This invention relates to apparatus for detecting {TAIL ~ charged particles} and in particular to {HEAD ~ apparatus} for detecting charged particles in a gaseous environment 
This invention relates to apparatus for detecting { TAIL ~ charged particles } and in particular to { HEAD ~ apparatus } for detecting charged particles in a gaseous environment
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH