High‐power, twin‐frequency FIR lasers for plasma diagnostic applications

1986 ◽  
Vol 57 (8) ◽  
pp. 1986-1988 ◽  
Author(s):  
T. Lehecka ◽  
R. Savage ◽  
R. Dworak ◽  
W. A. Peebles ◽  
N. C. Luhmann ◽  
...  
Keyword(s):  
High Power ◽  
Plasma Diagnostic ◽  
Fir Lasers ◽  
Diagnostic Applications

scholarly journals Novel Dual Beam Cascaded Schemes for 346 GHz Harmonic-Enhanced TWTs

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 195
Author(s):  
Ruifeng Zhang ◽  
Qi Wang ◽  
Difu Deng ◽  
Yao Dong ◽  
Fei Xiao ◽  
...  
Keyword(s):  
High Power ◽  
Peak Power ◽  
Low Cost ◽  
High Harmonic ◽  
Harmonic Signal ◽  
Input Power ◽  
Plasma Diagnostic ◽  
Dual Beam ◽  
Thz Sources ◽  
Simulation Results

The applications of terahertz (THz) devices in communication, imaging, and plasma diagnostic are limited by the lack of high-power, miniature, and low-cost THz sources. To develop high-power THz source, the high-harmonic traveling wave tube (HHTWT) is introduced, which is based on the theory that electron beam modulated by electromagnetic (EM) waves can generate high harmonic signals. The principal analysis and simulation results prove that amplifying high harmonic signal is a promising method to realize high-power THz source. For further improvement of power and bandwidth, two novel dual-beam schemes for high-power 346 GHz TWTs are proposed. The first TWT is comprised of two cascaded slow wave structures (SWSs), among which one SWS can generate a THz signal by importing a millimeter-wave signal and the other one can amplify THz signal of interest. The simulation results show that the output power exceeds 400 mW from 340 GHz to 348 GHz when the input power is 200 mW from 85 GHz to 87 GHz. The peak power of 1100 mW is predicted at 346 GHz. The second TWT is implemented by connecting a pre-amplification section to the input port of the HHTWT. The power of 600 mW is achieved from 338 GHz to 350 GHz. The 3-dB bandwidth is 16.5 GHz. In brief, two novel schemes have advantages in peak power and bandwidth, respectively. These two dual-beam integrated schemes, constituted respectively by two TWTs, also feature rugged structure, reliable performance, and low costs, and can be considered as promising high-power THz sources.

Existing and new applications of micropellet injection (MPI) in magnetic fusion

2016 ◽  
Vol 82 (2) ◽  
Author(s):  
Zhehui Wang ◽  
Robert Lunsford ◽  
Dennis K. Mansfield ◽  
Jacob H. Nichols
Keyword(s):  
Small Scale ◽  
Magnetic Fusion ◽  
Plasma Diagnostic ◽  
Minimal Impact ◽  
Basic Physics ◽  
Core Plasma ◽  
Design Selection ◽  
Diagnostic Applications ◽  
New Applications

The intense heat and energetic particle fluxes expected in ITER and future magnetic fusion reactors pose prohibitive problems to the design, selection and maintenance of the first wall and divertor. Micropellet injection (MPI) technologies can offer some innovative solutions to the material and extreme heat challenges. Basic physics of micropellet motion, ablation and interactions with high-temperature plasmas and energetic particles are presented first. We then discuss MPI technology options and applications. In addition to plasma diagnostic applications, controlled injection of micropellets of different sizes, velocities and injection frequencies will offer several possibilities: (1) better assessment of the core plasma cooling due to dust produced in situ; (2) better understanding of the plasma–material interaction physics near the wall; (3) new methods for plasma fuelling and impurity control; and (4) techniques for edge cooling with minimal impact on the plasma core. Dedicated small-scale laboratory experiments will complement major fusion experiments in development and applications of MPI.

Radiation assessment of hydrogen-loaded aluminium-coated pure silica core fibres for ITER plasma diagnostic applications

2007 ◽  
Vol 82 (15-24) ◽  
pp. 2451-2455 ◽  
Author(s):  
B. Brichard ◽  
A.L. Tomashuk ◽  
H. Ooms ◽  
V.A. Bogatyrjov ◽  
S.N. Klyamkin ◽  
...  
Keyword(s):  
Plasma Diagnostic ◽  
Pure Silica ◽  
Silica Core ◽  
Diagnostic Applications

Subharmonic mixer arrays for millimeter-wave plasma diagnostic applications (abstract)

1997 ◽  
Vol 68 (1) ◽  
pp. 422-422
Author(s):  
R. P. Hsia ◽  
W. R. Geck ◽  
C. W. Domier ◽  
N. C. Luhmann, Jr.
Keyword(s):  
Millimeter Wave ◽  
Plasma Diagnostic ◽  
Diagnostic Applications
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