A Mineral X-ray Linear Attenuation Coefficient Tool (MXLAC) to Assess Mineralogical Differentiation for X-ray Computed Tomography Scanning
Round 1
Reviewer 1 Report
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Comments for author File: 
Comments.pdf
Author Response
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Author Response File: Author Response.pdf
Reviewer 2 Report
Dear Authors,
The paper is well written, the presentation is well done and the results are sound. I found this work interesting and it will be surely very valuable to the X-ray CT community working in the field of mineralogy and more broadly in the geosciences. I would recommend the paper for publication with minor revision. I am attaching the PDF file with comments and also line by line in the below section.
Please find the details below:
Line 36-37: porosity and pore structure...X-ray micro and nano CT has been also widely used for characterising shale gas pore framework, e.g. Backeberg et al. 2017, Scientific Reports; Iacoviello et al. 2019, Scientific Reports; Ma et al. 2016, Marine and Petroleum Geology.
Line 86: The set voltage...Why did the Authors decide to use maximum energy of 180 kV instead of 225 kV? Given the fact you chose a Nikon XTH225ST for the Validation of Linear Attenuation Coefficients, I was expecting a 225 upper limit for the maximum energy. Could you please clarify that?
Line 95-96: Figure 1. I would suggest changing the secondary axis ticks to 5 keV increment so it will be more intuitive to read the values (e.g. 50 keV is now halfway between 40 and 60 but not in correspondence of a tick)
Line 122: the link is not working because one of the brackets was included in the link. Please check that.
Line 164: I have found a recurring 44.79 keV value. Could you please check that?
Line 168-169: Please provide more detail regarding the software.
Line 182: Could you also provide more detail concerning the mineral standards employed?
Figure 4: Does 44.79 keV value correspond to 68 kV tube voltage? For the example would it be better to use one of the values on the right? E.g. 45.50 keV?
Line 210: 44.79 keV, see the previous comment
Figure 5: I would suggest replacing the Spreadsheet label to MXLAC in the figure label.
Line 242: I would suggest keeping the letter the same, either all lower case or all upper case in both text and figures.
Figure 6: Are D and E positioned correctly within the figure? Shouldn't be there in the row below? Please check that
Line 261: Figure 6. Please see the previous comment. You could think of a better solution for mineral labelling in figure 6?
Line 277: 6%, Have the authors considered whether this value will change employing a different target material? (e.g. Mo, Ag or Cu?)
Line 291: Kaolinite should be lower case.
Line 313-314: The example shown...I found this a little bit confusing: you refer to figure 4 but when the reader goes to check, the linear coefficient 1.25 cm-1 differs from the one in the figure since a different starting Effective energy was used for the calculations. Could it be possible to use a more consistent effective energy throughout the whole manuscript?
Line 346; 5.26 and 5.18 g/cm3... add ", respectively"
Line 347: minimum density difference...Shouldn't this be 13.51%? Given the ratio between barite and magnetite? Could you please check that?
Line 397: geological samples. I truly believe that this tool could be valuable also to other fields e.g. material sciences and electrochemical studies. In fact, research groups working on electrode materials could benefit from the linear attenuation calculation. It might be worth adding a sentence in order to broaden the application of your MXLAC spreadsheet. Of course, this is just my personal point of view.
Supplementary materials:
I would make clearer which cells might be filled in and what are the output cells. It could sound unnecessary but some less experienced users could find the spreadsheet not very clear. I really liked the colour added to Figure 4. Could you possibly add a similar key?
Comments for author File: Comments.pdf
Author Response
Please see attached.
Author Response File: Author Response.pdf
