Studying the behavior of effective ion charge Zeff, which indicates the degree of pollution of plasma and can provide valuable information about many processes taking place in plasma, mechanisms of the releasing impur...Studying the behavior of effective ion charge Zeff, which indicates the degree of pollution of plasma and can provide valuable information about many processes taking place in plasma, mechanisms of the releasing impurities, transport, etc is of great interest. This paper describes the development of the Zeff diagnostic system for the Globus-M2 tokamak. The effective ion charge is determined on the basis of measurements of the bremsstrahlung intensity and Thomson scattering data-Te and ne profiles. The results of the first Zeff measurements obtained for several discharges on the Globus-M tokamak are presented in this paper. The results have been validated by simulation using the ASTRA transport code for the same discharges, and it has demonstrated a good agreement with the experimental results.展开更多
The advanced tokamak scenario is a promising operation scenario for ITER and fusion neutron sources.In this scenario the minimum value of the safety factor in the center of the plasma exceeds unity.In the compact sphe...The advanced tokamak scenario is a promising operation scenario for ITER and fusion neutron sources.In this scenario the minimum value of the safety factor in the center of the plasma exceeds unity.In the compact spherical tokamak Globus-M,the formation of such conditions is possible with neutral beam injection at the current ramp-up phase.Due to the slower diffusion of current inside the plasma,a zone is formed with reduced heat and particle transport across the magnetic field,which affects the temperature and density profiles of the plasma.This leads to the peaked density profile formation and improvement of the energy confinement time.To achieve a high fraction of the bootstrap current,it is necessary to increase the plasma pressure.At the same time,the maximum allowable pressure is limited to the normalized beta limit.展开更多
基金funded by RSF according to the research project(No.17-72-20076).The experimental investigations were performed on the Unique Scientific Facility ‘Spherical tokamak Globus-M’,which is incorporated in the Federal Joint Research Center ‘Material science and characterization in advanced technology’.The maintenance of routine diagnostics was supported by the Ioffe Institute
文摘Studying the behavior of effective ion charge Zeff, which indicates the degree of pollution of plasma and can provide valuable information about many processes taking place in plasma, mechanisms of the releasing impurities, transport, etc is of great interest. This paper describes the development of the Zeff diagnostic system for the Globus-M2 tokamak. The effective ion charge is determined on the basis of measurements of the bremsstrahlung intensity and Thomson scattering data-Te and ne profiles. The results of the first Zeff measurements obtained for several discharges on the Globus-M tokamak are presented in this paper. The results have been validated by simulation using the ASTRA transport code for the same discharges, and it has demonstrated a good agreement with the experimental results.
基金financially supported by an RSF research project (no. 17-7220076)
文摘The advanced tokamak scenario is a promising operation scenario for ITER and fusion neutron sources.In this scenario the minimum value of the safety factor in the center of the plasma exceeds unity.In the compact spherical tokamak Globus-M,the formation of such conditions is possible with neutral beam injection at the current ramp-up phase.Due to the slower diffusion of current inside the plasma,a zone is formed with reduced heat and particle transport across the magnetic field,which affects the temperature and density profiles of the plasma.This leads to the peaked density profile formation and improvement of the energy confinement time.To achieve a high fraction of the bootstrap current,it is necessary to increase the plasma pressure.At the same time,the maximum allowable pressure is limited to the normalized beta limit.
