When using ‘semilogy(X, 'r')’, the bin counts are plotted against the bin index rather than the actual energy value for each bin. To address this, I advise you to first calculate the bin centers to obtain the corresponding energy values and then use these values for plotting with the ‘semilogy’ function.
Additionally, if the peaks do not appear at the expected energies, calibration is necessary. For instance, if the left peak is located at bin ‘i1’ and the right peak at bin ‘i2’, with current energy values ‘E1’ and ‘E2’ respectively, these should be mapped to 511 keV and 1460 keV.
The following sample code demonstrates this approach:
[X,edges] = histcounts(Ge_table.energy,16384);
Z = histcounts(Ge_energy,edges);
bin_centers = (edges(1:end-1) + edges(2:end)) / 2;
[peakVals,peakLocs] = findpeaks(X);
[~, sortIdx] = sort(bin_centers(peakLocs));
peakLocsSorted = peakLocs(sortIdx);
i1 = peakLocsSorted(1);
i2 = peakLocsSorted(end);
E1 = bin_centers(i1);
E2 = bin_centers(i2);
a = (1460 - 511) / (E2 - E1);
b = 511 - a * E1;
bin_centers_calibrated = a * bin_centers + b;
semilogy(bin_centers_calibrated, X, 'r')
hold on
semilogy(bin_centers_calibrated, Z, 'b')
xlabel('Energy [keV]')
ylabel('Counts')
legend('X spectrum','Z spectrum')
title('Calibrated Spectrum')
grid on
By following this procedure, the spectrum will be displayed with the x-axis correctly calibrated to the desired energy values, ensuring that the peaks appear at the specified energies as shown below:
For more information, refer to the following documentations:
