The Opacity Project: R-Matrix Calculations for Opacities of High-Energy-Density Astrophysical and Laboratory Plasmas
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors are well versed experts with decades of experience in the field of
atomic computations and theoretical opacity studies. I would not expect to fault
them in their own field, but I already see a typo in their list of keywords
(missing an "n" in resonances").
Thus I guess that I should look for what the authors might have let slip,
because they are so self-assured?
L 26, ranges should be plural
L 28, transoport has an "o" too many
L 29, "... the laboratory for astrophysical processes to be benchmarked. They include ..."
Who is "they"? abundances are no processes -
in L 32 "they" seem to have morphed into parameters.
I did not expect such a density of language lapses, and such a feeling of misconstrued
phrases with words sounding specific (such as "countenance" as a verb), but not
actually hitting the point. The authors are living in the USA - how did they acquire
such a stilted, misplaced wordage?
L 35, what are "volatile elemental abundances"?
L 43, "R-matrix calculations hitherto proved to be intractable" - really? The authors have
been pursuing R-matrix calculations since decades. This lets me assume that their use
of "intractable" has deeper meanings. Maybe the authors could move themselves
to a communication style and level that is understandable also outside of their
inner circle. Instead of terse (computer) laboratory slang, I should hope for a
communication with the prospective readers in mind, readers who want to read and
learn, not just be shown that they are too far away to be taken into account.
L 40 to 50 provide a valid teaser that makes the reader want to learn more.
L 46: ref. 8 is cited twice in the same location, but not ref. 9, which apparently
is the subsequent paper in the same journal issue.
Citations in sequence 1,2,3,4,5,6,7,8,8,10,11,12,16,24,13,15,20,14,22,28,29,19,
6,15,6,9,9,15,9,12,11,etc reveal that the authors will have to spend more care on the
organization of their manuscript.
L 112ff tells of the shortcomings of another study (D21) compared to the authors' own work.
Such a catalogue of differences is sometimes interesting.
However, "... D21 did not directly compare their RM cross sections with NP16 cross sections."
is not a scientific shortcoming, but simply an observation. Such a comprehensive
critique might better separate technicalities and courtesies from scientific comments.
Thinking about a description that is easier to understand by somebody who is not
immediately involved and familiar with such problems might help with the clarity
of the comment, which does not have to be less damning, of course.
L 127 "... due to correspondence with energies with strong dipole transitions ..."
Please decipher.
Fig. 1 The legend praises the agreement of the RDW results with the background cross
sections, but this praise should be qualified: Outside of the range of resonances this
agreement is good, but within the range of the resonances, the situation is unclear at
best. What is truly background, what is the merger of many resonances?
Figure 2, "Exemplar" or "Example"? I suggest to add a hint that all curves are
computational; the red and blue curves show the result of "subjecting" the raw results
(black) to various electron densities.
Fig. 3 ought to use the full text width in order to be better readable
Line 167: " ... are and mainly autoionizing resonances ..." means what?
Figure 4, why are the axis labels in different styles?
dB/dT deserves to be explained
Section 5 is not easily understood by outsiders. Please try to rephrase in simpler
language.
L 231 "completness" is incomplete
Figure 5, why have the axis labels been distorted in different ways?
Sloppy editing: The punctuation in the reference section is missing blank, comma
or fullstop at least once each (refs. 1, 5, 18)
Is ref 4 still in press?
ref. 13 is incomplete,
is ref. 17 still only available as a Livermore preprint?
ref 20 has no location of the publisher
the citation style oscillates between different versions
In short: The topic is appropriate for the journal and a SI.
The care taken by the authors is visibly insufficient. It is one thing to excel in
physics, but another to let the reader trust in the authors' competence.
Poor text editing undermines any trust in the writers.
Mostly o.k. language-wise, but senselessly pretentious in parts.
It would be good to make the text more comprehensible by taking care of the flow
of logic and checking the actual meaning of the text formulated.
Author Response
See attached file
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsIn this work, Pradhan and Nahar report recent progress and numerical calculations concerning the Opacity Project, towards providing fundamental atomic data in support of high-energy-density astrophysical and laboratory plasma diagnostics. Utilizing standard R-matrix methodology in conjunction with a recently developed treatment of extrinsic plasma broadening effects, the authors compute photoionization cross-sections for Fe XVII and Fe XVIII, monochromatic and Rosseland mean opacities for these species and Fe XIX, as well as opacity data for Fe I. Notably, the authors investigate broadened photoionization spectra and opacity data under a range of plasma conditions, particularly in pertinence to the base of the Solar convective zone and experiments conducted at the Sandia Z Pulsed Power Facility, and also provide some commentary regarding the role of the equation of state.
The manuscript is logically organized and written in a reasonable manner. In my opinion, whilst the report provides an informative update to the broader community in atomic physics for plasma applications, the novelty and potential impact of the work are really rather limited. Beyond this, I would kindly ask the authors to address the following major and minor comments.
Major Comments:
(1) Perhaps the most significant issue surrounding the report is the lack of information that would allow other researchers to reproduce the data. Details concerning the atomic structure calculations and convergence of the photoionization cross-sections and opacities should be provided, as well as any assumed extrapolations. If such details have been provided elsewhere, then those sources should be cited appropriately. Disclosure of this information would aid the proper evaluation of the authors' work by others, and support informed comparisons with future calculations (which is, obviously, of crucial importance in this line of research).
Minor Comments:
(1) On p.g. 1, the keyword "resonances" is misspelled.
(2) The figures are poorly formatted and suffer from careless errors.
(i) In Fig. 1, the vertical axis label of each subplot should read log10 σPI (Mb).
(ii) In Fig. 2, the notation appearing in the vertical axis label of each subplot is inconsistent with respect to Fig. 1.
(iii) The axis labels are problematic in Fig. 3 as well, including "xsec" and "B" (instead of "b" for barn). The individual subfigures are also rather small and difficult to read. Additionally, why is photon energy now measured in keV instead of Ry? It is preferable to maintain the units (and the font for them) consistent throughout.
(iv) Figs. 4 and 5 appear disproportionately large.
(3) The authors state on p.g. 2 that they "examine the Mihalas-Hummer-Daeppen EOS used in the OP work and variants thereof". Contrary to this statement, the manuscript contains no detailed treatment of any such variants. Additionally, can the authors clarify if their findings concerning the equation of state on pp. 8 and 9 have any bearing on the treatment of Stark broadening?
On the basis of the above comments, I cannot recommend the manuscript for acceptance in its present state.
Author Response
See attached file
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsI thank the authors for their time and consideration in addressing my comments and suggestions. Having assessed the latest version of their manuscript, I can confirm that the amendments have been satisfactory. As such, I can recommend the work for publication in Atoms.
