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arXiv · 0704.1118

Observation of Anti-correlation between Scintillation and Ionization for MeV Gamma-Rays in Liquid Xenon

Abstract

A strong anti-correlation between ionization and scintillation signals produced by MeV gamma-rays in liquid xenon has been measured and used to improve the energy resolution by combining the two signals. The improvement is explained by reduced electron-ion recombination fluctuations of the combined signal compared to fluctuations of the individual signals. Simultaneous measurements of ionization and scintillation signals were carried out with Cs-137, Na-22 and Co-60 gamma rays, as a function of electric field in the liquid. A resolution of 1.7%(sigma) at 662 keV was measured at 1 kV/cm, significantly better than the resolution from either scintillation or ionization alone. A detailed analysis indicates that further improvement to less than 1%(sigma) is possible with higher light collection efficiency and lower electronic noise.

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E. Aprile, K. L. Giboni, P. Majewski, K. Ni, M. Yamashita. 2007-04-09. Observation of Anti-correlation between Scintillation and Ionization for MeV Gamma-Rays in Liquid Xenon. https://doi.org/10.1103/physrevb.76.014115

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