YOUNG-TYPE INTERFERENCE WITH SINGLE ELECTRONS IN THE AUTOIONIZATION OF ATOMS BY THE IMPACT OF MOLECULES: AN INDEPENDENT MEASUREMENT IN THE BACKWARD DIRECTION

S. SUÁREZ; D. FREGENAL; G. BERNARDI; P. FOCKE; F. FRÉMONT; J.-Y. CHESNEL; A. HAJAJI; R. O. BARRACHINA

CLUJ-NAPOCA, ROMANIA

Conferencia; 4th CONFERENCE ON ELEMENTARY PROCESSES IN ATOMIC SYSTEMS; 2008

In a recent article [1] we provided an unprecedented experimental evidence of a singleelectron interfering with itself in a set-up that was analogous to an atomic-size double-slitapparatus [2]. In that version of the famous gedanken experiment proposed by Feynmanin 1963 [3] to illustrate the wave-like nature of matter, the electron originates from theautoionization of a doubly-excited helium atom following a double capture process in a30 keV He2+ + H2 collision. The autoionizing He atom plays the role of a single-electronsource, that is independent of the two-center target interferometer. In that experiment,performed at GANIL (Grand Accélérateur National d’Ions Lourds), in Caen (France),at least three distinctive oscillations were observed in the angular distribution of theelectron emission cross section, in a range from 95 to 160 degrees. Here, we report the firstresults of an independent measurement performed at the Cockroft–Walton acceleratorof the Centro Atómico Bariloche, with 40 keV He2+ projectiles. The electron emissionwas observed from 155 to 180 degrees, overlapping with the previous experiment in asmall region of angles and extending its range all the way to the backward direction.The H2 gas target was provided by a needle of 0.3 mm bore located at the focus of thecylindrical mirror electron spectrometer [4] to reduce partially the extended gas targeteffect and increase the counting rate. The results are consistent with the oscillationsobserved with the Caen equipment. The prominent increase of the electron intensity at180 degrees, despite of no corrections due to gas target extension, can be ascribed to abackward Glory effect.