Production of low electron temperature ECR plasma

The experiments and simulations on the control of the plasma parameters are performed using large diameter electron cyclotron resonance (ECR) plasmas. It is found that the plasma parameters are controlled by diluting with N2 gas in the mirror magnetic field. The electron temperature (Te) decreases down to 40% and the electron density (ne) increases up to 80%, respectively, that is, a low Te ECR plasma with high ne is realized. Furthermore, the Te control is attempted by changing the spatial profile of the microwave power absorption. It is observed that Te decreases with changing the power absorption profile that is achieved by changing the external conditions such as incident microwave power, magnetic field configuration, and incident microwave frequency. The production mechanism of an ECR plasma with plasma parameter variable is also discussed.