MeV Ion beam analysis of granite in 10000 points

The dataset presents 10000 ion-beam-analysis (IBA) measurements of a granite using 2970+-20 keV protons. Figure 1 shows an example of the result. 10,000 points are acquired in a regular 100x100 point grid with 50 µm beam spot size and step-size. Four detectors acquire the data simultaneously for RBS, NRA, PIGE, and PIXE. The description of the end-station and detectors can be found here: https://doi.org/10.3390/instruments5010010.

Each point on the sample consists of 4 files, four detector spectra. The filename consists of the sample name, three positions in units of nm (X, Y, Z), a rotation in units of µ° followed by an underscore ( _ ) and the type of data contained in the file (RBS, NRA, PIXE, PIGE, or Meta). Only X and Z positions are relevant in this case as indicated in the attached figure.

The RBS, NRA, and PIGE detector files contain a header specifying the dead- and live-time followed by two columns. The first column represents the digital channel of the detector. The second column represents the counts acquired in this channel. This format is readable as ASCI by SimNRA7. The PIXE file contains the number of channels in the first row/header and only the counts in the subsequent rows. The channel is given by the row number. This format is readable by GUPIXWIN3.

The channels of the detector files can be re-calculated using a calibration shown in the following table 1. Certain drifts in the calibrations are possible, but should be limited to below 2% of the given value. All points are integrated to the same ion dose of 0.07 µC. This corresponds to a Particle*Sr of about 5.0E+09 (RBS detector), 5.4E+10 (NRA).

RBS Spectra can be empty or feature a strong low energy background due to excessive scintillation light. Empty spectra can be ignored. The background can be mitigated by ignoring channels <150.

Table 1: Detector calbration enabling a recalculation of channels to energy. Units are in keV