HELP

Selection of Cases

The available cases are shown in the entry page. The present version of the SAHA database includes results from the NLTE-3 Workshop [1,2] for steady-state calculations. Two links at the bottom of this page provide links to important relevant information. First, a user can access a list of codes and contributors. Second, a link to the Call for Submissions that contains detailed information on cases, submission formats, and other relevant issues.

Access to the database

There are two types of data access. The participants of the NLTE-3 Workshop are granted an unlimited password-protected access. All other users can retrieve exactly the same sets of data, and the only difference is that in this case the code labels are hidden. This is done in line with the general agreement achieved at the NLTE-3.

Selection of Parameters

The first output page provides the set of available parameters and options.

Plasma Parameters

Provides a list of available values of electron temperature and electron or ion (for Xe) densities.

Global Parameters

These parameters describe the most general kinetic characteristics, namely:

total number of ion stages
total number of energy levels
mean ion charge
second central moment
third central moment
fourth central moment
internal energy
internal energy time derivative
partition function
maximal principal quantum number n
total statistical weight for ion stage

A detailed description and units for these parameters can be found in the Call for Submissions section. The global parameters are displayed for a selected range of temperatures or densities. Therefore, a user has to select a corresponding X-axis (T_e or N_e).

Ion Parameters

This set describes parameters characterizing specific ion stages. Those are:

total fractional ion population (sum of all ion populations is 1)
maximal principal quantum number n
total ionization rate (averaged over all levels within a specific ion stage)
fractional collisional ionization rate (i.e., ratio of collisional to total ionization rate)
fractional photoionization rate
fractional autoionization rate
total recombination rate (averaged over all levels within a specific ion stage)
fractional collisional recombination rate
fractional photorecombination rate
fractional dielectronic recombination rate
total number of levels within a specific ion stage
total statistical weight of all levels within a specific ion stage
α/S ratio (i.e., ratio of total recombination to total ionization rates)

The output is generated as a function of the ion charge for a single pair of T_e/N_e values.

Spectrum

The Xe case also contains data on bound-bound, bound-free, free-free, and total emission within the range of 9 to 120 Angstrom.

Java Plot Options

Database interface allows online generation of Java 2-D plots using the PtPlot applet developed in the framework of the Ptolemy II project at the University of California at Berkeley. The first output page provides options to (i) choose whether or not to create the Java plot (default is create), and (ii) select applet size in pixels.

Output Plot Axis Options

A number of output options are available for static plots:

logarithmic scales for X- and Y-axes (applicable to Java plotting as well),
minimum and maximum limits on X- and Y-axes,
plot rescaling (normalization) so that the maximum parameter value is 1 for each set of data,
stack plot option allowing to create a separate plot for each set of data rather than displaying all on one plot (only for static plots),
use of absolute rather than relative values for process rates.

Output

The final output page contains a table of output parameters (both HTML and ASCII), a Java PtPlot applet, and links to plots in different formats, namely, Portable Network Graphics (PNG), Portable Data Format (PDF), PostScript (PS), and Encapsulated PostScript (EPS).

Java Plot

A user may use a mouse pointer to zoom in and zoom out different areas on the plot. There are four buttons in the upper right corner of the plot which provide advanced control:

print button -- shows print control panel,
reset of the X- and Y-ranges to original values,
plot format button,
rescale button.

The "plot format" button allows user to modify plot title, X- and Y-labels, X- and Y-ranges, grid appearance, connecting lines, color/BW switch, and also set up user-defined ticks.

References

Yu. Ralchenko, R. W. Lee, and C. Bowen, in: Proceedings of the 14th APS Topical Conference on Atomic Processes in Plasmas, Santa Fe, NM (2004).
C. Bowen, R. W. Lee, and Yu. Ralchenko, J. Quant. Spectr. Rad. Tranf. 99, 102 (2006).

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Online: February 2006 - Last update: February 2006