Happy 500!

An electron in $B$ orbit around the positive nucleus experiences a repulsive force given by,

$\cfrac{qq}{4\pi\varepsilon_or^2_e}\rightarrow\pi \cfrac{qq}{4\pi\varepsilon_or^2_e}=\cfrac{qq}{4\varepsilon_or^2_e}$

Two positive charges in parallel $B$ orbit experience an attractive force given by,

$F_a=-\cfrac{qq}{4\varepsilon_or^2_p}$

Similarly, two negative charges in parallel $B$ orbit experience an attractive force given by,

$F_a=-\cfrac{qq}{4\varepsilon_or^2_e}$

The charges are in orbit because of the initial speed it acquired due to electrostatic attraction between opposite charge.  They are held in orbit and kept from collapsing by a magnetic repulsive force.

What happen to two like charges then?  Do they coalesce?  When they are stopped in their $B$ orbits, they will immediately repel apart. An instant disintegration!

This might be the rationale behind a particle collider.