Tachyonic Particle Cores Edit
The Tachyonic Particle Core is used to craft Tachyon Prototype and Tachyon Device. To find one, you must navigate the Quantum Realm to a yellow sphere. Once you reach the sphere, dig down to the middle to obtain the core.
How to Reach the Quantum Realm Edit
To get to the Quantum Realm, you must use Atom or Ant Man to shrink down and wait till the green bar above your inventory diminishes completely. Around the red level, you will get a warning, and about 2 seconds after the warning you will be transported to the Quantum Realm.
WARNING: As Atom, make SURE you hit Right Shift before your journey to close your mask. Failure to do so will eventually suffocate you when you reach the Quantum Realm, losing your items in the process.