| Acronym | Meaning |
| FSR | Free Spectral Range |
| APD | Avalanche Photodiode |
| TRESR | Time-resolved Electron Spin Resonance |
| FCCU | Fluidized Catalytic Cracking Unit |
| ICRH | Ion Cyclotron Resonance Heating |
| RQDO | Relativistic Quantum Defect Orbital (method In Calcns. Of Oscillator Strengths) |
| LISA | Laser Interferometer Space Antenna |
| TDTF | Time-dependent Thomas-Fermi |
| SIDP | Sputter Ion Depth Profiling |
| MALDI | Matrix-Assisted Laser Desorption Ionization |