Run the
Application Running
the application
will download a Java
jar file
to run on your computer. Some browsers will cache the
jar file on your disk. Check for the
latest
version of Elfresco by going to Help-->About. The
latest version
is from 2/20/07. The jar
file will automatically start running when accessed from Windows
Internet Explorer. It may take a
few seconds before you see it displayed on your screen. Mozilla
browsers require setting up a helper
application to launch the jar file. Click on Java Helper Application to learn about that.
Run the Applet Running the applet will start Elfresco in your browser. For system requirements for the applet, click on Applet information.
Elfresco is a FusionGrid service hosted at the Princeton Plasma Physics Laboratory. Your computer running the applet or application must be within pppl.gov or authenticated through the PPL firewall to set up and run a simulation. In addition to a valid PPL computer account, you must have a certificate stored on the FusionGrid credential server to run the simulation. Request a certificate. The certificate will be valid for one year and will remain on the server. A proxy, valid for 14 days, will be created for you on the PPL cluster. Elfresco checks the proxy each time you run a simulation. If the proxy has expired then you will be prompted for your certificate passphrase. The status of your credential and proxy is shown in the Credential window. A green background indicates everything is valid and the simulation will run. A red background means the simulation will not run.
The system has several software components that run on different computers, as shown in the Multi-Tier Software Architecture figure below. The Java user interface typically runs on a user's desktop or notebook computer. It is portable to Windows XP, Linux, and the Macintosh OS. The graphical user interface enables the user to set up a simulation and verify the input visually. This client program sends requests to a Java servlet running on a PPL server. The servlet processes the request or runs programs on other PPL machines. The results are sent back to the GUI for visualization and interaction. Graphs of the input data and the computed solution are displayed with ElVis graph components. An overview of the system is shown in these screenshots.
The simulation is a 2-D wave propagation code. It takes an electron density profile as input and simulates a transmitter of different frequencies. The user defines separate regions for computing the full wave solution and the paraxial area. Visualization of the cut off frequency guides the user in placing the compute regions and setting the frequency of the transmitter. The full wave solution is computed and displayed as the intensity of the reflected component. If the user positions receivers then a correlation graph is produced. A description of the simulation, Two-dimensional simulations of correlation reflectometry in fusion plasmas by E.J. Valeo, G.J. Kramer, and R. Nazikian was published in Plasma Physics Control Fusion 44 (2002) L1- L10.
