Download or read book Delayed Neutrons from the Neutron Irradiation of 235U written by Aaron David Heinrich and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of experiments was performed with the Texas A & M University Nuclear Science Center Reactor (NSCR) to verify 235U delayed neutron emission rates. A custom device was created to accurately measure a sample's pneumatic flight time and the Nuclear Science Center's (NSC's) pneumatic transfer system (PTS) was redesigned to reduce a sample's pneumatic flight time from over 1,600 milliseconds to less than 450 milliseconds. Four saturation irradiations were performed at reactor powers of 100 and 200 kW for 300 seconds and one burst irradiation was performed using a $1.61 pulse producing 19.11 MW-s of energy. Experimental results agreed extremely well with those of Keepin. By comparing the first ten seconds of collected data, the first saturation irradiation deviated ~1.869% with a dead time of 2 microseconds, while the burst irradiation deviated ~0.303% with a dead time of 5 microseconds. Saturation irradiations one, three and four were normalized to the initial count rate of saturation irradiation two to determine the system reproducibility, and deviated ~0.449%, ~0.343% and ~0.389%, respectively.

Download or read book Delayed Neutrons from U235 After Short Irradiation written by and published by . This book was released on 1949 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Delayed Neutrons from Fissionable Isotopes of Uranium Plutonium and Thorium written by George Robert Keepin and published by . This book was released on 1957 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energies of the Delayed Neutrons from U235 Fission Products written by and published by . This book was released on 1946 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Delayed Neutron Emission Measurements from Fast Fission of U 235 and Np 237 written by and published by . This book was released on 1996 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments have been designed and conducted to measure the periods and yields of delayed neutrons from fast fission of 235U and 237Np. These measurements were performed in a pool type reactor using a fast flux in-core irradiation device. The energy dependent neutron flux spectrum within the irradiation device was characterized using a foil activation technique and the SAND-II unfolding code. Five delayed neutron groups were measured. The total yield (sum of the five group yields) for 235U was found to be 0.0141 ± 0. 0009. The total yield for 237Np was found to be 0.0102 ± 0. 0008. The total delayed neutron yield data were found to be in good agreement with previous measurements. The individual group yields reported here are preliminary and are being further refined.

Download or read book Delayed Neutrons written by George Robert Keepin and published by . This book was released on 1955 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive review is given of existing measurements as of October 1955 on the properties of delayed neutrons from various fissionable isotopes. The relation of these measurements to current theory and practice is discussed.

Download or read book Studies of the Delayed Neutrons written by and published by . This book was released on 1947 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Studies of the Delayed Neutrons written by and published by . This book was released on 1947 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Delayed Fission Neutrons written by International Atomic Energy Agency and published by . This book was released on 1968 with total page 268 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 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Absolute Yield of Delayed Neutrons from the Fast Neutron Induced Fission of Uranium 235 and 238 written by Mark Adrian Kellett and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Delayed Neutron Spectra from Short Pulse Fission of Uranium 235 written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Delayed neutron spectra from individual short pulse (approx. 50 .mu.s) fission of small 235U samples (50 mg) were measured using a small (5 cm OD x 5 cm length) NE 213 neutron spectrometer. The irradiating fast neutron flux (approx. 1013 neutrons/cm2) for these measurements was provided by the Godiva fast burst reactor at the Los Alamos Critical Experiment Facility (LACEF). A high speed pneumatic transfer system was used to transfer the 50 mg 235U samples from the irradiation position near the Godiva assembly to a remote shielded counting room containing the NE 213 spectrometer and associated electronics. Data were acquired in sixty-four 0.5 s time bins and over an energy range 1 to 7 MeV. Comparisons between these measurements and a detailed model calculation performed at Los Alamos is presented.

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 Energy Measurements of Delayed Neutron Groups from 235U written by Athar Naeem and published by . This book was released on 1971 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nondestructive Fissile Isotopic Measurement Technique for 233U 235U Fuels Using Prompt and Delayed Fission neutron Counting written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Assay and analysis procedures were developed for nondestructive fissile isotopic measurement of mixed 233U--235U fuel samples. For 233U much fewer delayed neutrons are released per fission than for 235U, although the number of prompt neutrons is approximately the same. By separately counting prompt and delayed neutrons released by a sample exposed to neutron irradiation, the amounts of 233U and 235U present in the sample can be estimated. Equations of delayed- and prompt-neutron counts versus 233U and 235U contents are solved simultaneously for the 233U and 235U contents of a sample. Eleven samples containing mixtures of 233U and 235U from no 233U to nearly 100% were prepared and assayed in prompt- and delayed-neutron assay devices. Constants for calibration equations, which are derived in this report, were fitted to data from nine of the samples. The maximum differences between counts calculated by the calibration equations and measured counts were 2.3% for delayed neutrons and 1.2% for prompt neutrons, indicating a good selection of the form for the calibration equations. The two remaining samples were treated as unknowns, and the uranium contents of these samples were estimated by simultaneously solving the two calibration equations. The maximum difference between estimated 233U or 235U content and actual content for either sample was 1.5%.