The Study of Beta-Delayed Neutron Decay Near the Neutron Drip Line
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KINETIC ANALYSIS of SUB-PROMPT-CRITICAL REACTOR ASSEMBLIES Hy S Das Theoretical Physics Division
BARC/1992/E/011 O 1 "o KINETIC ANALYSIS OF SUB-PROMPT-CRITICAL REACTOR ASSEMBLIES hy S Das Theoretical Physics Division 1992 BARC/1992/E/011 o UJ GOVERNMENT OF INDIA - AATOMIT C ENERGY COMMISSION U KINETIC ANALYSIS OF SUB-PROMPT-CRITICAL REACTOR ASSEMBLIES by S. Das Theoretical Physics Division BHABHA ATOMIC RESEARCH CENTRE BOMBAY, INDIA 1992 BARC/1992/E/011 BIBLIOBRAPHIC DESCRIPTION SHEET FOR TECHNICAL REPORT (as par IS i 94BNB - 1980) 01 Security classification i Unclassified 02 Distribution t External 03 Report status i New 04 Series i BARC External 05 Report type i Technical Report 06 Report No. i BARC/1992/E/011 07 Part No. or Volume No. i 08 Contract No. i 10 Title and subtitle i Kinetic analysis of sub-prompt- critical reactor assemblies 11 Collation i 14 p.f 4 figs., 1 tab. IS Project No. i 20 Personal author<s> i S. Das 21 Affiliation of author(s) i Theoretical Physics Division, Bhabha Atomic Research Centre, Bombay 22 Corporate author(s) i Bhabha Atomic Research Centre, Bombay - 400 085 23 Originating unit i Theoretical Physics Division, BARC, Bombay 24 Sponsor(s) Name i Department of Atomic Energy Type i Government 30 Date of submission i May 1992 31 Publication/Issue date i June 1992 Contd... (ii) 1 40 Publ i»h»r/Distributor t Head, Library and Information Division, Bhabha Atomic Rasaarch Contra, Bombay 42 Form of distribution t Hard Copy 50 Languaga of taxt i English 51 Languaga o-f summary i English 92 No. of references i % rafs. 53 Givas data on i 60 Abstract x Nautronic analysis of safaty-ralatad kinetics problams in experimental neutron multiplying assemblies has bean carried out using a sub-prompt-critical reactor model. -
Ft-216-1.982
CENTRAL INSTITUTE OF PHYSICS INSTITUTE FOR PHYSICS AND NUCLEAR ENGINEERING Department of Fundamental Physics \tiu- FT-216-1.982 . September THE RELATIVE IMPORTANCE OF RELATIVIST1C INDUCED INTERACTIONS IN THE BETA DECAY OF 17oTm D.Bogdan, Amand Faessler , M.I. Cristu, Suzana HoIan ABSTRACT : The log ft-values, the spectrum shape functions, and the beta-gamma angular correlation coefficients of the 17o Tm beta decay are computed in the framework of relativistic formfactor formalism using asymmetric rotor model wavefunctions, Main vector and axi*l vector hadron currents being strongly bindered, the relative importance of induced interaction matrix elements is accurately estimated» Good agreement with experi - ment is obtained for the beta decay observables when the main induced interaction terms were taken into account. The contri bution of the pseudos'îalar term was found insignificant. *) Permanent address : Institut fur Theoretische PhysiJc, Universităt Tubingen, D-7400 Tubingen, West - Germany 1 - 1. INTRODUCTION The theoretical evaluation of observables in the first forbidden beta decay provides an excellent mean to assess the relative importance of the so-called induced interaction cor - rection terms contributing to the beta decay probability when vector and axial vector nuclear beta matrix elements are strongly hindered by either mutual cancellation or selection rules. In this paper the log ft-values, the shape of the beta spectrum and the beta-gamma angular correlation were computed for the l" -* 2 and l" •• 0* beta transitions of the Tm ground 170 state towards the first excited and the ground state of Yb nucleus, respectively. For the Tm nucleus which is strongly deformed ( 02 = = 0.28)*the dominant coupling scheme should be the strong coupling. -
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High Precision Measurement of the 19Ne Lifetime by Leah Jacklyn Broussard Department of Physics Duke University Date: Approved: Albert Young Calvin Howell Kate Scholberg Berndt Mueller John Thomas Dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Physics in the Graduate School of Duke University 2012 Abstract (Nuclear physics) High Precision Measurement of the 19Ne Lifetime by Leah Jacklyn Broussard Department of Physics Duke University Date: Approved: Albert Young Calvin Howell Kate Scholberg Berndt Mueller John Thomas An abstract of a dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Physics in the Graduate School of Duke University 2012 Copyright c 2012 by Leah Jacklyn Broussard All rights reserved except the rights granted by the Creative Commons Attribution-Noncommercial Licence Abstract The lifetime of 19Ne is an important parameter in precision tests of the Standard Model. Improvement in the uncertainty of experimental observables of this and other 1 T = 2 mirror isotopes would allow for an extraction of Vud at a similar precision to that obtained by superallowed 0+ → 0+ Fermi decays. We report on a new high precision measurement of the lifetime of 19Ne, performed at the Kernfysich Versneller MeV 19 Instituut (KVI) in Groningen, the Netherlands. A 10.5 A F beam was used to 19 produce Ne using inverse reaction kinematics in a H2 gas target. Contaminant productions were eliminated using the TRIμP magnetic isotope separator. The 19Ne beam was implanted into a thick aluminum tape, which was translated to a shielded detection region by a custom tape drive system. -
Total Prompt Energy Release in the Neutron-Induced Fission Of
Nuclear Physics A 772 (2006) 113–137 Total prompt energy release in the neutron-induced fission of 235U, 238U, and 239Pu D.G. Madland Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA Received 12 January 2006; received in revised form 28 March 2006; accepted 29 March 2006 Available online 2 May 2006 Abstract This study addresses, for the first time, the total prompt energy release and its components for the fission of 235U, 238U, and 239Pu as a function of the kinetic energy of the neutron inducing the fission. The com- ponents are extracted from experimental measurements, where they exist, together with model-dependent calculation, interpolation, and extrapolation. While the components display clear dependencies upon the incident neutron energy, their sums display only weak, yet definite, energy dependencies. Also addressed is the total prompt energy deposition in fission for the same three systems. Results are presented in equation form. New measurements are recommended as a consequence of this study. © 2006 Elsevier B.V. All rights reserved. PACS: 24.75.+i; 25.85.Ec; 25.85.Ca; 27.90.+b Keywords: Energy release and energy deposition in neutron-induced fission; Experiment and Los Alamos model; 235U; 238U; 239Pu 1. Introduction This study is a consequence of open questions on the magnitudes of the total prompt energy re- lease in fission, the total prompt energy deposition in fission, the components of these quantities, and their dependencies upon the kinetic energy of the neutron inducing the fission. Our results are given in Eqs. (31)–(33) and Fig. 17 for the total prompt energy release in fission, and in Eqs. -
The Measurement and Interpretation of Superallowed 0+ to 0+ Nuclear
REVIEW ARTICLE The measurement and interpretation of superallowed 0+→ 0+ nuclear β decay J C Hardy and I S Towner Cyclotron Institute, Texas A&M University, College Station, TX 77843-3366, U.S.A. E-mail: [email protected], [email protected] Abstract. Measurements of the decay strength of superallowed 0+→ 0+ nuclear β transitions shed light on the fundamental properties of weak interactions. Because of their impact, such measurements were first reported 60 years ago in the early 1950s and have continued unabated ever since, always taking advantage of improvements in experimental techniques to achieve ever higher precision. The results helped first to shape the Electroweak Standard Model but more recently have evolved into sensitively testing that model’s predictions. Today they provide the most demanding test of vector-current conservation and of the unitarity of the Cabibbo-Kobayashi-Maskawa matrix. Here, we review the experimental and theoretical methods that have been, and are being, used to characterize superallowed 0+→ 0+ β transitions and to extract fundamentally important parameters from their analysis. 1. Introduction In 1953, Sherr and Gerhart published a paper [1] on “Experimental evidence for the Fermi interaction in the β decay of 14O and 10C.” It was less than five years since Sherr had first discovered these two nuclei [2], yet already the two authors were using the decays to probe for the first time the fundamental nature of β decay. They were arXiv:1312.3587v1 [nucl-ex] 12 Dec 2013 able to identify superallowed transitions in both decays – they called them “allowed favoured transitions” – and recognized that the Fermi theory of β decay predicted that the comparative half-lives, or ft values, for the two transitions should be the same, a prediction they could test. -
PROGRESS in RESEARCH April 1, 2002 – March 31, 2003
PROGRESS IN RESEARCH April 1, 2002 – March 31, 2003 Cyclotron Institute Texas A&M University College Station, Texas TABLE OF CONTENTS Introduction ............................................................................................................................................... ix R.E. Tribble, Director SECTION I: NUCLEAR STRUCTURE, FUNDAMENTAL INTERACTIONS AND ASTROPHYSICS Isoscalar giant dipole resonance for several nuclei with A ≥ 90.......................................................... I-1 Y. –W. Lui, X. Chen, H. L. Clark, B. John, Y. Tokimoto, D. H. Youngblood Giant resonances in 46, 48Ti ................................................................................................................... I-4 Y. Tokimoto, B. John*, X. Chen, H. L. Clark, Y. –W. Lui and D. H. Youngblood Determination of the direct capture contribution for 13N(p,γ)14O from the 14O →13N + p asymptotic normalization coefficient ..................................................................................................... I-6 X. Tang, A. Azhari, C. Fu, C. A. Gagliardi, A. M. Mukhamedzhanov, F. Pirlepesov, L. Trache, R. E. Tribble, V. Burjan, V. Kroha and F. Carstoiu Breakup of loosely bound nuclei at intermediate energies as indirect method in nuclear 8 astrophysics: B and the S17 astrophysical factor.................................................................................. I-8 F. Carstoiu, L. Trache, C. A. Gagliardi, and R. E. Tribble Elastic scattering of 8B on 12C and 14N ................................................................................................ -
Systematic of Delayed Neutron Parameters
RU0110988 40 XIV International Workshop on Nuclear Fission Physics Systematic of Delayed Neutron Parameters S.G. Isaev, V.M. Piksaikin Institute of Physics and Power Engineering, Obninsk, Russia Abstract The experimental studies of the energy dependence of the delayed neutron parameters for various fissioning systems has shown that the behavior of a some combination of delayed neutron parameters has a similar features. On the basis of this findings the systematics of delayed neutron experimental data for thorium, uranium, plutonium and americium isotopes have been investigated with the purpose to find a correlation of DN parameters with characteristics of fissioning system as well as a correlation between the delayed neutron parameters themselves. Below we will present the preliminary results which were obtained during this study omitting the physics interpretation of the results. Introduction The knowledge of the time dependence of P-delayed neutron emission is of great importance for the development of reliable data base required both for reactor-physics analysis and for the investigation of nuclei which are far from the valley of stability. Since discovery of delayed neutrons the time dependence of delayed neutron emission from neutron induced fission was studied in more than 238 experiments [1]. In parallel to the experimental studies of aggregate DN emission from neutron induced fission the group parameters of delayed neutron emission were calculated using microscopic approach (summation technique) [2]. These calculations are based on the knowledge of the emission probabilities values Pn, half-life values and yields of individual precursors of delayed neutrons [3]. One of the main results of the aggregate DN decay curve measurements was that the group periods (or decay constants) for various fissioning systems for fast neutrons induced fission do not differ from each other [4]. -
Radiation Detection from Fission
ORNL/TM-2004/234 RADIATION DETECTION FROM FISSION J. T. Mihalczo DOCUMENT AVAILABILITY Reports produced after January 1, 1996, are generally available free via the U.S. Department of Energy (DOE) Information Bridge. Web site http://www.osti.gov/bridge Reports produced before January 1, 1996, may be purchased by members of the public from the following source. National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 Telephone 703-605-6000 (1-800-553-6847) TDD 703-487-4639 Fax 703-605-6900 E-mail [email protected] Web site http://www.ntis.gov/support/ordernowabout.htm Reports are available to DOE employees, DOE contractors, Energy Technology Data Exchange (ETDE) representatives, and International Nuclear Information System (INIS) representatives from the following source. Office of Scientific and Technical Information P.O. Box 62 Oak Ridge, TN 37831 Telephone 865-576-8401 Fax 865-576-5728 E-mail [email protected] Web site http://www.osti.gov/contact.html This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. -
Nuclear Fission Dynamics: Past, Present, Needs, and Future
NT@UW-19-18,LA-UR-19-32211 Nuclear Fission Dynamics: Past, Present, Needs, and Future Aurel Bulgac,1 Shi Jin,1 and Ionel Stetcu2 1Department of Physics, University of Washington, Seattle, Washington 98195–1560, USA 2Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA (Dated: March 23, 2020) Significant progress in the understanding of the fission process within a microscopic framework has been recently reported. Even though the complete description of this important nuclear reac- tion remains a computationally demanding task, recent developments in theoretical modeling and computational power have brought current microscopic simulations to the point where they can pro- vide guidance and constraints to phenomenological models, without making recourse to parameters. An accurate treatment compatible with our understanding of the inter-nucleon interactions should be able to describe the real-time dynamics of the fissioning system and could justify or rule out assumptions and approximations incompatible with the underlying universally accepted quantum- mechanical framework. Of particular importance are applications to observables that cannot be directly measured in experimental setups (such as the angular momentum distribution of the fission fragments, or the excitation energy sharing between the fission fragments, or fission of nuclei formed during the r-process), and their dependence of the excitation energy in the fissioning system. Even if accurate predictions are not within reach, being able to extract the trends with increasing exci- tation energy is important in various applications. The most advanced microscopic simulations of the fission process do not support the widely used assumption of adiabaticity of the large amplitude collective motion in fission, in particular for trajectories from the outer saddle towards the scission configuration. -
Reactor Physics
REACTOR PHYSICS COURSE INTRODUCTION This Training Manual assumes prior knowledge of Nuclear Theory. It extends this information into a discussion of Reactor Physics, particularly as it relates to CANDU reactors. The course begins with the general principles of reactor configuration required to maintain a self- sustaining chain reaction. It continues with reactor dynamics (in both the critical and subcritical core), reactivity feedback effects (temperature effects, fission product poisoning, and fuel burnup), and ends with operational considerations (at low and high power). The material covers four main areas, subdivided into eight major sections as follows: • The Critical Reactor at Steady Power Output (Section 1) • The Dynamic Reactor (Sections 2 and 3) • Reactivity Feedback Effects (Sections 4, 5, and 6) • Reactor Operations (Sections 7 and 8) CNSC i Science and Reactor Fundamentals – Reactor Physics Technical Training Group TABLE OF CONTENTS Objectives 1 The Critical Reactor at Steady Power Output 9 1.0 INTRODUCTION 9 1.1 Fission 9 1.2 Harnessing Fission 15 1.3 Movement of Neutrons Through the CANDU lattice Lattice 18 1.4 The Finite Reactor 26 Response of The Critical Reactor to a Reactivity Change 31 2.0 INTRODUCTION 31 2.1 Exponential Power Rise 31 2.2 Corrections to Exponential Reactor Response 33 2.3 The Effect of Delayed Neutrons 36 2.4 Prompt Criticality 40 2.5 Power Rundown: The Prompt Drop 42 Responsiveness of The Subcritical Reactor 45 3.0 INTRODUCTION 45 3.1 Neutron Flux in a “Shut Down” Reactor 45 3.2 Dynamics in the Subcritical -
A Study of Weak Nuclear Response by Nuclear Muon Capture
OSAKA UNIVERSITY A Study of Weak Nuclear Response by Nuclear Muon Capture A thesis submitted in partial fulfillment for the degree of Doctor of Philosophy by IZYAN HAZWANI BINTI HASHIM in the Department of Physics Graduate School of Science November 2014 Abstract Nuclear matrix elements (NMEs) for double beta decays (DBD) are crucial for extracting fundamental neutrino properties from DBD experiments. In order to study the DBD NMEs, single β+ and β− NMEs are required. The present research developed an experimental approach towards the determination of weak nuclear response (square of the NME) for the importance of fundamental properties of neutrinos. Hence, the present research aims at experimental studies of muon capture strength distributions, the β+ side responses, to help/confirm theoretical evaluation for DBD NMEs. Nuclear muon capture induced the excitation of the nucleus by compound nuclear formation and de-excitation of the compound nucleus by neutron emission. However, captures on the excited states of nucleus are preferable in comparison with capture on the ground state. The gamma rays accompanied the neutron emission is from the transitions from an excited state to the ground state. The production of isotope after muon capture evaluated the capture strength via observation of nuclear gamma rays and X-rays. We used the enriched molybdenum thin film in our first measurement at J-PARC, MLF. The statistical neutron decay calculator explained the theoretical approach with the limitation to the excitation energy which corresponds to the Q-value of muon captures. Neutron binding energy is the threshold energy for emission of neutron and their cascade process after nuclear excitation is explained by emission of the fast pre-equilibrium neutrons(PEQ) and evaporating neutrons(EQ) fraction. -
1- TOPIC: 292001 KNOWLEDGE: K1.02 [3.0/3.1] QID: B45 the Term “Neutron Generation Time” Is Defined As the Average Time Betw
NRC Generic Fundamentals Examination Question Bank--BWR May 2020 TOPIC: 292001 KNOWLEDGE: K1.02 [3.0/3.1] QID: B45 The term “neutron generation time” is defined as the average time between... A. neutron absorption and the resulting fission. B. the production of a delayed neutron and subsequent neutron thermalization. C. neutron absorption producing a fission and absorption or leakage of resultant neutrons. D. neutron thermalization and subsequent neutron absorption. ANSWER: C. TOPIC: 292001 KNOWLEDGE: K1.02 [3.0/3.1] QID: B174 Which one of the following is the definition of the term, prompt neutron? A. A high-energy neutron emitted from a neutron precursor, immediately after the fission process. B. A neutron with an energy level greater than 0.1 MeV, emitted in less than 1.0 x 10-4 seconds following a nuclear fission. C. A neutron emitted in less than 1.0 x 10-14 seconds following a nuclear fission. D. A neutron emitted as a result of a gamma-neutron or alpha-neutron reaction. ANSWER: C. -1- Neutrons NRC Generic Fundamentals Examination Question Bank--BWR May 2020 TOPIC: 292001 KNOWLEDGE: K1.02 [3.0/3.1] QID: B245 Delayed neutrons are neutrons that... A. have reached thermal equilibrium with the surrounding medium. B. are expelled within 1.0 x 10-14 seconds of the fission event. C. are expelled with the lowest average kinetic energy of all fission neutrons. D. are responsible for the majority of U-235 fissions. ANSWER: C. TOPIC: 292001 KNOWLEDGE: K1.02 [3.0/3.1] QID: B1146 (P1945) Which one of the following types of neutrons has an average neutron generation lifetime of 12.5 seconds? A.