Spontaneous Emission of Positronium Negative Ions from Tungsten (100) Surface
Recently, we have observed spontaneous emission of positronium negative ions from polycrystalline tungsten surface. In the present work, we have extended the study to the emission from tungsten single crystal. The emission from tungsten (100) surface plane has been confirmed. The fraction of positrons yielding the ions at the target surface was ()4102.02.1−×±.
S. J. Wang, Z. Q. Chen, B. Wang and Y. C. Jean
Y. Nagashima et al., "Spontaneous Emission of Positronium Negative Ions from Tungsten (100) Surface", Materials Science Forum, Vol. 607, pp. 161-165, 2009