真空电子偶素原子的产生

PRODUCTION OF VACUUM POSITRONIUM ATOMS

用慢正电子束入射固体靶表面,通过测量湮没光子能谱随靶温度和入射慢正电子能量的变化,用“峰法”确定慢正电子产生电子偶素原子的转换率。转换率依赖于靶材料、靶温度和入射慢正电子能量。对材料锗转换率可达80％。

Positronium atoms are formed efficiently by slow positron beam hitting a solid target surface in vacuum. The fraction of positrons which formed positroniums is determined by applying the 'peak method' to the energy spectra of the positron annihilation radiation measured at different target temperatures and incident positron energies. The fraction is dependent on the target material, temperature and incident positron energy. For germanium, the fraction is as high as 80%.