ITER早先的无核运行期间(Pre-Fusion Power Operation, PFPO)，获得高约束氦（或氢）等离子体对其科学目标的实现具有重要意义。高约束氦等离子体L-H转换物理机制的实验研究是全面理解离子质量数与电荷数影响台基约束和输运的关键问题。本项目立足于EAST装置，通过实验结合数值模拟，在电子加热主导、低动量注入和钨偏滤器等类似ITER运行条件下，研究氦等离子体L-H转换功率阈值与氦浓度、电子密度、等离子体电流和环向磁场等关键物理参数的定量依赖关系，完善氦等离子体H-mode功率阈值定标律，阐明相关物理参数影响L-H转换过程中台基特性的物理机理，这不仅可以为L-H转换机制的物理模型提供更全面的信息，也将为ITER装置早期无核运行期间H-mode运行参数优化提供借鉴和参考。

Realization of high confinement helium (or hydrogen) plasmas is of important significance to achieve the scientific goals in ITER Pre-Fusion Power Operation (PFPO) phase. Experimental study on L-H mode transition mechanism in high confinement helium (He) plasmas is the key issue for fully understanding both the ion mass number and charge number impact on pedestal confinement and transport. Bases on the EAST device, this project, by combining modeling and experiment, aims to study the quantitative dependences of L-H transition power threshold in He plasmas on key physics parameters including He concentration, electron density, plasma current and toroidal field, to complete the H-mode power threshold scaling law for He plasmas, and to unravel the physics mechanism of the relevant physics parameters influence on pedestal characteristics during L-H transition, under the ITER-like operation conditions of electron heating dominant, low input torque and tungsten divertor, which not only provide more comprehensive information for buliding physics model on L-H transition mechanism, but will also provide reference for optimizing the H-mode operation parameters in ITER PFPO phase.