Using the CMapp Extended Conditioning Feature for the microCMA

CMapp (software for the microCMA) versions 1.2 and greater now have a feature which allows for extended conditioning of the integrated 3kV electron gun.

To access this feature, first make sure that the Beam Voltage and Filament Current in the Electron Gun Controller are both turned off.

Open the conditioning dialog box by selecting the System / Conditioning… menu command or by pressing the Conditioning Icon on the task bar. Next, follow these steps:

Conditioning Icon
CMapp Conditioning Dialog
CMapp Conditioning Dialog
  1. Check the Filament Degas box and set the time in minutes that you want the filament current to ramp up. For new installations the degas filament current value is imported from the factory properties file and can be set for a time of 60 minutes. After the electron gun has been fully conditioned you can reduce the Filament Degas Time to as short as 5 minutes.

  2. Next check the Beam Conditioning box and set the starting voltage to 0 and the ending voltage to 3000. For new installations this can be set to 120 or 180 minutes. That is how long it will take to bring the beam voltage all the way up. After the electron gun has been fully conditioned you can reduce the Beam Conditioning Time to as short as 5 minutes, but 20 or 30 minutes is the recommended minimum Beam Conditioning Time.

  3. Next check the Filament On box. Checking this will keep the filament on while the beam voltage is being ramped up. This helps to condition the electron gun by letting the heat from the filament keep the electron gun warm.

  4. Make sure that the Multiplier Conditioning box is not checked and then check the Extended Conditioning box. If the Multiplier Condition box is checked then the Extended Conditioning box is grayed out.

  5. With the Extended Conditioning box checked, enter the amount of time that you would like to let the electron gun sit with the filament current on and the beam voltage at 3kV.  Typically, this time is set to 120 to 180 minutes.

  6. Press the Start button and the Conditioning routine will ramp up the filament, then ramp up the beam voltage, then hold the beam voltage at 3000V and keep the filament ON until the time runs down.

The Extended Conditioning feature helps to outgas the electron gun and condition the electron gun ceramics which in turn helps with the stability of the electron beam and data signal to noise.

Learn more about Auger Electron Spectroscopy and RBD’s microCMA.

CMapp for the microCMA Version 1.0 Released

RBD has released Version 1 of CMapp – the data collection, analysis and control application for the microCMA. Of course, this is not the first version of CMapp available, but we had a set of features in mind for Version 1 that would truly represent the most feature-complete version of CMapp. Of course, this won’t be the last version – we’re already busy adding new features and working on a completely redesigned application for a future release.

Download the latest version here.

Cmapp Version 1

Electron Gun Control Pane

The key new feature in CMapp 1.0 is the addition of the Electron Gun Control Pane, which replaces the dialog window. All of the electron gun controls are always available on-screen in the familiar layout. There’s no longer a need to move or minimize a window in order to view acquisition data.

CMapp Electron Gun Control

Other Features and Changes

CMapp now offers the ability to differentiate and smooth data while acquiring. This is invaluable for getting important peak information in real-time, and removes the need to wait until the end of an acquisition to determine if the parameters are resulting in useful / expected data.

The latest version of CMapp also includes the ability of the edit the Wehnelt setpoints in the Hardware properties menu. Normally these values are factory set, but now they are easier to adjust without putting undo “stress” on the filament by ramping the beam voltage from 2 to 3 kV before having ballpark Wehnelt values.

Lastly, some minor changes have been made to improve the UI when working with Windows 11.

CMapp New Features

We have added a few new features to CMapp, our microCMA acquisition and data massage software.

For example, when you first open the electron gun dialog box, a filament warm-up reminder pops up:

It is recommended that you warm up the filament at the beginning of each session so that the microCMA can thermally stabilize. The filament warm-up routine brings the filament current up over a 5-minute period and then keeps the filament on.  What is nice about this feature is that you can just click “Yes” and then walk away and come back later when you want to use the microCMA.

Another new feature is the “Auto Set the Beam Voltage to 2 kV ” for alignments:

The alignment acquisition is typically used to acquire a 2 kV elastic peak that sets the analyzer to the sample distance. Surveys and multiplexes are typically acquired with the beam voltage set to 3 kV.  Then, if you move to a new sample, or if you move the same sample to a new location, you would need to re-acquire a 2 kV elastic peak. With the “Auto Set beam to 2 kV” feature, you can just acquire the elastic peak alignment and the beam voltage will automatically change from 3 kV to 2 kV.

The new Diff/Smooth feature combines the differentiate and smooth commands into one click:

Related to the Diff/Smooth command is the ability to automatically Diff/Smooth at the end of an acquisition:

By checking the “Auto Diff/Smooth After Acquisition” box, the data will automatically differentiate and then smooth when the acquisition is complete. The “Auto Diff/Smooth” feature works for surveys, multiplexes, and alignments. Since you need to differentiate the data for quantification anyway, you might as well have it happen automatically.

Finally, we have added a feature that provides estimated target current. This is helpful if your target is grounded internally on your sample manipulator and you have no way to measure the actual electron beam current. Rather than using the emission current to set the relative target current, you can use the estimated target current to set the electron beam current to the recommend 300 nA.

First, select Estimate Target (Beam) Current in the Hardware Properties dialog box:

The estimated target current will be displayed in the Electron Gun dialog box as shown below:

Each electron gun filament behaves a little bit differently so the user-settable Emission Current-to-Target Current ratio can be adjusted in the Hardware Properties dialog box. We will have a video soon that will show you how to set this ratio.

If you have our 9103 USB picoammeter or some other picoammeter, you can measure the target current and enter the value into an acquisition manually (or, in the case of the 9103, automatically). You define this setting in the Hardware Properties dialog box.

If Estimate Target Current is selected, then the estimated target current will be entered into the acquisition before the acquisition starts. Whether entered manually, automatically, or estimated, the target current is displayed on the left-hand side of the alignment, survey, or multiplex acquisition.

For more information on our microCMA compact Auger Electron Spectrometer visit our website:

RBD Instruments microCMA