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Vol. 31 No.
4
Simulation and analysis of lower hybrid
current drive on EAST
tokamak
LI Miao-hui, DING Bo-jiang, KONG Er-hua,
ZHANG Lei, SHAN Jia-fang,
LIU Fu-kun, WANG Mao, XU Han-dong
(Institute of Plasma Physics, Chinese
Academy of Sciences, Hefei 230031)
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Abstract:
The calculation processes and
consideration on the physical regime of
C3PO, a ray-tracing code, and LUKE, a
fast numerical solver for the 3-D
Fokker-Planck equation, are presented.
Bounce average is used and the
relativistic and particle-trapped
effects are taken into account in the
codes. The simulation and analysis of
plasma current influence on rays
propagation and current drive (CD)
efficiency in EAST divertor
configuration have been carried out
using these codes. The numerical results
indicate that, with the increase of
plasma current, the rotation of the
poloidal rays trajectory becomes faster,
the power deposition profile shifts on
axis, and the CD efficiency becomes
higher. In addition, it is discovered
that the trajectory provided high N||-upshift
when the
ray
propagated towards the edge density
cut-off at the top of the chamber and
then bounced back towards the plasma
centre. When the effect of radial
diffusion of fast electrons is
considered, the
shape of
driven current becomes broad, but CD
efficiency decreases due to the radial
loss and collisional loss of electrons
moving to the region where collision is
serious. While the diffusion coefficient
is assumed to be 1.5m2×s-1,
the modeling result of driven current
approaches to the
experimental value.
Key words:
LHCD;
Landau damping; Radial diffusion;
Numerical simulation |
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Studies on calibration method and FFT
analysis in power measurement
of pulse-modulated RF signal
HUO Wei-gang1, 2, SU Cheng1,
SUN Bin1, DING Zhen-feng1
(1. School of Physics and Optoelectronic
Technology, Dalian University of
Technology, Dalian 116023;
2. School of Physics and Electronic
Technology, Liaoning Normal University,
Dalian 116029)
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Abstract：The
capability of a commercial-available
voltage/current probe, intended to
monitor steady or slowly-varying RF
signals, is improved to measure
pulse-modulated RF signals. The
improvement is realized by means of
combination of voltage/current probe
sensor and a digital oscilloscope. The
outputs of voltage/current probes are
acquired with the digital oscilloscope,
and their amplitudes and phase
difference are obtained with FFT. Under
different frequencies, current/voltage
amplitude and phase difference are
calibrated in order to calculate RF
power. The phase difference between
voltage and current is the key factor
influencing calibration coefficients.
Results show the calibrated
current/voltage probe can provide
reliable and repetitive measurements.
FFT method is problematic in analyzing
nonstationary amplitude-modulated
voltage and current signals, and the
pulsed RF power can be only reliably
calculated at time when reactive power
is zero.
Key words:
Power
measurement of pulsed RF signal;
Voltage/current probes; Calibration;
Nonstationary FFT analysis; Phase
difference |
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Application of break-in-slope method in
calculating
HL-2A ECRH power deposition
LI En-ping, FENG Zhen, LI Chun-hua, YAO
Ke, NIE Lin, HUANG Yuan
(Southwestern Institute of Physics,
Chengdu 610041)
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Abstract：The
basic theory of break-in-slope method in
calculating the profile of auxiliary
heating power deposition is presented.
Using this method, the profile of ECRH
power deposition is carried out by
analyzing electron temperature and
density at the time of ECRH injection on
HL-2A for the first time. The
applicability of this method is proved.
Key words:
Break-in-slope; ECRH; Auxiliary heating;
Data analyze; Absorption profile |
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Numerical simulation of subcooled flow
boiling and application
to the EAST plasma facing components
KANG Qing-lan1, SONG Yun-tao1,
HUANG Sheng-hong2, WANG
Zhong-wei1, JI Xiang1
(1.
Institute of Plasma Physics, Chinese
Academy of Science, Hefei 230031;
2. University of Science and Technology
of China, Hefei 230026)
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Abstract：Numerical
simulation approaches to subcooled
boiling and their application to EAST
plasma facing components (PFC) was
described. A two-fluid model implemented
with a wall boiling model based on a
wall heat flux partition algorithm was
used to solve control equations for
mass, momentum and energy, which coupled
with additional closure relations
describing the exchange of two phases at
the interface. A user-defined function (UDF)
was written to define the source terms
of phase exchange and specify the
customized parameters of the multiphase.
And the physical model was verified by
experimental data of Lee et al. Also the
simulation of the EAST plasma facing
components was done with subcooled flow
boiling method for EAST PFCs cooling
structure optimization.
Key words:
EAST plasma facing components;
Subcooled flow boiling; Two-fluid model;
UDF |
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Influence on electron movement in
laser-plasma produced
by multi-photon nonlinear Compton
scattering
HAO Xiao-fei1, SUN Fu-zhao2,
HAO Dong-shan1
(1. Department of Information
Engineering, Huanghuai University,
Zhumadian 463000;
2. Department of Electron Science and
Engineering, Huanghuai University,
Zhumadian 463000)
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Abstract：Using
the model of multi-photon nonlinear
Compton scattering，the
influences on the electron movement in
the plasma produced by the multi-photon
nonlinear Compton scattering are studied，a
new mechanism of the acceleration
electrons in a mixed field produced by
the coupling optical formed by the
incident laser and scattered optical and
the self-magnetic field formed by the
action of the coupling optical and the
plasma has been given out，and
the momentum and energy equations of
electrons are revised and simulated. The
results show that when the amplitude of
the electric field of the mixed field
and its magnetic field amplitude is
equal，the
circle round resonance electron can be
accelerated to very high energy in the
action times of the circle round
resonance electron and the mixed field.
The electron accelerated energy is
increased along with the increasing of
the coupling optical peak value，the
cycles of the energy change are
decreased along with the increase of the
coupling initial angle of the electron，and
the accelerated energy is faster
increased at the initial stage，then
slowly increased，finally
hastened stability state along with the
increase of the coupling initial
transverse speed of the electron.
Key words:
Laser-plasma; Self-magnetic field;
Coupling; Multi-photon nonlinear Compton
scattering |
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Comparison
between capacitively coupled VHF and high frequency discharge in H2
YAO
Fu-bao, HAO Ying-ying, ZHANG Lian-zhu, ZHAO Hai-tao
(College of Physics Science and Information Engineering, Hebei Normal
University,
Shijiazhuang 050024)
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Abstract：This
paper presents PIC/MC model of
capacitively coupled very-high-frequency
discharge in hydrogen. We take
into account 21 kinds of collisions of
charged particles
(e, H+,H2+,
H3+) with H2,
have simulated the electric field
distribution, potential distribution,
density and mean
energy distribution of electrons and
hydrogen ions ( H+, H2+,
H3+), and have
compared with those
of the frequency of 13.56MHz. The
simulation results show that the plasma
space potential is enhanced with the
increase of driving frequency, which
results in the increase of electric
field near the two electrodes. Besides,
rf sheath thickness becomes thin and the
mean energy of electron and H3+
is decreased, while their total density
is increased with the increase of
frequency. H3+ is
the
dominant ion in the H2
very-high-frequency discharge, its
density being two or three orders of
magnitude higher than that of H2+.
Key words:
H2
capacitively coupled
very-high-frequency discharge; PIC/MC
model; H2 plasma
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Study on mean
ionization state for tungsten plasma
HUANG Hua1, JIANG Ming1,
MA Bo1, WU Shuang1,
YANG Zhi-jian1, GUO Fu-jun2
(1. College of
Electrical Information Engineering, Southwest University for Nationalities,
Chengdu 610041;
2. Institute for
Plasma Physics, Rijnhuizen, 3430BE Nieuwgein, The Netherlands)
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Abstract： Under
the local thermodynamics equilibrium
condition, the
mean ionization state about tungsten
plasma is calculated by SHML model with
temperatures in the range of 0.3keV to
10keV and density in the range of
0.001g·cm-3
to
0.1g·cm-3.
It is studied that the mean ionization
state
for tungsten plasma is related to
temperature and density. The results
show that Wu ionization is reducing as
the increase of density, but increasing
as the
rise of
temperature.
And the mean ionization state for
tungsten plasmas
appears three steps in graph as the
rise
of temperature. This article researches
the relationship
between
ionization state and ionization
potential, and
explains why steps appear.
Key words:
Tungsten
plasma; Mean ionization state;
Ionization potential
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Design of feedback control system for
HL-2M tokamak
ZHANG Guo-hui, XIA Fan, SONG Xian-ming,
LUO Cui-wen, SONG Xiao, ZHAO Li, LIAO
Min
(Southwestern Institute of Physics,
Chengdu 610041)
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Abstract： The
conceptual design of HL-2M control
system is simply presented, and the
feedback control system which is the
most important part of the whole control
system is mainly introduced，feedback
control program is rewrited. In order to
satisfy the further requirements from
control system in HL-2M, the feedback
control system program has been
redesigned. Some improvement of methods
on how to achieve partial functions has
been done. The real-time communication
network will be builded based on
reflection memory cards, and the
structure of feedback control system is
constructed through the real-time
network. In the Linux operating system,
simulation tests have been made on new
feedback control system with old
experiment data, the result of tests
shows well and meets the expected
requirements.
Key words:
Feedback control system; Linux operating
system; Object-oriented; Reflection
memory
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R&D for
discharge management platform of HL-2M
tokamak
SONG Xiao, XIA Fan, SONG Xian-ming,
ZHANG Guo-hui, PAN Yu-dong, PAN Li
(Southwestern Institute of Physics,
Chengdu 610041)
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Abstract：Main
function of discharge management
platform for HL-2M tokamak is to provide
a platform for operator to run timing
system, PLC logic protect system and
plasma feedback control system. During
discharge interval, the operator uses it
to preset the control parameters and
waveforms for the next shot, to
configure the operation parameters for
all subsystems, The communication way
based on reflective memory (RFM) is
responsible for transmitting the control
parameters and waveforms to all
subsystems effectively and reliably. The
results of commissioning between our
platform and other subsystem shows that
its design is reasonable, and its
operation is reliable.
Key words:
HL-2M
tokamak; Discharge management; PLC; SQL
server; Reflective memory |
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Activation calculation analysis for the
China 2×6 solid breeder
test blanket module
HAN Jing-ru1, CHEN Yi-xue1,
2, ZHANG Guo-shu3, CAO
Qi-xiang3
(1. School of Nuclear Science and
Engineering, North China Electric Power
University, Beijing 102206;
2. State Nuclear Power Software
Development Center, Beijing 100029;
3. Southwestern Institute of Physics,
Chengdu 610041)
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Abstract：Based
on the new design of China 2´6
helium cooled solid breeder (CH-HCSB)
test blanket module (TBM),
three-dimensional activation calculation
analysis was performed by using the
Monte Carlo particle transport code MCNP
and European activation code FISPACT.
The results show that, at the beginning
moment after shutdown, the total
activity is 1.78×1016Bq, and
the total
afterheat is 3.01kW. They are both
dominated by the structural material
CLF-1. Meanwhile, the dominant
radioactivity nuclides and reaction
pathways have been identified. The
results will provide useful indications
for materials selection and further
optimization design of the TBM. On basis
of the calculated contact dose rate, the
activated materials can be reused with
the remote handling recycling options.
That is effective for preventing from
the radiation environmental hazard.
Key words:
Activation;
Test blanket module; MCNP；FISPACT;
Interface code |
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Structural
design and analysis of in wall shielding
for ITER
SHAO Zhu-zhen1, WANG Chuan-li1,
SONG Yun-tao2
(1. Anhui University of Science and
Technology, Huainan 232001;
2. Institute of Plasma Physics, Chinese
Academy of Science, Hefei 230031)
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Abstract：In
order to shield the neutron current and
reduce the ripple during the ITER fusion
reaction process, the in-wall shielding
structures have been inserted between
the two shells of the ITER vacuum
vessel, and the safety of the reaction
could be ensured. The conceptual design,
the design guideline, the detail design
and the assembly scheme for the in-wall
shielding have been introduced. Choosing
one shielding block which formed the
in-wall shielding structure as the
research object, its heat-structure
coupling analysis has been fulfilled,
and component response stress is less
than the allowable stress，and
the rationality of its structural design
has been validated.
Key words:
In-wall shielding; Vacuum vessel; Detail
design; Shielding block |
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Introduction of ITER TBM first wall
fabrication methods and mockup
fabrication
YE Xing-fu, FENG Kai-ming, LUO Tian-yong,
ZHANG Guo-shu
(Southwestern Institute of Physics,
Chengdu 610041)
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Abstract：Four
methods of TBM FW fabrication are
introduced. A 304 stainless steel FW
mockup was fabricated with Machining-EBW-Bending
method. The fabricated FW mockup was cut
along one of square channels and
measured. The minimum area of the
channel at the bending place was 85% of
original. The thickness of the wall on
the outside of the channel at the
bending place was apparently reduced,
but could be controlled by machining. To
demonstrate the availability of this
processing technique, the RAFM which
actually used on FW should be used in
future work.
Key words:
TBM; FW; Welding; Bending |
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Influence research on energy deposition
in TFC
of CN HCCB
TBM for ITER
ZHAO Feng-chao, LI Zai-xin, ZHANG
Guo-shu, FENG Kai-ming, CAO Qi-xiang
(Southwestern
Institute of Physics, Chengdu 610041)
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Abstract：
Based on Alite model
of ITER and CN HCCB TBM, research of
influence on the energy deposition of
TFC caused by CN HCCB TBM is carried
out. The calculation is carried out by
MCNP code, and a mesh-based weight
window is used to reduce
variance.
The analysis indicates that installing
CN HCCB TBM could reduce the energy
deposition in TFC by 3%; most of the
energy deposition is local in the 1-14
sectors of inner-side; the power density
peak is located in the ninth sector and
the required limits satisfied.
Key words:
ITER; CN HCCB TBM; TFC; Energy
deposition; Distribution of power
density |
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Langmuir
probe and emission spectroscopy
diagnosis of low pressure hydrogen
plasma induced by helicon-wave
GAO Ying-xue1, 2, WU Wei-dong1,
2, DAI Yang1, 2, JIANG
Fan1, 3
(1. Research Center of Laser Fusion,
CAEP, Mianyang 621900;
2. College of Science, Southwest
University of Science and Technology,
Mianyang 621010;
3. Institute of Atomic and Molecular
Physics, Sichuan University, Chengdu
610065)
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Abstract：The
characteristics of helicon-wave hydrogen
low pressure plasma were investigated by
Langmuir probe and emission
spectroscopy. The variation law of
electron energy probability function (EEPF),
effective electron temperature (Teff),
electron density (ne)
and hydrogen atom excited state density
(nH*) were
analyzed in relation of different
experimental parameters by Druyvesteyn
method and corona model. The results
demonstrate that the peaks of higher
energy of EEPF curves move toward lower
energy with the increase of RF power,
pressure and controlled magnetic field,
Teff decreases. The
ne increases and jumps
with the increase of RF power from 25W
to 35W, and the nH*
increases linearly with the rise of RF
power; the ne and nH*
increases firstly and then
decrease with the rise of pressure; with
the rise of controlled magnetic field,
the ne increase
linearly and the nH*
increases firstly and then
decreases.
Key words:
Helicon-wave plasma; Langmuir
probe; Emission spectroscopy;
Druyvesteyn method; Corona |
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Preparation and researching progress of
iron nanoparticle by plasma
YANG Li-mei1, WANG Da-wang1,
2, ZHANG Yu-tao1, 3, MA
Teng-cai1
(1. School of Physics and Optoelectronic
Technology, Dalian University of
Technology, Dalian 116024;
2. Laboratory of Plasma Physical
Chemistry, Dalian University of
Technology, Dalian 116024;
3. School of Physics, Hunan University
of Science and Technology, Xiangtan
411201)
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Abstract：Preparation
of iron nanoparticle process with plasma
technology is presented. Comparing with
pyrolysis method and arc method to
prepare iron nanoparticle, the new
plasma method is efficient, clean,
suitable for industrial production.
Key words:
Iron
nanoparticle; Plasma; Preparation |
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