X23A2 Lab Notes 2000 Mar 1


Set up Displex.

Selenium sample in displex; displex not turned on.

First scans are motor scans.

Tried to adjust exit slit widths so that motor scans show a broad maximum, but didn't work.

Tried adjusting vertical entrance slit, but then it missed the exit slit

Sample appears almost unreasonably uniform on a horizontal motor scan.

Also on a vertical motor scan...perhaps It is saturating? Reduced gain to 8 and remeasured offsets.

Yup. It saturated, although it did so at 6.2 A. A bit weird, since I thought they were set up to go to 12, but maybe that's only on X23B.

Appears sample is smaller than beam both horizontally and vertically, but quite uniform. On Marten's advice, have calibrated at peak transmission and will run spectra.

01Mar00.001-019 Motor scans

Edge scan:

01Mar00.020 -300,300 5 1 Edge scan

Edge jump about 0.7.
 

01Mar00.021 -30,30 1 1 Edge scan

edge jump about 0.9 at higher resolution.

01Mar00.022-023 -200,-100,-20,50,25k 10,2,1,0.05k 3,3,3,3 room temp EXAFS

 
01Mar00.024-028 -200,-100,-20,50,25k 10,2,1,0.05k 3,3,3,3 270.0K temp EXAFS
aborted because no I0, no It
Tried increasing the gain of I0 and It to 9, but in vain.
need to use the oscilloscope.
problem seemed to be the water was turned off.

try again:

01Mar00.028-029 -200,-100,-20,50,25k 10,2,1,0.05k 3,3,3,3 270.0K temp EXAFS
aborted: the data looks funny. beam lost

after adjusting the oscilloscope:

01Mar00.030-031 -200,-100,-20,50,25k 10,2,1,0.05k 3,3,3,3 270.0K temp EXAFS

scans have a strange jump towards the end but look like room temp. scan before that.

01Mar00.032-032 -200,-100,-20,50,25k 10,2,1,0.05k 3,3,3,3 240K temp EXAFS

scan 32 aborted just to get more than two scans: 7 scans.

01Mar00.033-039 -200,-100,-20,50,25k 10,2,1,0.05k 3,3,3,3 240.0K temp EXAFS

Aborted before beginning #38; scans look funny;rising at higher energy, closer and closer to the edge. I hope there are a few ok scans. Let's try another temperature.

The later scans in this series were actually meaured on 2 Mar 00, but the numbering was not updated.