Experimental Facility to Study the Threshold Characteristics of Laser Action at the p-s-Transition of Noble Gas Atom upon Excitation by ⁶Li(n,α)³H Nuclear Reaction Products

Round 1

Reviewer 1 Report

The authors present a description of a experimental facility and device designed to study the $^6Li(n,\alpha)^3H. The paper is thus relevant for studies of nuclear-excited plasma and applications in reactor physics. The paper is well-written and I recommend it for publication. The only thing I believe is missing is that no comparison exist with other methods. Maybe, no comparable results are available. But, if it does it would be useful in order to understand the advantages/disadvantages with their method.

 

1) There is not a simple research question mentioned in the manuscript as mentioned in my introduction to this message. The described experimental framework aims to perform studies of the thresholds characteristics of laser action at the p-s-transition of noble gas atom upon ^6Li(n,\alpha)^3H. On the other hand, the authors could better describe what kind of open research questions which could be answered with such facility, which not is done.

2) The authors doesn't review the open research questions in the field. On the other hand, it is proposing a new method so in that sense it is original.

3) See my answer to 2)

4) I think what is missing as already mentioned is to review possible open questions in the field and how this proposed framework could be used to answer them.

5) As they don't pose any specific research question I don't know how to reply to this. They conclude that their proposed design works and it is supported by their results.

6) Yes, I think the references are appropriate.

 

7) The figure and tables are fine. However, it would add more to the paper if they included results from other frameworks.  For example, to see if the emission spectrum is clearer (less noise) with their framework or not.

Author Response

Than you for considering our manuscript. 

Below are detailed responses to your comments.

Please, see the attachment.

 

1) There is not a simple research question mentioned in the manuscript as mentioned in my introduction to this message. The described experimental framework aims to perform studies of the thresholds characteristics of laser action at the p-s-transition of noble gas atom upon the ⁶Li(n,\alpha)³H. On the other hand, the authors could better describe what kind of open research questions which could be answered with such facility, which not is done.

 

Experiments to study the spectral-luminescence properties of noble gases upon excitation of gas medium by 6Li(n,α)3H nuclear reaction products, which was practically not used before have been conducted at the IVG1.M stationary research reactor.

In [6] the authors present a description of the experimental facility and design of an experimental device designed for in-pile experiments to investigate the spectral-luminescent characteristics of nuclear-excited plasma of noble gases, formed in the neutron irradiation field of the IVG.1M reactor, which provided the basis for the development of a new experimental facility described in detail in this manuscript.

6. Gordienko, Yu.; Batyrbekov, E.; Skakov, M.; Ponkratov, Yu.; Khasenov, M.; Zaurbekova, Zh.; Barsukov, N.; Kulsartov, T.; Tulubayev, Ye. Experimental facility for reactor experiments on study of spectral-luminescent characteristics of nuclear-excited plasma, J. Phys.: Conf. Ser. 2016, 747, 012012. DOI: 10.1088/1742-6596/747/1/012012

 

Thus, the results of scientific research can find application in the creation of nuclear power plants that generate laser or spontaneous optical radiation, as well as in systems for monitoring the parameters of nuclear reactors [11-13].

11. Lamotte, M.; Izarra, G.de; Jammes C. Development and first use of an experimental device for fission-induced spectrometry applied to neutron flux monitoring. Nucl. Instrum. Methods Phys. Res. A: Accel. Spectrom. Detect. Assoc. Equip. 2020, 953, 163236. DOI: 10.1016/j.nima.2019.163236
12. Lamotte, M.; Izarra, G.de; Jammes C. Pulse-reactor core monitoring with an innovative optical neutron detector. Nucl. Instrum. Methods Phys. Res. A: Accel. Spectrom. Detect. Assoc. Equip. 2021, 995, 165086. DOI: 10.1016/j.nima.2021.165086
13. Lamotte, M.; Izarra, G.de; Jammes C. Design and irradiation test of an innovative optical ionization chamber technology. Nucl. Instrum. Methods Phys. Res. A: Accel. Spectrom. Detect. Assoc. Equip. 2020, 968, 163945. DOI: 10.1016/j.nima.2020.163945

 

2) The authors doesn't review the open research questions in the field. On the other hand, it is proposing a new method so in that sense it is original.

 

Similar research has been carried out by other research organizations, involved in nuclear-pumped gas lasers.

In [17], for instance, the authors present a description of the experimental setup and a measurement technique, as well as the results of the spectral-luminescent properties of noble gases and their mixtures, excited by uranium fission fragments, conducted at the VIR-2M water pulse nuclear reactor. In [18], the authors presents an experimental setup configuration and lasing experiments results on uranium fission fragments pumping of gas lasers conducted at the BARS-6 fast burst reactor. In [19], the authors reported an experimental investigation of lasing action, due to a 4p-4s transition of Ar atom (λ= 1149 nm), upon He-Ar mixture pumped by uranium fission fragments.

17. Abramov, A.; Gorbunov, V.; Melnikov, S.; Mukhamatullin, A.; Pikulev, A.; Sinitsyn, A.; Sinyanskii, A.; Tsvetkov, V. Luminescence of nuclear-induced rare-gas plasmas in near infrared spectral range, Proc. SPIE. 2006, Atomic and Molecular Pulsed Lasers VI, 6263, 626312; DOI: 10.1117/12.677457
18. Barzilov, A.; Bokhovko, M.; Gulevich, A.; Dyachenko, P.; Kachanov, B.; Kononov V.;, Kukharchuk O.;, Pashin E.;, Regushevsky V.;, Zrodnikov, A. Theoretical and experimental studies of gaseous laser pumped by a twin-core fast burst reactor. AIP Conference Proceedings. 1997, 406, 351. DOI: 10.1063/1.53555
19. Mel'nikov, S.; Sinyanskiĭ A. Quasi-cw lasing due to the 4p–4s transition of the argon atom in an He–Ar laser pumped by uranium fission fragments. Soviet Journal of Quantum Electronics. 1991, 21, 1332. DOI: 10.1070/QE1991v021n12ABEH004705

 

3) See my answer to 2)

 

See the answer to the previous question.

 

4) I think what is missing as already mentioned is to review possible open questions in the field and how this proposed framework could be used to answer them.

 

An extended response to this statement is provided in the first two answers, with an indication of the previous both experimental and theoretical, and the latest publications in the field.

 

5) As they don't pose any specific research question I don't know how to reply to this. They conclude that their proposed design works and it is supported by their results.

 

Data obtained as a result of experimental work were checked several times for reproducibility, which confirms the efficiency of the proposed design of an irradiation device. If there are literary sources with the results of such studies, the obtained data will be compared with the data of other authors

 

6) Yes, I think the references are appropriate.

 

Thank you for the remark

 

 

7) The figure and tables are fine. However, it would add more to the paper if they included results from other frameworks.  For example, to see if the emission spectrum is clearer (less noise) with their framework or not.

The figures and tables are presented pristine results, obtained during the reactor experiments, without smoothing the noises. We think that the pristine data is more valuable and indisputable to those, who is involved in nuclear-pumped gas lasers.

Besides, this facility was designed to record a laser action, not luminescence spectra. The luminescence spectra are given here to demonstrate the operability of the registration under the conditions of the IGR pulsed nuclear reactor and the sufficient sensitivity of the registration system. The luminescence spectra have been studied in detail by us in [6], as well as [7,8]. The data of [6-8] agree well with [17], except for the presence of lithium in the emission spectra. Also, in [17], for some reason the bands of heteronuclear molecules (ArXe)⁺, (KrXe)⁺, ArKr)⁺ are missing.

Author Response File: Author Response.docx

Reviewer 2 Report

This is a very interesting and important paper. I only have one comment for the authors. They state that the He-Argon mixture has good prospect for achieving lasing. However, it is not clear what would be needed to do this. Can they estimate the conditions (reactor power, etc.) needed? Where could such experiments be done?

Author Response

Thank you for considering our manuscript.

Bellow you can find a detailed response for your answer.

This is a very interesting and important paper. I only have one comment for the authors. They state that the He-Argon mixture has good prospect for achieving lasing. However, it is not clear what would be needed to do this. Can they estimate the conditions (reactor power, etc.) needed? Where could such experiments be done?

 

Response:

 An estimate was made of the laser action threshold of a laser based on an He-Ar mixture (without taking into account losses due to absorption in the active medium) upon pumping with ionizing radiation. Threshold pump power: W_thr≈40 W/cm³.

In addition, estimated at what thermal neutron flux density such a pump density is achieved. The cross section for the nuclear reaction ⁶Li(n,α)³H is 945 barn =9,45∙10^-22 cm^-2, α-particle energy 2,73 MeV, tritium ion energy 2,05 MeV.

The average energy input from α-particles was 1.5∙10^-15 F (W/cm³), from tritium ion 6∙10^-16 F (W/cm³), where F – thermal neutron flux density (n/cm²s).

Thus, the necessary pumping power is achieved with a thermal neutron flux equal to  F ≈ 2.0∙10¹⁶ n/cm²s.

 

Please, see the attachment.

Author Response File: Author Response.docx