John S. Hendricks, Andrea Favalli, Martyn T. Swinhoe
Monte Carlo N-Particle Simulations for Nuclear Detection and Safeguards
An Examples-Based Guide for Students and Practitioners
John S. Hendricks, Andrea Favalli, Martyn T. Swinhoe
Monte Carlo N-Particle Simulations for Nuclear Detection and Safeguards
An Examples-Based Guide for Students and Practitioners
- Broschiertes Buch
- Merkliste
- Auf die Merkliste
- Bewerten Bewerten
- Teilen
- Produkt teilen
- Produkterinnerung
- Produkterinnerung
This open access book is a pedagogical, examples-based guide to using the Monte Carlo N-Particle (MCNP®) code for nuclear safeguards and non-proliferation applications. The MCNP code, general-purpose software for particle transport simulations, is widely used in the field of nuclear safeguards and non-proliferation for numerous applications including detector design and calibration, and the study of scenarios such as measurement of fresh and spent fuel. This book fills a gap in the existing MCNP software literature by teaching MCNP software usage through detailed examples that were selected…mehr
Andere Kunden interessierten sich auch für
![Monte Carlo N-Particle Simulations for Nuclear Detection and Safeguards]( "Monte Carlo N-Particle Simulations for Nuclear Detection and Safeguards")
John S. HendricksMonte Carlo N-Particle Simulations for Nuclear Detection and Safeguards37,99 €![Proceedings of the 23rd Pacific Basin Nuclear Conference, Volume 1]( "Proceedings of the 23rd Pacific Basin Nuclear Conference, Volume 1")
Proceedings of the 23rd Pacific Basin Nuclear Conference, Volume 133,99 €![Proceedings of the 23rd Pacific Basin Nuclear Conference, Volume 1]( "Proceedings of the 23rd Pacific Basin Nuclear Conference, Volume 1")
Proceedings of the 23rd Pacific Basin Nuclear Conference, Volume 155,99 €![Proceedings of the 23rd Pacific Basin Nuclear Conference, Volume 3]( "Proceedings of the 23rd Pacific Basin Nuclear Conference, Volume 3")
Proceedings of the 23rd Pacific Basin Nuclear Conference, Volume 3162,99 €![Proceedings of the 23rd Pacific Basin Nuclear Conference, Volume 2]( "Proceedings of the 23rd Pacific Basin Nuclear Conference, Volume 2")
Proceedings of the 23rd Pacific Basin Nuclear Conference, Volume 2162,99 €![Proceedings of the 23rd Pacific Basin Nuclear Conference, Volume 2]( "Proceedings of the 23rd Pacific Basin Nuclear Conference, Volume 2")
Proceedings of the 23rd Pacific Basin Nuclear Conference, Volume 2227,99 €![Proceedings of the 23rd Pacific Basin Nuclear Conference, Volume 3]( "Proceedings of the 23rd Pacific Basin Nuclear Conference, Volume 3")
Proceedings of the 23rd Pacific Basin Nuclear Conference, Volume 3227,99 €-
-
-
This open access book is a pedagogical, examples-based guide to using the Monte Carlo N-Particle (MCNP®) code for nuclear safeguards and non-proliferation applications. The MCNP code, general-purpose software for particle transport simulations, is widely used in the field of nuclear safeguards and non-proliferation for numerous applications including detector design and calibration, and the study of scenarios such as measurement of fresh and spent fuel. This book fills a gap in the existing MCNP software literature by teaching MCNP software usage through detailed examples that were selected based on both student feedback and the real-world experience of the nuclear safeguards group at Los Alamos National Laboratory. MCNP input and output files are explained, and the technical details used in MCNP input file preparation are linked to the MCNP code manual. Benefiting from the authors¿ decades of experience in MCNP simulation, this book is essential reading for students, academic researchers, and practitioners whose work in nuclear physics or nuclear engineering is related to non-proliferation or nuclear safeguards. Each chapter comes with downloadable input files for the user to easily reproduce the examples in the text.
Hinweis: Dieser Artikel kann nur an eine deutsche Lieferadresse ausgeliefert werden.
Hinweis: Dieser Artikel kann nur an eine deutsche Lieferadresse ausgeliefert werden.
Produktdetails
- Produktdetails
- Verlag: Springer International Publishing / Springer International Publishing AG
- 1st ed. 2022
- Seitenzahl: 324
- Erscheinungstermin: 28. September 2022
- Englisch
- Abmessung: 235mm x 155mm x 18mm
- Gewicht: 493g
- ISBN-13: 9783031041310
- ISBN-10: 3031041313
- Artikelnr.: 64726672
- Verlag: Springer International Publishing / Springer International Publishing AG
- 1st ed. 2022
- Seitenzahl: 324
- Erscheinungstermin: 28. September 2022
- Englisch
- Abmessung: 235mm x 155mm x 18mm
- Gewicht: 493g
- ISBN-13: 9783031041310
- ISBN-10: 3031041313
- Artikelnr.: 64726672
Dr. John S. Hendricks has been one of the principal developers/leader of MCNP® software for more than 30 years. In addition, he has taught more than 100 MCNP classes and consulted internationally on the effective use of MCNP software. In 2007, he was elected fellow to the American Nuclear Society for his contributions to Monte Carlo development. Dr. Martyn T. Swinhoe was awarded the Vincent J. DeVito Distinguished Service Award in 2017 from the Institute for Nuclear Materials Management for-among many other achievements-pioneering the use of MCNP software for instrument design and enhancing the analysis of existing data sets to draw additional conclusions for nuclear materials management. Dr. Andrea Favalli was elected fellow to the American Physical Society in 2020 for his outstanding application of the methods and underlying science of nuclear physics to the crucial issues of nuclear safeguards and security. His work has focused on nondestructive assay of nuclear materials, ranging from new analytical approaches to experimental measurements.
Table of contents: Contents .......................................................................................................................................... 4 Introduction ..................................................................................................................................... 8 Section 1: Basic Concepts ............................................................................................................... 8 1.1 Geometry ............................................................................................................................... 8 1.1.1 Simplest possible input file............................................................................................. 8 1.1.2 Running MCNP
Simplest Case ................................................................................... 9 1.1.3 Simple Input File .......................................................................................................... 12 1.1.4 Running and plotting MCNP geometries ..................................................................... 14 1.1.5 Surfaces and Complicated Cells: Intersections and Unions ......................................... 17 1.1.6 Duplicate Cells, Compliments and Translations: LIKE BUT and TRCL .................... 22 1.1.7 Filled Cells: Universes.................................................................................................. 26 1.1.8 Lattice Geometries ........................................................................................................ 32 1.1.9 Fully Specified Lattice Geometries .............................................................................. 40 1.2 Materials and Cross Sections .............................................................................................. 45 1.2.1 Specifying Materials ..................................................................................................... 45 1.2.2 Neutron cross sections .................................................................................................. 46 1.2.3 Low-energy neutron problems
thermal free gas treatment ........................................ 49 1.2.4 Low-energy neutron problem data
S(
,ß) thermal treatment .................................... 50 1.2.5 Photon cross sections .................................................................................................... 53 1.2.6 Electron stopping powers for coupled photon and electron problems ......................... 57 1.2.7 Data and models for Ions and Charged Particles .......................................................... 61 1.2.8 Additional data diagnostics and recommendations ...................................................... 62 1.3 Sources ................................................................................................................................ 63 1.3.1 SDEF Fixed Sources ..................................................................................................... 63 1.3.2 SDEF Source Distributions .......................................................................................... 66 1.3.3 SDEF Dependent Distributions: DS ............................................................................. 69 1.3.4 Criticality Sources ........................................................................................................ 71 1.3.5 Surface Source Read and Write (SSR, SSW) ......................................................... 77 1.3.6 Checking sources .................................................................................................... 87 1.4 Output and Tallies ............................................................................................................... 87 1.4.1 Output Files .................................................................................................................. 87 1.4.2 MCNP Estimators and Tally Types .............................................................................. 93 DRAFT 5 1.4.3 Basic Tally Format ....................................................................................................... 95 1.4.4 Special Tally Treatments ............................................................................................ 111 1.4.5 Pulse-Height Tallies ................................................................................................... 128 1.4.6 Point Detectors and Next-Event Estimators ............................................................... 134 1.5 Plotting .............................................................................................................................. 143 1.5.1 Geometry Plotting and Command Files ..................................................................... 143 1.5.2 Cross Section plotting ................................................................................................. 145 1.5.3 Tally Plotting .............................................................................................................. 150 1.5.4 Mesh, Radiography, and Ring Tallies ........................................................................ 167 1.6 Statistics and Convergence ................................................................................................ 186 Section 2: Examples for nuclear safeguards applications ........................................................... 198 2.1 Example 1: Fuel Assembly in Water Tank ....................................................................... 198 2.1.1 Description.................................................................................................................. 198 2.1.2 Geometry description ................................................................................................. 203 2.1.3 Other data: sources, materials, tallies, and more ........................................................ 204 2.1.4 MCNP Output ............................................................................................................. 206 2.2 Example 2: Coincidence Counter with F4 and F8 Tallies for Coincidence and Multiplicity Counting Rates ........................................................................................................................ 207 2.2.1 Description.................................................................................................................. 207 2.2.2 Materials ..................................................................................................................... 212 2.2.3 Source ......................................................................................................................... 212 2.2.4 Tallies ......................................................................................................................... 213 2.2.5 Warning Messages ...................................................................................................... 214 2.2.6 Results ........................................................................................................................ 216 2.2.6A: From the Point Model ............................................................................................. 216 2.2.6B: Rates Calculated without Point Model assumptions............................................... 221 2.3 Gamma pulse height (to be completed) ................................................................................ 227 2.4 Active Neutron Example: Cf Shuffler ............................................................................... 231 2.4.1 Description and input file ........................................................................................... 231 2.4.2 Results ........................................................................................................................ 234 Section 3: Examples of Advanced Concepts .............................................................................. 240 Section 3.1 Variance Reduction .............................................................................................. 240 3.1.1 Introduction ................................................................................................................ 240 DRAFT 6 3.1.2 Multigroup Weight Windows and Time Splitting: Lead Slowing Down Spectrometer ............................................................................................................................................. 242 3.1.2.1 Input File Notes ....................................................................................................... 253 3.1.2.2 Variance Reduction Step 1: simplify problem and add weight window generator . 256 3.1.2.3 Iteration 2 ................................................................................................................. 261 3.1.2.4 Additional iterations ................................................................................................ 263 3.1.2.5 Cylindrical Mesh Weight Window Summary ......................................................... 267 3.1.3 Cell-based weight windows for the Lead Slowing Down Spectrometer .................... 271 3.1.4 Time splitting .............................................................................................................. 277 3.1.5 Variance Reduction for the Cf Shuffler ......................................................................... 280 3.1.5.1 Cf Shuffler modified input ...................................................................................... 280 3.1.5.2 Particle production bias, time splitting, and windows ............................................. 285 3.1.5.3 Analysis of Cf Shuffler Variance Reduction ........................................................... 288 3.2 DXTRAN and Other Capabilities for Distributed Source Problems .................................... 288 3.2.1 UF6 Cask Model ............................................................................................................ 290 3.2.2 DXTRAN ....................................................................................................................... 300 3.2.3 Source Position Biasing ................................................................................................. 307 3.2.4 Best Single Detector Solution ........................................................................................ 310 3.3 Neutron Detector Operation in More Detail ......................................................................... 318 3.3.1 Introduction .................................................................................................................... 318 (i) Make reaction products (model, data) and recoil nuclei .................................................... 318 (ii) Track created particles in real gas composition ................................................................ 321 (iii) Tally energy deposition of particles in active volume (F8 CAP EDEP for coincidence/multiplicity counting) .......................................................................................... 322 Examples ................................................................................................................................. 322 3He detector Pulse Height ................................................................................................... 322 3He Detector Coincidence Calculation ................................................................................ 324 10B-lined detectors ............................................................................................................... 325 References ............................................................................................................................... 332 Section 4: Additional Topics ...................................................................................................... 332 4.1 Troubleshooting or
How can I be confident in the results?
...................................... 332 4.1.1 Geometry and Materials ............................................................................................. 333 4.1.2 Detector modelling ..................................................................................................... 334 DRAFT 7 4.1.3 Source modelling ........................................................................................................ 334 4.1.4 Sample modelling ....................................................................................................... 335 4.1.5 Tracking limitations .................................................................................................... 335 4.1.6 Nuclear Data ............................................................................................................... 335 4.1.7 Statistics ...................................................................................................................... 336 4.1.8 User ............................................................................................................................. 337 4.1.9 Summary and Conclusions
What to do?.................................................................. 337 4.2.1 Analysis of Delayed Neutron Production ....................................................................... 338 4.2.2 Comparison of Table Physics vs Model Physics ........................................................... 342 5 References and Bibliography ................................................................................................... 354 6 Table of Figures ....................................................................................................................... 355
Simplest Case ................................................................................... 9 1.1.3 Simple Input File .......................................................................................................... 12 1.1.4 Running and plotting MCNP geometries ..................................................................... 14 1.1.5 Surfaces and Complicated Cells: Intersections and Unions ......................................... 17 1.1.6 Duplicate Cells, Compliments and Translations: LIKE BUT and TRCL .................... 22 1.1.7 Filled Cells: Universes.................................................................................................. 26 1.1.8 Lattice Geometries ........................................................................................................ 32 1.1.9 Fully Specified Lattice Geometries .............................................................................. 40 1.2 Materials and Cross Sections .............................................................................................. 45 1.2.1 Specifying Materials ..................................................................................................... 45 1.2.2 Neutron cross sections .................................................................................................. 46 1.2.3 Low-energy neutron problems
thermal free gas treatment ........................................ 49 1.2.4 Low-energy neutron problem data
S(
,ß) thermal treatment .................................... 50 1.2.5 Photon cross sections .................................................................................................... 53 1.2.6 Electron stopping powers for coupled photon and electron problems ......................... 57 1.2.7 Data and models for Ions and Charged Particles .......................................................... 61 1.2.8 Additional data diagnostics and recommendations ...................................................... 62 1.3 Sources ................................................................................................................................ 63 1.3.1 SDEF Fixed Sources ..................................................................................................... 63 1.3.2 SDEF Source Distributions .......................................................................................... 66 1.3.3 SDEF Dependent Distributions: DS ............................................................................. 69 1.3.4 Criticality Sources ........................................................................................................ 71 1.3.5 Surface Source Read and Write (SSR, SSW) ......................................................... 77 1.3.6 Checking sources .................................................................................................... 87 1.4 Output and Tallies ............................................................................................................... 87 1.4.1 Output Files .................................................................................................................. 87 1.4.2 MCNP Estimators and Tally Types .............................................................................. 93 DRAFT 5 1.4.3 Basic Tally Format ....................................................................................................... 95 1.4.4 Special Tally Treatments ............................................................................................ 111 1.4.5 Pulse-Height Tallies ................................................................................................... 128 1.4.6 Point Detectors and Next-Event Estimators ............................................................... 134 1.5 Plotting .............................................................................................................................. 143 1.5.1 Geometry Plotting and Command Files ..................................................................... 143 1.5.2 Cross Section plotting ................................................................................................. 145 1.5.3 Tally Plotting .............................................................................................................. 150 1.5.4 Mesh, Radiography, and Ring Tallies ........................................................................ 167 1.6 Statistics and Convergence ................................................................................................ 186 Section 2: Examples for nuclear safeguards applications ........................................................... 198 2.1 Example 1: Fuel Assembly in Water Tank ....................................................................... 198 2.1.1 Description.................................................................................................................. 198 2.1.2 Geometry description ................................................................................................. 203 2.1.3 Other data: sources, materials, tallies, and more ........................................................ 204 2.1.4 MCNP Output ............................................................................................................. 206 2.2 Example 2: Coincidence Counter with F4 and F8 Tallies for Coincidence and Multiplicity Counting Rates ........................................................................................................................ 207 2.2.1 Description.................................................................................................................. 207 2.2.2 Materials ..................................................................................................................... 212 2.2.3 Source ......................................................................................................................... 212 2.2.4 Tallies ......................................................................................................................... 213 2.2.5 Warning Messages ...................................................................................................... 214 2.2.6 Results ........................................................................................................................ 216 2.2.6A: From the Point Model ............................................................................................. 216 2.2.6B: Rates Calculated without Point Model assumptions............................................... 221 2.3 Gamma pulse height (to be completed) ................................................................................ 227 2.4 Active Neutron Example: Cf Shuffler ............................................................................... 231 2.4.1 Description and input file ........................................................................................... 231 2.4.2 Results ........................................................................................................................ 234 Section 3: Examples of Advanced Concepts .............................................................................. 240 Section 3.1 Variance Reduction .............................................................................................. 240 3.1.1 Introduction ................................................................................................................ 240 DRAFT 6 3.1.2 Multigroup Weight Windows and Time Splitting: Lead Slowing Down Spectrometer ............................................................................................................................................. 242 3.1.2.1 Input File Notes ....................................................................................................... 253 3.1.2.2 Variance Reduction Step 1: simplify problem and add weight window generator . 256 3.1.2.3 Iteration 2 ................................................................................................................. 261 3.1.2.4 Additional iterations ................................................................................................ 263 3.1.2.5 Cylindrical Mesh Weight Window Summary ......................................................... 267 3.1.3 Cell-based weight windows for the Lead Slowing Down Spectrometer .................... 271 3.1.4 Time splitting .............................................................................................................. 277 3.1.5 Variance Reduction for the Cf Shuffler ......................................................................... 280 3.1.5.1 Cf Shuffler modified input ...................................................................................... 280 3.1.5.2 Particle production bias, time splitting, and windows ............................................. 285 3.1.5.3 Analysis of Cf Shuffler Variance Reduction ........................................................... 288 3.2 DXTRAN and Other Capabilities for Distributed Source Problems .................................... 288 3.2.1 UF6 Cask Model ............................................................................................................ 290 3.2.2 DXTRAN ....................................................................................................................... 300 3.2.3 Source Position Biasing ................................................................................................. 307 3.2.4 Best Single Detector Solution ........................................................................................ 310 3.3 Neutron Detector Operation in More Detail ......................................................................... 318 3.3.1 Introduction .................................................................................................................... 318 (i) Make reaction products (model, data) and recoil nuclei .................................................... 318 (ii) Track created particles in real gas composition ................................................................ 321 (iii) Tally energy deposition of particles in active volume (F8 CAP EDEP for coincidence/multiplicity counting) .......................................................................................... 322 Examples ................................................................................................................................. 322 3He detector Pulse Height ................................................................................................... 322 3He Detector Coincidence Calculation ................................................................................ 324 10B-lined detectors ............................................................................................................... 325 References ............................................................................................................................... 332 Section 4: Additional Topics ...................................................................................................... 332 4.1 Troubleshooting or
How can I be confident in the results?
...................................... 332 4.1.1 Geometry and Materials ............................................................................................. 333 4.1.2 Detector modelling ..................................................................................................... 334 DRAFT 7 4.1.3 Source modelling ........................................................................................................ 334 4.1.4 Sample modelling ....................................................................................................... 335 4.1.5 Tracking limitations .................................................................................................... 335 4.1.6 Nuclear Data ............................................................................................................... 335 4.1.7 Statistics ...................................................................................................................... 336 4.1.8 User ............................................................................................................................. 337 4.1.9 Summary and Conclusions
What to do?.................................................................. 337 4.2.1 Analysis of Delayed Neutron Production ....................................................................... 338 4.2.2 Comparison of Table Physics vs Model Physics ........................................................... 342 5 References and Bibliography ................................................................................................... 354 6 Table of Figures ....................................................................................................................... 355
Chapter 1: Introduction.- Chapter 2: Basic Concepts.- Chapter 3: Examples for Nuclear Safeguards Applications.- Chapter 4: Examples of Advanced Concepts.- Chapter 5: Additional Topics.
Table of contents: Contents .......................................................................................................................................... 4 Introduction ..................................................................................................................................... 8 Section 1: Basic Concepts ............................................................................................................... 8 1.1 Geometry ............................................................................................................................... 8 1.1.1 Simplest possible input file............................................................................................. 8 1.1.2 Running MCNP
Simplest Case ................................................................................... 9 1.1.3 Simple Input File .......................................................................................................... 12 1.1.4 Running and plotting MCNP geometries ..................................................................... 14 1.1.5 Surfaces and Complicated Cells: Intersections and Unions ......................................... 17 1.1.6 Duplicate Cells, Compliments and Translations: LIKE BUT and TRCL .................... 22 1.1.7 Filled Cells: Universes.................................................................................................. 26 1.1.8 Lattice Geometries ........................................................................................................ 32 1.1.9 Fully Specified Lattice Geometries .............................................................................. 40 1.2 Materials and Cross Sections .............................................................................................. 45 1.2.1 Specifying Materials ..................................................................................................... 45 1.2.2 Neutron cross sections .................................................................................................. 46 1.2.3 Low-energy neutron problems
thermal free gas treatment ........................................ 49 1.2.4 Low-energy neutron problem data
S(
,ß) thermal treatment .................................... 50 1.2.5 Photon cross sections .................................................................................................... 53 1.2.6 Electron stopping powers for coupled photon and electron problems ......................... 57 1.2.7 Data and models for Ions and Charged Particles .......................................................... 61 1.2.8 Additional data diagnostics and recommendations ...................................................... 62 1.3 Sources ................................................................................................................................ 63 1.3.1 SDEF Fixed Sources ..................................................................................................... 63 1.3.2 SDEF Source Distributions .......................................................................................... 66 1.3.3 SDEF Dependent Distributions: DS ............................................................................. 69 1.3.4 Criticality Sources ........................................................................................................ 71 1.3.5 Surface Source Read and Write (SSR, SSW) ......................................................... 77 1.3.6 Checking sources .................................................................................................... 87 1.4 Output and Tallies ............................................................................................................... 87 1.4.1 Output Files .................................................................................................................. 87 1.4.2 MCNP Estimators and Tally Types .............................................................................. 93 DRAFT 5 1.4.3 Basic Tally Format ....................................................................................................... 95 1.4.4 Special Tally Treatments ............................................................................................ 111 1.4.5 Pulse-Height Tallies ................................................................................................... 128 1.4.6 Point Detectors and Next-Event Estimators ............................................................... 134 1.5 Plotting .............................................................................................................................. 143 1.5.1 Geometry Plotting and Command Files ..................................................................... 143 1.5.2 Cross Section plotting ................................................................................................. 145 1.5.3 Tally Plotting .............................................................................................................. 150 1.5.4 Mesh, Radiography, and Ring Tallies ........................................................................ 167 1.6 Statistics and Convergence ................................................................................................ 186 Section 2: Examples for nuclear safeguards applications ........................................................... 198 2.1 Example 1: Fuel Assembly in Water Tank ....................................................................... 198 2.1.1 Description.................................................................................................................. 198 2.1.2 Geometry description ................................................................................................. 203 2.1.3 Other data: sources, materials, tallies, and more ........................................................ 204 2.1.4 MCNP Output ............................................................................................................. 206 2.2 Example 2: Coincidence Counter with F4 and F8 Tallies for Coincidence and Multiplicity Counting Rates ........................................................................................................................ 207 2.2.1 Description.................................................................................................................. 207 2.2.2 Materials ..................................................................................................................... 212 2.2.3 Source ......................................................................................................................... 212 2.2.4 Tallies ......................................................................................................................... 213 2.2.5 Warning Messages ...................................................................................................... 214 2.2.6 Results ........................................................................................................................ 216 2.2.6A: From the Point Model ............................................................................................. 216 2.2.6B: Rates Calculated without Point Model assumptions............................................... 221 2.3 Gamma pulse height (to be completed) ................................................................................ 227 2.4 Active Neutron Example: Cf Shuffler ............................................................................... 231 2.4.1 Description and input file ........................................................................................... 231 2.4.2 Results ........................................................................................................................ 234 Section 3: Examples of Advanced Concepts .............................................................................. 240 Section 3.1 Variance Reduction .............................................................................................. 240 3.1.1 Introduction ................................................................................................................ 240 DRAFT 6 3.1.2 Multigroup Weight Windows and Time Splitting: Lead Slowing Down Spectrometer ............................................................................................................................................. 242 3.1.2.1 Input File Notes ....................................................................................................... 253 3.1.2.2 Variance Reduction Step 1: simplify problem and add weight window generator . 256 3.1.2.3 Iteration 2 ................................................................................................................. 261 3.1.2.4 Additional iterations ................................................................................................ 263 3.1.2.5 Cylindrical Mesh Weight Window Summary ......................................................... 267 3.1.3 Cell-based weight windows for the Lead Slowing Down Spectrometer .................... 271 3.1.4 Time splitting .............................................................................................................. 277 3.1.5 Variance Reduction for the Cf Shuffler ......................................................................... 280 3.1.5.1 Cf Shuffler modified input ...................................................................................... 280 3.1.5.2 Particle production bias, time splitting, and windows ............................................. 285 3.1.5.3 Analysis of Cf Shuffler Variance Reduction ........................................................... 288 3.2 DXTRAN and Other Capabilities for Distributed Source Problems .................................... 288 3.2.1 UF6 Cask Model ............................................................................................................ 290 3.2.2 DXTRAN ....................................................................................................................... 300 3.2.3 Source Position Biasing ................................................................................................. 307 3.2.4 Best Single Detector Solution ........................................................................................ 310 3.3 Neutron Detector Operation in More Detail ......................................................................... 318 3.3.1 Introduction .................................................................................................................... 318 (i) Make reaction products (model, data) and recoil nuclei .................................................... 318 (ii) Track created particles in real gas composition ................................................................ 321 (iii) Tally energy deposition of particles in active volume (F8 CAP EDEP for coincidence/multiplicity counting) .......................................................................................... 322 Examples ................................................................................................................................. 322 3He detector Pulse Height ................................................................................................... 322 3He Detector Coincidence Calculation ................................................................................ 324 10B-lined detectors ............................................................................................................... 325 References ............................................................................................................................... 332 Section 4: Additional Topics ...................................................................................................... 332 4.1 Troubleshooting or
How can I be confident in the results?
...................................... 332 4.1.1 Geometry and Materials ............................................................................................. 333 4.1.2 Detector modelling ..................................................................................................... 334 DRAFT 7 4.1.3 Source modelling ........................................................................................................ 334 4.1.4 Sample modelling ....................................................................................................... 335 4.1.5 Tracking limitations .................................................................................................... 335 4.1.6 Nuclear Data ............................................................................................................... 335 4.1.7 Statistics ...................................................................................................................... 336 4.1.8 User ............................................................................................................................. 337 4.1.9 Summary and Conclusions
What to do?.................................................................. 337 4.2.1 Analysis of Delayed Neutron Production ....................................................................... 338 4.2.2 Comparison of Table Physics vs Model Physics ........................................................... 342 5 References and Bibliography ................................................................................................... 354 6 Table of Figures ....................................................................................................................... 355
Simplest Case ................................................................................... 9 1.1.3 Simple Input File .......................................................................................................... 12 1.1.4 Running and plotting MCNP geometries ..................................................................... 14 1.1.5 Surfaces and Complicated Cells: Intersections and Unions ......................................... 17 1.1.6 Duplicate Cells, Compliments and Translations: LIKE BUT and TRCL .................... 22 1.1.7 Filled Cells: Universes.................................................................................................. 26 1.1.8 Lattice Geometries ........................................................................................................ 32 1.1.9 Fully Specified Lattice Geometries .............................................................................. 40 1.2 Materials and Cross Sections .............................................................................................. 45 1.2.1 Specifying Materials ..................................................................................................... 45 1.2.2 Neutron cross sections .................................................................................................. 46 1.2.3 Low-energy neutron problems
thermal free gas treatment ........................................ 49 1.2.4 Low-energy neutron problem data
S(
,ß) thermal treatment .................................... 50 1.2.5 Photon cross sections .................................................................................................... 53 1.2.6 Electron stopping powers for coupled photon and electron problems ......................... 57 1.2.7 Data and models for Ions and Charged Particles .......................................................... 61 1.2.8 Additional data diagnostics and recommendations ...................................................... 62 1.3 Sources ................................................................................................................................ 63 1.3.1 SDEF Fixed Sources ..................................................................................................... 63 1.3.2 SDEF Source Distributions .......................................................................................... 66 1.3.3 SDEF Dependent Distributions: DS ............................................................................. 69 1.3.4 Criticality Sources ........................................................................................................ 71 1.3.5 Surface Source Read and Write (SSR, SSW) ......................................................... 77 1.3.6 Checking sources .................................................................................................... 87 1.4 Output and Tallies ............................................................................................................... 87 1.4.1 Output Files .................................................................................................................. 87 1.4.2 MCNP Estimators and Tally Types .............................................................................. 93 DRAFT 5 1.4.3 Basic Tally Format ....................................................................................................... 95 1.4.4 Special Tally Treatments ............................................................................................ 111 1.4.5 Pulse-Height Tallies ................................................................................................... 128 1.4.6 Point Detectors and Next-Event Estimators ............................................................... 134 1.5 Plotting .............................................................................................................................. 143 1.5.1 Geometry Plotting and Command Files ..................................................................... 143 1.5.2 Cross Section plotting ................................................................................................. 145 1.5.3 Tally Plotting .............................................................................................................. 150 1.5.4 Mesh, Radiography, and Ring Tallies ........................................................................ 167 1.6 Statistics and Convergence ................................................................................................ 186 Section 2: Examples for nuclear safeguards applications ........................................................... 198 2.1 Example 1: Fuel Assembly in Water Tank ....................................................................... 198 2.1.1 Description.................................................................................................................. 198 2.1.2 Geometry description ................................................................................................. 203 2.1.3 Other data: sources, materials, tallies, and more ........................................................ 204 2.1.4 MCNP Output ............................................................................................................. 206 2.2 Example 2: Coincidence Counter with F4 and F8 Tallies for Coincidence and Multiplicity Counting Rates ........................................................................................................................ 207 2.2.1 Description.................................................................................................................. 207 2.2.2 Materials ..................................................................................................................... 212 2.2.3 Source ......................................................................................................................... 212 2.2.4 Tallies ......................................................................................................................... 213 2.2.5 Warning Messages ...................................................................................................... 214 2.2.6 Results ........................................................................................................................ 216 2.2.6A: From the Point Model ............................................................................................. 216 2.2.6B: Rates Calculated without Point Model assumptions............................................... 221 2.3 Gamma pulse height (to be completed) ................................................................................ 227 2.4 Active Neutron Example: Cf Shuffler ............................................................................... 231 2.4.1 Description and input file ........................................................................................... 231 2.4.2 Results ........................................................................................................................ 234 Section 3: Examples of Advanced Concepts .............................................................................. 240 Section 3.1 Variance Reduction .............................................................................................. 240 3.1.1 Introduction ................................................................................................................ 240 DRAFT 6 3.1.2 Multigroup Weight Windows and Time Splitting: Lead Slowing Down Spectrometer ............................................................................................................................................. 242 3.1.2.1 Input File Notes ....................................................................................................... 253 3.1.2.2 Variance Reduction Step 1: simplify problem and add weight window generator . 256 3.1.2.3 Iteration 2 ................................................................................................................. 261 3.1.2.4 Additional iterations ................................................................................................ 263 3.1.2.5 Cylindrical Mesh Weight Window Summary ......................................................... 267 3.1.3 Cell-based weight windows for the Lead Slowing Down Spectrometer .................... 271 3.1.4 Time splitting .............................................................................................................. 277 3.1.5 Variance Reduction for the Cf Shuffler ......................................................................... 280 3.1.5.1 Cf Shuffler modified input ...................................................................................... 280 3.1.5.2 Particle production bias, time splitting, and windows ............................................. 285 3.1.5.3 Analysis of Cf Shuffler Variance Reduction ........................................................... 288 3.2 DXTRAN and Other Capabilities for Distributed Source Problems .................................... 288 3.2.1 UF6 Cask Model ............................................................................................................ 290 3.2.2 DXTRAN ....................................................................................................................... 300 3.2.3 Source Position Biasing ................................................................................................. 307 3.2.4 Best Single Detector Solution ........................................................................................ 310 3.3 Neutron Detector Operation in More Detail ......................................................................... 318 3.3.1 Introduction .................................................................................................................... 318 (i) Make reaction products (model, data) and recoil nuclei .................................................... 318 (ii) Track created particles in real gas composition ................................................................ 321 (iii) Tally energy deposition of particles in active volume (F8 CAP EDEP for coincidence/multiplicity counting) .......................................................................................... 322 Examples ................................................................................................................................. 322 3He detector Pulse Height ................................................................................................... 322 3He Detector Coincidence Calculation ................................................................................ 324 10B-lined detectors ............................................................................................................... 325 References ............................................................................................................................... 332 Section 4: Additional Topics ...................................................................................................... 332 4.1 Troubleshooting or
How can I be confident in the results?
...................................... 332 4.1.1 Geometry and Materials ............................................................................................. 333 4.1.2 Detector modelling ..................................................................................................... 334 DRAFT 7 4.1.3 Source modelling ........................................................................................................ 334 4.1.4 Sample modelling ....................................................................................................... 335 4.1.5 Tracking limitations .................................................................................................... 335 4.1.6 Nuclear Data ............................................................................................................... 335 4.1.7 Statistics ...................................................................................................................... 336 4.1.8 User ............................................................................................................................. 337 4.1.9 Summary and Conclusions
What to do?.................................................................. 337 4.2.1 Analysis of Delayed Neutron Production ....................................................................... 338 4.2.2 Comparison of Table Physics vs Model Physics ........................................................... 342 5 References and Bibliography ................................................................................................... 354 6 Table of Figures ....................................................................................................................... 355
Chapter 1: Introduction.- Chapter 2: Basic Concepts.- Chapter 3: Examples for Nuclear Safeguards Applications.- Chapter 4: Examples of Advanced Concepts.- Chapter 5: Additional Topics.