Hair particles clumping in Cycles render First time posting :)

I'm relatively new to Blender, and I'm having trouble with hair particles rendering correctly.

This is my viewport render preview, which is the appearance I'm looking for:


And this is my render, where the hair clumps unexpectedly:


Can anyone suggest how I might fix this?

Here are my settings:


Thanks in advance.
This is caused by the particle children.
for every 10 hairs displayed in the preview you render 2000 hairs with the same propertys in the final render. Thats why it looks smooth and lumpy.