Observation of a Peak Structure in Positron Spectra from U+Cm Collisions

J. Schweppe; A. Gruppe; K. Bethge; H. Bokemeyer; T. Cowan; H. Folger; J. S. Greenberg; H. Grein; S. Ito; R. Schule; D. Schwalm; K. E. Stiebing; N. Trautmann; P. Vincent; M. Waldschmidt

doi:10.1103/PhysRevLett.51.2261

Observation of a Peak Structure in Positron Spectra from U+Cm Collisions

J. Schweppe, A. Gruppe, K. Bethge, H. Bokemeyer, T. Cowan, H. Folger, J. S. Greenberg, H. Grein, S. Ito, R. Schule, D. Schwalm, K. E. Stiebing, N. Trautmann, P. Vincent, and M. Waldschmidt

Phys. Rev. Lett. 51, 2261 – Published 19 December 1983

Abstract

A narrow peak structure has been observed in positron spectra from U+Cm collisions at bombarding energies near the Coulomb barrier whose origin cannot be associated with established dynamic mechanisms of positron production involving Rutherford trajectories only. The peak's energy is centered at 316±10 keV. Its width of ∼ 80 keV, dominated by Doppler broadening, implies that the emitting system exists for longer than ∼ $10^{- 20}$ sec.

Received 8 November 1983

DOI:https://doi.org/10.1103/PhysRevLett.51.2261

Authors & Affiliations

J. Schweppe, A. Gruppe, K. Bethge, H. Bokemeyer, T. Cowan, H. Folger, J. S. Greenberg, H. Grein, S. Ito, R. Schule, D. Schwalm, K. E. Stiebing, N. Trautmann, P. Vincent, and M. Waldschmidt

Gesellschaft für Schwerionenforschung, D-6100 Darmstadt, Federal Republic of Germany, and A. W. Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06511, and University of Frankfurt, D-6000 Frankfurt am Main, Federal Republic of Germany, and University of Heidelberg, D-6900 Heidelberg, Federal Republic of Germany, and Rutgers, The State University, New Brunswick, New Jersey 08903, and University of Mainz, D-6500 Mainz, Federal Republic of Germany