Implications of conflicting cross sections for the 40Ca(n,α)37Ar reaction as applied to nuclear explosion monitoring

Shah, Khiloni A.; Luna, Brandon De; Haas, Derek A.

doi:10.1007/s10967-022-08522-8

Cited by 4 publications

(2 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The potential release activity of 37 Ar was calculated in a recently published study by Shah et al (2022). First, an MCNP model with a 235 U Watt fission spectrum point source surrounded by granite was used to find the representative neutron flux spectrum resulting from fission neutrons being moderated in the geologic material.…”

Section: Methodsmentioning

confidence: 99%

Quantifying the Potential of Argon Detection Capabilities for Nuclear Explosion Monitoring

Adhikari,

Gordon,

Shah

et al. 2024

Pure Appl. Geophys.

Self Cite

View full text Add to dashboard Cite

Current noble gas detection systems for nuclear explosion monitoring are based on the detection of four radioxenon isotopes—Xe-131m, -133, -133m and -135. The data provided by radioxenon detection could be enhanced by other radionuclide signatures such as Ar-37. Activation of Ca-40 in rock by neutrons produces Ar-37, and monitoring for this additional nuclide could help distinguish detections of nuclear explosions from background sources, such as medical isotope production. This work studies the capabilities of a hypothetical argon detection network. A 10 kt explosion was modeled using MCNP and SCALE to determine the inventory of Ar-37 created in a representative granite rock layer, assuming either 0.1, 1 or 10% of the total inventory was released. The Ar-37 inventory was combined with atmospheric transport data from HYSPLIT compiled in a previous study, along with the detection limits of standard Ar-37 detection systems, to determine how many hypothetical monitoring stations would detect Ar-37 from an explosion. This method was repeated for 365 HYSPLIT data sets to create a year’s worth of hypothetical explosions, releases, and detections. The study quantified the average number of detections per release, the number of stations detecting Ar-37, and the possibility of detecting Ar-37 in coincidence with xenon.

show abstract

Section: Methodsmentioning

confidence: 99%

Quantifying the Potential of Argon Detection Capabilities for Nuclear Explosion Monitoring

Adhikari,

Gordon,

Shah

et al. 2024

Pure Appl. Geophys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The release activity of 37 Ar was calculated using a basic model of a UNE developed using MCNP and SCALE (Shah et al, 2022). First, an MCNP model with a 235 U Watt ssion spectrum point source surrounded by granite was used to nd the representative neutron ux spectrum resulting from ssion neutrons being moderated in the geologic material.…”

Section: Introductionmentioning

confidence: 99%

Quantifying the Potential of Argon Detection Capabilities for Nuclear Explosion Monitoring

Adhikari,

Gordon,

Shah

et al. 2023

Preprint

Self Cite

View full text Add to dashboard Cite

Current noble gas detection systems for nuclear explosion monitoring are based on the detection of four radioxenon isotopes – Xe-131m, -133, -133m and − 135. The data provided by radioxenon detection could be enhanced by other radionuclide signatures such as Ar-37. Activation of Ca-40 in rock by neutrons produces Ar-37, and monitoring for this additional nuclide could help distinguish detections of nuclear explosions from background sources, such as medical isotope production. This work studies the capabilities of a hypothetical argon detection network. A 10 kt explosion was modeled using MCNP and SCALE to determine the inventory of Ar-37 created in a representative granite rock layer, assuming either 0.1, 1, or 10% of the total inventory was released. The Ar-37 inventory was combined with atmospheric transport data from HYSPLIT compiled in a previous study, along with the detection limits of standard Ar-37 detection systems, to determine how many hypothetical monitoring stations would detect Ar-37 from an explosion. This method was repeated for 365 HYSPLIT data sets to create a year’s worth of hypothetical explosions, releases, and detections. The study quantified the average number of detections per release, the number of stations detecting Ar-37, and the possibility of detecting Ar-37 in coincidence with xenon.

show abstract

Reexamination of a 40Ca(n,α)37Ar cross section measurement from existing literature

Shah,

Haas

2023

nuclscitechnolopenres

View full text Add to dashboard Cite

Background 37Ar, produced from the neutron activation of 40Ca in sub-surface rock and soil, is important for nuclear explosion monitoring. Most of the cross section measurements done for the 40Ca(n,α) 37 Ar reaction are in the fast neutron region. A thermal cross section measurement was attempted in 1989, with the assumption that the 4-8 MeV neutrons would be completely thermalized with 8-cm of water. Methods The experimental setup was modeled using Monte Carlo N-Particle code to see if the assumptions for the neutron distribution were accurate. A model of a 3.0 MeV deuteron source was used to recreate the neutron source from the experiment. Additional modeling was done using SCALE to compare the predictions of 37Ar yields when using the measured cross section from 1989 compared to current nuclear data models. Results Modeling showed the neutron distribution was closer to 10% thermal and 90% fast as opposed to entirely thermalized. The additional modeling showed how the overestimation of the thermal cross section would affect the predicted yield of 37Ar. Conclusions Based on the modeling results, the assumption that all the 4-8 MeV neutrons are thermalized with 8-cm of water is not accurate. The high fraction of fast neutrons interacting with the Ca will result in an overestimation of the thermal cross section.

show abstract

Implications of conflicting cross sections for the 40Ca(n,α)37Ar reaction as applied to nuclear explosion monitoring

Cited by 4 publications

References 11 publications

Quantifying the Potential of Argon Detection Capabilities for Nuclear Explosion Monitoring

Quantifying the Potential of Argon Detection Capabilities for Nuclear Explosion Monitoring

Quantifying the Potential of Argon Detection Capabilities for Nuclear Explosion Monitoring

Reexamination of a 40Ca(n,α)37Ar cross section measurement from existing literature

Contact Info

Product

Resources

About