The virtual cathode as a transient double sheath

摘要

The twohyphen;dimensional plasma potential measurements are given of a spacehyphen;charge dominated double sheath near a hot cathode. Laboratory data show that a virtual cathode is a selfhyphen;consistent solution only for a transient cathodehyphen;plasma system. Slow charge exchange ions get trapped in the potential dip that forms the virtual cathode and eventually destroy it.