2001 June 19 - 22

Set up in-situ cell; Li4Ti5O12. Takes time to find beam at Ti edge; must calibrate at Cu, then check at Cr or V before going to Ti, Joe says.
 
Filename Time Range(s) Stepsize Time/pt Comments
19Jun01.001 17:15 -200,200 2 1 Looking for Cu K edge on our way to lower energy.
Found it; now let's try Co
19Jun01.002 17:38 Co edge - looks fine, only ~ 1 eV off in calibration
19Jun01.003 18:10 Cr edge; looks fine; calibration ~ 1 ev off
19Jun01.004 -10,10 0.5 Ti edge; don't go more than ~ 30 eV below edge
19Jun01.005 18:40 -10,50 0.5 Ti edge; weird step and no peak?
19Jun01.006 18:45 glitch in I0 at ~20 eV above edge; change mono settigs and see if it's still there
19Jun01.007 19:40 New beam; see if glitch is still there
19Jun01.009 20:05 Remove exit slit assembly, try again; glitch is still there
19Jun01.010 20:20 -50,400 1 1 Look for more glitches
19Jun01.01x Cell appears to be too thick; too much absorption
At higher energy, get some transmission
at 10 kev, I is 0.55 w/ nothing, 0.31 w/ Al only, & 0.18 w/ Al + membrane
=> perhaps the electrolyte? Calculate est. thickness using www-cxro.lbl.gov; if electrolyte is ~1 mm thick, as Fabio estimates, this may e enuf to account for absorption seen
Turning up gain on It b 100 allows a very slight Ti edge to be seen
19Jun01.014 8:30 -10,30 1 1 Next day; still only very small Ti edge - actually, this "edge" is merely the glitch just above the Ti edge
20Jun01.001 8:40 -20,20,50,200 0.5,1,1 2,2,2 Just the membrane + Al backing; these are fine spectra
20Jun01.002
Membrane gives good spectra; try cell again. Many glitches; much lower transmitted current -> probably too much absorption.
20Jun01.005 10:00 4,4,4 Cell again; get same glitches as w/ shorter tim/point, merely better statistics
20Jun01.006 10:40 2,2,2 Wider beam (18 mm instead of 8 mm); retry cell
20Jun01.007 11:20 Try another cell; 27.5 mg
20Jun01.008 12:31 -10,10 1 1 Fluorescence on the Ti membrane.
20Jun01.009 12:36 -10,20,100 0.5,1 1,1 Fluorescence on a wider range.
20Jun01.010 12:56
20Jun01.012 13:12 Fluorescence of cell after vertical positioning
20Jun01.013 13:40 -20,20,50,200 0.5,1 2,2,2 Fluorescence exafs scan on Ti cell. Noisy, but there's some exafs present. Let's try a longer scan.
20Jun01.014 14:20 -20,20,100,500 0.5,1,12 3,3,3,3
20Jun01.015
20Jun01.016 16:08 -20,0,100 0.5,1 1,1 Back of membrane (through Al foil) fluorescence, to check why we're not getting signal
20Jun01.017 18:22 -20,20,100,500 0.5,1,2 1,1,1 Exafs scan test. Edge jump of about 0.6. Almost linear soon after
20Jun01.018 18:36 -20,20,25k 0.5,0.5k 3,3 Ti B exafs scan with longer integration times in hopes of less noise, and longer range. One small peak and no oscillations thereafter. Oscillations confined to a very small region after the edge. Strange Io, varies a great deal.
20Jun01.019 18:52 -20,20,500 0.5,1.0 3,3 Ti B third exafs scan. shorter range. 1 good scan.
See 21Jun01.013-014 for 2 more exafs scans.
20Jun01.020 20:57 -20,20,500 0.5,1 3,3 Ti C exafs scan. shorter range. 1 good scan.
See 21Jun01.015-016 for two more Ti C scans.
20Jun01.021 21:47 -20,20,500 0.5,1 3,3 Ti D exafs scan. shorter range. 1 good scan.
See 21Jun01.018-019 for 2 more exafs scans.
20Jun01.022 " " " Ti E exafs scan. Beam interrupted.
20Jun01.023 " " " Ti E exafs scan. 1 good scan
20Jun01.024 01:04 -20,20,500 0.5,1 3,3 Ti E exafs scan.
Problem with Io, beam shifted. Big glitch in Io, even after we got the beam back in place.
It is possible that the first small peak is due to the glitch rather than to the pre-edge. Computer in loop. Needed reboot.
21Jun01.001 02:07 -20,20,500 0.5,1 3,3 Ti E exafs scan. Note: typo in comments line. x=0.0 after one cycle for Ti E
21Jun01.002 02:58 " " " "
21Jun01.003-012 03:54 " " " Ti F exafs scan (10 scans)
21Jun01.013-.014 10:04 -20,20,500 0.5,1 3,3 Ti B Li(4/3+x)Ti(5/3)O4, x=0.75; 2 more exafs scans.
Beam dump during second scan.
21Jun01.015-016 11:54 " " " Ti C; 2 more exafs scans.
Last scan was not good....25 minutes left to go and no oscillations.
21Jun01.017 12:42 " " " Ti C exafs scan. Note: glitches in Io early in the energy range.
Do not mistake this for the pre-edge!
21Jun01.018-019 13:22 " " " Ti D exafs scans.
21Jun01.020-21 16:17 -20,20 0.5 2 PV10R1 energy calibration.
At 20 we are right before the edge.
21Jun01.022 16:24 0,50 0.5 2 PV10R1 energy calibration.
New range 0,50.
21Jun01.023 16:29 -20,20 0.5 2 Energy calibration for PV10R1.
The derivative was broad and showed the edge about 33 eV after Eo.
Derivative graph shows 12.69 keV.
21Jun01.024 17:10 0,50 0.5 2 PV10R1 energy calibration with a reference. Eo for the the reference Se foil is 12.66 keV, about 30 eV below the edge of our sample.
21Jun01.025 17:20 -200,-100,-20,50,22k 10,2,1,0.05k 2,2,2,2 PV10R1 exafs scans (3)  However, at approx 5 ,mintes into run. scan stated that detector has exceeded 10 volts and may be saturated.  Intensity and current have dropped considerably after 10 after 10 minutes into the scan.  After 20 minutes, I aborted scan and shut off beam line. Reason: the reference Se fell off of place.
21Jun01.026-028 18:01 -200,-100,-20,50,22k 10,2,1,0.05k 2,2,2,2 exafs scans.  Beam dumped during third scan.
21Jun01.029 21:43 -200,-100,-20,50,22k 10,2,1,0.05k 2,2,2,2 oops, reference beam had voltage > 10 volts. Reduce gain on Ir and start again.
21Jun01.030 21:47 " " " PV10R1 exafs scan
21Jun01.031 22:19 -1,1 0.1 1 PV15R1 vertical motor scan....wrong range--oops and sample way too low.  Adjust motors and recalibrate.
21Jun01.032 22:28 -10,10 0.1 1 vertical motor scan 2
21Jun01.033 22:34 -10,4 0.1 1 horizontal motor scan
21Jun01.034 22:39 -10,10 0.1 1 oops typo in range for vertical motor scan.
21.Jun01.035 22:43 -10,10 0.1 1 vertical motor scan
21Jun01.036 22:47 -10,10 0.1 1 horizontal motor scan.  Sample is quite even.
21Jun01.037-039 22:47 -200,-100,-20,50,22k 0.1 1 PV15R1 exafs scans
21Jun01.040 00:58 scan aborted
22Jun01.001-003 00:59 -200,-100,-20,50,22k 10,2,1,0.05k 2,2,2,2 PVw/Ga exafs scans.  Glitches in Io appear in the exafs around 13425-500 and after, well after the edge.
22Jun01.004 02:43 " " " PV10R1 In K edge exafs scans.  Maximized It with vertical and horizontal motor scans.  Energy calibration with In reference shows very similar Eos.  Aborted--getting much too much noise.  Increase gain for Io and It, tweak current suppression.  Decreased current by an order of magnitude.  Numbers are good on feedback, but signal on oscilloscope begins to oscillate wildly on its way to losing lock.
22Jun01.005 03:03 -10,10 0.1 1 PV10R vertical motor scan after recalibrating.
22Jun01.006 03:10 -10,4 0.1 1 horiztontal motor scan
22Jun01.007-009 03:11 -200,-100,-20,50,22k 10,2,1,0.05k 2,2,2,2 PV10R1 exafs scans (In K edge).  Scan 1 is now much less noisy than the first attempt.  Scans are very similar but there is a slight decrease in amplitude after each scan. 
22Jun01.010 04:25 -10,10 0.1 1 PV15R1 vertical motor scan at In K edge.
22Jun01.011 04:26 -10,4 0.1 1 PV15R1 horizontal motor scan
22Jun01.012-021 04:30 -200,-100,-20,50,22k 10,2,0.05k 2,2,2,2 PV15R1 exafs scans. Scans 18 and on are not good....
22Jun01.022 09:33 -10,10 0.1 1 PVw/Ga Vertical motor scan #1- oops scanned for horizontal by accident.
Beam dump til 1 pm. argg!
22Jun01.023-031 15:01 various motor scan by Joe Woicik after big problems with Io and gain.
Joe worked over an hour trying to diagnose problem...we got up and running for exafs scans but Joe is still uncertain about the cause.
There must be some problem with the lock on the monochromator after the long beam dump.
Unfortunately, with the gain at 9, our scan is noisy but Io and It are much too weak with a lower gain.
22Jun01.032-40 15:19 -200,-100,-20,50,22k 10,2,0.05k 2,2,2,2 PVw/Ga In K edge exafs scans.
23Jun01.041-48 09:39 -200,-100,-20,50,22k 10,2,0.05k 2,2,2,2 PVw/Ga In K edge exafs scans. Aborted 48 (enough scans).