Ship Effect Neutron Measurements And Impacts On Low-Background Experiments

Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Siciliano, Edward R.

doi:10.2172/1115835

Title: Ship Effect Neutron Measurements And Impacts On Low-Background Experiments

Full Record
Other Related Research

Abstract

The primary particles entering the upper atmosphere as cosmic rays create showers in the atmosphere that include a broad spectrum of secondary neutrons, muons and protons. These cosmic-ray secondaries interact with materials at the surface of the Earth, yielding prompt backgrounds in radiation detection systems, as well as inducing long-lived activities through spallation events, dominated by the higher-energy neutron secondaries. For historical reasons, the multiple neutrons produced in spallation cascade events are referred to as “ship effect” neutrons. Quantifying the background from cosmic ray induced activities is important to low-background experiments, such as neutrino-less double beta decay. Since direct measurements of the effects of shielding on the cosmic-ray neutron spectrum are not available, Monte Carlo modeling is used to compute such effects. However, there are large uncertainties (orders of magnitude) in the possible cross-section libraries and the cosmic-ray neutron spectrum for the energy range needed in such calculations. The measurements reported here were initiated to validate results from Monte Carlo models through experimental measurements in order to provide some confidence in the model results. The results indicate that the models provide the correct trends of neutron production with increasing density, but there is substantial disagreement between the model and experimentalmore »« less

Authors:

Aguayo Navarrete, Estanislao ^[1]; Kouzes, Richard T. ^[1]; Siciliano, Edward R. ^[1]

Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

Publication Date:: Tue Oct 01 00:00:00 EDT 2013

Research Org.:: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

Sponsoring Org.:: USDOE

OSTI Identifier:: 1115835

Report Number(s):: PNNL-22953
KB0401022

DOE Contract Number:: AC05-76RL01830

Resource Type:: Technical Report

Country of Publication:: United States

Language:: English

Subject:: 54 ENVIRONMENTAL SCIENCES; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY

Citation Formats


                    Aguayo Navarrete, Estanislao, Kouzes, Richard T., and Siciliano, Edward R. Ship Effect Neutron Measurements And Impacts On Low-Background Experiments.  United States: N. p., 2013. 
        Web.  doi:10.2172/1115835.

Copy to clipboard


                    Aguayo Navarrete, Estanislao, Kouzes, Richard T., & Siciliano, Edward R. Ship Effect Neutron Measurements And Impacts On Low-Background Experiments.  United States.  https://doi.org/10.2172/1115835

Copy to clipboard


                    Aguayo Navarrete, Estanislao, Kouzes, Richard T., and Siciliano, Edward R. 2013.  
        "Ship Effect Neutron Measurements And Impacts On Low-Background Experiments".  United States.  https://doi.org/10.2172/1115835.  https://www.osti.gov/servlets/purl/1115835.

Copy to clipboard


                    
@article{osti_1115835,

  title        = {Ship Effect Neutron Measurements And Impacts On Low-Background Experiments},

  author       = {Aguayo Navarrete, Estanislao and Kouzes, Richard T. and Siciliano, Edward R.},

  abstractNote = {The primary particles entering the upper atmosphere as cosmic rays create showers in the atmosphere that include a broad spectrum of secondary neutrons, muons and protons. These cosmic-ray secondaries interact with materials at the surface of the Earth, yielding prompt backgrounds in radiation detection systems, as well as inducing long-lived activities through spallation events, dominated by the higher-energy neutron secondaries. For historical reasons, the multiple neutrons produced in spallation cascade events are referred to as “ship effect” neutrons. Quantifying the background from cosmic ray induced activities is important to low-background experiments, such as neutrino-less double beta decay. Since direct measurements of the effects of shielding on the cosmic-ray neutron spectrum are not available, Monte Carlo modeling is used to compute such effects. However, there are large uncertainties (orders of magnitude) in the possible cross-section libraries and the cosmic-ray neutron spectrum for the energy range needed in such calculations. The measurements reported here were initiated to validate results from Monte Carlo models through experimental measurements in order to provide some confidence in the model results. The results indicate that the models provide the correct trends of neutron production with increasing density, but there is substantial disagreement between the model and experimental results for the lower-density materials of Al, Fe and Cu.},

  doi          = {10.2172/1115835},

  url          = {https://www.osti.gov/biblio/1115835},
  journal      = {},
number       = ,

  volume       = ,

  place        = {United States},

  year         = {Tue Oct 01 00:00:00 EDT 2013},

  month        = {Tue Oct 01 00:00:00 EDT 2013}

}

Copy to clipboard

Technical Report:

View Technical Report

https://doi.org/10.2172/1115835

Save / Share:

Export Metadata

Save to My Library

Similar records in OSTI.GOV collections:

Simulation of HEAO 3 background

Journal Article Graham, B; Phlips, B; Kroeger, R; ... - AIP Conference Proceedings

A Monte Carlo technique for modeling background in space-based gamma-ray telescopes has been developed. The major background components included in this modeling technique are the diffuse cosmic gamma-ray flux, the Earth's atmospheric flux, and decay of nuclei produced by spallation of cosmic rays, trapped protons and their secondaries, the decay of nuclei produced by neutron capture, and the de-excitation of excited states produced by inelastic scattering of neutrons. The method for calculating the nuclear activation and decay component of the background combines the low Earth orbit proton and neutron spectra, the spallation cross sections from Alice91, nuclear decay data frommore »« less
https://doi.org/10.1063/1.54027
First 5 tower WIMP-search results from the Cryogenic Dark Matter Search with improved understanding of neutron backgrounds and benchmarking

Thesis/Dissertation Hennings-Yeomans, Raul

Non-baryonic dark matter makes one quarter of the energy density of the Universe and is concentrated in the halos of galaxies, including the Milky Way. The Weakly Interacting Massive Particle (WIMP) is a dark matter candidate with a scattering cross section with an atomic nucleus of the order of the weak interaction and a mass comparable to that of an atomic nucleus. The Cryogenic Dark Matter Search (CDMS-II) experiment, using Ge and Si cryogenic particle detectors at the Soudan Underground Laboratory, aims to directly detect nuclear recoils from WIMP interactions. This thesis presents the first 5 tower WIMP-search results frommore »« less
https://doi.org/10.2172/1415806

Full Text Available
High-Energy Neutron Backgrounds for Underground Dark Matter Experiments

Thesis/Dissertation Chen, Yu

Direct dark matter detection experiments usually have excellent capability to distinguish nuclear recoils, expected interactions with Weakly Interacting Massive Particle (WIMP) dark matter, and electronic recoils, so that they can efficiently reject background events such as gamma-rays and charged particles. However, both WIMPs and neutrons can induce nuclear recoils. Neutrons are then the most crucial background for direct dark matter detection. It is important to understand and account for all sources of neutron backgrounds when claiming a discovery of dark matter detection or reporting limits on the WIMP-nucleon cross section. One type of neutron background that is not well understoodmore »« less
https://doi.org/10.2172/1350521

Full Text Available
Measurements and simulations of the cosmic-ray-induced neutron background

Journal Article Becchetti, M.; Flaska, M.; Clarke, S.; ... - Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment

The cosmic-ray-induced neutron background at ground level has been measured and simulated in conjunction with EJ-309 organic liquid scintillators with an approximate deposited energy range of 0.5–6 MeV. Specifically, the pulse height distributions, net neutron count rates, and angular dependences were obtained. The simulations were carried out using the Monte Carlo transport code MCNPX-PoliMi combined with the (Cosmic-Ray Shower Generator) CRY source subroutine that returns secondary particles produced by cosmic rays. A scaling formula from literature was also implemented in the simulation. The angular dependence of the neutron count rate was measured by collimating the liquid scintillator with polyethylene tomore »« less
https://doi.org/10.1016/j.nima.2014.10.077

Full Text Available
Update of the GEANT4/MAX Simulation Anthropomorphic Model for High-Energy Neutrons Effective Dose Calculation

Journal Article Paganini, Silvia; Correia, Eudice - AIP Conference Proceedings

The crews of present-day jet aircrafts are a significant occupationally exposed group, receiving relatively high effective doses from exposure to cosmic radiation, with the possibility of higher effective doses if the cruising altitudes of future aircrafts increase. To assess effective doses from exposure to cosmic radiation, the MAX (Male Adult voXel) phantom has been coupled with the GEANT4 Monte Carlo code. This radiation transport code has been distributed and upgraded by a group of international scientists at CERN/Switzerland, and, among other types of radiation, allows for the simulation of neutron transport through matter. The high-energy neutrons contribute to about 70%more »« less
https://doi.org/10.1063/1.2128356

Similar Records