Only electron, no ion in Species block

[SillyTom]

For many example laser wake code files, like 'tst3d_v_o2_laser_wake_yee_boris,py', only electron is defined in the 'Species' block, why is there no ion in plasma?

[mccoys]

@SillyTom Please do not use issues for questions. Use the chatroom or these discussions.

[Z10Frank]

@SillyTom You can find the answer in the section A subtlety: why ions are not present in this tutorial: https://smileipic.github.io/tutorials/advanced_wakefield_AMcylindrical.html#a-subtlety-why-ions-are-not-present