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Component | Specification |
Active area | 50 mm x 16 mm; 1600 pixels |
Max 2θ range covered | 12° at 435 mm diameter; 11° at 500 mm |
Usable wavelength | Cr-Kα to Mo-KαCr–Kα to Mo–Kα |
Max local count rate | 400,000 cps |
Spatial resolution | <50 µm; >1600 channels |
Gas fill | 3.04 bar Xe-CO2; no external supply needed |
Power rating | 120 W |
Ambient temperature | 41°–104°F (5°–40°C) |
Operating temperature | 57°–93°F (14°–34°C) |
Relative humidity | Maximum 80%80 %, noncondensing |
Detector Optics
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- Add 25 ml of 1% Borax solution to the clay plug
- Dismembrated Dismembrate the sample (machine is auto set on time), to remove the >2 µm clay fraction
- Centrifuge for 4 mins at 750 rpm, decant the suspended liquid into a separate centrifuge tube (you should end up with a ~full centrifuge tube of suspended clay)
- Repeat steps 1-–3 on the remaining >2 µm fraction
- Centrifuge the <2 µm fraction for 15 mins at 1500 rpm to remove the Borax solution
- Decanted and Decant and add 25 ml of nanno pure water
- Centrifuged for 60 mins at 3000 rpm, the liquid decanted before loading onto a zero background silica disk.
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- Take the <2 µm clay fraction, this should be rinsed and free of any treatments, in centrifuge tube add ~20 ml of 1N HCl
- Vortex the sample to completely dislodge all material before pouring sample into a 100 ml beaker, add stir bar once sample is in place
- Set hotplate to 300°C (boiling point of HCl is ~101, but in order to maintain a continuous boil the hotplate needs to be much hotter)
- Set the stir RPM below 100, this is only to keep the material suspended within the HCl
- Start time once the samples have come to a complete boil, leave for 2 hours - — add more HCl as necessary (DO NOT, let the sample go dry and burn)
- Once the sample has boiled for 2 hours, turn off hot plate and allow sample to return to room temperature before pouring beaker contents back into a clean centrifuge tube, rinse beaker with DI water to collect all material
- Centrifuge down for 15 mins at 1500 rpm, decant acid and rinse with 25 ml nannopure (3X)
- After samples has been washed 3X and is free of HCl, centrifuge for 60 mins at 30 rpm
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5. Select the area around each peak as shown below in Figure 32. Click on either scan so that it is highlighted (Figure 32). Then click "Create Area" (Figure 32-232–2). A New window will pop up where you can enter the left angle and right angle (Figure 32-332–3, 32-4).
Figure 32: Create Area for Scan Angles. (1) Arrow points to scan name (2) Create Area tool (3) Left Angle entry field (4) Right Angle entry field
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- For 2θ Obs, use the Chord. Mid values from the Kα2 appended scan areas (Figure 31-131–1)
- For I Obs, use Net Area from the background subtracted scan areas (Figure 32-132–1)
- For FWHM, use the FWHM from the Kα2 appended scan areas (Figure 31-131–1)
Figure 31: Kα2 subtracted Scan Area column view. (1) Chord Mid value (2) FWHM value
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Scan Parameters includes the scanned angle range, angle step size, number of steps, time per step, and delay time (Figure 42). Adjust the angle range depending on the material and scientific objectives. For example, if looking for clays, set a low angle (3° – 30°3°–30°). The step size determines how much the goniometer will move before recording more data. The number of steps will adjust itself based the step size and angle range. Time/Step controls how long each step is measured. The Delay Time will add in an amount of time to wait before scanning the next sample. The machine does have limits on these settings and if something is entered outside of its range it will alert you. Click "OK" and move onto Generator Settings. At low angles (2-4° 2theta2–4°2theta) there is a very sharp peak. This is caused by beam overspill onto the sample holder.
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