For the Alpha check the Invert, Soft and image Alpha boxes and use Positerizer as the texture

Click on Poziterizer and add Fresnel as a texture

Here is the gradient

Set glow up as in the image shown

OK now for the fun, lets do some TP... Create a Null Object, this is the basis of most particle emitters in TP as the null will not render but can be used to manipulate the emitters rotation and position

Now right click on the null in the object manager and choose new expression, xpresso expression

Here is the xpresso tag, now double click this to get to the xpresso window

And drag the null from the object manager into xpresso

Now as I said we will use the null object to control our emitter so right click on the red output box and choose Global position

For rotation etc we add a Global matrix port

Right click in an empty area of the xpresso window and add a PStorm particle emitter

Click on the emitters blue input node and add an emitter alignment port

We connect the Global position port of the mull to the emitter position port on the PStorm and do the same for the Global matrix