Ultra-high sensitive study of the identity of β-rays with atomic electrons

• Published in: Physics letters. B 1990-12, Vol.252 (2), p.301-302
• Main Authors: Tang, X.W., Wu, Y.G., Zhang, S., Chen, Q.W., Xie, X.Q.
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; Physics; Statistical physics, thermodynamics, and nonlinear dynamical systems
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/0370-2693(90)90876-8

Goldhaber and Scharff-Goldhaber have carried out an experiment studying the nature of β-rays emitted by the radioactive nucleus which was based on the Pauli exclusion principle. Davies and Grace have repeated that experiment and reported that less than one captured X-ray was observed for 4 × 10 5 β-rays. But the sensitivities of these experiments were low. The development of experimental techniques including a strong β-ray source and a high resolution X-ray detector enables us to perform an ultra-high sensitive experiment to test the identity of β-rays with atomic electrons. Here we report our experimental result which shows that less than 1.4 × 10 −13 (95% confidence level) of the tritium β-rays stopped in the erbium target are captured into the K shell of these atoms. This limit is about seven orders of magnitude lower than the previous experiment.