Manual

for the

LabView Control of the ims3f Ion Microprobe

Introduction

The old HP 9845B computer has been used to control the 3f for so many years, that replacement parts were difficult to come by. In addition, all the trusted old analysis programs have grown into a such a maze of different, "personalized" versions, that it is hard to keep track of what is up-to-date, what works and what not.

That is the reason, why we have (in 2002) replaced the instrument control with a new one that runs on a NT workstation and uses the LabView programming language. This new software is supposed to cover all the applications that the 3f has routinely been used for, while allowing maximum flexibility.

This manual discusses the different programs and subroutines one-by-one as shown in the table of content below. Individual pages can easily be printed from the web browser.

Frank J. Stadermann

This manual is also available as a pdf-file for download.

1. Starting Hardware and Software

This sections describes all the steps that are necessary to activate the new interface and shows how the LabView software has to be started on the NT workstation.

2. Side Menu Bar

When the LabView software is running, this window is the central anchor point around which everything else is arranged. From here all the other programs and subroutines can be started, many of which can run simultaneously.

3. Initialize

This program covers everything the old INITIA program on the HP could do and then some. The basic operating conditions of the instrument can be set here, as can the user name which will be saved along with every data and setup file that gets created.

4. Main

This is the Main program, which shows currents, count rates and masses. All those things that are important when you are setting up the instrument.

5. Periodic Table

This periodic table can be accessed from several other programs, whenever input of a mass is required. It shows all elements with their isotopes, relative abundances and atomic masses. It takes only a few clicks to determine the most abundant Nd isotopes or the exact mass of 28SiH.

6. Mass Calibration

Another one of those un-exciting, but extremely useful tools. It does the same job of mass calibration that you could always do with the HP, only better. By using interactive graphic, it is easy to see what you are actually doing (or doing wrong) when calibrating masses.

7. Stability

This routine will just monitor one of three signals (primary beam in the FC, secondary signal in FC or EM) over any length of time. Both axes can be set to scale automatically, so you always know where you are.

8. High Mass Resolution Scan

Here you can look at the details of mass peak and find out how good a tuning job you did. To make life easier, this program automatically calculates the mass resolution after each scan.

9. Holder Control

This tool controls the movement of the sample stage. You can store any number of locations and move to them later with just one click. Among the niftier features is the option to load an SEM image of your sample into the "background" of your holder display. Once everything is nicely aligned, it is possible to just click into the image to have the stage move to the respective location.

10. Setup 1 for Isotopic Measurements

The setup for isotopic measurements is spread out over several windows. In this first one, the masses that are to be measured and the measurement times are entered. It is possible to load previously saved setups and to pick elements/isotopes directly from the a periodic table. This program also understands what something like "13C H" means and automatically calculates the right mass (14.01118 amu). In addition, the mass resolution necessary for separating peaks can be calculated.

Note: There is another measurement type ("Trace", see section 21 below) which is frequently used on this instrument. Both of these measurement types are much more versatile than their names imply. The basic difference is that "Isotopic Measurement" refers to an analysis at high mass resolution, while a "Trace Element Measurement" is done at low mass resolution.

11. Setup 2 for Isotopic Measurements

Once we know what we want to measure, we do all the other adjustments in this window. Among the things entered here are: number of cycles and blocks, reference peak for energy offset, peaks to track. You can also choose what signals and ratios are to be monitored during the measurement.

12. Setup 3 for Isotopic Measurements

If you make several measurements with the same basic setup, this window is the one that you will always come back to. (Setup windows 1 & 2 only show up once.) Here we set things that might change for different measurement spots: stage position, file name, sample description. You can also define certain "stop conditions" that will cause the program to abort immediately should they come up (e.g. unexpected switch to FC or count rate going below a certain level).

13. Isotopic Analysis Running

While an isotopic measurement is running, this window is the central anchor. It displays which BLOCK and which RUN is currently being executed and it allows real-time changes to these parameters. In addition, there are several subwindows that can be accessed from here that are useful to watch the progress of the measurement.

14. Analysis Record

This is another window that always shows up during a measurement. It gives step-by-step information on what the instrument is currently doing, what the next 7 steps are and what the results of the previous 14 steps were. This large window can be reduced in size if necessary.

15. Manual Calibration

When positions of mass peaks need to be calibrated manually at the beginning of a measurement, this window shows up. It waits for user interaction, while the primary beam is turned off. After the user starts the actual calibration, the beam is turned on and remains on for the measurement.

16. Graph of Magnetic Field Shift

If a running measurement uses automatic peak centering (the default), it can be helpful to check for shifts of the magnetic field. This window displays the relative shifts in single bit B-field values.

17. Graph of Counts and Ratios

Here it is possible to watch the cycle and block results while they are 'coming in' in real time. This is not only helpful for the very impatient operator who wants to know the samples composition immediately, it also helps to decide whether a measurement should be shortened e.g. because a sample is sputtering away or because something else went wrong with the analysis.

18. Data File View

Up to three different data files are simultaneously being produced during a measurement. These data file windows make it possible to watch these files growing.

19. Remote Control Server

It is possible to watch the progress of a measurement on the 3f from any internet-connected computer in the world. Access options can be controlled from this remote control server window

20. Remote Control Client

This is the program that runs on a client computer (i.e. not the one attached to the 3f) anywhere in the world or just next door. When started, it will try to establish a connection to the server and show what is going on with the measurement. If the connection fails (e.g. because remote control is disabled) it tries to connect again every 10 seconds.

21. Setup 1 for Trace Element Measurements

This analysis type is used for measurements at low mass resolution and does not necessarily have to include trace elements. In this first setup step the masses that are to be measured are selected from an array of buttons, representing the masses 1 through 240. In addition, several other masses for calibration and tune-up are chosen here. It is also possible to save these set-ups in a file for later use.

22. Setup 2 for Trace Element Measurements

Here the details of the measurements are set. This includes file names, number of cycles, sample description and the like. Between measurements, you always come back to this window to change these details for the next analysis spot.

23. Trace Analysis Running

Once a measurement is started, the trace anlysis running window shows up. The options in this window change depending on which phase of the analysis is currently executed. Some initial steps require operator interaction to tune up the beam or the magnetic field.

24. Manual Mass Peak Centering

This program can be used to perform a mass peak centering routine manually. It is fairly flexible and automatically calculates the mass resolution. This program is also called several times by the analysis programs Iso and Trace, but the user interface is limited in these automated measurements. The main difference between this program and the 'High Mass Resolution Scan' (Section 8) is that this routine is optimized only for finding the center of a given mass peak in the shortest possible time. It does not perform a complete scan across the peak as the 'High Mass Resolution Scan' does.

25. Manual Energy Edge Determination

This is the same routine that is called by the analysis programs Iso and Trace, with the only difference that here it is being started manually. It finds the center of the secondary ion energy distribution and the 'energy edge'. It can be used to set the extraction voltage to a predetermined offset value.

26. Image Acquisition

For secondary ion image acquisition, the control over the instrument is turned over to the Silicon Graphics computer. The Image Acquisition program acts as an intermediary with only limited direct user interaction. Its main function is to pass commands and responses back and forth between the Silicon Graphics computer and the 3f instrument.

27. Deadtime Measurement

A deadtime measurement consists of many repeated isotopic measurements, where the count rate is constantly changed between runs. A typical deadtime measurement on Si runs over night and consists of more than a hundred individual Si isotopic measurements with the 28Si count rate varying between 200,000 and 1,000,000 c/s. Here we discuss the changes that have to be made to a normal isotopic measurement to make it useful as a deadtime measurement.

50. Files and Folders

The software needs to know the paths to many different setup files and data has to be saved somewhere, too. All of these paths can be set from here. Thus it is possible to "personalize" the program without affecting other users.

Note: This function is for advances users and not necessary for a general understanding of the 3f software otherwise.

FJ Stadermann, 9/2000
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