scholarly journals Resolving the fast ion distribution from imaging neutral particle analyzer measurements

2020 ◽  
Vol 60 (11) ◽  
pp. 112001
Author(s):  
X.D. Du ◽  
M.A. Van Zeeland ◽  
W.W. Heidbrink ◽  
L. Stagner ◽  
A. Wingen ◽  
...  
Keyword(s):  
Neutral Particle ◽  
Ion Distribution ◽  
Fast Ion ◽  
Neutral Particle Analyzer

scholarly journals A Code that Simulates Fast-Ion Dα and Neutral Particle Measurements

2011 ◽  
Vol 10 (3) ◽  
pp. 716-741 ◽  
Author(s):  
W. W. Heidbrink ◽  
D. Liu ◽  
Y. Luo ◽  
E. Ruskov ◽  
B. Geiger
Keyword(s):  
Neutral Particle ◽  
Radiative Transition ◽  
Efficient Solutions ◽  
Tokamak Plasmas ◽  
Exchange Reactions ◽  
Ion Distribution ◽  
Neutral Beams ◽  
Atomic States ◽  
Fast Ion ◽  
Neutral Particle Analyzer

AbstractA code that models signals produced by charge-exchange reactions between fast ions and injected neutral beams in tokamak plasmas is described. With the fast-ion distribution function as input, the code predicts the efflux to a neutral particle analyzer (NPA) diagnostic and the photon radiance of Balmer-alpha light to a fast-ion Dα (FIDA) diagnostic. Reactions with both the primary injected neutrals and with the cloud of secondary “halo” neutrals that surround the beam are treated. Accurate calculation of the fraction of neutrals that occupy excited atomic states (the collisional-radiative transition equations) is an important element of the code. Comparison with TRANSP output and other tests verify the solutions. Judicious selection of grid size and other parameters facilitate efficient solutions. The output of the code has been validated by FIDA measurements on DIII-D but further tests are warranted.

The Sawtooth Oscillation Effect on Fast-Ion Energy Spectra in ITER Plasma and Neutral Particle Analyzer Measurements

2018 ◽  
Vol 63 (3) ◽  
pp. 100-103
Author(s):  
F. S. Zaitsev ◽  
N. N. Gorelenkov ◽  
M. P. Petrov ◽  
V. I. Afanasyev ◽  
M. I. Mironov
Keyword(s):  
Neutral Particle ◽  
Energy Spectra ◽  
Oscillation Effect ◽  
Ion Energy ◽  
Sawtooth Oscillation ◽  
Fast Ion ◽  
Neutral Particle Analyzer

scholarly journals Progress in modelling fast-ion D-alpha spectra and neutral particle analyzer fluxes using FIDASIM

2020 ◽  
Vol 62 (10) ◽  
pp. 105008
Author(s):  
B. Geiger ◽  
L. Stagner ◽  
W.W. Heidbrink ◽  
R. Dux ◽  
R. Fischer ◽  
...  
Keyword(s):  
Neutral Particle ◽  
Fast Ion ◽  
Neutral Particle Analyzer

scholarly journals Анализ потерь быстрых ионов, вызванных распространением тороидальных альфвеновских мод в плазме сферического токамака Глобус-М2

2022 ◽  
Vol 92 (1) ◽  
pp. 45
Author(s):  
И.М. Балаченков ◽  
Н.Н. Бахарев ◽  
В.И. Варфоломеев ◽  
В.К. Гусев ◽  
М.В. Ильясова ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Neutron Flux ◽  
Beam Energy ◽  
Neutral Particle ◽  
Plasma Current ◽  
Plasma Edge ◽  
Energy Channel ◽  
Alfven Eigenmodes ◽  
Fast Ion ◽  
Neutral Particle Analyzer

With an increase of magnetic field up to 0.8 T and plasma current to 400 kA, fast ion losses rate in the discharges with toroidal Alfven eigenmodes decreased in tokamak Globus-M2 comparing with Globus-M tokamak discharges. Taking into account the data on the discharges with increased magnetic field and plasma current, the regression fit of neutral particle analyzer flux drop in energy channel close to neutral beam energy on relative eigenmode magnitude, the value of magnetic field and plasma current was analyzed. The power of flux drop dependence on TAE magnitude was found to be ~0.5 and inverse proportional on the value of product of magnetic field and plasma current, which is highly likely is determined only by plasma current due to weak dependence on magnetic field. The result obtained indicates that fast ion losses in Globus-M2, stimulated by toroidal Alfven eigenmodes are mostly determined by the shift of passing orbits to the plasma edge. With the increase of plasma current and magnetic field, neutron flux drops arising in the moments of toroidal mode bursts have also decreased.

Design and simulation of an imaging neutral particle analyzer for the ASDEX Upgrade tokamak

2021 ◽  
Vol 92 (4) ◽  
pp. 043554
Author(s):  
J. Rueda-Rueda ◽  
M. García-Muñoz ◽  
E. Viezzer ◽  
P. A. Schneider ◽  
J. García-Domínguez ◽  
...  
Keyword(s):  
Neutral Particle ◽  
Neutral Particle Analyzer

scholarly journals A simulation study of a windowless gas-stripping room in an E//B neutral particle analyzer

2021 ◽  
Vol 32 (7) ◽  
Author(s):  
Yuan Luo ◽  
Wei-Ping Lin ◽  
Pei-Pei Ren ◽  
Guo-Feng Qu ◽  
Jing-Jun Zhu ◽  
...  
Keyword(s):  
Simulation Study ◽  
Neutral Particle ◽  
Gas Stripping ◽  
Neutral Particle Analyzer

Measurement of the fast ion distribution using active NPA diagnostics at the Globus-M2 spherical tokamak

2021 ◽  
Author(s):  
Nikolai Nikolaevich Bakharev ◽  
I M Balachenkov ◽  
F V Chernyshev ◽  
Vasily K Gusev ◽  
Evgeniy Kiselev ◽  
...  
Keyword(s):  
Charge Exchange ◽  
Neutral Beam ◽  
Scanning System ◽  
Spatial Distributions ◽  
Spherical Tokamak ◽  
Ion Distribution ◽  
Fast Ion ◽  
Additional Charge

Abstract Active NPA measurements of the fast ion distribution using the neutral beam as an additional charge exchange target are discussed. Expressions for the calculation of the NPA signal based on the fast ion distribution and for the reconstruction of the fast ion distribution from the NPA signal are provided. Demonstration of the described approach is carried out on the Globus-M2 spherical tokamak, where a scanning system for the NPAs was recently installed. Main features of the active NPA application on Globus-M2 are considered. The energy and spatial distributions of fast deuterium ions at dedicated pitch angles are obtained and compared with the calculated ones. Key traits of the obtained distributions are considered and explained.

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