the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
URANOS v1.0 – the Ultra Rapid Adaptable Neutron-Only Simulation for Environmental Research
- 1Physikalisches Institut, Heidelberg University, Heidelberg, Germany
- 2Physikalisches Institut, University of Bonn, Bonn, Germany
- 3Dep. Monitoring and Exploration Technologies, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
- 1Physikalisches Institut, Heidelberg University, Heidelberg, Germany
- 2Physikalisches Institut, University of Bonn, Bonn, Germany
- 3Dep. Monitoring and Exploration Technologies, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
Abstract. The understanding of neutron transport by Monte-Carlo simulations led to major advancements towards precise interpretation of measurements. URANOS (Ultra Rapid Neutron-Only Simulation) is a free software package, which has been developed in the last years in a cooperation of Particle Physics and Environmental Sciences, specifically for the purposes of cosmic-ray neutron sensing (CRNS). Its versatile user interface and input/output scheme tailored for CRNS applications offers hydrologists a straightforward access to model individual scenarios and to directly perform advanced neutron transport calculations. The geometry can be modeled layerwise, whereas in each layer a voxel geometry is extruded using a two-dimensional map from pixel images representing predefined materials and allowing to construct objects on the basis of pixel graphics without a 3D editor. It furthermore features predefined cosmic-ray neutron spectra and detector configurations and allows also a replication of important site characteristics of study areas – from a small pond to the catchment scale. The simulation thereby gives precise answers to questions like: From which location do neutrons originate? How do they propagate to the sensor? What is the neutron response to certain environmental changes? In recent years, URANOS has been successfully employed by a number of studies, for example, to calculate the cosmic-ray neutron footprint, signals in complex geometries like mobile applications on roads, urban environments and snow patterns.
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Notice on discussion status
The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
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Preprint
(5352 KB)
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The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
Journal article(s) based on this preprint
Markus Köhli et al.
Interactive discussion
Status: closed
-
RC1: 'Comment on gmd-2022-93', Anonymous Referee #1, 01 Aug 2022
The authors present an excellent overview of the URANOS code in great detail. Given the continued use of CRNS this streamlined neutron transport code will be of great use to the community for evaluating and designing future experiments. The paper is well written and acceptable following some minor revisions. My only moderate comment is the need for more complex field data for validating the results (say irrigated row crops). These data would be greatly supported by URANOS model simulations to help untangle the complexity of this system. There have now been a number of papers developing this code (L600-620). Please see below for a few minor comments to address.
L58: Use of ontop is a bit awkward, please revise.
L126: is l the path length, please define here as well as sigma.
L252. "in a converter takes place". I don't follow this statement please revise.
L440. A space is needed between the words to start sentence.
L498: Replace "As far as" with "If".
L520: Figure 11 is discussed before figure 10.
L522: Neutron paths not neutrons paths
L585: For more than 50 years ...
L604: fine tune.
L600-620: I think a table summarizing the various studies with URANOS would be easier to read and reference for the reader. Please consider changing.
L627. I don't follow this sentence about the evaluation of cross sections. Think there may be a missing word somewhere?
- AC3: 'Reply on RC1', Markus Köhli, 28 Oct 2022
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RC2: 'Comment on gmd-2022-93', Anonymous Referee #2, 16 Sep 2022
This is a well developed manuscript, demonstrating the applicability of a novel though well-tested code. The manuscript is well readable, inspirational and easy to access for environmental scientists although containting dense information on physical processes and modelling. I recommend publication in GMD with minor revisions urging the authors to expand on a few minor points (see below) and add a new section on limitations and outlook. This section will benefit the readers and inspire the next generation of researchers to build on this code, increase the user space and the capabilities of CRNS to deliver accurate environmental observations.
Please adress following questions (in the new section):
What is the run time on a standard architecture (e.g. interl Core i5, 8GB RAM, Windows or Unix)?
Is the code parallelized for HPC applications?
What are the most expensive calculations and how to they scale from 2D to 3D for a "simple" geometric set up?
Can the atmosphere and cosmic ray interactions be modelled using URANOS code?
What is needed and what is the uncertainty to expand the code to include uncertainty from the cosmic ray energy spectrum at the top of the atmosphere and further particles?
Given URANOS is applied to simulate each CRNS locations, what are the remaining major uncertainties constraining the accuracy of cosmic ray neutron sensor derived hydrogen content in the CRNS footprint?Line 132: It is unclear for the reader, how TRandom3 is programmed, language, and what a "modern architecture" is. Are the authors referring to HPC systems, GPU based HPCs or Laptops build in 2019? Please specify what you refer to as modern architecture ideally in the flops as measure for computational performance.
Line 133: Please also mention possible other random number generators and are they available? If those are not relevant questions, then it seems the technical details are not needed and I recommend to simply state that "the TRandom3 random number generator is used" and remove the technical details on random number generation from the manuscript in this paragraph 2.2.
Line 208: Please clarify what "MT numbers" are. Random "Mersenne Twister" numbers would not define reaction types, I assume.
Line 215: What is ensemble statistics?
Line 219: Please state which relevant and non-relevant interactions you are referring and what are the "two different types"?
Line 222: Please clarify, how is it possible that myons are not contributing while myons are the major cosmic rays entering the atmosphere, and neutrons are only a product of myon inter-action?
Line 325: Please state recommended default setting for the source.
Line 332: Please state recommended default starting angle.
- AC4: 'Reply on RC2', Markus Köhli, 28 Oct 2022
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AC1: 'Comment on gmd-2022-93', Markus Köhli, 28 Oct 2022
This review targets the first part of the manuscript, especially regarding the technical aspects. It is posted by the author due to the discussion section already being closed.
The publication shows an profound knowledge of the authors about the existing programs and the underlying physics and IT concepts. There are, however, some points that would improve the document:
* For people from other fields of research it is partly difficult to read, because the methods are not always described, e.g. half a sentence on how CRNS works would be helpful.
* Similarly, there are terms used that are not common to all fields. They should either be explained or alias names added, especially
* Is ‘evaporation’ of neutrons the same as ‘spallation’ of neutrons?
* Is ‘ray-casting’ the same as ‘ray-tracing’?
* Equation (1) to (4) are only consistent, if (3) and (4) calculate p(x) dp, not p(x) dx* In Eq.(5), the second ξ should be replaced by anything else, e.g. ξ’. As it is written now, the equation is not correct.
* Surprisingly, it sounds like the authors have doubts about the Monte Carlo method.
* Some suggestion for text improvement:
* 47 – 49: can be omitted, as the programs are described in the following paragraphs* Chapter 1.2: it could be added that the programs dedicated to neutron instrumentation and virtual neutron experiments (McStas, VITESS, RESTRAX, …) also allowed fast simulations by restricting its use to neutrons and ignoring nuclear reactions
* 106 – 112:: I cannot see the problem of the multigroup method
* 119: performance of GEANT4: what is missing, speed or accuracy or …?
* 156 – 15: I don’t understand that
* 214f: Why? What is done instead?
* 226: ‘Whereas’ -> ‘While’
* Style: often there are too few commas in too long sentences.* Figure 1:
* I wonders if neutrons are generated in the source or the soil layer.* An explanation of the particle symbols and a vertical scale would be good
* Figure 2:
* I think the ‘Layer stack’ is still a ‘Neutron stack’.* Is there no flight direction stored?
- AC2: 'Comment on gmd-2022-93 (Reviewer No.3 Response)', Markus Köhli, 28 Oct 2022
Peer review completion
Interactive discussion
Status: closed
-
RC1: 'Comment on gmd-2022-93', Anonymous Referee #1, 01 Aug 2022
The authors present an excellent overview of the URANOS code in great detail. Given the continued use of CRNS this streamlined neutron transport code will be of great use to the community for evaluating and designing future experiments. The paper is well written and acceptable following some minor revisions. My only moderate comment is the need for more complex field data for validating the results (say irrigated row crops). These data would be greatly supported by URANOS model simulations to help untangle the complexity of this system. There have now been a number of papers developing this code (L600-620). Please see below for a few minor comments to address.
L58: Use of ontop is a bit awkward, please revise.
L126: is l the path length, please define here as well as sigma.
L252. "in a converter takes place". I don't follow this statement please revise.
L440. A space is needed between the words to start sentence.
L498: Replace "As far as" with "If".
L520: Figure 11 is discussed before figure 10.
L522: Neutron paths not neutrons paths
L585: For more than 50 years ...
L604: fine tune.
L600-620: I think a table summarizing the various studies with URANOS would be easier to read and reference for the reader. Please consider changing.
L627. I don't follow this sentence about the evaluation of cross sections. Think there may be a missing word somewhere?
- AC3: 'Reply on RC1', Markus Köhli, 28 Oct 2022
-
RC2: 'Comment on gmd-2022-93', Anonymous Referee #2, 16 Sep 2022
This is a well developed manuscript, demonstrating the applicability of a novel though well-tested code. The manuscript is well readable, inspirational and easy to access for environmental scientists although containting dense information on physical processes and modelling. I recommend publication in GMD with minor revisions urging the authors to expand on a few minor points (see below) and add a new section on limitations and outlook. This section will benefit the readers and inspire the next generation of researchers to build on this code, increase the user space and the capabilities of CRNS to deliver accurate environmental observations.
Please adress following questions (in the new section):
What is the run time on a standard architecture (e.g. interl Core i5, 8GB RAM, Windows or Unix)?
Is the code parallelized for HPC applications?
What are the most expensive calculations and how to they scale from 2D to 3D for a "simple" geometric set up?
Can the atmosphere and cosmic ray interactions be modelled using URANOS code?
What is needed and what is the uncertainty to expand the code to include uncertainty from the cosmic ray energy spectrum at the top of the atmosphere and further particles?
Given URANOS is applied to simulate each CRNS locations, what are the remaining major uncertainties constraining the accuracy of cosmic ray neutron sensor derived hydrogen content in the CRNS footprint?Line 132: It is unclear for the reader, how TRandom3 is programmed, language, and what a "modern architecture" is. Are the authors referring to HPC systems, GPU based HPCs or Laptops build in 2019? Please specify what you refer to as modern architecture ideally in the flops as measure for computational performance.
Line 133: Please also mention possible other random number generators and are they available? If those are not relevant questions, then it seems the technical details are not needed and I recommend to simply state that "the TRandom3 random number generator is used" and remove the technical details on random number generation from the manuscript in this paragraph 2.2.
Line 208: Please clarify what "MT numbers" are. Random "Mersenne Twister" numbers would not define reaction types, I assume.
Line 215: What is ensemble statistics?
Line 219: Please state which relevant and non-relevant interactions you are referring and what are the "two different types"?
Line 222: Please clarify, how is it possible that myons are not contributing while myons are the major cosmic rays entering the atmosphere, and neutrons are only a product of myon inter-action?
Line 325: Please state recommended default setting for the source.
Line 332: Please state recommended default starting angle.
- AC4: 'Reply on RC2', Markus Köhli, 28 Oct 2022
-
AC1: 'Comment on gmd-2022-93', Markus Köhli, 28 Oct 2022
This review targets the first part of the manuscript, especially regarding the technical aspects. It is posted by the author due to the discussion section already being closed.
The publication shows an profound knowledge of the authors about the existing programs and the underlying physics and IT concepts. There are, however, some points that would improve the document:
* For people from other fields of research it is partly difficult to read, because the methods are not always described, e.g. half a sentence on how CRNS works would be helpful.
* Similarly, there are terms used that are not common to all fields. They should either be explained or alias names added, especially
* Is ‘evaporation’ of neutrons the same as ‘spallation’ of neutrons?
* Is ‘ray-casting’ the same as ‘ray-tracing’?
* Equation (1) to (4) are only consistent, if (3) and (4) calculate p(x) dp, not p(x) dx* In Eq.(5), the second ξ should be replaced by anything else, e.g. ξ’. As it is written now, the equation is not correct.
* Surprisingly, it sounds like the authors have doubts about the Monte Carlo method.
* Some suggestion for text improvement:
* 47 – 49: can be omitted, as the programs are described in the following paragraphs* Chapter 1.2: it could be added that the programs dedicated to neutron instrumentation and virtual neutron experiments (McStas, VITESS, RESTRAX, …) also allowed fast simulations by restricting its use to neutrons and ignoring nuclear reactions
* 106 – 112:: I cannot see the problem of the multigroup method
* 119: performance of GEANT4: what is missing, speed or accuracy or …?
* 156 – 15: I don’t understand that
* 214f: Why? What is done instead?
* 226: ‘Whereas’ -> ‘While’
* Style: often there are too few commas in too long sentences.* Figure 1:
* I wonders if neutrons are generated in the source or the soil layer.* An explanation of the particle symbols and a vertical scale would be good
* Figure 2:
* I think the ‘Layer stack’ is still a ‘Neutron stack’.* Is there no flight direction stored?
- AC2: 'Comment on gmd-2022-93 (Reviewer No.3 Response)', Markus Köhli, 28 Oct 2022
Peer review completion
Journal article(s) based on this preprint
Markus Köhli et al.
Markus Köhli et al.
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The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
- Preprint
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