Positron beams brightness enhanced

Fig. 1.10. The fully electrostatic high-brightness positron beam developed by the Brandeis group. The positron Soa gun is located near B. The beam is deflected at C using a cylindrical mirror analyser and focussed onto a remoderator in chamber D. The extracted beam is then focussed and remoderated at the lower left of D. The double brightness-enhanced beam is then transported into the target chamber, E. Reprinted from Nucl. Instrum. Methods B143, Charlton, Review of Positron Physics, 11-20, copyright 1998, with permission from Elsevier Science.

Mills (1984) pointed out that it might soon be experimentally feasible to realize systems containing positrons which overlapped one with another, both spatially and temporally. This was due to the production of time-focussed beams and the prospects (since demonstrated) for brightness-enhanced, highly focussed beams. 

Fig. 8.6. Schematic of a proposed configuration for the production of conditions for Bose-Einstein condensation of positronium using a pulsed, brightness-enhanced positron beam (see text for details). Reprinted from Physical Review B 49, Platzman and Mills, Possibilities for Bose condensation of positronium, 454-458, copyright 1994 by the American Physical Society.

Mills Jr., A.P. (1980). Brightness enhancement of slow positron beams. Appl. Phys. 23 189-191. 

If sufficient positrons can be confined, studies of particle transport within the plasma, etc., similar to those conducted with electrons can be carried out. It may be possible to use the enhanced detection possibilities afforded since positron-electron annihilations can be detected. An ultra-cold source of positrons would also have a variety of other applications.24 For example, it has been proposed to eject trapped positrons into a plasma as a diagnostic.25 Also, positrons initially in thermal equilibrium at 4.2K within a trap would form a pulsed positron beam of high brightness when accelerated out of the trap. 

Brightness enhancement is achieved in positron beams by repeated... 

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