Transport beam line for ultraslow monoenergetic antiprotons

A beam line for the transportation of slow antiprotons from a multiring electrode trap to an experimental chamber is described. The beam line is equipped with a three-stage differential pumping system in order to maintain a pressure lower than 1×10−12 Torr in the trap region while simultaneously having a pressure of around 1×10−6 Torr in the chamber. Tests have shown that 105 positive ions per trapping cycle were successfully extracted at 250 eV from the trap positioned in a superconducting solenoid. The ions were then further transported through three small apertures to the target area located 3.5 m downstream of the trap. Results from the first delivery of a 250 eV antiproton beam are described.