Atom Smasher

Can you build an atom smasher out of household materials? -Cosmic Cat

Short answer: No.

Long answer:

In a way, you already probably have one in your house. The cathode ray tubes found in televisions and computers use electromagnets to smash electrons into phosphors.[1] But this is another
case where the easiest solution is boring. And we wanted to build an atom smasher out of household materials, not find one in the house.

There are two types of atom smashers (linear and circular; the names are pretty self-explanatory), and both contain a laundry list of parts. They are: electromagnets, which keep the flying particles on the right path; targets, which the flying particles collide with; detectors (self-explanatory); vacuum systems, which keep the atom smasher clean of air; cooling systems (self-explanatory); computers to analyze data, a monitoring system for safety (safety, schmafety), electrical power for the atom smasher; copper tubes for the particles to fly down; klystrons, which are powerful microwave generators; and storage rings to store particles when they're not being used. Oh and, protective shielding so that you won't be killed by deadly radiation. If you forget that, you could have a minor problem on your hands.[2]

The first part of this would be to see if we can buy or build the parts at a reasonable price. Let's start with the particle generator part. The SLAC particle accelerator fires an electron beam at tungsten. I was surprised to learn that you can actually generate an electron beam with a cathode ray tube.[3]
You may not have tungsten in the house, but you can buy it in the form of tungsten shot or welding electrodes (look for ones with green tips), according to Theorore Gray's book The Elements. This will generate positron-electron pairs. Copper tube can be found at hardware stores and it isn't illegal to possess.^{[citation needed]} The problem is that you'll need several miles of it, but with enough money you could probably get that. Next up is a klystron, a microwave generator a million times as powerful
as a microwave oven.[4] I thought this would be impossible to get, but it turns out you can buy them on ebay for a few hundred to a few thousand dollars.[5] You can get a lot of stuff on ebay. Next step: magnets. They are fairly common^{[citation needed]}, so it's probably possible to buy sufficiently powerful ones. Targets can vary, but the simplest ones are probably thin sheets of metal foil. Go look in the kitchen and you'll probably find some. Still stuck? Or, if you insist, you can try gold foil. Detectors are where we get stuck. One typical detector is described as a "barrel-shaped, solid-state detector that stands more than six stories tall and weighs more than 4,000 tons". I don't typically gamble, but I'd gladly bet any amount of money that one of these won't be found in the typical home. Or hardware store. Or ebay.

Sorry.