X-Ray Diffraction under Extreme Conditions at the Advanced Light Source
Round 1
Reviewer 1 Report
Review of "X-ray diffraction under extreme conditions at the Advanced LightSource" by Camelia V. Stan et al.
The authors present recent achievements at the ALS with respect to x-ray diffraction at high pressure and high temperature. The authors intention is to provide an introduction to high- pressure and diffraction research performed at the ALS. For this purpose they include a summary of
single-, powder-, and Laue x-ray diffraction as well as a brief description of diamond-anvil cells and the constraints they impose to high pressure and high temperature (laser heating) experiments. Three case studies were chosen to outline the instrumentation available at the high-pressure beamlines of the ALS.
This manuscript has been submitted to a special issue that, according to the guest editor "aims to highlight the latest and most promising research" in the field of materials at extreme conditions. In this respect, the manuscript provides a brief overview of the basic requirements for x-ray diffraction
experiments at high pressure and temperature and could serve as a starting point for newcomers to the field. With this in mind I can recommend publication after my comments below have been considered.
Although a long list of references is included in the manuscript, references to textbooks and review papers are missing, in particular in sections 2 and 3.
line 63: Add here the text of line 74-75 to define h,k,l
I am wondering whether fig 1 and the subsequent equations (line 70-73) are really necessary or if a reference to a textbook is sufficient. The same holds for line 77-82.
line 97: It's not clear what the authors distinguish between "powder" and "polycrystal diffraction".
line 102: it should read "used"
line 105: strange character occurring twice
line 109: here the white beam option should be mentioned and a reference for a scanning monochromator included.
line 110: Nothing is mentioned about calibrating the scattering geometry (e.g. energy, sample-detector distance etc). Was this deliberate?
line 118 - 139: A reference for typical corrections applied to the recorded intensities should be added. Do the three equations (Delta, R_1 and wR_2) really help the novice reader or wouldn't a reference be better to not disturb the flow?
line 158: In my view powder diffraction is also used in "mineral physics" to identify phases but not most commonly. I suggest to delete "mineral".
Please add reference at the end of the sentence in line 143, 157, 164, and 169.
line 170: "in an ideal universe..." too philosophical, please adapt language.
line 191: it should read "pair-distribution"; add reference.
line 204: the sentence "a pair of left..." is not needed unless the author give a reason.
line 214: caption of figure 2 could contain a bit more information, like opening angle, overall dimensions, or the purpose of the Belleville washers.
line 229: "Q" is not defined.
line 230: delete "angular- and energy-dispersive"
line 236: Reference to Almax webpage
line 246: delete "confining ring". "In the case of both..."?
line 270: delete "anecdotically" and add at the end of the sentence "...when
used in high-temperature experiments".
line 272 - 280: this paragraph is not at the right place; consider moving it to section 3.2
line 290: use "non-hydrostatic" instead of "unhydrostatic"
line 328" delete "scales"
line367: replace "Light" by "X-rays"
page 11: some beamlines are not listed in the table: ESRF: ID15B (DAC) and ID06 (LVP); Soleil: beamline PSICHE; ALBA: BL04
line 493-502: the authors should consider including references to laser heating achievements at other facilities (e.g APS, ESRF, PetraIII)
line 595-608: nothing is mentioned about the calibration of the scattering geometry (e.g. LaB6 and Fit2D...).
line 747 (caption fig 6): not evident what "IIC" stands for.
Author Response
We have submitted replies to both reviewers and the editor in the attached pdf. Thank you very much for your hard work and comments. We believe they have substantively improved the quality of our submission.
Sincerely,
Dr. Camelia Stan.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
At present I’m afraid this manuscripts reads far too much as a thesis chapter than a review paper, and I feel that this should be addressed before it can be accepted (but this is at the editor’s discretion). I found that it was far too general and that the manuscript could be much more focused to the topic in hand. For instance, rather than describing how a synchrotron works in general terms – section 4 should really only start at line 391 with a summary of beamlines undertaking static high-pressure experiments and the following paragraph should focus on how synchrotron lights is advantageous to these types of experiments. The manuscript is also in need of quite a bit of editing, there are a number of times that points are repeated (such as the source for the beamlines in sector 12). Such editing and focusing of the paper to the contributions and experiments held at the ALS beamlines I think would make for a much stronger and more useful contribution.
In such papers I would not expect to see an outline of the basics of crystallography – but I would expect to hear about special or unique capabilities of the instruments described. In this sense sections 5 and 6 read well and are of interest and informative – but large sections of the previous sections do not.
I would suggest that the authors discard sections 2 and 3, edit sections 4-7 appropriately and resubmit the manuscript in a more focused form.
Some minor points:
Line 148 and 150 LeBail and Rietveld refinement should be referenced.
Line 159 – The ICDD is not a structural database, only a diffraction database – I assume the authors should refer to the ICSD or CSD
Figure 3 – I’m not sure it the term ‘insulation’ is quite appropriate here – isn’t this really the pressure transmitting medium?
Paragraph starting at line 363 is really a repeat of earlier points
Table 1: instert a reference for the Paris-Edinburgh press
Line 426 missing full-stop
Photos/layouts of the end stations of each of the three ALS beamlines would be helpful
Line 449 expalin what RDI is?
Figure 4 would be more useful earlier in the paper where DAC geometry is first discussed.
Author Response
We have submitted replies to both reviewers and the editor in the attached pdf. Thank you very much for your hard work and comments. We believe they have substantively improved the quality of our submission.
Sincerely,
Dr. Camelia Stan.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Very happy to hear that my review was useful to the authors - I have no further comments on the paper now.
