Direct measurements of the stopping power for antiprotons of light and heavy targets

S. P. Møller, E. Uggerhøj, H. Bluhme, H. Knudsen, U. Mikkelsen, K. Paludan, E. Morenzoni

Research output: Contribution to journalArticle

67 Citations (Scopus)


Measurements of antiproton stopping powers around the stopping-power maximum are presented for targets of Al, Si, Ti, Cu, Ag, Ta, Pt, and Au. The Low Energy Antiproton Ring antiproton beam of 5.9 MeV is degraded to 50–700 keV, and the energy loss is found by measuring the antiproton velocity before and after the target. Target thicknesses have been determined accurately by weighing and Rutherford backscattering techniques. The antiproton stopping powers are found to be reduced by around 35% for both light and heavy elements near the electronic stopping-power maximum as compared to the equivalent proton stopping power. The antiproton stopping powers and the Barkas effect; that is, the difference in stopping power between protons and antiprotons is compared to theoretical estimates, based on a harmonic-oscillator model and an electron-gas model, and good agreement is obtained.

Original languageEnglish
Pages (from-to)2930-2939
Number of pages10
JournalPhysical Review A - Atomic, Molecular, and Optical Physics
Issue number4
Publication statusPublished - Jan 1 1997


ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this