The design of the new Antiproton Decelerator (AD) at CERN will allow t
he easy measurement of the energy deposit of the antiproton-proton ann
ihilation remnants within a hydrogen plasma. For this purpose, a react
ion chamber filled with gaseous hydrogen is put into the beam line. Th
e antiprotons coming directly from the AD at 7 MeV/c or from a Penning
trap are injected into the chamber through a window in such a way, th
at they come to rest at the center of the chamber, where annihilation
occurs. The resulting high energy annihilation products are trapped in
the chamber using a pulsed magnetic bottle. The energy deposit in the
hydrogen gas can then be measured using Schlieren optics or an interf
erometric set-up, by determining the density changes due to the temper
ature rise within the gas.