Remote Analysis on Earth

The Ion Beam Analysis facility at ASU allows you to peek at the work currently being done. By connecting to the Ion Beam Analysis web site, you can view the control screen of the accelerator as it is currently being seen by the researcher. (You may even catch a view of him as well.)

If you are using a Netscape Navigator Browser, you will see the spectrum on the screen updating every few seconds (dependent on the speed of your connection).

Other browser users can reload the screen periodically to see the progress of the analysis. (If the control screen or the button bar at the bottom is not in full view on your browser window, drag the lower right corner of your browser window to maximize its size.)

Analysis is being performed at the facility using both PIXE (the technique you will use) and RBS (Rutherford Backscattering Spectrometry). It is possible that you will be watching an analysis using the latter technique.

You might be interested in a description of the principles of RBS, which can be found in Fundamentals of Surface and Thin Film Analysis by L. Feldman and J. Mayer (North-Holland, New York, 1986).

Performing your Own Analysis

At the time of reserving a session at the Ion Beam Analysis facility, you will have chosen a specimen to analyze in your session. An operator will load this specimen at the start of your session. (Further developments at the ASU Ion Beam facility will allow the user to remotely load his specimen, but this is not yet functional.)

You will also have been given a user name and password. When you first try to control the accelerator, your browser will return with "Authorization Failed". This is because the system sees your Patterns password, which it does not authorize. You can then select to "Retry", and can then enter your Analysis User name and Password.

Read the following brief description of the controls you will need to perform an analysis, and then, at the scheduled time, perform the analysis .

In the lower-most frame you will see a series of buttons:

  • The "Acquire" button switches the analysis on and off. When you start the analysis, the previous analysis is cleared from memory, so you should have saved it if you want to keep it.

  • The "Save" button saves the spectrum you have just acquired. Your User name and current run number appear in red, in the central box near the top of the screen. When a "Save" has been successfully performed, this changes to yellow.

  • The arrow buttons move the cursors. The cursors identify the X-ray line corresponding to the energy at which they are located. The Ka, Kb, La and Lb lines of all elements are included in the data base. (Ka is used for Kalpha etc). Qualitative analysis of the specimen is possible in this way. (On slow web links, it is however rather time- consuming. Faster feedback is currently being developed.)

  • The red and yellow buttons select which cursor will be moved by the arrow buttons. (It is possible to move both red and yellow simultaneously)

  • The "Exit" button returns control to the Ion Beam Lab. You are however free to regain control again by pressing "Analysis" again.

During your scheduled session, an operator will be standing by in the laboratory. You may reach him with both loading/unloading requests and any difficulties at:

(602) 965-9613.

Go on to the PIXE Reading

Activity by Cecil Churms, National Accelerator Centre, Faure, South Africa


Page authored by the ACEPT W3 Group and Cecil Churms
Department of Physics and Astronomy, Arizona State University, Tempe, AZ 85287-1504
Copyright © 1995-2000 Arizona Board of Regents. All rights reserved.
Images courtesy of NASA