Measurements of x-rays from antiprotonic helium

The absolute yields of X-rays from p̄He atoms for 14 transitions covering the L, M and N series have been measured at target gas densities of 0.125, 0.25, 0.92, 1.0, 1.23, 2.0, 3.0 and 10.0ϱSTP and compared with the predictions of cascade calculations. The strong interaction width of the 3d state, has been determined to be 2.07 ± 0.11 meV.