Hello, I'm 15 and very interested in physics. I'm building a safe nuclear fusion reactor as a science project. (I know how to safely handle high voltage and radiation) I have a question about the power supply. First off, I know that fusion takes around 40 Kilo-volts and it needs to have a negative polarity. I'm on a budget and cant spend hundreds of dollars on a high voltage negative polarity power supply. The only cheap power supplies I found find had no specification on polarity. So, I decided that if I could not find one, I might as well solder a circuit together to make my own, and I would like to know how or where a source is that could instruct me. I may use a battery or cap. bank if I create one. Also, if there are any power supplies under $75 at the most that are like this, please direct me where to get one. This is for science purposes, not to cause any kind of harm or anything like that. Lastly, I would like to know if there is just an IC that reverses polarity, and if I could just use that and a boost converter.