A still further advantage of my invention is that the radioactive gas completely surrounds the phosphor particles, thus causing {TAIL ~ light emission} from {HEAD ~ 100 percent} of the surface of said particles 
A still further advantage of my invention is that the radioactive gas completely surrounds the phosphor particles , thus causing { TAIL ~ light emission } from { HEAD ~ 100 percent } of the surface of said particles
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH