Can global simulations of magnetically confined plasmas be done with the implicit particle in cell method ECSim?

Implicit PIC is an alternative to other reduced models that step over smaller scales. While reduced models rely on analytical derivations to eliminate the scales deemed not of interest, the implicit method uses numerical techniques that automatically step over and damp the unresolved scales. The approach has had significant success in space applications [1]. But can the method also be used for magnetically confined plasmas? A new recent development is the ECsim method that conserves energy exactly and allows more flexibility on the choice of resolved scales [2-4]. To apply the new code to fusion devices we will address a number of questions arising. For example the presence of boundary layers, typically non present in space, but source of many important processes directly affecting confinement [5]. We will present our recent results on the application of the method to several alternative fusion concepts such as field reversed configurations, poly well, spherical torus etc. In particular, we will consider the opportunities for ECsim in spherical tokamaks.