Download or read book A Precision Neutron Detector for p n Reaction Measurements written by Rajat Kudchadker and published by . This book was released on 1992 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of a Halpern type 4 pi Neutron Detector written by H. M. Gerstenberg and published by . This book was released on 1967 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: The response to various neutron spectra of a 2-inch diameter BF3 proportional counter in a Halpern-type geometry has been studied as a function of moderator thickness. Neutron sources used were a calibrated RaDBe(a,n) source and a series of photoneutron sources using a number of bremsstrahlung spectra. The reactions used were: 16PO(gamma,n), 31P(gamma,n) and d(gamma,n). For these sources absolute neutron yields were determined either from the residual B+ activity or from the known cross section and the absolute bremsstrahlung intensity. Using these empirical data a final detector with 13 BF3 counters was constructed. Over the spectral range covered by the above sources the measured efficiency for counting neutrons of the final detector was 9.6 percent with an estimated uncertainty of plus or minus 0.5 percent, independent of spectrum. The detector was used to measure the neutron yields from Pb, Au, Ta, Ho, Ag, Cu, Co, Ca, P, Al, O and C for a series of bremsstrahlung energies between 12.0 and 29.0 MeV. These yields were compared with those calculated from previously published neutron yield cross sections. The data indicate that previously reported discrepancies in neutron yield data can probably be traced to the determination of neutron detector efficiencies. (Author).

Download or read book A Methane Proportional Counter System for Natural Radiocarbon Measurements written by Ward Diethorn and published by . This book was released on 1956 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of Neutron Flux and Spectra for Physical and Biological Applications written by National Committee on Radiation Protection and Measurements (U.S.) and published by . This book was released on 1960 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Neutron Detectors for Fusion Reaction rate Measurements written by and published by . This book was released on 1994 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fusion reactions in an inertial-confinement fusion (ICF) target filled with deuterium or a deuterium/tritium fuel release nearly monoenergetic neutrons. Because most the neutrons leave the compressed target without collision, they preserve reaction-rate information as they travel radially outward from their point of origin. Three fast, neutron detector techniques, each capable of measuring the fusion reaction-rate of ICF targets, have been demonstrated. The most advanced detector is based on the fast rise-time of a commercial plastic scintillator material (BC-422) which acts as a neutron-to-light converter. Signals, which are recorded with a fast optical streak camera, have a resolution of 25 ps. Good signals can be recorded for targets producing only 5 x 107 DT neutrons. Two other detectors use knock-on collisions between neutrons and protons in a thin polyethylene (CH2) converter. In one, the converter is placed in front of the photocathode of an x-ray streak camera. Recoil protons pass through the photocathode and knock out electrons which are accelerated and deflected to produce a signal. Resolutions

Download or read book Neutron Standards and Applications written by Charles D. Bowman and published by . This book was released on 1977 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spectrally matched Neutron Detectors Designed Using Computational Adjoint S sub N for Plug in Replacement of Helium 3 written by Scottie Walker and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutron radiation detectors are an integral part of the Department of Homeland Security (DHS) efforts to detect the illicit trafficking of radioactive or special nuclear materials into the U.S. In the past decade, the DHS has deployed a vast network of radiation detection systems at various key positions to prevent or to minimize the risk associated with the malevolent use of these materials. The greatest portion of this detection burden has been borne by systems equipped with 3He because of its highly desirable physical and nuclear properties. However, a dramatic increase in demand and dwindling supply, combined with a lack of oversight for the existing 3He stockpile has produced a critical shortage of this gas which has virtually eliminated its viability for detector applications. A number of research efforts have been undertaken to develop suitable 3He replacements; however, these studies have been solely targeted toward simple detection cases where the overall detection efficiency is the only concern. For these cases, an insertion of additional detectors or materials can produce reaction rates that are sufficient, because the neutron spectral response is essentially irrelevant. However, in applications such as safeguards, non-proliferation efforts, and material control and accountability programs (MC & A), a failure to use detectors that are spectrally matched to 3He can potentially produce dire consequences. This is because these more difficult detection scenarios are associated with fissile material assessments for 239Pu and other actinides and these analyses have almost universally been calibrated to an equivalent 3He response. In these instances, a "simple" detector or material addition approach is neither appropriate nor possible, due to influences resulting from the complex nature of neutron scattering in moderators, cross sections, gas pressure variations, geometries, and surrounding structural interference. These more challenging detection cases require a detailed computational transport analysis be performed for each specific application. A leveraged approach using adjoint transport computations that are validated by forward transport and Monte Carlo computations and laboratory measurements can address these more complex detection cases and this methodology was utilized in the execution of the research. The initial task was to establish the fidelity of a computational approach by executing radiation transport models for existing BF3 and 3He tubes and then comparing the modeling results to laboratory measurements made using these identical devices. Both tubes were 19.6 cm in height, 1-inch in diameter, and operated at 1 and 4 atm pressure respectively. The models were processed using a combination of forward Monte Carlo and forward and adjoint 3-D discrete ordinates (SN) transport methods. The computer codes MCNP5 and PENTRAN were used for all calculations of a nickel-shielded plutonium-beryllium (PuBe) source term that provided a neutron output spectra equivalent to that of weapons-grade plutonium (WGPu). Once the computational design approach was validated, the adjoint SN method was used to iteratively identify six distinct plug-in models that matched the neutron spectral response and reaction rate of a 1-inch diameter 3He tube with a length of 10 cm and operating at 4 atm pressure. The equivalent designs consist of large singular tubes and dual tubes containing BF3 gas, 10B linings, and/or 10B-loaded polyvinyl toluene (PVT). The reaction rate for each plug-in design was also verified using forward PENTRAN and MCNP5 calculations. In addition to the equivalent designs, the adjoint method also yielded various insights into neutron detector design that can lead to additional designs using a combination of different detector materials such as BF3/10B-loaded PVT, 10B-lined tubes/10B-loaded PVT, etc.

Download or read book Flat Response Neutron Detector written by A. O. Hanson and published by . This book was released on 1946 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Neutron Detectors written by International Atomic Energy Agency and published by . This book was released on 1966 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: A child speculates about sleeping next to various animals in various places other than one's own, and most desirable, warm bed.

Download or read book Novel Neutron Detector for N n Scattering Length Measurement written by Eva Wilcox and published by . This book was released on 2005 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: The neutron-neutron (n-n) scattering length is a fundamental parameter in nuclear physics; however, measurements are plagued with large uncertainties caused by neutron detector cross talk. Many experimentalists also rely upon computer code to calibrate their neutron detectors. Experiments give one of two different numbers but there is still no adequate explanation for this discrepancy. We have developed a new neutron detector expressly for the purpose of improving the n-n scattering length measurement. It offers two important advantages: 1) minimal cross talk and 2) high counting efficiency. We calibrated the detector from 1 MeV to 6 MeV at 1 MeV increments. We have shown that the computer code, MCNP, does not always give the correct detector efficiency, and that reliance upon this code for calibration could be a large factor for error in previous experiments. Preliminary tests show no cross talk between two like detectors and suggest that these detectors in a n-n scattering length measurement.

Download or read book Measurement of Neutron Flux and Spectra for Physical and Biological Applications written by National Committee on Radiation Protection and Measurements (U.S.) and published by . This book was released on 1960 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook of Nuclear Engineering written by Dan Gabriel Cacuci and published by Springer Science & Business Media. This book was released on 2010-09-14 with total page 3701 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is an authoritative compilation of information regarding methods and data used in all phases of nuclear engineering. Addressing nuclear engineers and scientists at all levels, this book provides a condensed reference on nuclear engineering since 1958.

Download or read book Precision Measurement of Neutron Detection Efficiency written by Brian Lee Groft and published by . This book was released on 1990 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Passive Nondestructive Assay of Nuclear Materials written by Doug Reilly and published by . This book was released on 1991 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NBS Special Publication written by and published by . This book was released on 1968 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Particle Physics Reference Library written by Christian W. Fabjan and published by Springer Nature. This book was released on 2020 with total page 1083 pages. Available in PDF, EPUB and Kindle. Book excerpt: This second open access volume of the handbook series deals with detectors, large experimental facilities and data handling, both for accelerator and non-accelerator based experiments. It also covers applications in medicine and life sciences. A joint CERN-Springer initiative, the "Particle Physics Reference Library" provides revised and updated contributions based on previously published material in the well-known Landolt-Boernstein series on particle physics, accelerators and detectors (volumes 21A, B1,B2,C), which took stock of the field approximately one decade ago. Central to this new initiative is publication under full open access

Download or read book Neutron Detectors for Scattering Applications written by Yacouba Diawara and published by Springer Nature. This book was released on 2023-08-04 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the most common neutron detectors used in neutron scattering facilities and all of those in use at Oak Ridge National Lab. It starts describing the facilities, instruments and the critical detector parameters needed by various instruments. Then the key components of the 3He-based linear position-sensitive detectors as well as on their electronics, which require particular attention to signal processing and noise reduction, are introduced. One chapter is dedicated to the 3He alternatives where scintillators play a critical role. It also covers emerging neutron detection technologies including semiconductors, vacuum-based devices and their associated readouts, which will be required in the future for high rate and high-resolution neutron detectors. The authors explain the logic behind the choice of materials as well as the various constraints that neutron detectors must respect to be useful. Some of these constraints, such as efficiency and gamma-ray sensitivity are common to all neutron counters while others, like timing resolution, dynamic range, and peak counting rate, depend on the applications. The book guides experts, the nuclear science community, and young scholars through the physical processes and the required electronics in a way that is accessible for those not professionally involved in designing detector’s components and electronic circuits.