Building a Homemade Linear Accelerator (On the Cheap!)

A couple years ago, I built a small linear accelerator loosely based on old plans from the Amateur Scientist section in Scientific American. It was a functional device, but nothing too exciting. My goal now is to build a new acceleration, versatile and useful for some basic experimentation.

The original accelerator was built on a budget of 100 $. For this one, the max budget is 350 $.

These are mains components to a linear accelerator :

-Vacuum System
-High Voltage Power Supply
-Ion gun or Ion Source

I will start building soon. All feedback, ideas and suggestions of all sorts are very welcome.