A while ago I decide to try to make a simple demo of particle accelerator, and I finally managed to do it. In this Instructable I will show you step by step how to make it.

Before we start, let me explain briefly how particle accelerators work and what is the role of electric and magnetic filed in them.

Particle accelerators use electric fields to speed up and increase the energy of a beam of particles, which are steered and focused by magnetic fields. The particle source (hydrogen gas for example) provides charged particles (protons or electrons), that can be accelerated. The beam of particles travels inside a vacuum in the metal beam pipe. The vacuum is crucial to maintaining an air and dust free environment for the beam of particles to travel unobstructed. Electromagnets are used to steer and focus the beam of particles while it travels through the vacuum tube and collide them at designated detector.

In other words the electric field is used to accelerate particles (speed them up) and magnetic field is used to bend and steer them. It is worth mentioning that for the accelerators to work the particles must have an electric charge (positive or negative). Neutron for example, don’t have an electric charge therefore they can’t be accelerated by electric filed.

My simple demo accelerator works slightly differently. As it is difficulty to produce charged particles out of hydrogen gas at home, I decided to try slightly different approach. Instead of charged particle I used magnetic ball bearing and instead of electric filed I used electronic circuit to vary the magnetic filed produced by two coils. Once the electronics is switched on, the magnetic ball bearing will start moving inside circular track and accelerating it until it finds an equilibrium. At that point magnetic sphere will move with constant speed.

Supplies:
- 1x 9V battery with battery clip
- 8mm magnetic sphere (10mm is fine if you scale 3D model model by 10%)
- 25 SWG enameled copper wire
- 1x 1000uF electrolytic capacitor
- 1x 1MOhm potentiometer
- 2x 100kOhm resistors
- 1 x 100Ohm resistor
- 1 x 1kOhm resistor
- 1 x 12kOhm resistor
- BC558 PNP transistor
- BC337 NPN transistor
- BD135 NPN transistor
- 1x 3mm Red LED
- 1x PCB on/off switch
- Prototyping strip board (PCB for etching is optional)
- PLA (3d printing material)
- 2x M3 x 15mm screw with nut
- Equipment wire
- Solder
Tools:
- Wire strippers/cutters
- Soldering iron
- FDM 3D printer”