Download or read book Derivation of Nuclear Parameters for Delayed Neutron Measurements of Neutron Yields for D T Plasma Operation at JET written by M. Angelone and published by . This book was released on 1992 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurements of Delayed Neutron Parameters for U 235 and Np 237 written by and published by . This book was released on 1997 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Delayed neutrons are emitted by excited nuclei formed in beta decay of fission products called delayed neutron precursors. About 1% of the total neutrons released in fission are delayed neutrons; however, this small fraction plays an important role in nuclear reactor control. The delayed neutrons determine the time-dependent behavior of reactors, and knowledge of parameters used to predict neutron emission rate is essential for establishing reactivity worths. The delayed neutron yields, decay constants, and the absolute yield for the six-group delayed neutrons have been measured for U-235 and Np-237. This experiment has been called for in the forecast of experiments needed to support operations in the US. The bare U-235 metal assembly Godiva IV at the Los Alamos Critical Experiment Facility (LACEF) provided the source of neutrons. Godiva IV generated about 107 total fissions in the samples for the infinite and instantaneous irradiation needed to accentuate the shorter and longer-lived groups of delayed neutrons. The detection system used in the experiment consisted of 20 He-3 tubes embedded in a polyethylene cylinder. The delayed neutron activity resulting from the fast neutron-induced fission has been measured. The measured absolute yield for U-235 was determined to be 0.0163 " 0.009 neutrons/fission. This value compares very well with the well-established Keepin absolute yield of 0.0165 " 0.0005. The newly measured absolute yield value for Np-237 was 0.0126 " 0.0007, which compares well to the recently reported value of 0.0129 " 0.0004 by Saleh and Parish. The measured values for U-235 are corroborated with period (e-folding time) versus reactivity calculations.

Download or read book The Determination of the Ranges of the Fission Fragments Emitting Delayed Neutrons Chemical Identification of the 4 51s Delayed Neutron Activity written by N. Sugarman and published by . This book was released on 1946 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of Calculated and Measured Time Dependent Delayed Neutron Yields TX for Calculating Delayed Neutron Yields MATINV for Matrix Inversion in FORTRAN for LSI II Minicomputer written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Time-dependent delayed neutron emission is of interest in reactor design, reactor dynamics, and nuclear physics studies. The delayed neutrons from neutron-induced fission of 232U, 237Np, 238Pu, 241Am, /sup 242m/Am, 245Cm, and 249Cf were studied for the first time. The delayed neutron emission from 232Th, 233U, 235U, 238U, 239Pu, 241Pu, and 242Pu were measured as well. The data were used to develop an empirical expression for the total delayed neutron yield. The expression gives accurate results for a large variety of nuclides from 232Th to 252Cf. The data measuring the decay of delayed neutrons with time were used to derive another empirical expression predicting the delayed neutron emission with time. It was found that nuclides with similar mass-to-charge ratios have similar decay patterns. Thus the relative decay pattern of one nuclide can be established by any measured nuclide with a similar mass-to-charge ratio. A simple fission product yield model was developed and applied to delayed neutron precursors. It accurately predicts observed yield and decay characteristics. In conclusion, it is possible to not only estimate the total delayed neutron yield for a given nuclide but the time-dependent nature of the delayed neutrons as well. Reactors utilizing recycled fuel or burning actinides are likely to have inventories of fissioning nuclides that have not been studied until now. The delayed neutrons from these nuclides can now be incorporated so that their influence on the stability and control of reactors can be delineated. 8 figures, 39 tables.

Download or read book An Investigation of the Delayed Neutron Decay Curves Resulting from Uranium and Plutonium Fission written by C. Redman and published by . This book was released on 1944 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of Delayed Neutron Parameters for the D T Operation Phase at JET written by M. Angelone and published by . This book was released on 1991 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A New Experimental Design and Method for Improved Delayed Neutron Data of Group Abundances written by Heejun Chung and published by . This book was released on 2014 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: The nuclear data on the physics of delayed neutrons coming from fission events are of key importance in reactor kinetics and safeguards applications. The accuracy of reactor kinetics calculations, reactor physics validation studies and techniques for non-destructive assay of special nuclear material are all limited by the quality of these data. The uncertainties on the delayed neutron group abundances of the longest-lived delayed neutron groups are particularly large - up to 13 % for thermal fissions of 235U, 16 % for fast fissions of 238U, and 38 % for fast fissions of 239Pu [1]. There are also several competing data sets with significant variation in values. Recent work indicates that these already large uncertainties are underestimated due to numerical instabilities in the parametric fitting methods [2]. A novel approach to experimentally measure delayed neutron group yields has been proposed by Jordan and Perret [3]. This approach combines gamma-ray scanning and delayed neutron fission rate measurement techniques. With two independent estimates of the same fission rate, a higher uncertainty delayed neutron parameters can be linked to lower uncertainty delayed gamma parameters. An experimental apparatus implementing these techniques has been designed, optimized, and built. The apparatus consists of a D-D neutron generator, a detector bundle, a sample handler, and related electronics.

Download or read book A Study of Calculated and Measured Time Dependent Delayed Neutron Yields written by Raymond Waldo and published by . This book was released on 1980 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurements of Delayed Neutron Yields from Thermal Neutron Induced Fission of 235U 233U 239Pu and 237Np written by S. B. Borzakov and published by . This book was released on 1998 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurements of DT and DD Neutron Yields by Neutron Activation on TFTR written by Cris W. Barnes and published by . This book was released on 1995 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Preliminary Pulsing Experiments to Measure Delayed Neutron Emission Parameters written by and published by . This book was released on 1998 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent interest in delayed neutron parameters including comparisons between macroscopic (experimental) and microscopic (calculated) results have prompted a set of experiments using the 1MW Triga Reactor at the Texas A and M University (TAMU) Nuclear Science Center (NSC) designed to measure the complete set of seven-group delayed neutron parameters for several higher actinides. Operating the Nuclear Science Center Reactor (NSCR) in a pulsed mode, a complete set of delayed neutron parameters were measured for Np-237 and Am-243. The total delayed neutron yield per 100 fissions for Np-237 and Am-243 was found to be 1.14 " 0.07 and 0.85 " 0.05, respectively. Comparisons to previous measurements are made where such measurements are available.

Download or read book INIS Atomindex written by and published by . This book was released on 1995 with total page 682 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Fractional Thermonuclear Neutron Yield During Deuterium Neutral beam Injection Into Deuterium Plasmas written by P. Van Belle and published by . This book was released on 1989 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation and Application of Delayed Neutron Precursor Data written by Michaele Clarice Brady and published by . This book was released on 1988 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Measurement of the Delayed Neutron Yield from Fast Fission in Natural Uranium written by Salem A. Benayad and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Delayed Neutron Emission Measurements for U 235 and Pu 239 written by Yong Chen and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The delayed neutron emission rates of U-235 and Pu-239 samples were measured accurately from a thermal fission reaction. A Monte Carlo calculation using the Geant4 code was used to demonstrate the neutron energy independence of the detector used in the counting station. A set of highly purified actinide samples (U-235 and Pu-239) was irradiated in these experiments by using the Texas A & M University Nuclear Science Center Reactor. A fast pneumatic transfer system, an integrated computer control system, and a graphite-moderated counting system were constructed to perform all these experiments. The calculated values for the five-group U-235 delayed neutron parameters and the six-group Pu-239 delayed neutron parameters were compared with the values recommended by Keepin et al. (1957) and Waldo et al. (1981). These new values differ slightly from literature values. The graphite-moderated counting station and the computerized pneumatic system are now operational for further delayed neutron measurement.

Download or read book Advanced Diagnostics for Magnetic and Inertial Fusion written by Peter E. Stott and published by Springer Science & Business Media. This book was released on 2011-06-28 with total page 449 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the International Conference on Advanced Diagnostics for Magnetic and Inertial Fusion, held September 3-7, 2001 at Villa Monastero, Varenna, Italy. This volume focuses on future diagnostic requirements for fusion energy research emphasizing advanced diagnostics, new techniques and areas where further progress is required.