A spectrometer for the study of angular correlations in polarized-orthopositronium decay
- 33 Downloads
We describe a setup for experimental testing of the CPT-invariance by observing the angular correlations in the decay of polarized orthopositronium atoms. Annihilation events are detected by five NaI(T1) sensors of 150-mm diameter and 100-mm thickness, located at the vertices of a regular pentagon. The sensor signals are detected in the double-coincidence circuits gated by signals with different time delays from the positron escape. The setup has a time resolution of 8.0 ns. In order to reduce the effect of the long-term instability and the instrumental asymmetry on the experimental results, the direction of positron incidence on a SiO2 target was reversed with a program-driven period during data acquisition. The value of the asymmetry, measured with due account of statistical and systematic errors, is 0.0008±0.00091, which is twice better as compared with the previous experiment.
KeywordsCount Rate Angular Correlation Background Count Rate Gate Signal Positron Source
Unable to display preview. Download preview PDF.
- 3.Gol'danskii, V.I.,Fizicheskaya khimiya pozitrona i pozitroniya (Physical Chemistry of Positron and Positronium), Moscow: Nauka, 1968.Google Scholar
- 4.Berestov, A.V. and Zyazyulya, F.E.,Prib. Tekh. Eksp., 1983, no. 5, p. 47.Google Scholar
- 5.Aleksandrov, A.A., Mokrousov, V.A., and Pyatkov, Yu.V.,Prib. Tekh. Eksp., 1982, no. 4, p. 122.Google Scholar
- 6.Abdurasulev, Z.R., Arifov, P.U., Arutyunov, N.Yu.,et al., Metody pozitronnoi diagnostiki i rasshifrovki spektrov annigilyatsii pozitronov (Methods of Positron Diagnostics and Identification of Positron Annihilation Spectra), Tashkent: Izd. FAN, 1985.Google Scholar
- 8.Brandt, W. and Dupasquier, A.,Positron Solid-State Physics, Amsterdam: North-Holland, 1983.Google Scholar