Name:Spectrum Wobbler Version:1.0.0

Required Hardware:

Gatan EELS

Required Software:



This plug-in shifts (wobbles) the spectrum on the detector during the SI data acquisition. The spectrum will be accumulated after adjusting the spectrum shift to reduce the channel gain/dark current variation.



Download:   Spectrum Wobbler plug-in

for GMS 3.x (64bit)
for GMS 2.3 32bit    GMS 2.3 64bit
for GMS 2.1 32bit    GMS 2.1 64bit


1) Copy the files to DM Plug-Ins folder, and then launch the DM again.

The Spectrum Wobbler will appear in the sub menu of Floating Windows under Window menu.

2) Select the Spectrum Wobbler from the Floating Windows sub menu to open the tool palette.

3) Start the Spectrum Wobbler before acquiring an SI data, and stop the Wobbler after data acquisition.

4) The obtained spectrum should be adjusted by yourself using cross-correlation of the spectrum feature or the zero-loss shift of the low-loss spectrum in the case of DualEELS.

Recommended settings:

Step: a small fraction of channel energy width (dispersion)

(e.g. 0.2 x channel energy width)
NOTE: Since the energy shift will occur asynchronously with the SI data acquisition, we cannot control an energy shift timing. Therefore, the energy scan step should be a small fraction of an energy dispersion not to degrade an energy resolution.

Interval: close to an exposure time of the spectrum

Range: close to (channel energy width) x (number of channels to be averaged)

(e.g. channel energy width x 50)

Example settings:

Step = 0.05 eV for the channel energy width (dispersion) of 0.25 eV/channel (0.25 x 0.2)
Interval = 0.01 mec for the spectrum exposure time of 5 msec (0.005 x 2)
Range = 10 eV for the channel energy width (dispersion) of 0.25 eV/channel (0.25 x 40)


Reference(s) to be cited:Spectrum Wobbler plug-in provided by HREM Research Inc. and freely downloaded at