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The BOUT++ transport code is run to study the effects of plasma drifts on the divertor out-in asymmetries (DOIAs) of particle and heat fluxes and their decay widths for EAST lower single null H-mode discharges. The diamagnetic drift seems to have no effects on the DOIAs of total particle and heat fluxes due to its divergence-free nature. However, it could significantly increase the DOIAs of peak particle and heat fluxes and the flux decay widths. The E × B drift is found to induce a large plasma flow to the divertor region, enhancing the DOIAs of both total and peak particle and heat fluxes and the flux decay widths. Both the radial and poloidal components of the E × B drift are necessary in increasing the DOIAs, however, the radial E × B drift seems to play a more important role. The effects on the DOIAs caused by both diamagnetic and E × B drifts are reversed with the reverse of toroidal magnetic field. The heat flux decay width λ q and spreading width S q are important physical and engineering parameters for the divertors and could be obtained by fitting the heat flux profiles at divertor targets. The λ q at the outer target from the simulation case with all drifts could well match with the multi-machine scaling proposed by Eich and the DOIA of λ q is in reasonable agreement with the scaling proposed by Goldston.

The environment of Mt. Qomolangma (Everest) area is of great significance to the global environmental background and environmental change research. However, there are few studies on the content and distribution of soil trace elements in the area. About 130 soil samples were collected nearby the Rongbuk valley at the northern slope of the Qomolangma from 4,400 to 6,600 m elevations. Nine soil trace elements, Cr, Zn, Sr, Pb, Ni, Co, Cd, Mn, Cu, were analyzed with ICP-AES (inductively coupled plasma atom emission spectrometry). The results showed that soil trace elements content increased with altitude; the content of the Cd in this area was very high, which was 5.8 times of the average content of Chinese soil. There was a noticeable change point for soil trace elements content at the altitude of 5,800 m, and the content of Cd increased abruptly above 5,800 m. This point was just located at the boundary of two types of rocks. The Late Precambrian-Neoproterozoic granite-gneiss and metacryst migmatized interbedded with marble located below 5,800 m; black-dark slate and marl of Cambrian located above 5,800 m (including 5,800 m), the geochemical characteristic of different rocks was the main factors controlling the soil trace elements content in the northern slope of Qomolangma Mountain.[PUBLICATION ABSTRACT]

I-mode is a promising regime for future fusion reactors due to the high energy confinement and the moderate particle confinement. However, the effect of lithium, which has been widely applied for particle recycling and impurity control, on I-mode plasma is still unclear. Recently, experiments of real-time lithium powder injection on I-mode plasma have been carried out in EAST Tokamak. It was found that the confinement performance of the I-mode can be improved by the lithium powder injection, which can strongly reduce electron turbulence (ET) and then trigger ion turbulence (IT). And it was observed that the ET intensity is inversely proportional to the velocity shear, which suggests that the injection of lithium powder leads to a gradual enhancement of the shear flow, whereby the turbulence is reduced and consequently the confinement is improved. Four different regimes of I-mode have been identified in EAST. The Type I I-mode plasma is characterized by the weakly coherent mode (WCM) and the geodesic-acoustic mode (GAM). The Type II I-mode is featured as the WCM and the edge temperature ring oscillation (ETRO). The Type III I-mode corresponds to the plasma with the co-existence of ETRO, GAM, and WCM. The Type IV I-mode denotes the plasma with only WCM but without ETRO and GAM. It was observed that the WCM intensity is increased with lithium powder injection by the confinement improvement/pedestal temperature increase. EAST experiments demonstrate that lithium powder injection is an effective tool for real-time control and confinement improvement of I-mode plasma.

During the island divertor operation of W7-X, especially in standard magnetic configuration (with 5/5 island chain in the scrape-off-layer (SOL)), quasi-periodic electromagnetic oscillation is observed. It appears in the frequency range of 1 kHz–2 kHz, therefore it is called the low frequency mode (LFM) within this paper. It is observed by multiple diagnostics, amongst them, a poloidal correlation reflectometer allowing radial localization of the LFM. The LFM is localized in the SOL and shows an obvious modulation effect on the plasma perpendicular velocity ( V ⊥ ). Furthermore, broadband turbulence is observed in the fluctuation spectra of the electron density and the magnetic field and the perpendicular correlation length of turbulence eddies are modulated. The calculation of the poloidal flow velocity and its oscillation allows us to study the effect of the LFM on the flow. Cross correlation analysis shows that the perpendicular flow oscillation and the turbulence modulation are closely correlated. The application of external control coils to adjust the island size and position result in a strong modification of the magnetic topology at the plasma edge which affects the appearance, amplitude and frequency of the LFM. Bi-coherence analysis indicates that nonlinear interactions among turbulence components is a possible mechanism for the generation of the LFM.

A bstract Using 24.1 fb − 1 of e + e − collision data collected with the BESIII detector at the BEPCII collider, the Born cross sections and effective form factors of the e + e − → Σ + Σ ¯ − reaction are measured. The measurements are performed at center-of-mass energies ranging from 3.510 to 4.951 GeV. No significant evidence for the decay of the charmonium(-like) states, ψ (3770), ψ (4040), ψ (4160), Y (4230), Y (4360), ψ (4415), and Y (4660), into a Σ + Σ ¯ − final state is observed. Consequently, upper limits for the products of the branching fractions and the electronic partial widths at the 90% confidence level are reported for these decays.

A bstract The Born cross sections of the e + e − → D *+ D * − and e + e − → D *+ D − processes are measured using e + e − collision data collected with the BESIII experiment at center-of-mass energies from 4.085 to 4.600 GeV, corresponding to an integrated luminosity of 15 . 7 fb − 1 . The results are consistent with and more precise than the previous measurements by the Belle, Babar and CLEO collaborations. The measurements are essential for understanding the nature of vector charmonium and charmonium-like states.

A bstract Using (2712 ± 14) × 10 6 ψ (3686) events collected with the BESIII detector, we perform the first amplitude analysis of the radiative decay ψ 3686 → γ K S 0 K S 0 within the mass region M K S 0 K S 0 < 2.8 GeV/ c 2 . Employing a one-channel K-matrix approach for the description of the dynamics of the K S 0 K S 0 system, the data sample is well described with four poles for the f 0 -wave and three poles for the f 2 -wave. The determined pole positions are consistent with those of well-established resonance states. The observed f 0 and f 2 states are found to be in agreement with those produced in radiative J/ψ decays. The production behaviors of f 0 and f 2 poles in ψ 3686 → γ K S 0 K S 0 are qualified with their residues and the converted branching fractions. By comparing with J / ψ → γ K S 0 K S 0 decay, the ratios B ψ 3686 → γ f 0 , 2 B J / ψ → γ f 0 , 2 are determined, which provides crucial experimental inputs on the internal structure of the f 0 , 2 states, especially their potential mixing with glueball components.

A bstract Using e + e − collision data collected with the BESIII detector at the BEPCII collider at center-of-mass energies between 3.510 and 4.914 GeV, corresponding to an integrated luminosity of 25 fb − 1 , we measure the Born cross sections for the process e + e − → K − Ξ ¯ + Λ / Σ 0 at thirty-five energy points with a partial-reconstruction strategy. By fitting the dressed cross sections of e + e − → K − Ξ ¯ + Λ / Σ 0 , evidence for ψ 4160 → K − Ξ ¯ + Λ is found for the first time with a significance of 4.4 σ , including systematic uncertainties. No evidence for other possible resonances is found. In addition, the products of electronic partial width and branching fraction for all assumed resonances decaying into K − Ξ ¯ + Λ / Σ 0 are determined.

A bstract Using 15 . 6 fb − 1 of e + e − collision data collected at twenty-four center-of-mass energies from 4 . 0 to 4 . 6 GeV with the BESIII detector, the helicity amplitudes of the process e + e − → π + π − ω are analyzed for the first time. Born cross section measurements of two-body intermediate resonance states with statistical significance greater than 5 σ are presented, such as f 0 (500), f 0 (980), f 2 (1270), f 0 (1370), b 1 (1235) ± , and ρ (1450) ± . In addition, evidence of a resonance state in e + e − → π + π − ω production is found. The mass of this state obtained by line shape fitting is about 4 . 2 GeV/ c 2 , which is consistent with the production of ψ (4160) or Y (4220).

A bstract Using (447.9 ± 2.3) million ψ (3686) events collected with the BESIII detector, the decays of χ cJ → ϕϕ ( J = 0 , 1 , 2) have been studied via the decay ψ (3686) → γχ cJ . The branching fractions of the decays χ cJ → ϕϕ ( J = 0 , 1 , 2) are determined to be (8 . 59 ± 0 . 27 ± 0 . 20) × 10 − 4 , (4 . 26 ± 0 . 13 ± 0 . 15) × 10 − 4 , and (12 . 67 ± 0 . 28 ± 0 . 33) × 10 − 4 , respectively, which are the most precise measurements to date. From a helicity amplitude analysis of the process ψ (3686) → γχ cJ , χ cJ → ϕϕ, ϕ → K + K − , the polarization parameters of the χ cJ → ϕϕ decays are determined for the first time.