Plasma start-up design for initial discharges in HL-2M

Li, J.X.; Song, Xiao; Zhang, J.H.; Zheng, Guoyao; Wei, Pan; Xue, Lei; Wang, S.; Li, B.; Mao, Rui; Pan, Yuwei

doi:10.1016/j.fusengdes.2019.111366

Cited by 5 publications

(2 citation statements)

References 9 publications

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“…state can contribute about 714 (701) fb which is nearly 96.3% (96.2%)of the corresponding total cross section. The summation of cross section for the processes pp → t tχ cJ with J = 0, 1, 2, can reach 1350 fb, which will provide abundant and fascinating studies of phenomenology at the LHC [46].…”

Section: The Results At the The Production Levelmentioning

confidence: 99%

Prompt J/ψ production in association with a top quark pair at the LHC

Pan

Song

et al. 2019

Phys. Rev. D

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In this work, we investigate the prompt J/ψ production in associated with top quark pair to leading order in the nonrelativistic QCD factorization formalism at the LHC with √ s = 13 TeV. In addition to the contribution from direct J/ψ production, we also include the indirect contribution from the directly produced heavier charmmonia χcJ and ψ . We present the numerical results for the total and differential cross sections and find that the 3 S (8) 1 states give the dominant contributions. The prompt ttJ/ψ signatures at the LHC are analyzed in the tetralepton channel pp →, with the J/ψ mesons decaying into muon pair, and the top quarks decaying leptonically or hadronically. We find that ttJ/ψ proudction can be potentially detected at the LHC, whose measurement is useful to test the heavy quarkonium production mechanism.

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Section: The Results At the The Production Levelmentioning

confidence: 99%

Prompt J/ψ production in association with a top quark pair at the LHC

Pan

Song

et al. 2019

Phys. Rev. D

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“…In order to fulfill the above-mentioned requirements for plasma initiation, the pressure of neutral gas has been scanned based on the HL-2A (the predecessor of HL-2M) data [6], and an optimal value ∼ 10 −2 Pa at ∼ 450 ms before application of the loop voltage has been found. Although the poloidal magnetic field null condition is not straightforward to form due to ∼ 100 kA eddy current induced in the vacuum vessel under a 10 V loop voltage (E tor ∼ 1 V • m −1 ), the work presented in [7] has shown that the dominant stray field produced by this eddy current is vertical and quite homogeneous, implying that it can be almost perfectly offset by a moderate current in dedicated coils. Wall conditioning on HL-2M consists of baking and glow discharge cleaning, and it is observed that impurities (H 2 O, N 2 , CO 2 , etc) absorbed in the first wall can be effectively removed.…”

Section: Introductionmentioning

confidence: 99%

Plasma initiation and preliminary magnetic control in the HL-2M tokamak

Song

Zhou

et al. 2021

Nucl. Fusion

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The first plasmas have been achieved in the HL-2M tokamak by fulfilling the usual criteria for plasma breakdown, i.e. optimal working gas pressure, field null configuration of poloidal magnetic field, reasonable toroidal electrical field and clean wall conditions. The characterization of plasma initiation, such as identification of initiation time and position, is performed by diagnostic data analysis and numerical simulation. A model-based method, which enables dedicated pick-up sensors to estimate plasma radial position in real time, is applied for the limiter plasma shape in the first plasma commissioning phase. For a circular cross-section plasma, feedback control on plasma current and radial position allowed us to extend discharge durations to ∼250 ms associated with a 120 kA plasma current in flat-top. Preliminary plasma equilibrium reconstruction by the NICE code from pick-up sensors and flux loops, as well as interferometry measurements, gives plasma boundaries, plasma profiles of toroidal current density and safety factor, as well as electron density, in an offline way.

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