Help for ORNL/UGA Charge Transfer Database

This page is intended to assist the reader in navigating and using the WWW pages of this site, describing the types of data found here, and indicating the function of various buttons and options.

Cross Section or Rate Coefficient Index Page

Charge Transfer Data

This database consists of charge transfer cross sections and rate coefficients obtained primarily from the literature, but also from unpublished external sources as well as data produced by the ORNL Atomic Physics Group. The data consists of experimental, theoretical, and recommended results.

Please note that in many cases the data have been scanned and digitized from graphs and so may not reproduce exactly the original data. Acronyms used throughout the database are :

BEA - binary-encounter approximation
CDW - continuum distorted wave
CTMC - classical trajectory Monte Carlo
E - experimental data
LZ - Landau-Zener
QMOCC - quantal molecular-orbital close-coupling
SCAOCC - semiclassical atomic-orbital close-coupling
SCMOCC - semiclassical molecular-orbital close-coupling
QWP - quantal wave packet

Cross Section or Rate Coefficient Index Page

The index page and all pages below it in the website structure rely upon Java and Javascript for proper functioning. Select the ion for which cross sections or rate coefficients are required from the appropriate drop-down list then press the "GO" button.

Data Selection Page

Once you have selected the desired system from the Index, you will be presented one or more available data sets for that system. The form on the topmost part of this page allows you to select one or more experimental data sets as well as one or more theoretical data sets. If you select no data sets, you will receive an empty graph. You can choose whether to plot the interaction energy on a logarithmic scale and whether to use grids or ticks to indicate the axis scales. The standard plot features colored data points on a white background; to see a black background, choose the "reverse video" option. Once you have made your selections for data sets to include and plotting options, press the "Plot Selected Data Sets" button to open the Java-driven plot window. Please see the following section for information about the Plot window.

The middle section of the Data Selection page allows the user to view the data sets in tabular form one at a time via the drop-down list. Select the data set of interest and press the "Display Selected Data Table" button to open the Data Table window.

The bottom section of the Data Selection page lists the references for the original publications of the experimental and theoretical data. If the data is unpublished, the researchers involved in the work are listed along with the year the experiment was performed. Note that in many cases, a joint paper with experimental and theoretical results was published, resulting in a single reference.

Plot Window

The plotting is done by the ptPlot applet (version 1.13) written by Edward A. Lee and Christopher Hylands © University of California, Berkeley. The user may zoom in on any portion of the graph for closer examination by left-clicking the mouse and dragging the zoom rectangle to enclose the desired area. The zoom-in process can continue almost indefinitely. Zooming out to the original view is accomplished by clicking the "fill" button in the upper right-hand corner of the window.

The cross sections are always in units of cm² and the energy in units of eV/u. The plot applet sometimes scales the axes by factors of powers of ten; these are indicated at the far-right (x-axis) or top (y-axis).

Printing: At the present, most browsers are not capable of printing Java applets and simply leave a blank space in the output. For this reason, the browser menu and toolbar have been disabled for the Plot Window. Hopefully, future versions of browsers will remove this limitation. If you require hardcopy of any plot, we suggest you employ a screen-capture program to capture the graph from your screen as a bitmap image and then print it with a standard graphics viewer.

Data Table Window

The Data Tables are created from the same raw data files used to produce the plots. An HTML page is created with crude formatting (to be improved later). The data can be easily saved or printed. Hence, the browser menu (including Print) is enabled for this window.

Navigation Buttons

The following is a brief description of the navigation buttons found at the left side of the Data Selection pages:

	Return to the Cross Section or Rate Coefficient Index page (Javascript version).
	Return to the Introduction page of the ORNL/UGA Charge Transfer Database for Astrophysics..
	Return to the homepage for the Controlled Fusion Atomic Data Center at ORNL.
	Displays this help page.

Last Modified: June 28, 2001
By Phillip C. Stancil based on a version by Mark E. Bannister.