B.A.R.C-1177 i 0 OP GOVERNMENT OF INDIA ATOMIC ENERGY COMMISSION RESEARCH & DEVELOPMENT ACTIVITIES OF THE NEUTRON PHYSICS DIVISION For the period January 1981 - December 1981 Edited by Sandhya Bhakay-Tamhane and Falguni Roy BHABHA ATOMIC RESEARCH CENTRE BOMBAY, INDIA 1982 B.A.ft.C. - 1177 GOVERNMENT OP INDIA ATOMIC BNERGI COMMISSION RESEARCH i DEVELOPMENT ACTIVITIES OF THE NEUTRON PHYSICS DIVISION For 'ih« period January 1981 - D«e«mb«r 1981 by Sandhya Bhakay-Tanhane and Falgunl Roy BHABHA ATOMIC RESEARCH CENTRE BOMBAY, INDIA 1982 FOREWORD This year has been a period of consolidation and growth of the research activities in the Division. The current interests of the Purnlma Group include 233-U critical systems and minimum critical mass systems, applica- tions of the Trombay .Criticality Formula, oil-well logging applications of 14 MeV neutrons, fusion blanket neutronlcs, plasma pinches and various advanced fusion concepts. The 233-U fuelled neutron source reactor project at RHC, Kalpakkam waa accorded sanction during this year enabling it to enter the phase of procurement and fabrication. Several fusion plasma related experiments have been carried out with the available 80 KJ capacitor bank anti a much larger 500 KJ facility is being set up at the Purnlma Complex for pulsed fusion studies. In neutron crystallography, the emphasis waa on structural phase transitions and the physics of diffraction, particularly the physical reasonableness of the parameters characterising a crystal as obtained from a study of extinction effects. Several molecules of pharmacological Importance have also been studied using X-rays. In macroaolecular crystallography, the refinement of two important enzyme structures-human erythrocyte carbonic anhydrase B and Cu 2+ lysozyme complex- waa carried out. Several computer programs for biological crystallography were also implemented on the computers accessible to us. The main thrust of the materials physics research programme is on high pressure and shock wave phenomena. The equation of state studies have continued and it was shown that the valence charge in a solid at OK can' be viewed as a pressure ionisation effect. In another study, the non-thermallsation of positrons at very low temperatures in alk&li metals was shown to be interpretable in terms of a charge-density-wave ground state. The R&D work of the Seismology Section is centered around the development of new methods of detecting underground nuclear explosions and of new algorithms for extracting the signals and discriminating between nuclear explosions and earthquakes. The expertise acquired, particularly from the Qauribidanur Seismic Array, is finding use in the seismic risk estimation for siting large structures including nuclear power plants. In the collaborative project for rockburst studies in the Kolar (told Fields, the feasibility study for a three-dimensional network of sensors close to the working mines was completed. The seismology research has both a strong Instrumentation base and an extensive - i. - - il - theoretical back-up. The workshop facilities for the Division are provided by the Fhyslcs Group Workshop whose staff Is affiliated to the Nuclear Physics Division. We are also grateful for the collaboration and support froa several Divisions In B.A.R.C. (It. Chldaabaraa) CONTENTS Page FOREWORD 4 1 PURNIMA LABORATORIES 233 1.1 U Fuelled Neutron Source Reactor at RRC, Kalpakkam - Progress Report i 1.2 Purnima-II, Beo Reflected 233U Uraayl Nitrate Solution System - Progress Report .. 3 1.3 Reactivity Contribution due to (n,2n) Multiplication in BeHg /Moderated Minimum Critical Mass Systems ., 4 1.4 Probability Distribution in Time of Occurrence of Fission Burst and its Effect on' Peak Fission Power and Yield in Solution Systems 6 1*5 Analysis of CRAC Series of Kinetic Experi- ments on Enriched Uranyl Nitrate Solution Systems - Some Results 7 1.6 Systematic* of Variation of Reflector Savings with Reflector Thickness for Snail Reactor Assemblies 8 1.7 "Development of Neutron Transport Theory Codes Using Finite Element Technique ...... 10 1.8 Neutron Pulse Propagation in a Fissile Medium and Multiplication Aspects of Micro- Fission Systems 11- 1.9 Neutron Multiplication due to 14-MeV Neutrons in Spherical Fertile Blankets: Calculations 12 1.10 Multilayered Blanket Concept for Tritium Breeding Assemblies 14 1.11 Composite Lead-Bsryllium Neutron Multipliers for Fusion Blankets 16 - iii - - ir - 1.12 Absolute Neutron Yield Determination Using Associated oC-particle Method 17 1.13 Neutron Physics Studies for Oil Well Logging Applicationa 18 1.14 Optimum Moderator Thickneoti for Maximum Charged Particle Conversion Efficiency for the Detection of D-D Fusion Neutrons ... 20 1.15 Use of SSTD for the Detection of Neutrons from Low Yield Plasma Experiments 21 1.16 Scaling of Plasma Focus Properties with Capacitor Bank Current 22 1*17 Use of an Electric Gun for Compression of Deuterium Gas In Conical Targets ........ 23 1.18 Some Aspects of Modelling • MXQMA Fusion Reactor 25 1.19 Proposed.500 KJ Capacitor Bank Facility for Pulsed Fusion Studies 27 CRYSTALLOGRAPHY 2.1 Structural Study of LiKSO^ 31 2.2 Comparative Study of Mosaic Structure in Crystals by Refinement of Extinction Parameters from Neutron Data and by X-Ray Topography 32 2.3 The Crystal and Molecular Structure of N- Methyl-Crotananium Iodide, C)7H25O5N-CH3I .. 34 2.4 The Crystal and Molecular Structure of Falladium-L-Hydroxyproline Trihydrate ...... 35 2.5 Crystal Structure of a Substituted Ethylene LI-Methyl. 2~<Nitro Methylene)Pyrrolidine3.. 36 2.6 Structure of (NH.)-CuCl,.2H-0 in its Ordered Phase ..7.7...."...7 36 2.7 Refinement or the Structure of Huacn Brythrocyte Carbonic Anhydrase B ,, 37 2.8 X-Ray Piffractiok n Study of Cus*-Lysotyme Complex at 2S* Resolution 39 21 1,9 Magnetic Tap* Controller for tha TDC-312 Computer Controlled X-Ray Diffraetometeri Statua Report • 40 2*10 Printout Syatea for Double Cryatal Dlffractomater (D1) and Positron Angular Correlation (PAC) Experiments 40 t.11 Computer Program for Thermal Motion Analysis 41 t.it Computer Program MULTAN , 41 t,13 Computer Programs Related to Biological Crystallography 41 MATBRXAL PHYSICS 3.1 Kon-Thermallxation of Positrons in Alkali Metals: An Alternative Interpretation In Terms of a Charge-Denslty»Wave around State.. 43 3.2 Valence Charge in a Solid at OK Viewed as a Pressure lonlsation Effect .....•••*«.•. 44 3.3 Positron Annihilation Studies la Thermal Cycled Uranium 46 3.4 Single Crystal Neutron Diffraction Study of High Pressure Omega Polymorph of Zr ..... 46 3.5 A Semiemplrical Bquatlon of State for Metallic Solids 47 3.6 Liquid Disorder and Shock Hugoniot of Lead •• 49 -Tt - S1ISM0L00T 4.1 Velocity Variations in Kolar Oold Qold Fields (KOF) 52 4.2 Processing of Core-Reflected F Phase 52 4.3 Further Studies on Source Discrimination in "Difficult" Cases 54 4.4 Synthesis of F-trave Selsmogram* from Earthquakes 55 4.5 Data Requests for Research and Development Purposes ..................... «« 56 4.6 automation of the Daily Calibration ........ 56 4.7 Magnetic Tape Controller » 57 4.8 Digital Telemetry 58 4.9 Rockburst Research Project: Phase XI Studies 59 4.10 Some Examples of Detection of PcP Signal from Earthquake* 59 4*11 Encoding and Decoding Circuitry for Modified Miller Code, Manchester Sods and Biphase M Code 60 4.12 Multichannel Analog Data Acquisition System' for Field Use ............................. 61 4.13 Multichannel Low Frequency Analog Signal Recording on a Common Track of an Audio Tape Using rDMT«chniq«« .................. 61 4.14 On the Problem of Enumeration of Rooted Trees 63 4.15 Application of Discrete Probability Distribution of Rooted Trees to Outenberg- Rlchter Frequency-Magnitude Relation ...... 64 4.16 Further Studies on the Statistics of Koyna Tremors ................................... 65 4.17 Fracture as a time depending topology of Incluaions , 66 Tii - Pace 4.18 Depth Estimation Using Multistation Data .. 66 4.19 Data Compression by Auto Regressive (Alt) Methodt Son* Case Studies 68 4.20 Selsnotectonic Studies of the Decoan Plateau 69 4.21 Siting Nuclear Power Plants 70 4.22 Beam Forming Unit as an Aid to Study the Slowness of the Seismic Signals 71 4.23 Tripartite Microbarograph and Seismic Unit 71 4.24 Modification to TD10 Tape Deck 72 4.25 Attenuation and Velocity of waves Propagating Along Steel-Steel Interface ... 72 4.26 Seismic-Instrumentation 74 APPENDIX Papers Published/Accepted for Publication in Scientific Journals etc. 77 BARC Reports 80 Papers Presented/Accepted for Presenta- tion at Symposia, Seminars, Conferences etc. 81 Lectures Given in Training School etc. ..... 86 Awards and Degrees 87 Neutron Physics Division Staff 88 1. FORHIMA LABORATORIES 1.1 233U Fuelled Neutron Source Boactor at BRC.Kalpskkam - Progress Report i (C.S. Fasupathy, M. Srinivasan, V, Anandkumar* • S. Srinlvaaan") This project was accorded financial sanction In July 1981 enabling it to enter the second phase of activity namely procurement and fabrication in areaa where designs were froxen. Design computational activity was continued In other areas. (A) Reactor Core Prototype Fuel Sub-assembly and Reflectort Baaed on the phyaica calculations performed so far, /1/f it was decided to lnorease the fuel content in the 333U-A1 alloy to 25% to permit an Increased core loading without increasing the core volume. A prototype fuel sub-assembly la to be fabricated shortly with the above uranium alloy content and other.specifications by the Radiometallurgy Division. BARC, using natural uranium and tasted as p*r the guidelines provided in ANS-15.2,/2/. The final fabrication and testing procedure for the fuel will be drawn up on the basis of these trials. (B) Reactor Structure: The earlier reflector module design is being scrutinized to reduce the overall streaming and also work out special beryllium requirements in the region of beam holes. The reactor structure comprising of the reactor tank, catcher vessel and top structure are to be fabricated as per ASME code for Nuclear components (sec.