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The successful validation of theory-based models of transport, magnetohydrodynamic stability, heating and current drive, with tokamak measurements over the last 20 years, has laid the foundation for a new era where these models can be routinely used in a ‘predict first’ approach to design and predict the outcomes of experiments on tokamaks today. The capability to predict the plasma confinement and core profiles with a quantified uncertainty, based on a multi-machine, international, database of experience, will provide confidence that a proposed discharge will remain within the operational limits of the tokamak. Developing this predictive capability for the first generation of burning plasma devices, beginning with ITER, and progressing to tokamak demonstration reactors, is a critical mission of fusion energy research. Major advances have been made implementing this predict first methodology on today’s tokamaks. An overview of several of these recent advances will be presented, providing the integrated modeling foundations of the experimental successes. The first steps to include boundary plasmas, and tokamak control systems, have been made. A commitment to predicting experiments as part of the planning process is needed in order to collect predictive accuracy data and evolve the models and software into a robust whole discharge pulse design simulator.

High harmonic fast wave (HHFW) current drive at frequency near the lower hybrid wave is calculated under CFETR conditions. Modelling results show that the HHFW has excellent off-axis current drive capacity with high efficiency in a wide range of n// (1.5–2.9) and wave frequency (0.6–2.4 GHz), the peak driven current is about 35 kA/MW and the current drive efficiency η = neICDR/P ∼ 2.7×1019 AW−1 m−2. Under the same parameters, smaller n// leads to more peaked driven current and higher wave frequency corresponding to more outside current peak position. The comparisons of driven current properties with LHCD indicate that the current drive efficiency of HHFW is comparable to LHCD and the driven current profile is also more flexible. Scanning results of density and temperature show that low density and/or high temperature help to obtain more driven current, and the current drive efficiency can be improved at high temperatures and/or high densities.

Conductive concrete not only retains the advantages of ordinary concrete but also possesses high electrical conductivity. It can be applied to snow and ice control on the roads. In preparing the conductive concrete, sand as the conductive fine aggregate was replaced with graphite powder. Its properties and microstructure were also investigated. The conductive concrete strength is shown to decrease with a graphite powder ratio. The conductive concrete resistivity goes down with the powder fineness and content; the temperature grows after electrification, and the concrete exhibits a high heating effect. Graphite powder exerts little influence on the hydration products of the concrete. With an increase in the content and fineness of graphite powder, its filling efficiency becomes rather helpful to form the conductive path.

A critical issue for achieving the integrated operation of steady-state long-pulse high-confinement (H-mode) plasmas on experimental advanced superconducting tokamak (EAST) is to improve beam ion population confinement during neutral beam injection (NBI). To study the characterization of beam ion loss and improve beam ion confinement, the steady-state long pulse scenario discharges were conducted on EAST (β p ⩾ 2.0, β N ⩾ 1.7, q 95 ⩾ 6.7 and H 98y2 ⩾ 1.1) with NBI heating. Based on neutron yield, the beam voltage and line-averaged electron density were adjusted from 50 kV to 60 kV and 4.4 × 1019 m−3 to 5.0 × 1019 m−3, respectively. The results show that the dominant mechanisms of beam ion loss are shine-through loss, prompt loss, and stochastic ripple loss. The shine-through loss fraction is determined by initial velocity, flight time and entire beam path. The change in prompt loss fraction is caused by the change in the deposition of beam ions. The change in stochastic ripple loss fraction is caused by the change in the initial fraction of trapped-confined ions. Detailed physics shows that the prompt loss fraction during counter-Ip injections (∼45%) is far larger than during co-Ip injections (∼5%) due to the finite orbit width. The lost ions are mainly deposited on the lower divertor or below the midplane since the direction of magnetic drift is vertical down. The orbit types of prompt loss during counter-Ip injections are mainly trapped-lost and ctr-passing lost. To minimize the prompt loss fraction during counter-Ip injections, a reversed Ip configuration (rev-Ip) discharge #94758 was conducted. The result suggests that the beam ion wall load fraction during counter-Ip tangential injection (∼3%) is far lower than that in normal Ip configuration (nor-Ip) discharge #94820. It is also found that the confinement of beam ion population in the counter-Ip injection #94758 was greatly improved when compared to #94820. This study can provide unique support for the improvement of beam ion population confinement and for the performance evaluation of the NBI system on EAST and future tokamaks.

先天性房室传导阻滞是临床少见病，多数无特定病因、不可逆，临床可表现为运动耐量受限、生长发育迟缓，甚至导致心力衰竭、阿斯综合征等，需要置入永久性心脏起搏器治疗。然而目前患该疾病的学龄前儿童起搏器类型、置入部位、起搏模式选择并不完全明确。本文报道了1例先天性房室传导阻滞行左束支区域起搏的3岁学龄前儿童，以期为学龄前儿童行生理性起搏治疗提供一定的经验及依据。.

The dependence of fishbone cycle on energetic particle intensity has been investigated in EAST low-magnetic-shear plasmas. It is observed that the fishbone mode growth rate, saturation amplitude as well as fishbone cycle frequency clearly increase with increasing neutral beam injection (NBI) power. Moreover, enhanced electron density and temperature perturbations as well as energetic particle loss were observed with greater injected NBI power. Simulation results using M3D-K code show that as the NBI power increases, the resonant frequency and the energy of the resonant particles become higher, and the saturation amplitude of the mode also changes, due to the non-perturbative energetic particle contribution. The relationship between the calculated energetic particle pressure ratio and fishbone cycle frequency is obtained as ${f_{\textrm{FC}}} = 2.2{(1000{\beta _{\textrm{ep,calc}}} - 0.1)^{5.9 \pm 0.5}}$ . Results consistent with the experimental observations have been achieved based on a predator–prey model.

The behavior of heavy/high-Z impurity tungsten (W) in an improved high-performance fully non-inductive discharge on EAST with ITER-like divertor (ILD) is analyzed. It is found that W could be well controlled. The causes of no W accumulation are clarified by analyzing the background plasma parameters and modeling the W transport. It turns out that the electron temperature (T e) and its gradient are usually high while the toroidal rotation and density peaking of the bulk plasma are small. In this condition, the modeled W turbulent diffusion coefficient is big enough to offset the total turbulent and neoclassical pinch, so that W density profile for zero particle flux will not be very peaked. Combining NEO and TGLF for the W transport coefficient and the impurity transport code STRAHL, not only the core W density profile is predicted but also the radiated information mainly produced by W in the experiment can be closely reconstructed. At last, the physics of controlling W accumulation by electron cyclotron resonance heating (ECRH) is illustrated considering the effects of changed T e by ECRH on ionization balance and transport of W. It shows that the change of ionization and recombination balance by changed T e is not enough to explain the experimental observation of W behavior, which should be attributed to the changed W transport. By comparing the W transport coefficients in two kinds of plasmas with different T e profiles, it is shown that high T e and its gradient play a key role to generate large turbulent diffusion through increasing the growth rate of linear instability so that W accumulation is prevented.

Ion cyclotron resonance heating (ICRH), one of the main auxiliary methods, for high-power and long-pulse plasma heating had been developed in Experimental Advanced Superconducting Tokamak (EAST). An impedance matching system, one important part of ICRH, had been developed for high-power injection and transmitter protection by reducing the reflected power from the antenna. The input impedance in the outlet of the stub tuner can be measured by voltage–current probes installed on the coaxial transmission line between the antenna and triple liquid stub tuners, and the optimum liquid levels in the stub tuners can be calculated based on the input impedance. The calculation and adjustment process of the optimum liquid levels are described comprehensively in this article. Finally, impedance matching had been achieved between two shots during EAST experiments. In the near future, a real-time impedance matching system will be developed to prevent large variations of the ICRH antenna impedance and achieve steady-state and long-pulse operation with the ICRH system.

High poloidal beta scenarios with a favorable energy confinement ( β p ∼ 1.9 , H 98 y 2 ∼ 1.4 ) have been achieved on the Experimental Advanced Superconducting Tokamak using only radio frequency wave heating. Gyrokinetic simulations are carried out with experimental plasma parameters and tokamak equilibrium data of a typical high β p discharge using the gyrokinetic toroidal code. Linear simulations show that electron-temperature scale length and electron-density scale length destabilize the turbulence, collision effects stabilize the turbulence, and the instability propagates in the electron diamagnetic direction. These properties indicate that the dominant instability in the core of high β p plasma is a collisionless trapped electron mode. Ion thermal diffusivity, calculated by nonlinear gyrokinetic simulations, is consistent with the experimental value, in which the electron collision effects play an important role. Further analyses show that instabilities with 0.38$?> k θ ρ s > 0.38 are suppressed by collision effects and collision effects reduce the radial correlation length of turbulence, resulting in the suppression of the turbulence.

Plasma very low-density lipoprotein (VLDL) can be used to select for low body fat or abdominal fat (AF) in broilers, but its correlation with AF is limited. We investigated whether any other biochemical indicator can be used in combination with VLDL for a better selective effect. Nineteen plasma biochemical indicators were measured in male chickens from the Northeast Agricultural University broiler lines divergently selected for AF content (NEAUHLF) in the fed state at 46 and 48 d of age. The average concentration of every parameter for the 2 d was used for statistical analysis. Levels of these 19 plasma biochemical parameters were compared between the lean and fat lines. The phenotypic correlations between these plasma biochemical indicators and AF traits were analyzed. Then, multiple linear regression models were constructed to select the best model used for selecting against AF content. and the heritabilities of plasma indicators contained in the best models were estimated. The results showed that 11 plasma biochemical indicators (triglycerides, total bile acid, total protein, globulin, albumin/globulin, aspartate transaminase, alanine transaminase, gamma-glutamyl transpeptidase, uric acid, creatinine, and VLDL) differed significantly between the lean and fat lines (P < 0.01), and correlated significantly with AF traits (P < 0.05). The best multiple linear regression models based on albumin/globulin, VLDL, triglycerides, globulin, total bile acid, and uric acid, had higher R2 (0.73) than the model based only on VLDL (0.21). The plasma parameters included in the best models had moderate heritability estimates (0.21 ≤ h2 ≤ 0.43). These results indicate that these multiple linear regression models can be used to select for lean broiler chickens.

The Chinese Fusion Engineering Test Reactor (CFETR), which aims to fill the gaps between the International Thermonuclear Experimental Reactor (ITER) and DEMO, is in the design stages. Plasma equilibrium is an important basis for tokamak plasma research. We present a method for constructing CFETR equilibria with a self-consistent pedestal structure, using an EPED-like model and the Sauter bootstrap current model. With this method, the pedestal structures of the snowflake (SF) divertor configuration for CFETR are calculated as well. It is shown that the pedestal heights and widths of SF+ and SF- are slightly larger than those in the standard divertor configuration.

An advanced scenario with high poloidal beta, large-radius internal transport barriers (ITBs) and localized reversed-shear q-profile, has been demonstrated in DIII-D/EAST joint experiments recently on the DIII-D tokamak. This scenario is also one of the future explorations on EAST. In this article, integrated modeling has been utilized to explore the regime with localized reversed-shear q-profile and high performance based on the developed long-pulse scenario on EAST. A scenario with a strong reversed-shear q-profile has been achieved with the combination of 2 MW off-axis ECH, 2.6 MW LHW and 2 MW NBI (H98y2 ∼ 1.35, β P ∼ 2.56, β N ∼ 2.23, f bs ∼ 56 % ). In addition, a small amount (∼0.1 MW) of centrally deposited ECH facilitates the generation of the bootstrap current on or near the axis, and hence reduces the level of the q-profile in this region; thus, a scenario with localized magnetic shear reversal and strong large-radius ITBs is obtained (H98y2 ∼ 1.4, β P ∼ 2.66, β N ∼ 2.31, f bs ∼ 60 % ). Modeling predictions indicate that off-axis ECH/LHW and high plasma density promote the formation of large-radius ITBs. A further increase in the injected power of centrally deposited ECH (0.15 MW) or NBI (4 MW) leads to an increase in the temperature gradient, especially the electron temperature near the axis, and large-radius ITBs disappear in all channels (T e, T i, n e); also, the confinement quality decreases. The bootstrap current density profiles and LHW-driven current profiles tend to peak near the axis due to the increase in electron temperature profiles, which eventually leads to peaked total current profiles, similar to the EAST long-pulse scenario. Changes in magnetic shear result in the disappearance of large-radius ITBs. Modeling validation will be carried out in the near future on the EAST tokamak.

In austere environments, for example, in outer space, on surfaces of extra-terrestrial bodies (Moon, Mars, etc.), or under water, technologies that can enable continuous, reliable, and authentic monitoring of movement of human operators and devices can be critical. We report here the production and human body test of wearable, flexible graphene oxide stress sensors suitable for real-time monitoring of body parameters, state and position of humans, and automatic equipment. These sensors have excellent sensitivity and signal strength across a wide strain range, alleviating the need for additional instrumentation for signal processing and amplification. Their low cost makes them virtually disposable, which may benefit such applications as smart clothing. The sensors were fabricated by a concomitant reduction and N-doping of graphene oxide on polydimethylsiloxane in N2-H2 plasma. The direct bias and other plasma parameters have a significant effect on the reduction and properties of graphene oxide sensors, as shown by optical emission, Raman and X-ray photoelectron spectroscopies, and X-ray diffraction. Optical emission showed different excitation and ionization processes involving atomic and molecular species in the N2-H2 discharge. The photoelectron spectroscopy has confirmed the graphene reduction and introduction of nitrogen doping into the reduced graphene oxide. The bias efficiently controls plasma-induced electric fields, and plasma-related effects determine the N-doping levels. The reduced graphene oxides demonstrate excellent tensile properties, which make them suitable for efficient but cheap stress sensors. This eco-friendly, fast, room-temperature method shows a great potential for fabrication of efficient, flexible sensors.

By scanning toroidal rotation with a combination of co- and counter-current direction neutral beam injection (NBI) on the Experimental Advanced Superconducting Tokamak, it is found the size of edge localized mode (ELM) decreases with increasing toroidal rotation in counter-current direction. The synergistic effect of plasma rotation and collisionality on ELM behavior is also studied by statistical analysis. Three-field module in BOUT++ framework is employed to study the impacts of toroidal rotation/E × B flow shear on ELM behaviors. The BOUT++ simulation results show that both Co- and Ctr-NBI induced net flow have stabilization effects on the peeling-ballooning modes, especially for counter NBI case, high-n ballooning mode can be totally stabilized. With larger E × B shear, the mode number of most unstable mode downshifts in the counter NBI case, with larger E × B shear, the mode number of most downshifts in the counter NBI case, correlated with reduced ELM size.

Experimental and modeling investigations of high βp scenarios on DIII-D and EAST tokamaks show advantages in high energy confinement, avoidance of n = 1 MHD, and core-edge integration with reduced heat flux, making this scenario an attractive option for China Fusion Engineering Test Reactor steady-state operation. Experiments show that plasmas with high confinement and high density can be achieved with neutral beam injection on DIII-D (βp ∼ 2.2, βN ∼ 3.5, fBS ∼ 50%, fGw ∼ 1.0, and H98y2 ∼ 1.5) and pure RF power on EAST (βP ∼ 2.0, βN ∼ 1.6, fBS ∼ 50%, fGw ∼ 0.8, and H98y2 > 1.3). By tailoring the current density profile, a q-profile with local (off-axis) negative shear is achieved, which yields improved confinement and MHD stability. Transport analysis and simulation suggest that the combination of a high density gradient and high Shafranov shift allows turbulence stabilization and higher confinement. Using on-axis Electron Cyclotron Heating injection, tungsten accumulation is avoided on EAST, and this is reproduced in modeling. Reduced heat flux (by > 40%) and maintenance of high core confinement is achieved with active feedback control of the radiated divertor, an important result for long pulse operation in tokamaks. The improved physics understanding and validated modeling tools are used to design a 1 GW steady-state scenario for CFETR.

The confinement of alpha particles in burning plasma is a key issue in fusion reactor design, including particle interaction with instabilities. This paper includes two topics: the effect of neoclassical tearing modes (NTMs) and toroidal field ripple on alpha particle loss, and the assessment of particle redistribution under an NTM with a reduced model. We consider Chinese fusion engineering test reactor parameters, the alpha particle distribution given by TRANSP/NUBEAM and the NTM perturbation function given by the initial value code TM1. We show that the synergistic effect of the NTM and ripple is negligible; the particle loss fraction does not change with increasing NTM amplitude. Only passing particles are affected by the mode particle resonance, producing profile flattening but no increased loss because only trapped particles are influenced by ripple. To study alpha particle profile flattening, the work adopts an innovative method of phase vector rotation to determine regions of good and broken Kolmogorov–Arnold–Moser surfaces and equilibrates the particle density according to local stochasticity.

The pedestal structure of the high-confinement mode (H-mode) operation strongly impacts global confinement and fusion performance in tokamak devices. Studies of the pedestal structure also play an important role in better understanding the characterization of H-mode plasma discharges with type-I edge localized modes on the Experimental Advanced Superconducting Tokamak (EAST). The EPED model has been widely validated to predict the pedestal structure of several tokamak devices. The mean pedestal width Δ ψ correlates with the square root of the poloidal pedestal beta β p , p e d 1 / 2 and is in good agreement with Δ ψ = 0.12 β p , p e d 1 / 2 from experimental observations. It is also found that the scaling coefficients of Δ ψ and β p , p e d 1 / 2 may have no dependence on the heating schemes. The comparison of predictions with measurements indicates that the REPED model could be used to predict the pedestal height for a range of experimental pedestal pressures ( 1.7 < p p e d < 2.6 kPa ) on EAST.

Extensive experiments of advanced scenario development, which contribute to the ITER hybrid operational scenario have been carried out on experimental advanced superconducting tokamak (EAST) tokamak recently with the ITER-like tungsten divertor. The β N in this operational scenario is intermediate up to 2.1 (EAST#78987, β N ∼ 2.1, I p ∼ 0.45 MA, q 95 = 3.7, B T ∼ 1.5 T, 3 MW neutron beam injection and 1 MW 4.6 GHz lower hybrid wave). In these hybrid H-mode plasmas, the internal transport barrier (ITB) has been frequently observed with central flat q profile and it is found that the fishbone mode (m/n = 1/1) can be beneficial to sustain the central flat (q(0) ∼ 1) q profile, thus a stable ITB can be obtained. In this case, better plasma performance is achieved. The formation of the ITB of the electron density is related to the fishbone activities. Energy transport analysis shows that the fishbone instabilities have a suppression on electron turbulent energy transport, while the ITB of ion temperature is due to the suppression of high-k modes (electron temperature gradient). The mechanism of turbulence suppression from fishbone instabilities in the EAST tokamak is not clear and needs more investigation. It is also observed that the power threshold for ITB formation is ≥ 3.5 MW, which is consistent with the scaling law for other tokamaks. The dimensionless parameter G ( = H 89 β N / q 95 2 ) obtained in the EAST reaches 0.3, but is still lower than the ITER hybrid scenario design (G ≥ 0.4) and needs more extension. Further investigation of extending the operational regimes, such as expanding the ITB foot outwards, would be important for the development of the hybrid and steady-state scenarios for next-step fusion devices like ITER and CFETR.

The edge localized mode (ELM) has been mitigated by n=1 resonant magnetic perturbation (RMP) in EAST tokamak. The turbulence characteristics and transport during the ELM mitigation have been measured by a series of diagnostics. The edge coherent mode (ECM) with a frequency about 25 kHz almost disappears when ELM is mitigated. The scrape-off layer (SOL) radial turbulent transport is measured by a four-tip Langmuir probe mounted on the manipulator at the outer midplane, exhibiting a strong enhancement of outward particle during the ELM mitigation in the SOL region (3-25 mm outside the LCFS). This enhanced outward radial transport is mainly driven by the low frequency turbulence (

Recently, the first ever 100 s long, steady-state H-mode discharge with good control of impurities, core and edge MHD stabilities, and heat exhaust was demonstrated in the Experimental Advanced Superconducting Tokamak (EAST) using the ITER-like (International Tokamak Experimental Reactor) tungsten upper divertor. Using both radio frequency (RF) power and neutral beam injection (NBI) heating, EAST has demonstrated fully non-inductive scenarios with an extension of fusion performance at high density and low rotation: β P ∼ 2.5, β N ∼ 2.0, H98,y2 ∼ 1.2, bootstrap current fraction fBS ∼50% at q95 ∼ 6.8. With pure RF power heating, plasmas have been maintained for up to 21 s (over 40 times the current relaxation time) with zero loop voltage and small edge localized modes (ELMs) at high density (ne/nGW ∼ 0.6–0.8), β P ∼ 2.0, β N ∼ 1.6, and ƒBS ∼47%. Experimental investigations show how plasma current profiles, turbulent transport and radiation properties self-consistently evolve toward fusion relevant steady state conditions. Modeling and physics experiments have confirmed the synergistic effects between electron cyclotron heating (ECH) and low hybrid wave (LHW), where ECH enhances the heating and current drive from LHW injection, enabling fully non-inductive operation at higher density. Small/no ELMs facilitate the RF power coupling in the H-mode phase and reduce divertor erosion. A low tungsten concentration was observed at high β P with a hollow profile in the core. Reduction of the peak divertor heat flux with f rad of up to 40% was compatible with the high β P scenario by using active radiation feedback control. With features such as dominant electron heating, zero/low NBI torque and an ITER-like tungsten divertor, fully non-inductive high-performance experiments on EAST offer unique contributions towards the succesful operation of ITER and CFETR (the Chinese Fusion Engineering Testing Reactor).

In the last few years, long-pulse H-mode plasma discharges (with small edge-localized modes and normalized beta, β N ~ 1) have been realized at the Experimental Advanced Superconducting Tokamak (EAST). This paper reports on high-β N (>1.5) discharges in the 2015 EAST campaign. The characteristics of these H-mode plasmas have been presented in a database. Analysis of the experimental limit of β N has revealed several main features of typical discharges. Firstly, efficient, stable high heating power is required. Secondly, control of impurity radiation (partly due to interaction between the plasma and the in-vessel components) is also a critical issue for the maintenance of high-β N discharges. In addition an internal transport barrier (ITB) has recently been observed in EAST, introducing further improvement in confinement surpassing H-mode plasmas. ITB dynamics is another key issue for high-β N plasmas in EAST. Each of these features is discussed in this paper. Study and improvement of these issues could be considered as the key to achieving long-pulse high-β N operation with EAST.

A far-infrared (FIR) polarimeter/interferometer (PI) system is under development for measurements of the current-density and the electron-density profiles in the EAST tokamak. The system will utilize three identical 432-μm CHCOOH lasers pumped by a CO2 laser. Measurements of the laser beam’s waist size and position are basic works. This paper will introduce three methods with a beam profiler and several focusing optical elements. The beam profiler can be used to show the spatial energy distribution of the laser beam. The active area of the profiler is 12.4 × 12.4 mm2. Some focusing optical elements are needed to focus the beam in order for the beam profiler to receive the entire laser beam. Two principles and three methods are used in the measurement. The first and the third methods are based on the same principle, and the second method adopts an other principle. Due to the fast and convenient measurement, although the first method is a special form of the third and it can only give the size of beam waist, it is essential to the development of the experiment and it can provide guidance for the choices of the sizes of the optical elements in the next step. A concave mirror, a high-density polyethylene (HDPE) lens and a polymethylpentene (TPX) lens are each used in the measurement process. The results of these methods are close enough for the design of PI system’s optical path.

The attainment of long-pulse, high-performance, fully non-inductive plasma is one of the major scientific objectives of EAST, using the ITER-like tungsten upper divertor. Understanding and optimizing the fast-ion behaviors is the critical issue to extending the performance of EAST. Recently, using both neutral beam injection (NBI) and radio frequency (RF; low hybrid, electron cyclotron, and ion cyclotron) heating, fully non-inductive high-βP scenarios with extension of fusion performance at high density and low rotation have been achieved, with βP up to 2.5, βN up to 2.0, H98y 2 > 1.1, and bootstrap current fraction (f BS) up to 50%. For previous long-pulse H-mode plasma at medium density, when NBI is added into RF plasma, βP is increased from 1.2 to 2.0 compared with RF-only discharges. In fact, f BS for both discharges is nearly the same, at ~22%. Analysis shows that the increase in βp is mostly due to fast ions which do not contribute significantly to the neoclassical bootstrap current. Thus, to obtain high-performance plasmas with improved bootstrap current fraction, key parameters (e.g. density, beam energy, etc.) must be further optimized. Experimental results show that high density improves bootstrap fraction also by reducing fast-ion slowing-down time and loss. The lower beam energy also mitigates fast-ion loss, which is better for heating and CD performance. The extension of high-performance, fully non-inductive experiments on EAST at high density and zero/low NBI torque can potentially offer unique contributions towards ITER and CFETR.

Recent Experimental Advanced Superconducting Tokamak (EAST) experiments have successfully demonstrated a long-pulse steady-state scenario with improved plasma performance through integrated operation since the last IAEA FEC in 2016. A discharge with a duration over 100 s using pure radio frequency (RF) power heating and current drive has been obtained with the required characteristics for future long-pulse tokamak reactors such as good energy confinement quality (H98y2 ~ 1.1) with electron internal transport barrier inside ρ < 0.4, small ELMs (frequency ~100–200 Hz), and good control of impurity and heat exhaust with the tungsten divertor. The optimization of X-point, plasma shape, the outer gap and local gas puffing near the low hybrid wave (LHW) antenna were integrated with global parameters of B T and line-averaged electron density for higher current drive efficiency of LHW and on-axis deposition of electron cyclotron heating in the long-pulse operation. More recently, a high β P RF-only discharge (β P ~ 1.9 and β N ~ 1.5, /n GW ~ 0.80, f bs ~ 45% at q 95 ~ 6.8) was successfully maintained over 24 s with improved hardware capabilities, demonstrating performance levels needed for the China Fusion Engineering Test Reactor steady-state operation. A higher energy confinement is observed at higher β P and with favorable toroidal field direction. Towards the next goal (≥400 s long-pulse H-mode operations with ~50% bootstrap current fraction) on EAST, an integrated control of the current density profile, pressure profile and radiated divertor will be addressed in the near future.

To observe the clinical characteristics of bone disease in patients with multiple myeloma (MM) and the clinical significance of monitoring bone metabolic markers.The data of 178 MM cases newly diagnosed in Beijing Ji Shui Tan Hospital from January 2009 to June 2014 were reviewed to analysis the types and classification of bone disease and to observe the clinical characteristics of patients with different grades of bone disease. The levels of bone metabolic markers total procollagen type Ⅰ N-terminal peptide (tPINP) and β C-terminal telopeptide of type Ⅰ collagen (β-CTX) were monitored regularly in the two years following treatment in 66 cases.(1) Among the 178 newly diagnosed MM cases, 167 cases complained of pain in bones on first visit, 35 cases combined with hypercalcemia, 83 cases combined with osteoporosis, 154 cases combined with osteolytic bone destruction, and 73 cases combined with pathologic fracture. The most common osteolytic location was the spine. The most common fracture sites was the spine. (2) According to bone disease grading, the 178 cases were divided into group A (bone grade 0-2, n=51) and group B(bone grade 3-4, n=127). There were no significant differences between group A and group B in gender, median age, therapeutic effect/ineffec, median overall survival, median progress-free survival, mean serum lactic dehydrogenase, mean albumin, urine light chains and serum creatinine(all P0.05). Compared with group A, group B had lower hemoglobin level[(99.78±29.93)vs (108.84±29.30) g/L], and higher blood calcium level[(2.47±0.40)vs (2.30±0.29) mmol/L], serum β2-microglobuin level[(6.04±4.84)vs (4.12±3.97)mg/L], and bone marrow plasma cells percentage(33.30%±24.87% vs 23.51%±22.67%)(all P0.05). (3) Before treatment, the levels of β-CTX and tPINP in patients of group B(n=47) were higher than those in group A(n=19)(median 0.78 vs 0.42 μg/L, 60.95 vs 43.47 μg/L, both P0.05). The ratio of β-CTX /tPINP in group B was higher than that in group A (median 0.017 vs 0.012, P0.05). After chemotherapy for 3 months, there were no differences in the level of tPINP compared with that before treatment in both group A and group B (both P0.05), the level of β-CTX decreased significantly compared with that before treatment in both groups(median 0.16 vs 0.42 μg/L, 0.26 vs 0.78 μg/L, both P0.05); the ratio of β-CTX /tPINP decreased significantly compared with that before treatment in both group A and in group B(median 0.008 vs 0.012, 0.011 vs 0.017, both P0.05). There were no differences in the level of β-CTX, tPINP and β-CTX/tPINP ratio after treatment for 6 months, 1 year and 2 years compared with that after 3 months in both group A and group B (all P0.05). (4)All patients were divided into two groups according to the therapeutic effect: effective group included patients who reach the effect of partial remission or better remission(n=48), while ineffective group included patients who did not reach the effect of partial remission(n=18). Before treatment there were no differences in the level of β-CTX, tPINP and β-CTX/tPINP ratio between the effective groupand the ineffective group (all P0.05). After chemotherapy for 3 months, there were no differences in the level of tPINP compared with that before treatment in both effective group and ineffective group (all P0.05), but the level of β-CTX decreased significantly compared with that before treatment both in effective group and ineffective group (median 0.24 vs 0.60 μg/L, 0.44 vs 0.95 μg/L, both P0.05). The ratio of β-CTX /tPINP decreased significantly compared with that before treatment both in effective group and ineffective group (median 0.005 vs 0.012, 0.005 vs 0.011, both P0.05). There were no differences in the level of β-CTX, tPINP and β-CTX/tPINP ratio after treatment for 6 months, 1 year and 2 years compared with that for 3 months both in effective group and ineffective group (all P0.05).Pain in bones, osteolysis and pathological fracture are the most common clinical manifestations in myeloma-related bone disease. The severity of bone disease can reflect the tumor load, but may not affect the therapeutic effect and the overall survival. The bone metabolic markers tPINP and β-CTX can be used to evaluate the severity of myeloma-related bone disease at diagnosis and to monitor the effect of treatment for bone disease.

Time-dependent integrated modeling of DIII-D ITER-like and high bootstrap current plasma ramp-up discharges has been performed with the equilibrium code EFIT, and the transport codes TGYRO and ONETWO. Electron and ion temperature profiles are simulated by TGYRO with the TGLF (SAT0 or VX model) turbulent and NEO neoclassical transport models. The VX model is a new empirical extension of the TGLF turbulent model [Jian et al., Nucl. Fusion 58, 016011 (2018)], which captures the physics of multi-scale interaction between low-k and high-k turbulence from nonlinear gyro-kinetic simulation. This model is demonstrated to accurately model low Ip discharges from the EAST tokamak. Time evolution of the plasma current density profile is simulated by ONETWO with the experimental current ramp-up rate. The general trend of the predicted evolution of the current density profile is consistent with that obtained from the equilibrium reconstruction with Motional Stark effect constraints. The predicted evolution of β N , l i , and β P also agrees well with the experiments. For the ITER-like cases, the predicted electron and ion temperature profiles using TGLF_Sat0 agree closely with the experimental measured profiles, and are demonstrably better than other proposed transport models. For the high bootstrap current case, the predicted electron and ion temperature profiles perform better in the VX model. It is found that the SAT0 model works well at high I P (>0.76 MA) while the VX model covers a wider range of plasma current ( I P > 0.6 MA). The results reported in this paper suggest that the developed integrated modeling could be a candidate for ITER and CFETR ramp-up engineering design modeling.Time-dependent integrated modeling of DIII-D ITER-like and high bootstrap current plasma ramp-up discharges has been performed with the equilibrium code EFIT, and the transport codes TGYRO and ONETWO. Electron and ion temperature profiles are simulated by TGYRO with the TGLF (SAT0 or VX model) turbulent and NEO neoclassical transport models. The VX model is a new empirical extension of the TGLF turbulent model [Jian et al., Nucl. Fusion 58, 016011 (2018)], which captures the physics of multi-scale interaction between low-k and high-k turbulence from nonlinear gyro-kinetic simulation. This model is demonstrated to accurately model low Ip discharges from the EAST tokamak. Time evolution of the plasma current density profile is simulated by ONETWO with the experimental current ramp-up rate. The general trend of the predicted evolution of the current density profile is consistent with that obtained from the e...

In the 2017 EAST experimental campaign, a steady-state long-pulse H-mode discharge lasting longer than 100 s has been obtained using only radio frequency heating and current drive, and the confinement quality is slightly better than standard H-mode, H98y2 ~ 1.1, with stationary peaked electron temperature profiles. Integrated modeling of one long-pulse H-mode discharge in the 2016 EAST experimental campaign has been performed with equilibrium code EFIT, and transport codes TGYRO and ONETWO under integrated modeling framework OMFIT. The plasma current is fully-noninductively driven with a combination of ~2.2 MW LHW, ~0.3 MW ECH and ~1.1 MW ICRF. Time evolution of the predicted electron and ion temperature profiles through integrated modeling agree closely with that from measurements. The plasma current (I p ~ 0.45 MA) and electron density are kept constantly. A steady-state is achieved using integrated modeling, and the bootstrap current fraction is ~28%, the RF drive current fraction is ~72%. The predicted current density profile matches the experimental one well. Analysis shows that electron cyclotron heating (ECH) makes large contribution to the plasma confinement when heating in the core region while heating in large radius does smaller improvement, also a more peaked LHW driven current profile is got when heating in the core. Linear analysis shows that the high-k modes instability (electron temperature gradient driven modes) is suppressed in the core region where exists weak electron internal transport barriers. The trapped electron modes dominates in the low-k region, which is mainly responsible for driving the electron energy flux. It is found that the ECH heating effect is very local and not the main cause to sustained the good confinement, the peaked current density profile has the most important effect on plasma confinement improvement. Transport analysis of the long-pulse H-mode experiments on EAST will be helpful to build future experiments.

This study compared bone status between Chinese and Caucasian infants at birth, showing that Chinese neonates have lower tibial speed of sound, which is influenced by gender, gestational age, season of birth, and maternal vitamin D status. The effects of these factors on fetal bone development were discussed. We compared the differences of speed of sound (SOS) accessed by quantitative ultrasound between Chinese and Caucasian infants at birth and explored the relationship between the concentrations of serum 25-hydroxyvitamin D [25(OH)D] and bone SOS in maternal–infant pairs. SOS for the tibial bone was measured at birth in 267 Chinese infants. We used the Z-scores for the direct comparisons which were available from the instrument based data of gender and age-matched Caucasian peers. The concentrations of serum 25(OH)D and bone SOS in 32 maternal–infant pairs were measured at birth in winters. The Chinese infants had lower SOS demonstrated by the Z-scores. Significant differences of SOS and Z-scores were found between genders, gestational ages, birth weight, and seasons of birth. The differences of Z-scores negatively decreased with gestational age, suggesting that the bone status of Chinese infants lags behind that of the Caucasian infants during the last trimester of pregnancy in utero. The tibial SOS of infants born in winters was 2.0% higher than those born in summers after adjustment. The infant SOS correlated with maternal serum 25(OH)D (r = 0.399, P = 0.024) and infant serum 25(OH)D (r = 0.394, P = 0.026). Chinese neonates have lower SOS which is influenced by gender, gestational age, season of birth, and maternal vitamin D status. It is inferred that, in pace with gestational age, race and gender effects on fetal bone development are modified by materno-fetal vitamin D status.

Plasma equilibrium reconstruction plays an important role in the tokamak plasma research. With a high temporal and spatial resolution, the POlarimeter-INTerferometer (POINT) system on EAST has provided effective measurements for 102s H-mode operation. Based on internal Faraday rotation measurements provided by the POINT system, the equilibrium reconstruction with a more accurate core current profile constraint has been demonstrated successfully on EAST. Combining other experimental diagnostics and external magnetic fields measurement, the kinetic equilibrium has also been reconstructed on EAST. Take the pressure and edge current information from kinetic EFIT into the equilibrium reconstruction with Faraday rotation constraint, the new equilibrium reconstruction not only provides a more accurate internal current profile but also contains edge current and pressure information. One time slice result using new kinetic equilibrium reconstruction with POINT data constraints is demonstrated in this paper and the result shows there is a reversed shear of q profile and the pressure profile is also contained. The new improved equilibrium reconstruction is greatly helpful to the future theoretical analysis.

The distinctions of edge localized mode (ELM) frequency distributions between moderate and high edge current density cases were observed on the experiment advanced superconducting tokamak. In this paper, a current relaxation model is applied to explain this new observation. It has been demonstrated that the ELM frequency is very sensitive to the edge current density and the edge safety factor by the model predictions. The results also show that, in the large edge current density case, the ELM frequency is subject to a single-peak distribution; while in the moderate edge current density case, the ELM frequency is subject to a roughly multi-peak distribution.

The internal transport barrier (ITB) has been obtained in ELMy H-mode plasmas by neutron beam injection and lower hybrid wave heating on the Experimental Advanced Superconducting Tokamak (EAST). The ITB structure has been observed in profiles of ion temperature, electron temperature, and electron density within ρ < 0.5. It was also observed that the ITB formation is stepwise. Due to the ITB formation, the confinement quality H 98y2 increases from 1 to 1.1 and the normalized beta, β N, increases from 1.5 to near 2. The fishbone activity observed during the ITB phase suggests the central safety factor q(0) ~ 1. Transport coefficients are calculated by particle balance and power balance analysis, showing an obvious reduction after the ITB formation.

Implementing the “practice teaching oriented” concept of vocational education, in order to develop training as the main theoretical courses dependent on practical courses of professional training programs. Curriculum integration with the professional standards, teaching content should be covered by national vocational qualification standards, teaching students skills identification and evaluation combine to make teaching assessment can remain occupational direction, but also to avoid duplication of assessment.

The detection of impact damage in fibre reinforced composites is of significant concern because such damage can reduce the load-bearing ability of the composite. A number of factors can influence the nature and extent of impact damage development in composites including: (a) the type of reinforcing fibre and resin system; (b) the magnitude of the residual (fabrication) stresses; (c) the lay-up sequence; and (d) other factors such as the nature of the impactor, impact velocity, impact energy, temperature, moisture content in the composites, etc. From a structural health monitoring point of view, it is necessary to investigate the distribution of damage through the thickness of the composite. This paper reports on a simple, partially multiplexed optical fibre strain sensor system for in-situ strain and residual strain measurements in a carbon fibre reinforced epoxy composite. An extrinsic Fabry-Perot interferometric (EFPI) sensor design was used along with single-mode fibres. The multiplexing scheme was based on wavelength division via the use of two super luminescent diodes (SLDs) at different wavelengths. A low-cost fibre optic CCD spectrometer was used as the detector. The multiplexing scheme was demonstrated using two EFPI sensors. In principle, a number of EFPI sensors can be multiplexed using the proposed scheme provided that each sensor is illuminated at a specified and different wavelength. The feasibility of detecting the residual strain in the composite was demonstrated successfully at two specified positions within a 16-ply carbon fibre reinforced composite panel. Preliminary results indicated that the sensor system was also capable of detecting the effects of a 3.2 J impact. Excellent correlation was obtained between the EFPI sensor output and that obtained using surface mounted strain gauges.

This paper presents a general overview of a number of optical fibre sensor systems which have been developed and used in advanced fibre-reinforced composites for in-situ process and condition monitoring. The in-situ process monitoring techniques were optical-fibre-based evanescent wave spectroscopy, transmission near-infrared spectroscopy and refractive index monitoring. The optical fibre sensors were successful in tracking the cure reaction. The condition monitoring of advanced fibre-reinforced composites was carried out using two intensity-based optical fibre sensor systems: an extrinsic multi-mode Fabry-Perot sensor and Bragg gratings. In addition to this, the feasibility of using the reinforcing fibre as a light guide was demonstrated. These sensor systems were evaluated under quasi-static, impact and fatigue loading. The test specimens consisted of prepreg-based carbon-fibre-reinforced epoxy and glass-fibre-reinforced epoxy filament-wound tubes. Excellent correlation was obtained between surface-mounted strain gauges and the embedded optical fibre sensors. The feasibility of using these sensor systems for the detection of impact damage and stiffness reduction in the composite due to fatigue damage was successfully demonstrated.

We report an experimental and theoretical study of very low-energy photoelectrons in tunneling ionization process from noble gas atoms interacting with ultrashort intense infrared laser pulses. A universal peak structure with electron energy well below 1 eV in the photoelectron spectrum, corresponding to the double-hump structure in the longitudinal momentum distribution, is identified experimentally for all atomic species. Our quantum and semiclassical analysis reveal the role of long-range Coulomb potential in the production of this very low-energy peak structure.

The application of Genetic Algorithms (GAs) to the optimization design method, such as Simplex method and Powell method etc, can determine the final optimum structure and electric parameters of an electron optical system from given electron optical properties, but it may be landed in the localization of optimum search process. The GAs is a novel direct search optimization method based on principles of natural selection and survival of the fittest from natural evolution. Through the reproduction, crossover, and mutation iterative process, GAs can search the global optimum result. We applied the GAs to optimize an electron emission system and an extended field lens (EFL) respectively. The optimal structure and corresponding electrical parameters with a criterion of minimum objective function value, crossover radius for electron emission system and spherical aberration coefficient for EFL, have been searched and presented in this paper. The GAs, as a direct search method and an adaptive search technique, has significant advantage in the optimization design of electron optical systems.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.