Inward diffusion driven by low frequency fluctuations in self-organizing magnetospheric plasma

2021 ◽  
Author(s):  
Naoki Kenmochi ◽  
Yuuki Yokota ◽  
Masaki Nishiura ◽  
H Saitoh ◽  
Naoki Sato ◽  
...  

Abstract The new findings for dynamic process of inward diffusion in the magnetospheric plasma are reported on the RT-1 experiment: (i) The evolution of local density profile in the self-organized process has been analysed by the newly developed tomographic reconstruction applying a deep learning method. (ii) The impact of neutral-gas injection excites low-frequency fluctuations, which continues until the peaked density profile recovers. The fluctuations have magnetic components (suggesting the high-beta effect) which have two different frequencies and propagation directions. The phase velocities are of the order of magnetization drifts, and both the velocities and the intensities increase in proportion to the electron density. The self-regulating mechanism of density profile works most apparently in the naturally made confinement system, magnetosphere, which teaches the basic physics of long-lived structures underlying every stationary confinement scheme.

2021 ◽  
Vol 2 (1) ◽  
pp. 70-92
Author(s):  
Reiner L Stenzel ◽  
Johannes Grünwald ◽  
Codrina Ionita ◽  
Roman Schrittwieser ◽  
Manuel Urrutia

The properties of sheaths and associated potential structures and instabilities cover a broad field which even a review cannot cover everything. Thus, the focus will be on about a dozen examples, describe their observations and focus on the basic physical explanations for the effects, while further details are found in the references. Due to familiarity the review focuses mainly on the authors work but compared and referenced related work. The topics start with a high frequency oscillations near the electron plasma frequency. Low frequency instabilities also occur at the ion plasma frequency.The injection of ions into an electron-rich sheath widens the sheath and forms a double layer. Likewise, the injection of electrons into an ion rich sheath widens and establishes a double layer which occurs in free plasma injection into vacuum. The sheath widens and forms a double layer by ionization in an electron rich sheath. When particle fluxes in "fireballs" gets out of balance the double layer performs relaxation instabilities which has been studied extensively. Fireballs inside spherical electrodes create a new instability due to the transit time of trapped electrons. On cylindrical and spherical electrodes the electron rich sheath rotates in magnetized plasmas. Electrons rotate due to $\mathbf E \times \mathbf B_0$ which excites electron drift waves with azimuthal eigenmodes. Conversely a permanent magnetic dipole has been used as a negative electrode. The impact of energetic ions produces secondary electron emission, forming a ring of plasma around the magnetic equator. Such "magnetrons" are subject to various instabilities. Finally, the current to a positively biased electrode in a uniformly magnetized plasma is unstable to relaxation oscillations, which shows an example of global effects. The sheath at the electrode raises the potential in the flux tube of the electrode thereby creating a radial sheath which moves unmagnetized ions radially. The ion motion creates a density perturbation which affects the electrode current. If the electrode draws large currents the current disruptions create large inductive voltages on the electrode, which again produce double layers. This phenomenon has been seen in reconnection currents. Many examples of sheath properties will be explained. Although the focus is on the physics some examples of applications will be suggested such as neutral gas heating and accelerating, sputtering of plasma magnetrons and rf oscillators.


2020 ◽  
Vol 29 (4) ◽  
pp. 2097-2108
Author(s):  
Robyn L. Croft ◽  
Courtney T. Byrd

Purpose The purpose of this study was to identify levels of self-compassion in adults who do and do not stutter and to determine whether self-compassion predicts the impact of stuttering on quality of life in adults who stutter. Method Participants included 140 adults who do and do not stutter matched for age and gender. All participants completed the Self-Compassion Scale. Adults who stutter also completed the Overall Assessment of the Speaker's Experience of Stuttering. Data were analyzed for self-compassion differences between and within adults who do and do not stutter and to predict self-compassion on quality of life in adults who stutter. Results Adults who do and do not stutter exhibited no significant differences in total self-compassion, regardless of participant gender. A simple linear regression of the total self-compassion score and total Overall Assessment of the Speaker's Experience of Stuttering score showed a significant, negative linear relationship of self-compassion predicting the impact of stuttering on quality of life. Conclusions Data suggest that higher levels of self-kindness, mindfulness, and social connectedness (i.e., self-compassion) are related to reduced negative reactions to stuttering, an increased participation in daily communication situations, and an improved overall quality of life. Future research should replicate current findings and identify moderators of the self-compassion–quality of life relationship.


2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Ritu ◽  
Madhu Anand

Parental Modernity is an important aspect for the psycho-social development of the child. The present study aims to study the effect of parental modernity on rejection sensitivity and self-esteem of adolescents and the relationship between rejection sensitivity and self-esteem. The research is carried out on a sample of 240 parents (including 120 fathers and 120 mothers) and their 120 children. For observing the impact of modernity of parents on their children, Individual Modernity Scale was used and administered on father and mother. Rejection Sensitivity Questionnaire and Self-Esteem Inventory were used to measure the rejection sensitivity and self-esteem of children (age ranges from 14 to 19 years). The results suggest that parental modernity has an effect on the rejection sensitivity and personally perceived self of the self – esteem of adolescents. Furthermore, the rejection sensitivity has been found negatively associated with self-esteem.


Author(s):  
Guilherme Borzacchiello ◽  
Carl Albrecht ◽  
Fabricio N Correa ◽  
Breno Jacob ◽  
Guilherme da Silva Leal

Author(s):  
Benjamin R. Levy

After John Cage’s 1958 Darmstadt lectures, many European composers developed an interest in absurdity and artistic provocation. Although Ligeti’s fascination with Cage and his association with the Fluxus group was brief, the impact it had on his composition was palpable and lasting. A set of conceptual works, The Future of Music, Trois Bagatelles, and Poème symphonique for one hundred metronomes, fall clearly into the Fluxus model, even as the last has taken on a second life as a serious work. This spirit, however, can also be seen in the self-satire of Fragment and the drama and irony of Volumina, Aventures, and Nouvelles Aventures. The sketches for Aventures not only show the composer channeling this humor into a major work but also prove to be a fascinating repository of ideas that Ligeti would reuse in the years to come.


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