《PILE NEUTRON RESEARCH》

CHAPTER 1.FUNDAMENTAL CONCEPTS OF NEUTRON PHYSICS1

1-1The neutron1

1-2 Properties of the neutron2

1-3 Cross sections as nuclear area5

1-4 Quantum mechanical analysis of neutron cross sections7

1-5 Compound state in nuclear reactions10

1-6 Cross sections at high energy13

1-7 Neutron resonances14

1-8 Principles of cross-section measurements17

1-9 Neutron activation21

1-10 Moderation of fast neutrons24

1-11 Neutron diffusion30

CHAPTER 2.THE PILE AS A NEUTRON SOURCE35

2-1Fission35

2-2 Pile reproduction factor, k40

2-3 Critical size45

2-4 Pile reactivity49

2-5 Types of piles53

2-6 Distribution of fast neutrons in pile58

2-7 Resonance neutrons61

2-8 Thermal neutrons66

CHAPTER 3.NEUTRON STANDARDIZATION72

3-1Source strength72

3-2 Absolute neutron flux79

3-3 Relative flux84

3-4 Neutron temperature89

CHAPTER 4.FAST NEUTRON RESEARCH93

4-1Threshold reactions in fission neutron flux93

4-2 Measurement of threshold reactios inside pile98

4-3 Use of fast neutrons for solid state studies102

4-4 Fission source in thermal beam106

4-5 Measurement of fast neutron capture cross sections109

4-6 Use of H2（H3,n）He4 reaction117

4-7 Photoneutron sources120

4-8 Neutron age measurements123

CHAPTER 5.RESONANCE NEUTRONS IN THE PILE129

5-1Resonance integral by activation129

5-2 Resonance absorption integral134

5-3 Effective resonance integral138

5-4 Filter methods143

CHAPTER 6.RESONANCE NEUTRON BEAMS147

6-1Resonance detectors148

6-2 Resonance scatterers152

6-3 Filtered beams156

6-4 Crystal monochromator159

6-5 Mechanical velocity selector （fast chopper）165

6-6 Analysis of neutron resonances171

CHAPTER 7.THERMAL NEUTRONS INSIDE THE PILE179

7-1 Activation by Maxwell velocity distribution179

7-2 Measurement of activation cross sections182

7-3Production of radioisotopes188

7-4 Activation analysis195

7-5 Absorption cross sectionsDanger coefficient method196

7-6 Absorption cross sections Pile oscillator201

7-7 Mass spectrometric methods206

CHAPTER 8.NEUTRON DIFFUSION MEASUREMENTS211

8-1Use of diffusion for measurement of small capture cross sections211

8-2 The “sigma pile”214

8-3 Use of thermal column as source for diffusion experiments218

8-4 Measurement of diffusion length in beryllium219

8-5 Exponential experiments224

CHAPTER 9.THERMAL NEUTRON BEAMS227

9-1Production of thermal neutron beams227

9-2 Cross-section measurements with Maxwell velocity distribution235

9-3 Filters239

9-4 Mechanical velocity selectors （“choppers”）243

9-5 Chopper measurements with cold neutrons249

9-6 Mechanical unonochromators254

CHAPTER 10.NEUTRON DIFFRACTION258

10-1 Coherence and incoherence of neutron scattering258

10-2 Calculation of coherent and incoherent cross sections262

10-3 Methods of neutron diffraction266

10-4 Neutron transmission in polycrystals269

10-5 Powder diffraction method272

10-6 Applications of neutron diffraction280

CHAPTER11.NEUTRON REFRACTION, PEFLECTION, AND POLARIZATION287

11-1 Small-angle scattering287

11-2 Neutron mirrors292

11-3 Determination of coherent amplitudes with mirrors295

11-4 Refiection from magnetic mirrors301

11-5 Balancing techniques in mirror reflection306

11-6 Measurement of coherent neutron-proton scattering by liquid mirrors309

11-7 Measurement of neutron-electron interaction by reflection316

11-8 Neutron polarization319

11-9 Production of polarized neutrons by reflection and diffraction321

CHAPTER 12.HEALTH PHYSICS328

12-1 Effects of radiation on tissue328

12-2 Units and limits of radiation exposure330

12-3 Measurement of radiation for personnel protection334

12-4 Radiation protection for pile experiments338

APPENDIX 1.CONSTANTS, CONVERSION FACTORS, AND FORMULAS343

APPENDIX 2.ATOMIC MASSES347

APPENDIX 3.THERMAL CROSS SECTIONS349

APPENDIX 4.A SET OF EXPERIMENTS FOR A PILE PHYSICS COURSE367

SYMBOL INDEX376

INDEX379