Preface

Research on fine particle plasmas, which are also called "dusty plasmas", began with the theoretical study of the origin and existence of cosmic dust and their observations. Since the early 1980s, planet images sent from exploring space crafts have interested astronomers and space scientists studying cosmic dust and dusty plasmas in planetary rings. In the late 1980s, many researchers in the field of electronic devices began to study dusty plasmas, the fine particles generated during plasma processing or introduced from outside reactors, thus contaminating the reactors, and reducing the production yield of microdevices. In 1994, epoch-making experimental discoveries of Coulomb crystals in dusty plasmas were made in several laboratories around the world. Research on dusty plasmas in fields of basic science as well as their applications has increased significantly since that time. The study of Coulomb crystals is also related to basic physical research, such as on strongly coupled plasmas, phase transitions, and critical phenomena.

A plasma that contains a large number of fine particles exhibits unique properties because it includes not only electrons and ions but also large negatively charged particles, which markedly change the plasma properties simply composed of electrons and ions. The mixed system of three kinds of charged particles can be approximately treated as that of negatively charged particles that are embedded in a uniform positive background, which can form a Coulomb crystal. On the other hand, a plasma containing a small number of fine particles can be analyzed as a general plasma containing negatively charged particles. The behaviors of dust in reactors in nuclear-fusion experiments have been analyzed assuming that dust exist in a high-temperature and high-density plasma under constant conditions.

The main feature of the experimental analyses of a fine particle plasma is that individual particles in the plasma can be directly observed and recorded using video cameras. Therefore, the analysis of the dynamic motion or behavior of individual charged particles in an electromagnetic field is possible, which is carried out in comparison with theoretical analysis. From the relationship between the obtained results of the analysis of individual particles and the macroscopic properties of the fine particle plasma, it is expected to be possible to investigate the relationship between microscale and macroscale physics.

Many international conferences on fine particle plasmas or dusty plasmas have been held over the last few decades. In Japan, the international meeting of the Workshop on Fine Particle Plasmas was started 20 years ago and has taken place every year at NIFS (National Institute for Fusion Science). In 2019, the 20th Workshop on Fine Particle Plasmas was held. The publication of this book was planned to commemorate the 20th workshop.

In this book, the recent progress of experimental and theoretical studies on fine particle plasmas is described. In Chapter 1, the generation of fine particle plasmas and Coulomb crystals is reviewed. The observation of these fine particles is described. In Chapter 2, the theoretical analysis of fine particle plasmas under gravity and microgravity is described. In Chapter 3, the observation of fine particle plasmas under

**II**

**Section 3**

**Section 4**

**Section 5**

**Section 6**

*by Sandip H. Gharat*

*by Viktor Gerasimenko*

*by Junsheng Zeng and Heng Li*

Generation of Nanoparticles **115**

**Chapter 7 117**

Wave Propagations **137**

**Chapter 8 139**

Granular Particles **149**

**Chapter 9 151**

**Chapter 10 163**

**Chapter 11 179**

Neutrinos and Galaxy Custering **193**

**Chapter 12 195**

Comparison of Concentration Transport Approach and MP-PIC Method

Massive Neutrinos and Galaxy Clustering in *f*(R) Gravity Cosmologies *by Jorge Enrique García-Farieta and Rigoberto Ángel Casas Miranda*

Tungsten Nanoparticles Produced by Magnetron Sputtering Gas Aggregation: Process Characterization and Particle Properties *by Tomy Acsente, Lavinia Gabriela Carpen, Elena Matei, Bogdan Bita, Raluca Negrea, Elodie Bernard, Christian Grisolia and Gheorghe Dinescu*

Turbulence Generation in Inhomogeneous Magnetized Plasma

Flow and Segregation of Granular Materials during Heap Formation

Pertaining to Damping Effects on Wave Propagation

*by Ravinder Goyal and R.P. Sharma*

Kinetic Equations of Granular Media

for Simulating Proppant Transport Process

microgravity using a jet plane is reviewed. In Chapter 4, the investigation of the dynamic behavior of a flow of fine particles in a plasma under gravity is reported, and the results are described, focusing on the discovery of the bow shock phenomenon. In Chapter 5, the results from a 3D and microscopic observation of particles in plasmas using a specially developed camera are clearly described. In Chapter 6, the generation of a fine particle plasma in supercritical carbon dioxide is reported, and the experimental results are clearly described. In Chapter 7, in relation to the wall study of nuclear-fusion plasmas, the production of tungsten nanoparticles by magnetron sputtering and their characteristics are discussed. In Chapter 8, turbulence generation in magnetized plasmas including fine particles is theoretically studied and the analysis results are described. In Chapter 9, the flow and segregation of granular materials are theoretically studied and their characteristics are described. In Chapter 10, kinetic equations of granular media including inelastic collisions are studied and the physical properties are described. In Chapter 11, related with liquid flow including a lot of grain particles, proppant transport process was simulated. In Chapter 12, effects of massive neutrinos and galaxy clustering in space were studied from various angles and influence of their gravity was analyzed.

We expect that readers will discover new and attractive aspects of fine particle plasmas within this book, and that the results of the studies described will inspire them to investigate new physical and chemical phenomena related to their fields of study.

Finally, the editors express cordial gratitude to the support of late professor Noriyoshi Sato of Tohoku University, Japan.

The research in this book was partly supported by JSPS KAKENHI 18K04999.

**Tetsu Mieno** Professor, Graduate School of Science and Technology, Shizuoka University, Japan

> **Yasuaki Hayashi** Professor, Faculty of Science and Engineering, Yamato University, Japan

> > **Dr. Kun Xue**  Beijing Institute of Technology, China

> > > **1**

Section 1

Coulomb Crystals
