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Message ID: 525     Entry time: Mon Jun 19 11:36:37 2006
Author: Eric Dufresne 
Type: Other 
Category: Commissioning 
Subject: Don Walko's work on 6/18-19/06 (edited by ED 6/19) 
Date: Mon, 19 Jun 2006 05:55:02 -0500 (CDT)
From: Don Walko <d-walko@anl.gov>
To: MHATT-CAT Staff <staff@mhatt.aps.anl.gov>, Jin Wang <wangj@aps.anl.gov>
Subject: 7ID beamline flux
Parts/Attachments:
1 Shown 37 lines Text
2 OK 7.6 KB Image
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Hi all,

Attached is the flux I measured in the front of 7ID-C for the range of
accessible energies by the new diamond mono. The white-beam slits were
set to 0.5 x 0.5 mm^2. I'm not guaranteeing that every possible parameter
was optimized, but it's pretty close to what we can expect.

The lower energy limit of the mono is 4.68 keV, set by the upper limit of
theta (40 deg). The official upper energy limit is 23.9 keV, set by the
end of travel of Z2. But by fixing Z2 at its maximum, I was able to go to
the Ta edge at 24.43 keV.

I also corrected the offset of theta by performing EXAFS scans at multiple
edges. I determined the energy offset of the EXAFS features (greater at
higher energy) and converted that to an angular offset of 0.026 deg. I
put this number into EPICS, so it is now correct. EXAFS scans at the Cr
edge (6 keV) and the Mo edge (20 keV) were both correct within an eV.

See you all tomorrow, when I will be working with Michael Borland to
optimize our steering. Maybe we'll get even more flux out of that
procedure...

Don

P.S. From the editor: I add below two energy scans after calibration FYI.
Att. 2 and 3 Cr and Mo EXAFS
Attachment 1: 7IDCSpectrum.png  7 kB  | Hide | Hide all
7IDCSpectrum.png
Attachment 2: 7idc_0009_D04.png  7 kB  | Hide | Hide all
7idc_0009_D04.png
Attachment 3: 7idc_0010_D04.png  7 kB  | Hide | Hide all
7idc_0010_D04.png
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