Exploring the Nuclear Chart via Precision Mass Spectrometry with the TITAN MR-TOF MS
, Soenke Beck 3,4, Julian Bergmann 3, Callum L. Brown 5, Thomas Brunner 1,6, Timo Dickel 3,4, Jens Dilling 1,7, Eleanor Dunling 1, Jake Flowerdew 1,8, Danny Fusco 1,9, Leigh Graham 1, Zach Hockenbery 1,6, Chris Izzo 1, Andrew Jacobs 1,7, Brian Kootte 1,10, Yang Lan 1,7, Stephan Malbrunot-Ettenauer 11, Fernando Maldonado Millán 1, Ali Mollaebrahimi 1,3,4, Erich Leistenschneider 1,7, Wolfgang R. Plaß 3,4, Moritz Pascal Reiter 1,3,5, James L. Tracy, Jr. 1 and add
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Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis manuscript presents an overview of the TITAN MR-TOF-MS system at TRIUMF. It begins with an overview of the TITAN MR-TOF setup and the MR-TOF-MS experimental technique and analysis. This is demonstrated through the mass measurements of 104-107Sn as well as those of 89Zr,90Y, and 91Y, which were present in the beams delivered to TITAN as molecular contaminants. A discussion of the benefits of MR-TOF mass spectrometry follows, as well as the calculation of the S2N values to demonstrate that sufficient precision was achieved for nuclear structure studies.
Overall, this is a well-written paper that presents a good snapshot MR-TOF-MS and of TITAN. While the mass results themselves do not improve on the current AME values, being somewhere between a factor of six to ten less precise, they are in good agreement with previous results, and are used to good effect in this paper in the discussion of the analysis and of the benefits of the TITAN MR-TOF. I believe that generally this paper aligns well with this special issue of Atoms. However, I have several revisions I recommend the authors consider before its acceptance.
Firstly, while I appreciate the lyricism of the title, I do not believe the authors have made clear the connection between these results and the limits of nuclear existence. It is also my understanding that `TITAN-TRIUMF' refers to the whole array of traps, while this paper only discusses the MR-TOF, so the title should mention that device.
Second, given the discussion of the simultaneous measurement of the isobaric Zr and Y oxides, a figure similar to Figure 2 showing their presence in the measured spectra of the appropriate isobar would be good.
Finally, while the digression discussing the benefits of direct vs indirect mass measurements is well written, it provides a level of detail that I believe to be unnecessary for a special issue on ion trapping, particularly since the historical example chosen for the well-known shortcomings of beta-endpoint measurements for determining masses does not seem to have any particular connection to the data shown.
Minor Comments:
16-17:"The limits of stability ... is called..." -> "The limits of stability ... are called ..."
52-53: "... differing their ratio ..." -> "... differing in their ..."?
65-69: While I know that the TFS and then the change to an isochronus turn is done with electrostatic mirror electrodes, I do not think that is clear in these sentence
161: Why is the 'on' in 'on-line' italicized?
170: "Capable of half-lives of a few nanoseconds" is probably missing 'measurements' or 'measuring' somewhere
Figure 4 caption: Why is the 'i' in 'indirectly' italicized?
Author Response
Comment 1: Overall, this is a well-written paper that presents a good snapshot MR-TOF-MS and of TITAN. While the mass results themselves do not improve on the current AME values, being somewhere between a factor of six to ten less precise, they are in good agreement with previous results, and are used to good effect in this paper in the discussion of the analysis and of the benefits of the TITAN MR-TOF. I believe that generally this paper aligns well with this special issue of Atoms. However, I have several revisions I recommend the authors consider before its acceptance.
Response 1: Thank you for your thoughtful and constructive feedback! We are pleased to hear that you found the paper well-written and that the results align with the goals of this special issue. We appreciate your recognition of the value in the discussion of the analysis and the advantages of the TITAN MR-TOF. We are grateful for your recommendations and will carefully consider each one to further strengthen the manuscript. Thank you again for your time and valuable input!
Comment 2: Firstly, while I appreciate the lyricism of the title, I do not believe the authors have made clear the connection between these results and the limits of nuclear existence. It is also my understanding that `TITAN-TRIUMF' refers to the whole array of traps, while this paper only discusses the MR-TOF, so the title should mention that device.
Response 2: We have adjusted the title to be more specific of the device used (MR-TOF MS) and the goals that we accomplished. The new title is "Exploring the Nuclear Chart via Precision Mass Spectrometry with the TITAN MR-TOF MS".
Comment 3: Second, given the discussion of the simultaneous measurement of the isobaric Zr and Y oxides, a figure similar to Figure 2 showing their presence in the measured spectra of the appropriate isobar would be good.
Response 3: We have added a figure showing the presence of Zr and Y at mass number A=106.
Comment 4: Finally, while the digression discussing the benefits of direct vs indirect mass measurements is well written, it provides a level of detail that I believe to be unnecessary for a special issue on ion trapping, particularly since the historical example chosen for the well-known shortcomings of beta-endpoint measurements for determining masses does not seem to have any particular connection to the data shown.
Response 4: We have adjusted the discussion to take your comments into account, removing the unnecessary level of detail.
Comment 5: Minor comments.
Response 5: We have addressed your minor comments.
Comment 6: 161: Why is the 'on' in 'on-line' italicized?
Response 6: 'On' in on-line was italicized to emphasize that the identification of contaminants can only be done on-line i.e. with RIB. We have un-italicized it as this is an unnecessary detail.
Comment 7: Figure 4 caption: Why is the 'i' in 'indirectly' italicized?
Response 7: 'In' in indirectly was italicized to emphasize the indirect nature of the measurements (as opposed to direct). We have un-italicized it as this is an unnecessary detail.
Reviewer 2 Report
Comments and Suggestions for AuthorsManuscript atoms-3210249 “Exploring the Western Shoreline of the Nuclear Chart: What Precision
Mass Spectrometry with TITAN-TRIUMF Can Teach Us About Nuclear Existence” by Annabelle Czihaly, Soenke Beck, Julian Bergmann, Callum L. Brown, Thomas Brunner, Timo Dickel, Jens Dilling, Eleanor Dunling, Jake Flowerdew, Zach Hockenbery, Andrew Jacobs, Brian Kootte, Stephan Malbrunot-Ettenauer, Fernando Maldonado Millán, Ali Mollaebrahimi, Erich Leistenschneider, Eleni Marina Lykiardopoulou, Ish Mukul, Stefan F. Paul, Wolfgang R. Plaß, Moritz Pascal Reiter, Christoph Scheidenberger, James L. Tracy, Jr., A. A. Kwiatkowski presents the status/progress report concerning the recently completed facility TITAN MR-TOF MS at Triumf RIB-facility. This kind of devices allow more detailed studies of properties of short-lived unstable nuclei, in particular of masses of rare isotopes, and they are being built at several RIB-facilities and other nuclear facilities around the world. The manuscript presents technical details of the device and experimental techniques and on the example of proton-rich tin isotopes demonstrates its sensitivity and potential. Measured masses suggest that AME2020 nuclear mass evaluation provides reasonable estimates of masses in isotopic chains. Such information is relevant especially for nuclear astrophysics. One particular concern related to manuscript is multiplicity of self-citations, but since the manuscript gives overview of activities related to construction and development of the device I don’t think that it is a major issue. In summary, I consider the manuscript as informative and recommend its publication.
Author Response
Comment 1: This kind of devices allow more detailed studies of properties of short-lived unstable nuclei, in particular of masses of rare isotopes, and they are being built at several RIB-facilities and other nuclear facilities around the world. The manuscript presents technical details of the device and experimental techniques and on the example of proton-rich tin isotopes demonstrates its sensitivity and potential. Measured masses suggest that AME2020 nuclear mass evaluation provides reasonable estimates of masses in isotopic chains. Such information is relevant especially for nuclear astrophysics. One particular concern related to manuscript is multiplicity of self-citations, but since the manuscript gives overview of activities related to construction and development of the device I don’t think that it is a major issue. In summary, I consider the manuscript as informative and recommend its publication.
Response 1: Thank you for your feedback! We're glad that you found the manuscript informative. Regarding your concern about the multiplicity of self-citations, we acknowledge this observation and understand the importance of maintaining a balance. Since the device used is well-established within the field and has had many detailed reviews published, we thought it would be a better use of this manuscript to discuss our results and their impact. Thank you for your recommendation for publication!
Reviewer 3 Report
Comments and Suggestions for AuthorsIt could be helpful in Table 1 to cite published measurements instead of AME2020....and avoid mixing extrapolated results with measured results.
Author Response
Comment 1: It could be helpful in Table 1 to cite published measurements instead of AME2020....and avoid mixing extrapolated results with measured results.
Response 1: Thank you for your valuable feedback. Since the Atomic Mass Evaluation (AME) is the most comprehensive and frequently updated mass evaluation, incorporating the latest datasets and publications, we believe it serves as the best reference for the presentation of these results. Additionally, we have cited the publications for which the AME has retrieved their results, specifically for the presentation for tin. We appreciate you pointing out the mixing of extrapolated and measured data, and we will clarify this in the text to prevent any potential misinterpretation. Thank you again for taking the time to review our manuscript.
