NADS – Java Issues and Frequently Asked Questions

Java certificate issues?

There was a security change to Jave 1.6.0_19 that is causing an issue with loading the NADS applet. The following site explains what you need to do to resolve the issue:

What is NADS?

Nuclear and Atomic Data Systems. It is a Java Applet that connects to a FUDGE server that allows for the user to chart and display nuclear cross sections and data.

What is FUDGE?

For Updating Data and Generating ENDL. It is a Python program that allows for the user to manipulate, plot and evaluate nuclear data.

What is the difference between FUDGE and NADS?

FUDGE is designed to be powerful and scriptable. However, this comes at a price of not being portable and simple. NADS is a user-friendly interface to FUDGE that is accessible by anyone with an internet connection.

What do I need to run NADS?

A browser with Java 1.4+ enabled and an internet connection.

How do I get Java 1.4+ for my browser?

This is one of the hardest part new users encounter. It varies by browser and OS. Here are some general tips:

How do I cut and paste or save data to a file?

You must first enable your Java policy to give the Java Applet permission to do this.

How do I set my Java policy?

Edit the .java.policy file in your home directory. On Windows it may be C:\Documents and Settings\$user\.java.policy or C:\WINNT\Profiles\$User\.java.policy. On Macintosh, orLinux, it is ~/.java.policy. The file may or may not previously exist.

Add the following lines to the file:

/* Gives the following permission to all Applets in the domain */
grant codeBase "" {
/* Permission to access the clipboard for cut and paste */
permission java.awt.AWTPermission "accessClipboard";
/* Permission to read and write all files on local computer */
permission "<<ALL FILES>>", "write, read";
/* Permission to read some user details like home directory */
permission java.util.PropertyPermission "*", "read, write";
/* Permission to modify thread properties */
permission java.lang.RuntimePermission "modifyThread";

If you are uncomfortable with any of the above permissions, then you can leave them off or restrict them more. For example, you could only allow for "read" privilidges. Or you can change "<<ALL FILES>>" to "${user.home}" or "c:\\temp\\-" or "c:\\temp\\*". Note: an asterik (*) is a wildcard and a minus (-) means directory recursion.

To just have the above text as your policy file, just save the following link to your home directory: .java.policy (Windows users should chose "All Files" under a Save As option or rename the file with the command prompt if it is saved as ".java.policy.txt".)

You may have to reload the applet and browser after updating the policy.

How do I perform a calculation?

First use the Database Directory (from the Data...Add menu) to find a set of data you would like to assign to a variable. Select the data and click on the Computation with Selected button. If more than one set of data was selected then the sum of the data will be assigned to a variable. Select additional data and click on the Computation with Selected button for each.

In the computation window, each set of data will be listed with an associated variable. Type in an equation like "(a + 2 ^5 * b) / 33" and hit the Process button or press return. The computation will be sent to the FUDGE server and the results will be displayed.

How do I reference NADS?

M. S. McKinley, B. Beck, and D. P. McNabb,, Lawrence Livermore National Laboratory Report No. UCRL-WEB-152626-REV-1, 2004 (unpublished).

What if I am stuck or have a question?

Send an email to


Updated:  October 18, 2004