Neutron monitors and muon detectors for solar modulation studies: Interstellar flux, yield function, and assessment of critical parameters in count rate calculations

Maurin, D.; Cheminet, A.; Derome, L.; Ghelfi, A.; Hubert, G.

doi:10.1016/j.asr.2014.06.021

Cited by 44 publications

(53 citation statements)

References 149 publications

(217 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Data analysis as well as Monte Carlo simulations have often been used to provide estimates of the neutron monitor response function [Clem and Dorman, 2000;Caballero-Lopez and Moraal, 2012;Mishev et al, 2013;Nuntiyakul et al, 2014;Maurin et al, 2015]. NMs are sensitive to secondary particles that undergo nuclear interaction with a dense lead producer, inducing tertiary neutrons that are detected by proportional counters filled with BF 3 or 3 He gas.…”

Section: Introductionmentioning

confidence: 99%

Dependence of the neutron monitor count rate and time delay distribution on the rigidity spectrum of primary cosmic rays

et al. 2016

View full text Add to dashboard Cite

Neutron monitors are the premier instruments for precisely tracking time variations in the Galactic cosmic ray flux at GeV‐range energies above the geomagnetic cutoff at the location of measurement. Recently, a new capability has been developed to record and analyze the neutron time delay distribution (related to neutron multiplicity) to infer variations in the cosmic ray spectrum as well. In particular, from time delay histograms we can determine the leader fraction L, defined as the fraction of neutrons that did not follow a previous neutron detection in the same tube from the same atmospheric secondary particle. Using data taken during 2000–2007 by a shipborne neutron monitor latitude survey, we observe a strong dependence of the count rate and L on the geomagnetic cutoff. We have modeled this dependence using Monte Carlo simulations of cosmic ray interactions in the atmosphere and in the neutron monitor. We present new yield functions for the count rate of a neutron monitor at sea level. The simulation results show a variation of L with geomagnetic cutoff as observed by the latitude survey, confirming that these changes in L can be attributed to changes in the cosmic ray spectrum arriving at Earth's atmosphere. We also observe a variation in L with time at a fixed cutoff, which reflects the evolution of the cosmic ray spectrum with the sunspot cycle, known as solar modulation.

show abstract

Section: Introductionmentioning

confidence: 99%

Dependence of the neutron monitor count rate and time delay distribution on the rigidity spectrum of primary cosmic rays

et al. 2016

View full text Add to dashboard Cite

show abstract

“… Deb82: Debrunner et al [], Cle00: Clem and Dorman [], Flu08: Flückiger et al [], Mat09: Matthiä et al [], Cab12: Caballero‐Lopez and Moraal [], Mis13: Mishev et al [], and Mau15: Maurin et al [].…”

Section: Response and Yield Function Estimationsmentioning

confidence: 99%

“…Numerous papers have been published on this method [see, for instance, Nagashima et al, 1989;Moraal et al, 1989;Clem and Dorman, 2000;Bieber et al, 1997;Caballero-Lopez and Moraal, 2012]. On the other hand, the second method calculates the yield function by using generic numerical codes such as FLUKA, GEANT4, and CORSIKA (KASKADE) to simulate the atmospheric cascade process and then adding detector-specific details to these models [see, for instance, Hatton, 1971;Debrunner et al, 1982;Clem and Dorman, 2000;Flückiger et al, 2008;Matthiä et al, 2009;Mishev et al, 2013;Maurin et al, 2015].…”

Section: 1002/2016ja022690mentioning

confidence: 99%

An estimation of the yield and response functions for the mini neutron monitor

Caballero─López

2016

JGR Space Physics

View full text Add to dashboard Cite

The present study estimates the yield and response functions of the mini neutron monitor (miniNM). This relatively new cosmic ray detector is the mobile version of the standard NM64. It can be use not only to calibrate the NM64 but also to study the modulation processes. Due to its portability, the miniNM can be easily placed in a suitable location to measure secondary particles, which give information about the intensity variations of galactic and solar cosmic rays. In order to perform these modulation studies with miniNMs, it is crucial to know their sensitivity to detect secondary cosmic ray flux, i.e., we must know their yield function. A previous study found that miniNM and NM64 have slightly different response functions. This work analyzes the observed counting rate ratio (miniNM to NM64) and gives for the first time an useful expression for the yield function of the miniNM. The results found here will allow to interpret the new measurements with this mobile neutron monitor. For comparison, a brief summary of the NM64 yield functions reported by other authors is presented.

show abstract

“…As underlined in several studies, the use of several IS flux parametrisations (Garcia-Munoz et al 1975;Burger et al 2000;Langner et al 2003;Webber & Higbie 2003O'Neill 2006;Shikaze et al 2007) leads to shifts of these time series up to ∆φ ∼ ±200 MV (e.g. Maurin et al 2015). This motivates us even more to find a better characterisation of the IS flux, modulation level, and of the correlations between these parameters.…”

Section: Introductionmentioning

confidence: 99%

“…In the former approach, we benefit from sampling the same IS flux at the cost of one additional modulation parameter per snapshot: depending on the data precision and the periods used, ideally both high and low solar activity periods, the degeneracy is mostly lifted, although some significant uncertainties can remain (e.g. Maurin et al 2015). In the second approach, the modulation level φ(t i ) is now the quantity sampled several times by different species, each new species requiring several additional shape parameters: the benefit is that species with different Z/A (e.g.…”

Section: Analysis and χmentioning

confidence: 99%

Non-parametric determination of H and He interstellar fluxes from cosmic-ray data

Ghelfi

Barão

Derome

et al. 2016

A&A

Self Cite

107

View full text Add to dashboard Cite

Context. Top-of-atmosphere (TOA) cosmic-ray (CR) fluxes from satellites and balloon-borne experiments are snapshots of the solar activity imprinted on the interstellar (IS) fluxes. Given a series of snapshots, the unknown IS flux shape and the level of modulation (for each snapshot) can be recovered. Aims. We wish (i) to provide the most accurate determination of the IS H and He fluxes from TOA data alone; (ii) to obtain the associated modulation levels (and uncertainties) while fully accounting for the correlations with the IS flux uncertainties; and (iii) to inspect whether the minimal force-field approximation is sufficient to explain all the data at hand. Methods. Using H and He TOA measurements, including the recent high-precision AMS, BESS-Polar, and PAMELA data, we performed a non-parametric fit of the IS fluxes J IS H, He and modulation level φ i for each data-taking period. We relied on a Markov chain Monte Carlo (MCMC) engine to extract the probability density function and correlations (hence the credible intervals) of the sought parameters. Results. Although H and He are the most abundant and best measured CR species, several datasets had to be excluded from the analysis because of inconsistencies with other measurements. From the subset of data passing our consistency cut, we provide readyto-use best-fit and credible intervals for the H and He IS fluxes from MeV/n to PeV/n energy (with a relative precision in the range [2−10%] at 1σ). Given the strong correlation between J IS and φ i parameters, the uncertainties on J IS translate into ∆φ ≈ ±30 MV (at 1σ) for all experiments. We also find that the presence of 3 He in He data biases φ towards higher φ values by ∼30 MV. The force-field approximation, despite its limitation, gives an excellent (χ 2 /d.o.f. = 1.02) description of the recent high-precision TOA H and He fluxes. Conclusions. The analysis must be extended to different charge species and more realistic modulation models. It would benefit from the AMS-02 unique capability of providing frequent high-precision snapshots of the TOA fluxes over a full solar cycle.

show abstract

Neutron monitors and muon detectors for solar modulation studies: Interstellar flux, yield function, and assessment of critical parameters in count rate calculations

Cited by 44 publications

References 149 publications

Dependence of the neutron monitor count rate and time delay distribution on the rigidity spectrum of primary cosmic rays

Dependence of the neutron monitor count rate and time delay distribution on the rigidity spectrum of primary cosmic rays

An estimation of the yield and response functions for the mini neutron monitor

Non-parametric determination of H and He interstellar fluxes from cosmic-ray data

Contact Info

Product

Resources

About