 mrad, 21 pts, (at least 1 sec of positioner settling time)<br /> | ||
Set roll to maximum intensity - correct for backlash.<br /> | |||
NOTES:<br /> | NOTES:<br /> | ||
i) Correct for backlash by driving to first scan point, then to maximum (e.g. after scan drive relative position -0. | i) Correct for backlash by driving to first scan point, then to maximum (e.g. after scan drive relative position -0.1, then drive absolute position to max)<br /> | ||
ii) Settling time of at least 1 second is necessary for this scan (this axis is UHV picomotor driven in PID) | ii) Settling time of at least 1 second is necessary for this scan (this axis is UHV picomotor driven in PID) | ||
| Line 65: | Line 67: | ||
| BDA || 2 ||| - | | BDA || 2 ||| - | ||
|} | |} | ||
Scan control voltage for DCM piezo tweak with a scan width of ~3V, 21pts.<br /> | |||
Set piezo to maximum intensity.<br /> | |||
NOTES:<br /> | NOTES:<br /> | ||
i) if voltage is trending out of range (1V<V<9V), set tweak to 4.5V and scan theta2 motion +/- 0.1mrad<br /> | i) if voltage is trending out of range (1V<V<9V), set tweak to 4.5V and scan theta2 motion +/- 0.1mrad<br /> | ||
| Line 71: | Line 74: | ||
'''5) Scan Undulators:''' | '''5) Scan Undulators:''' | ||
Scan upstream and downstream undulators | Scan upstream and downstream undulators with a scan width of 0.5 keV (1 sec settling time), drive to maximum intensity<br /> | ||
NOTES:<br /> | NOTES:<br /> | ||
i) Settling time of at least 1 second is necessary for this scan (possibly more)<br /> | i) Settling time of at least 1 second is necessary for this scan (possibly more)<br /> | ||
[[Category:XMG]][[Category:Controls]][[Category:Beamline]] | [[Category:XMG]][[Category:Controls]][[Category:Beamline]] | ||
Revision as of 21:02, October 5, 2010
Back to X-Ray Microscopy
1) Select x-ray energy:
Calculate scattering angle of Si 111 for desired energy with Bragg law calculator (or approximate Theta ~ asin(1.977084/E keV) )
Drive DCM Theta to the correct Bragg angle for the desired energy
Drive both undulators to the desired energy plus an approximate offset of +0.1keV
NOTES:
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)
ii) Approximate undulator offsets are ~ desired energy +0.1 keV at ~8keV, +0.2keV at 12 keV
2) Scan mirror piezo:
Set slits to
| Slit | H Size (mm) | V Size (mm) |
| PBS | 0.2 | 2 |
| NES | 2 | 2 |
| BDA | 2 | - |
Scan mirror piezo with a scan width of ~2V, ~ 21 points.
Set mirror piezo to the maximum intensity.
NOTES:
i) mirror piezo feedback should be OFF (MIR flag on main beamline screen)
ii) CCD azsol shutter should be set to "manual open" or removed from beam path
3) Scan DCM 2nd crystal roll:
Set slits to
| Slit | H Size (mm) | V Size (mm) |
| PBS | 0.2 | 2 |
| NES | 0.2 | 2 |
| BDA | 2 | - |
Scan DCM Chi2 (roll) with a scan width of ~0.2 mrad, 21 pts, (at least 1 sec of positioner settling time)
Set roll to maximum intensity - correct for backlash.
NOTES:
i) Correct for backlash by driving to first scan point, then to maximum (e.g. after scan drive relative position -0.1, then drive absolute position to max)
ii) Settling time of at least 1 second is necessary for this scan (this axis is UHV picomotor driven in PID)
4) Scan DCM 2nd crystal pitch:
Set slits to
| Slit | H Size (mm) | V Size (mm) |
| PBS | 2 | 2 |
| NES | 2 | 2 |
| BDA | 2 | - |
Scan control voltage for DCM piezo tweak with a scan width of ~3V, 21pts.
Set piezo to maximum intensity.
NOTES:
i) if voltage is trending out of range (1V<V<9V), set tweak to 4.5V and scan theta2 motion +/- 0.1mrad
5) Scan Undulators:
Scan upstream and downstream undulators with a scan width of 0.5 keV (1 sec settling time), drive to maximum intensity
NOTES:
i) Settling time of at least 1 second is necessary for this scan (possibly more)