Had to scale it down a bit, but still plenty of space for LEDs
I used these to get a pulsing effect for the LEDs https://www.amazon.com/gp/product/B07CVDRV79/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1
3 question around the LEDs:
1) How/where did you place them to make the plasma 'core' light up?
2) Did you use transparent printing material for the core, and put the LEDs inside somehow?
3) Where did you house the power supply for the LEDs and the on/off switch?