SOP: EDAX Eagle III Microspot XRF Page 1 of 6 SOP: EDAX Eagle III Microspot XRF 1. Scope 1.1 This document describes the standard operating procedure (SOP) for the EDAX Eagle III Microspot XRF. This X-ray Fluorescence (XRF) tool has the capability to achieve both fast and accurate elemental analysis of specific spots on even bulk samples. Although it is a closed cabinet system, because it uses an x-ray source, using this machine independently requires completing an x-ray safety training 2. Table of Contents 1. Scope... 1 2. Table of Contents... 1 3. Reference Documents... 1 3.1 Referenced within this Document... 1 4. Safety... 1 5. Setup Procedures... 1 6. Hardware... 2 6.1 Handles... 2 6.2 Loading a Sample... 2 6.3 Lights and controls... 2 7. Viewing the Sample... 3 7.1 Set up... 3 8. Collecting a Spectrum... 4 8.1 Getting Counts... 4 9. Characterizing a Spectrum... 4 9.1 Determining Elements... 4 10. Quantifying Results... 6 11. Shutting Down... 6 11.1 Saving... 6 11.3 Process Summary... 6 12. Revision History... 6 3. Reference Documents 3.1 Referenced within this Document 3.1.1 None 4. Safety 4.1 Follow all Nanofab safety procedures. 4.2 In order to use this instrument someone with Radiation Safety Training must be present 5. Setup Procedures 5.1 The liquid nitrogen reservoir must be filled at least an hour before using the XRF
5.2 Turn on the computer towers SOP: EDAX Eagle III Microspot XRF Page 2 of 6 5.3 The order the computers are turned on matters, so first turn on the silver EDAX tower and then the black PC tower. PC Tower EDAX Tower Cooling Tower Viewing Window X-ray Indicator Chamber Door Figure 2: XRF Towers Figure 1: Eagle III XRF 5.3.1 Make sure that both blue lights are visible on the EDAX tower 6. Hardware 6.1 Handles 6.1.1 With both handles up, the chamber is pumping and the x-ray source is on 6.1.2 With one handle up and one down, chamber is venting and the x-ray source is off 6.1.3 With both handles down, the chamber will open once the venting process is complete 6.2 Loading a Sample 6.2.1 Turn both handles down and wait for the door to open 6.2.2 Place the sample on the stage within the drawn white box 6.2.3 If the sample is a powder make sure to pile it up a little so the x-rays do not pass through 6.2.4 Close the door and turn both handles up 6.3 Lights and controls 6.3.1 Turn on the Power Key 6.3.2 Wait for the Pump Indicator AND Vacuum Indicator to turn on Place Samples Here HV Button Vent Indicator Pump Indicator Vacuum Indicator Power Key Figure 3: Chamber Stage Figure 4: Indicator Panel
SOP: EDAX Eagle III Microspot XRF Page 3 of 6 7. Viewing the Sample 7.1 Set up 7.1.1 With your sample in the chamber and the machine on, open the Vision 32 software icon on the desktop (Fig. 5) 7.2 Driving 7.2.1 Make sure the U-Probe Control tab is selected (Fig. 6) 7.2.2 Control stage motion with the Joystick Control (Fig. 6) by clicking to place the red crosshairs 7.2.2.1 The red crosshair represents the center of the stage, and the blue crosshair represents the center of the chamber 7.2.3 Stage motion may also be controlled using the Stage Control (Fig. 6) scroll bars, or by inputting numbers into the Stage Control boxes Main Toolbar U Probe Control Tab Figure 5: Software Icon Image Window Voltage Current Stage Controls Characterization Peaks Magnification Joystick Control Autofocus Data Bar Figure 6: Vision 32 Software
SOP: EDAX Eagle III Microspot XRF Page 4 of 6 7.2.4 Check the stage position by looking into the Viewing Window (Fig. 2) 7.2.5 For smaller adjustments, click the Joystick Control Button (Fig. 6), which will enable you to drag the Image Window (Fig. 6) 7.2.6 The red circle in the Image Window represents the area to be scanned 7.3 Focusing 7.3.1 Focus by adjusting the stage height 7.3.1.1 Adjust the stage height using the Stage Control (Sec. 7.2.3) 7.3.1.2 When the sample is roughly in focus, click the Autofocus button (Fig. 6) 7.3.1.2.1 If the Autofocus fails to run, this means the focus wasn t close enough 7.3.1.3 With the image now in focus, click the Magnification button (Fig. 6) to toggle to the higher magnification (there are only two magnifications on the XRF) 7.3.1.4 Focus at the higher magnification, adjust position if necessary (Sec. 7.2.5) 8. Collecting a Spectrum 8.1 Getting Counts 8.1.1 Press the HV (High Voltage) Button on the Indicator Panel (Fig. 4) to turn on the source 8.1.2 The Counts Per Second (CPS) can be found in the Data Bar (Fig. 6), and ideally should be over 1000 8.1.2.1 Beware having too many counts and saturating the detector, if the counts show up red during a scan they will need to be lowered 8.1.3 Counts are can be adjusted by changing the voltage or current in the U-Probe tab (Fig. 5) 8.1.4 Although the best settings differ by sample, a good place to start would be 30 kv and 750 ua 8.1.5 The Dead Time (DT) found in the Data Bar, should be between 20-40% 8.1.5.1 As Dead Time affects the number of counts, 20-40% is the ideal balance between signal and saturation 8.1.6 Adjust the Dead Time by changing the Amp Time located on the Main Toolbar (Fig. 6) 8.2 Generating Data 8.2.1 Once the CPS is satisfactory, it is now possible to collect data 8.2.2 If necessary clear any previous data by clicking the Clear button on the Main Toolbar 8.2.3 Click Start on the Main Toolbar to start collecting data. 8.2.4 The data will collect for a preset amount of time or until the Stop button on the Main Toolbar is clicked 9. Characterizing a Spectrum 9.1 Determining Elements 9.1.1 Make sure the Characterization tab is selected
SOP: EDAX Eagle III Microspot XRF Page 5 of 6 9.1.2 Click the Auto button within this tab. This will give the computer s best guess of what elements match the peaks WARNING Automatic Characterization is not a foolproof approach. It is not necessarily correct, but only close. The user will need to make adjustments only using the computer s guess as a starting point. 9.1.3 Select an element in the Sidebar, under the Identified Elements (Fig.7) that was generated by the auto characterization 9.1.4 Vertical bars should appear and line up with the peaks of the element selected 9.1.4.1 If the bars and peaks do not match up this is likely an indication the element is not present 9.1.5 To delete an selected element that doesn t seem to fit, simply click the Delete button 9.1.6 Check to see if another element would fit the peak better using the Z+ and Z- buttons 9.1.6.1 Z+ will step to the next element on the periodic table, while Z- will step to the next element down 9.1.7 Follow this procedure with every element that has been identified 9.1.8 If a characteristic peak has not been identified it may be necessary to add an element in 9.2 Adding Elements 9.2.1.1 Right click on a peak 9.2.1.2 Possible Elements (Fig. 7) should appear 9.2.1.3 Select the possible elements to judge their validity 9.2.1.3.1 Remember, to judge the accuracy the vertical bars and peaks should match up 9.2.1.4 Alternatively, simply use the Z+ and Z- buttons (Sec. 9.1.6) to find an element 9.2.1.5 Click Add 9.3 Peak Fit Figure 7: Sidebar 9.3.1 To check the accuracy of the elements found, added, and deleted perform a Peak Fit 9.3.2 Peak Fit will make an outline of the peaks that should exist based on the elements chosen 9.3.3 The peaks that exist and the expected peaks should fit each other well Characterization Tab Identified Elements Possible Elements
9.3.4 To run a Peak Fit simply click the Peak Fit button 10. Quantifying Results SOP: EDAX Eagle III Microspot XRF Page 6 of 6 10.1 Quantifying gives such useful information as atomic percent and percent by weight 10.1.1 With the spectrum characterized (Sec.9) select the Conc menu 10.1.2 A table containing the quantification should appear 10.1.2.1 Make sure to save this as a csv. file type 11. Shutting Down 11.1 Saving 11.1.1 If saving a quantification table make sure to save it as a csv. file 11.1.2 If saving a spectrum, save as a spc. file to edit the data in the future 11.1.3 If saving a spectrum, save as a jpg. file to view it on another computer 11.2 Powering Down 11.2.1 Go back to the U-probe Control (Fig. 6) 11.2.2 Turn down the voltage and current to their lowest settings using the slider bars 11.2.3 Turn one handle down (Fig. 2) to begin venting of the chamber and turn off the source 11.2.4 Once vented, turn the other handle down to remove samples from the chamber 11.2.5 Turn the Power Key (Fig. 2) off 11.2.6 Shut chamber door and turn ONE handle up to secure the door (but not pump down) 11.2.7 Exit the software 11.2.8 Shutdown the PC 11.2.9 Turn off the EDAX tower (Fig. 1) 11.3 Process Summary 12. Revision History Rev Date Originator Description of Changes 1 8/09/2010 Kathryn Ecsedy First Draft