Hi! I'm ZxWhatever (Short for Zxblqcktptydfkjsplkn, my username elsewhere). This is my first post here. I'm going in to high school next year, and physics has always fascinated me, specifically quantum physics. You may think this is WAY to early to be thinking about a science fair, but I want to get my project done early this year. I have never won any sort of award at any science fair. The judging in my district is done by parents, stupidly. I had done several projects that I considered excellent, but I think dying Barbie's hair with different dyes, including soy sauce, and seeing which lasted the longest was more impressive. Sadly, this was an actual winning project, from the seventh grade. Well, physics is my best area of science, and science is my best area in school, so I knew that project was garbage. However, my project simply didn't have the wow factor required. I was doing some reading on Wikipedia (Please don't tell me it's a bad resource. I know I should never use information from it, so this was for my own interest.), and I came across a page on Quantum Key Distribution. I was intrigued, so I did some more research. I finally decided I want to do a project on it. It seemed like, if I could pull it off, a demonstration of QKD would be a great, possibly winning project. The problem is, I need a very low-intensity source of photons. I was thinking of using a very small amount of a positron emitter such as cesium. The annihilation of electrons and positrons would release small amounts of light, which could be polarized and used to demonstrate QKD. However, I am afraid that I won't be allowed to have even the milligram or less this would require because people would be terrified of even a micro-curie source of radiation, and would not even the tiniest bit of antimatter into the hands of a minor. Even though the computer I'm typing this on is almost certainly more radioactive than the source I would require, I doubt I would be allowed to have any material labelled "Radioactive." After doing more research, I discovered that commercial QKD uses an extremely low-intensity laser, but I couldn't find where to buy one. I have two questions for you. First, where can I get an extremely low-intensity laser? It needs to emit one or two photons in bursts I can control, and can't cost more than about $150, as that's my budget. Second, if the answer to my first question is it is impractical or impossible to get one in that price range, how can I get a positron emitter? Do I need some sort of license? Where would I buy it? I have parental permission, will be supervised by an adult (an adult with a PHD in particle physics, no less), and will keep the thing encased in lead, if required. Third, is there any other low-intensity source of photons I can use? I want to go with the most cost-effective, least objectionable option, so if there are any other options, I'd like to know. If you need any other information, just ask. I'm sorry if this is poorly written, poorly edited, and rambling, but it's late and I'm going to bed. I don't care to stay up any later that I have to to write this. Thanks for reading!