Charged Field

A 10-foot-radius sphere of Electrically charged air springs into existence centered on a point you choose within range. The sphere remains for the spell’s duration. Each creature in the sphere when it appears, enters the area, or ends its turn there must succeed on a Constitution saving throw or take 1d8 lightning damage. 

At Higher Levels.  The spell’s damage increases by 1d8 when you reach 5th level (2d8), 10th level (3d8), and 15th level (4d8).