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17.1 Getting Started With NIST DTSA-II
17.1.1 Motivation
Reading about a new subject is good but there is nothing like
doing to reinforce understanding. With this in mind, the
authors of this textbook have designed a number of practical
exercises that reinforce the book’s subject matter. Some of
these exercises can be performed with software you have
available to you—either instrument vendor software or a
spreadsheet like MS Excel or LibreOffice/OpenOffice Calc.
Other exercises require functionality which may not be pres-
ent in all instrument vendor’s software. Regardless, it is much
easier to explain an exercise when everyone is working with
the same tools.
To ensure that everyone has the tools necessary to perform
the exercises, we have developed the National Institute of
Standards and Technology software called DTSA-II (Ritchie,
2009 , 2010 , 2011a, b, c, 2012 , 2017a, b). NIST DTSA-II is
quantitative X-ray microanalysis software designed with edu-
cation and best practices in mind. Furthermore, as an output
of the US Federal Government, it is not subject to copyright
restrictions and freely available to all regardless of affiliation
or nationality. From a practical perspective, this means that
you can install and use DTSA-II on any suitable computer.
You can give it to colleagues or students. You can use it at
home, in your office, or in the lab. If you are so inclined, the
source code is available to allow you to review the implemen-
tation or to enhance the tool for your own special purposes.
Exercises in the textbook will be designed around the
capabilities of DTSA-II. Many will take advantage of the
graphical user interface to manipulate and interrogate spec-
tra. A number will take advantage of the command line
scripting interface to access low-level data or to perform
advanced operations.17.1.2 Platform
NIST DTSA-II is written in the multi-platform run-time
environment Java. This means that the same program runs
on Microsoft Windows (XP, Vista, 7, 8.X, 10.X), Apple OS X
10.6+, and many flavors of Linux and UNIX. The run-time
environment adjusts the look-and-feel of the application to
be consistent with the standards for each operating system.
For Windows, Linux, and UNIX, the main menu is part of
the main application window. In OS X, the main menu is at
the top of the primary screen.
To make installation as easy as possible on each environ-
ment, an installer has been developed which works on
Windows, OS X, and Linux/UNIX. The installer verifies that
an appropriate version of Java is available and place the exe-
cutable and data files in a location that is consistent with
operating system guidelines. Detailed installation instruc-
tions are available on the download site.17.1.3 Overview
DTSA-II was designed around common user interface meta-
phors and should feel consistent with other programs on
your operating system. It has a main menu which provides a
handful of high-level interactions such as file access, process-
ing, simulation, reporting, and help. Many of these menu
items lead to “wizard-style” dialogs which take you step-by-
step through some more complex operation like experiment
design, spectrum quantification, or spectrum simulation.
The goal is to make common operations as simple as possible.
Additional tools are often available through context sen-
sitive menus. Each region on the DTSA-II main window pro-
vides different functionality. Within these regions, you are
likely to want to perform various context sensitive opera-
tions. These operations are accesses through menus that are
accessed by placing the mouse over the region and issuing a
“right-button click” on Windows/Linux/UNIX or an Apple-
Command key + mouse click on OS X. The context-sensitive
menu items may perform operations immediately, or they
may request additional information through dialog boxes.
On the main screen, the bottom half of window is three
tabs—the Spectrum tab, the Report tab, and the Command
tab. The spectrum tab is useful for investigating and manipu-
lating spectra. The report tab provides a record of the work
completed during this invocation of the program. Since the
report is in HTML (Hypertext Markup Language) and stored
by date, it is possible to review old reports either in DTSA-II
or in a standard web browser. Some operating systems will
index HTML documents making it easy to find old designs,
analyses or simulations.
The final tab contains a command line interface. The
command line interface implements a Python syntax script-
ing environment. Python is a popular, powerful and com-
plete scripting language. Through Python it is possible
(though not necessarily easy) to perform anything that can
be done through the GUI. It is also possible to do a lot more.
For example, the GUI makes available some common, useful
geometries for performing Monte Carlo simulations of spec-
trum generation. Through scripting, it is possible to simulate
arbitrary sample and detector geometries. Some of the exam-
ples in the text will involve scripting. These scripts will be
installed with the software so they are readily available and so
you can use these as the basis for your own custom scripts.
An important foundational concept in DTSA-II is the
definition of an X-ray detector. The software comes with a
“default detector” which represents a typical Si(Li) detector
on a typical SEM. This detector will produce adequate results
for many purposes. However, it is better and more useful if
you create your own detector definition or definitions to
reflect the design and performance of your detector(s) and
SEM. You define your own detector using the “Preferences”
dialog which is access through the “File → Preferences” main
menu item. To select and activate your detector, you select it
in the “Default Detector” drop down lists on the middle, left
side of the main DTSA-II window on the “Spectrum Tab.”Chapter 17 · DTSA-II EDS Software