Article
Chemistry, Multidisciplinary
Chi Chen, Wenjie Fu, Chaoyang Zhang, Dun Lu, Meng Han, Yang Yan
Summary: This paper presents a dual-frequency microwave plasma source based on a coaxial transmission line for flexible control of plasma characteristics. Experimental results show that plasma electron density and electron temperature can be adjusted by feeding in different frequencies, improving the operation frequency of dual-frequency microwave plasma sources.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Multidisciplinary
Sung Il Cho, Hyun Keun Park, Surin An, Sang Jeen Hong
Summary: Plasma is crucial in semiconductor processes, especially in the miniaturization and integration of devices. However, the increase in wafer surface temperature caused by the high RF power has posed challenges to the etching process. This study investigates the plasma characteristics using invasive and non-invasive diagnostic methods and proposes a real-time calculation of heat flux to anticipate wafer temperatures and address ion heating issues.
APPLIED SCIENCES-BASEL
(2023)
Article
Physics, Fluids & Plasmas
Chengwei Zhao, Xiaoping Li, Yanming Liu, Donglin Liu, Chao Sun, Gelu Ma, Lishan Tian, Weimin Bao
Summary: This paper proposes a noncontact plasma microwave diffraction measurement method, which can obtain the electron density of cylindrical plasma at different diameters. The method utilizes the diffraction phenomenon and characteristic frequency of plasma to measure the size and distribution of electron density. The method is demonstrated through experimental measurements and compared with a Langmuir probe diagnosis, showing good agreement and potential for wider applications.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Computer Science, Information Systems
Lutong Li, Haoquan Hu, Pu Tang, Bo Chen, Jing Tian, Bixiao Jiang
Summary: The behavior of plasma generated in the shock tube was investigated using microwave reflectometry and interferometry. A calibration process and three-layered medium model were introduced, and a time-dependent reconstruction algorithm was applied. The study demonstrated the effects of plasma diffusion, observed nonuniform flow in the plasma, and discussed the determination of effective time regions for electron density and collision frequency extraction.
Article
Chemistry, Multidisciplinary
Guoqing Zhou, Gang Lu, Oleg Prezhdo
Summary: Auger-type energy exchange is crucial in nanomaterials due to strong carrier-carrier interactions. A new ab initio technique was developed to accurately model Auger scattering with nonadiabatic molecular dynamics, describing charge-charge and charge-phonon scattering in a nonperturbative manner. This technique successfully reproduced experimental processes, providing detailed insights into carrier dynamics in nanomaterials with strong carrier-carrier interactions.
Article
Instruments & Instrumentation
P. W. Shi, Z. C. Yang, Z. B. Shi, L. F. Xu, W. C. Deng, M. Jiang, W. Chen, W. L. Zhong, J. Wen, K. R. Fang, R. H. Tong, G. Q. Xue, X. Yu, Y. G. Li, X. Q. Ji, Y. P. Zhang, Q. W. Yang, M. Xu, Z. X. Wang, X. R. Duan
Summary: A solid state terahertz interferometer has been successfully developed on the HL-2M tokamak, working in a wide frequency range with the use of phase locking and frequency multiplying technique. The phase processor based on FPGA technology enables real-time display of electron density, and a novel numerical algorithm written on the FPGA chip allows extraction of phase information without interference. This interferometer achieves precise measurement of electron density and low frequency tearing mode in plasma diagnosis.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2021)
Article
Physics, Applied
H. Yuan, W. Ke, J. Q. Liu, M. Y. Chen, X. H. Wang, A. J. Yang, J. F. Chu, D. X. Liu, M. Z. Rong
Summary: In this study, the spatial and temporal resolved spectra of laser-induced plasma (LIP) at different air pressures were collected, and the radial distribution characteristics of LIP along the target surface under the influence of air pressure were investigated. The spatial-temporal evolution of electron density n(e) and electron temperature T(e) were also studied. It was observed that air pressure has a significant effect on the radial distribution of LIP.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Optics
Qusay Adnan Abbas, Ala F. Ahmed, Falah A. -H. Mutlak
Summary: The study investigated the discharge characteristics in the magnetized hollow cathode system and the impact of gas pressure, where increasing pressure led to cathode compression and dimmer negative glow. The spectroscopic method using argon's emission atomic spectra was utilized to evaluate electron temperature and calculate electron number density.
Article
Optics
M. Oujja, J. J. Camacho, D. Paradela, M. Castillejo, R. de Nalda
Summary: The emission characteristics of laser-ablated calcium fluoride CaF2 plasma were investigated using optical emission spectroscopy. Different species showed varying decay rates, and different excitation temperatures were observed.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2021)
Article
Physics, Fluids & Plasmas
Elena Kralkina, Polina Nekludova, Aleksander Nikonov, Konstantin Vavilin, Ilya Zadiriev, Vladimir Tarakanov
Summary: Systematic experimental studies and numerical modeling were conducted to investigate the electron density, temperature, and RF power coupling efficiency in RF inductive discharge plasma at different gas pressures. The results show that the maximum electron density and minimum temperature are achieved within a certain pressure range.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2021)
Article
Multidisciplinary Sciences
Nikita Medvedev, Fedor Akhmetov, Ruslan A. Rymzhanov, Roman Voronkov, Alexander E. Volkov
Summary: The authors present a concurrent Monte Carlo-molecular dynamics approach to modeling matter response to excitation of its electronic system at nanometric scales. The method enables a time-resolved tracing of the excitation kinetics of both the electronic and atomic systems and their simultaneous response to a deposited dose.
ADVANCED THEORY AND SIMULATIONS
(2022)
Article
Physics, Applied
Kam-Hong Chau, Yoshinobu Kawai, Chi-Wai Kan, Jia-Lin Syu, Yen-Chun Liu, Ying-Hung Chen, Chen-Jui Liang, Ju-Liang He
Summary: A homemade Langmuir probe was used to investigate the plasma characteristics of high power impulse magnetron sputtering (HIPIMS) for copper deposition. The study revealed the physics of HIPIMS, including the double peaks and the mechanism behind the generation of the second peak.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2022)
Article
Instruments & Instrumentation
A. Megia-Macias, E. Barrios-Diaz, O. D. Cortazar
Summary: This review focuses on the recent advances in temporal resolved plasma diagnostics for pulsed operated 2.45 GHz microwave-driven hydrogen discharges over the past ten years, highlighting studies on breakdown and decay processes, vacuum ultraviolet spectroscopy, ultra-fast photography, and ion mass spectroscopy measurements.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2021)
Article
Multidisciplinary Sciences
R. D'Arcy, J. Chappell, J. Beinortaite, S. Diederichs, G. Boyle, B. Foster, M. J. Garland, P. Gonzalez Caminal, C. A. Lindstrom, G. Loisch, S. Schreiber, S. Schroeder, R. J. Shalloo, M. Thevenet, S. Wesch, M. Wing, J. Osterhoff
Summary: The interaction between particle bunches and plasma can generate plasma wakes capable of sustaining high-intensity electric fields. Plasma wakefields offer the opportunity to accelerate charged particles to higher energies with smaller accelerator facilities. However, the current plasma-wakefield technology cannot meet the high repetition rates required by high-energy physics and photon science. By measuring the recovery time of plasma after perturbation by a wakefield, this study establishes the in-principle attainability of megahertz rates of acceleration in plasmas. The experimental results confirm the feasibility of developing plasma-wakefield modules as high-repetition-rate energy boosters in particle-physics and photon-science facilities.
Article
Chemistry, Multidisciplinary
James A. Quirk, Bin Miao, Bin Feng, Gowoon Kim, Hiromichi Ohta, Yuichi Ikuhara, Keith P. McKenna
Summary: An experimental and theoretical study of anatase grain boundaries fabricated by epitaxial growth on a bicrystalline substrate provides accurate atomic-scale models. The electronic structure in the vicinity of stoichiometric grain boundaries is relatively benign to device performance, but segregation of oxygen vacancies introduces barriers to electron transport. An intrinsically oxygen-deficient boundary exhibits charge trapping consistent with electron energy loss spectroscopy measurements.