Simplified coaxial ion trap: Simulation-based geometry optimization, unidirectional ejection, and trapping conditions - ScienceDirect
The Coax trap program computes design parameters for the construction of coaxial traps for HF usage. Typically these are constructed from PVC tube and RG58/59 coax
Coax Trap
Bootstrap coax traps for antennas
antenna - What is an expected SWR plot for a trap dipole? - Amateur Radio Stack Exchange