A large area detector for neutrons between 2 and 100 MeV

Grannan, R.T.; Koga, R.; Millard, W. A.; Preszler, A. M.; Simnett, G. M.; White, R. S.

doi:10.1016/0029-554x(72)90465-x

Cited by 18 publications

(14 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Until better neutron detecting systems are flown (e.g. Grannan et al, 1972 andFriling, 1972), the upper limits set for this energy region will remain large. It is to be noted that all the observations of neutrons with E> 20 MeV are orders of magnitude greater than the calculated fluxes of Roelof (1966) assuming that all the low energy 'quiet-time' (< 50 MeV) protons are the results of solar neutron decay and that the protons diffuse isotropically through the interplanetary region.…”

Section: Summary Of Current Status Of Experimental Resultsmentioning

confidence: 99%

“…Thus, a detecting system with a large geometrical factor might be able to observe the time-dependent energy for solar neutrons. For example, with the large proton-recoil detector proposed by White (1968) and developed by Grannan et al (1972) the minimum detectable neutron flux at 25-50 MeV is ~2 x 10 -6 neutrons cm -2 s -1 MeV -1. This corresponds to the peak solar neutron flux for Po = 125 MV in Figure 8.…”

Section: Neutron Energy (Mev)mentioning

confidence: 99%

“…In such a detector the protons resulting from the elastic collisions of the incident neutron with the hydrogeneous producer are detected by a system of scintillators, solid state detectors, or multi-gap spark chambers. Many different types of high-energy proton recoil telescopes have been designed and flown to measure the solar and terrestrial neutron fluxes White, 1968;Grannan et al, 1971Grannan et al, , 1972Zych, 1968;Gollnitz et aL, 1969;and Eyles et aL, 1971). In comparing these proton recoil detectors it must be kept in mind that the inelastic interactions of neutrons with carbon in the producer layer and other materials in the detector are much greater than the elastic (n, p) scattering events at energies >~ 50 MeV.…”

Section: High Energy Neutron Detectorsmentioning

confidence: 99%

“…This places serious limitations on the usefulness of this type of detector. Grannan et al, 1972). White (1968) and Grannan et al (1971Grannan et al ( , 1972 use the double scattering of neutrons in two large hydrocarbon scintillators separated by one meter to determine the direction and energy of the neutrons (Figure 13).…”

Section: High Energy Neutron Detectorsmentioning

confidence: 99%

See 3 more Smart Citations

Neutron measurements in space

Lockwood

1973

Space Sci Rev

View full text Add to dashboard Cite

The experimental measurements of the neutron flux and energy spectrum in space since 1964 are reviewed and related to the theoretical predictions. A discussion of the neutron sources is presented. The difficulties associated with neutron measurements of both the atmospheric neutron leakage flux and solar neutrons are included. Particular emphasis is placed upon the neutron leakage flux and energy measurements at energies greater than about 1 MeV. The possibilities of CRAND as a source for the energetic trapped protons are discussed in light of recent measurements of the 10-100 MeV neutron flux. The current status of the solar neutron flux observations is also presented.The primary purposes of neutron measurements in space have been to determine the neutron leakage flux from the atmosphere of the Earth and the solar neutron flux. As a consequence of the inefficient methods for neutron detection and the difficulties of conducting the measurements in the presence of the galactic and solar cosmic-ray backgrounds, the experimental results are very conflicting. It is the purpose of this review to interpret and discuss recent neutron measurements. In order to understand these results the theoretical predictions of the neutron fluxes and energy spectra from possible neutron sources will be briefly presented. Since comparisons of the different neutron measurements depend critically upon the experimental techniques, we will briefly discuss neutron detection methods applicable to space measurements. The emphasis will be upon measurements since 1964 made outside the Earth's atmosphere, but considerable reference will be made to high energy neutron experiments conducted within the Earth's atmosphere at <10 gcm -2 altitude. A review of earlier neutron measurements of terrestrial and solar neutrons has been made by Haymes (1965).

show abstract

Section: Summary Of Current Status Of Experimental Resultsmentioning

confidence: 99%

Section: Neutron Energy (Mev)mentioning

confidence: 99%

Section: High Energy Neutron Detectorsmentioning

confidence: 99%

Section: High Energy Neutron Detectorsmentioning

confidence: 99%

See 2 more Smart Citations

Neutron measurements in space

Lockwood

1973

Space Sci Rev

View full text Add to dashboard Cite

show abstract

“…It had a threshold at 50 MeV and an efficiency of 0.1~ at 100 MeV. The UCR group achieved a significantly lower threshold of 2 MeV with a double layer of liquid scintillator cells where the first scatter took place in one layer and the second scatter in the other layer (Grannan et al, 1972). The maximum efficiency of 8~o occurs at 5 MeV falling to 0.4~o at 100 MeV.…”

Section: Introductionmentioning

confidence: 98%

Neutron techniques

et al. 1988

View full text Add to dashboard Cite

Three experimental methods are described which hold the most promise for improved energy resolution, time resolution and sensitivity in the detection of solar neutrons on satellites and/or long duration balloon flights. These are: (1) The Neutron Calorimeter, (2) SONTRAC (Solar Neutron Track Chamber), and (3)The Solar Neutron Decay Proton Detector. The characteristics of the three methods as to energy range, energy resolution, time resolution, detection efficiency, and physical properties are delineated. The Introduction gives a brief description of earlier techniques which were used to measure the intensity of high-energy cosmic-ray neutrons at the top of the atmosphere and to search for solar neutrons. The past three decades of detector development has now reached the point where we have the capability of making comprehensive and detailed measurements of solar neutrons on future space missions.

show abstract