I am a new user working with SAXS. Recently, I got SAXS data with exposure time 0.5sec and 1.0 second .After processing the data, the two curves have different peak intensities for same q range.
The overall beam intensity is not only dependent on exposure time. At particular moments during a day the synchrony is injected with new electrons. This gives a fast increase in intensity and afterwards it slowly decays again until the next injection.
Therefore, it is better to use the signal of the ion 1 counter for normalizing your data, since it counts the overall intensity within a particular exposure time at that particular moment. Thus it also normalizes for exposure time. This data is typically being listed in the raw files
@Rogier Besselinkthanks for response...Actually, my problem is more concerned regarding processing the data at different exposure times. if you can advice me regarding that , it will be more help full for me. actually, i did experiment to investigate filler effect on matrix material. but as the concentration of the filler is chnged, there is saturation and to aviod saturation exposure time was reduced. so i got 5 samples with increasing concentrations, among them three have a different exposure time like 1st have 5sec, seconed with 4, third with 4sec, fourth with 3sec, and fifth with 0.5 sec. Now if i straight away plot this data , it does not make any sense because the number of photons bombarded on each samples are different so probability of scattering is definitely changed.
So, is that i need to manually process this data or i need to use any particular software as the data is in the form of 2-d images.One of the thing which i am doing is to process 2-d image, convert it into dat file and then open it with excell and manually normalise it with max intensity but in this method the out put file has excell file extension that again needs to change.
berside that, is it possible that i can compare two samples with different exposure times?
thanks
yes, I understand. Nevertheless, it does not change my answer: Ion 1 counter gives a sum of the intensity during a given exposure time. Therefore it scales with exposure time (large exposure time gives large ion 1). Devide it by ion 1 corrects for both filter setting and exposure time. On the other hand, for the samples where the detector is saturated, you will not obtain a reliable value of the intensity. Thus you cannot fairly compare that data.
Moreover, the ".dat" file is most likely an ASCI file.
In such file data is listed as text, with some spacer in between: this can either be a space, tab, comma. (you can view it with a text viewer)
After changing data in excel, you can again write an ASCI file, either:
.csv (comma separated asci file)
.prn (space separated asci)
.txt as an tab delimited text-file
You save it as such file and change the extension in windows explorer to .dat
If you have used the same spacer and kept the same arrangement, this data can be read by other programs again.
@Rogier Besselink..............bundle of thanks.....valuable discussion.......hopefully will remain in contact ................thanks
You must divide the intensity by the exposure time for purposes of comparison.
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