EXTREMELY COLD ANTIPROTONS FOR ANTIHYDROGEN PRODUCTION

The possibility to produce, trap and study antihydrogen atoms rests up on the recent availability of extremely cold antiprotons in a Penning trap. Over the last five years, our TRAP Collaboration has slowed, coo led and stored antiprotons at energies 10(10) lower than was previousl y possible. The storage time exceeds 3.4 months despite the extremely low energy, which corresponds to 4.2 K in temperature units. The first example of measurements which become possible with extremely cold ant iprotons is a comparison of the antiproton inertial masses which shows they are the same to a fractional accuracy of 4 x 10(-8). (This is 10 00 times more accurate than previous comparisons and large additional increases in accuracy are anticipated.) To increase the number of trap ped antiprotons available for antihydrogen production, we have demonst rated that we can accumulate or ''stack'' antiprotons cooled from succ essive pulsed injections into our trap.