S Do ~~t retur n this copy. * tsin or destroy .• .~~~~~~~~. . o closed-loop CCD structure s , a 256-stage and a 1024-sta ge devices wer . designed fabricat ed , and operated to dun onstr at . a low-loss mod. of operation for a very long CCD delay line or a closed-loop CCD structure.The low-loss CCD concept consists of operati ng a CCD with each signal charge well followed by one or more trailing-bias-charge wells. Two orders of magnitude improv . nt in the effective trans fer losses were desonstrated sxp.rim.ntally by periodical ly recombining at a signal-regeneration stags the (first-order) signal-charge -~~