skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Arc spot grouping: An entanglement of arc spot cells

Abstract

In recent experiments, clear transitions in velocity and trail width of an arc spot initiated on nanostructured tungsten were observed on the boundary of the thick and thin nanostructured layer regions. The velocity of arc spot was significantly decreased on the thick nanostructured region. It was suggested that the grouping decreased the velocity of arc spot. In this study, we try to explain the phenomena using a simple random walk model that has properties of directionality and self-avoidance. And grouping feature was added by installing an attractive force between spot cells with dealing with multi-spots. It was revealed that an entanglement of arc spot cells decreased the spot velocity, and spot cells tend to stamp at the same location many times.

Authors:
 [1]; ;  [2];  [3];  [4]
  1. EcoTopia Science Institute, Nagoya University, Nagoya 464-8603 (Japan)
  2. Graduate School of Engineering, Nagoya University, Nagoya 464-8603 (Japan)
  3. Lebedev Physical Institute, Russian Academy of Sciences, Moscow 119991 (Russian Federation)
  4. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow 119991 (Russian Federation)
Publication Date:
OSTI Identifier:
22402801
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 23; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; GRAPH THEORY; LAYERS; NANOSTRUCTURES; QUANTUM ENTANGLEMENT; RANDOMNESS; TUNGSTEN; VELOCITY; WIDTH

Citation Formats

Kajita, Shin, E-mail: kajita.shin@nagoya-u.jp, Hwangbo, Dogyun, Ohno, Noriyasu, Tsventoukh, Mikhail M., and Barengolts, Sergey A. Arc spot grouping: An entanglement of arc spot cells. United States: N. p., 2014. Web. doi:10.1063/1.4904917.
Kajita, Shin, E-mail: kajita.shin@nagoya-u.jp, Hwangbo, Dogyun, Ohno, Noriyasu, Tsventoukh, Mikhail M., & Barengolts, Sergey A. Arc spot grouping: An entanglement of arc spot cells. United States. doi:10.1063/1.4904917.
Kajita, Shin, E-mail: kajita.shin@nagoya-u.jp, Hwangbo, Dogyun, Ohno, Noriyasu, Tsventoukh, Mikhail M., and Barengolts, Sergey A. 2014. "Arc spot grouping: An entanglement of arc spot cells". United States. doi:10.1063/1.4904917.
@article{osti_22402801,
title = {Arc spot grouping: An entanglement of arc spot cells},
author = {Kajita, Shin, E-mail: kajita.shin@nagoya-u.jp and Hwangbo, Dogyun and Ohno, Noriyasu and Tsventoukh, Mikhail M. and Barengolts, Sergey A.},
abstractNote = {In recent experiments, clear transitions in velocity and trail width of an arc spot initiated on nanostructured tungsten were observed on the boundary of the thick and thin nanostructured layer regions. The velocity of arc spot was significantly decreased on the thick nanostructured region. It was suggested that the grouping decreased the velocity of arc spot. In this study, we try to explain the phenomena using a simple random walk model that has properties of directionality and self-avoidance. And grouping feature was added by installing an attractive force between spot cells with dealing with multi-spots. It was revealed that an entanglement of arc spot cells decreased the spot velocity, and spot cells tend to stamp at the same location many times.},
doi = {10.1063/1.4904917},
journal = {Journal of Applied Physics},
number = 23,
volume = 116,
place = {United States},
year = 2014,
month =
}
  • Tryptophan transfer RNA from chick cells chromatographs reacts differently in the reversed-phase column chromatographic system 5 depending upon whether it is aminoacylated or not. This property was utilized to prepare pure tryptophan tRNA. Oligonucleotide fingerprints of tryptophan tRNA purified in this manner are identical with those reported for ''spot 1'' RNA isolated from Rous sarcoma virus. (auth)
  • A model is presented that explains the ''flat-spot'' power-loss phenomenon observed in silicon solar cells operating under deep space (low temperature, low intensity) conditions. Evidence is presented suggesting that the effect is due to localized metallurgical interactions between the silicon substrate and the contact metallization. These reactions are shown to result in localized regions in which the PN junction is destroyed and replaced with a metal-semiconductor-like interface. The effects of thermal treatment, crystallographic orientation, junction depth, and metallization are presented along with a method of preventing the effect through the suppression of vacancy formation at the free surface of themore » contact metallization. Preliminary data indicating the effectiveness of a TiN diffusion barrier in preventing the effect are also given.« less
  • Purpose: To determine the relative biological effectiveness (RBE), oxygen enhancement ratio (OER), and contribution of the indirect effect of spot scanning proton beams, passive scattering proton beams, or both in cultured cells in comparison with clinically used photons. Methods and Materials: The RBE of passive scattering proton beams at the center of the spread-out Bragg peak (SOBP) was determined from dose-survival curves in 4 cell lines using 6-MV X rays as controls. Survival of 2 cell lines after spot scanning and passive scattering proton irradiation was then compared. Biological effects at the distal end region of the SOBP were also investigated. Themore » OER of passive scattering proton beams and 6 MX X rays were investigated in 2 cell lines. The RBE and OER values were estimated at a 10% cell survival level. The maximum degree of protection of radiation effects by dimethyl sulfoxide was determined to estimate the contribution of the indirect effect against DNA damage. All experiments comparing protons and X rays were made under the same biological conditions. Results: The RBE values of passive scattering proton beams in the 4 cell lines examined were 1.01 to 1.22 (average, 1.14) and were almost identical to those of spot scanning beams. Biological effects increased at the distal end of the SOBP. In the 2 cell lines examined, the OER was 2.74 (95% confidence interval, 2.56-2.80) and 3.08 (2.84-3.11), respectively, for X rays, and 2.39 (2.38-2.43) and 2.72 (2.69-2.75), respectively, for protons (P<.05 for both cells between X rays and protons). The maximum degree of protection was significantly higher for X rays than for proton beams (P<.05). Conclusions: The RBE values of spot scanning and passive scattering proton beams were almost identical. The OER was lower for protons than for X rays. The lower contribution of the indirect effect may partly account for the lower OER of protons.« less