Display MoreYou're spot on!
These thoughts troubled me as well, here's how I explained it to myself:
"As far as I understand there is no dielectric surface in Egely's device." --> There is 0.5bar of H2 gas and/or water vapor. Water has one of the highest dielectric constants out there (asymmetry of molecule).
"Ken Shoulders' texts show diagrams where there is that component also." --> yes, but it's not mandatory for the formation of CPs, it helps fuel the CP?
"And where is the magnetic field in Egely's device ? The discharge current creates of course magnetic field but as far as I understand it's perpendicular instead of parallel to the plasmoid."
--> I think Egely's "deceptively simple looking" device has some tricks up it's sleeve. Here is what I think happens (disclaimer - nobody reviewed it, it might be very very wrong):
1. In the relaxation oscillator circuit you charge up capacitor C1, and inadvertently charge up capacitor C2 - formed by 2 electrodes, distance d and low pressure gas as dielectric. Charges accumulate to electrode tip, electric field E builds up.
This kind of very fast capacitance discharges is also present in Correa devices