Antiproton X-ray Spectroscopy in the Cyclotron Trap: Preliminary Results

Abstract

The principle of the experiment designed to measure the X-ray spectrum of protonium was verified by the Karlsruhe group* during the December, 1983 run at LEAR. The experiment relies on the cyclotron trap, whose characteristics are summarized in the discussion of its application to neutral current experiments in muonic atoms¹ and in contributions to previous ERICE proceedings^{2, 3}. The cyclotron trap yields high stopping densities at low gas pressures. During the December run, about 15% of the beam of antiprotons at 300 MeV/c could be accepted by the trap at pressures between 4 00 and 600 mbar. A stopping density of 2 · 10⁵ antiprotons per gram per second was achieved. This density represents an increase by a factor of almost 300 compared to alternative techniques for stopping antiprotons in gases.