Liquid scintillation analysis: principles and practice

The chapter begins with a treatment of the basic theory of liquid scintillation and the interactions of alpha-, beta-, and gamma rays in liquid scintillator. Basic design and concepts of operation of a liquid scintillation counter are described. This is followed by a comprehensive treatment of quench effects and the methods of quench correction in liquid scintillation counting (LSC). A detailed treatment of the preparation and use of quenched standards and quench correction curves is provided. A discussion of direct DPM methods is also included. This is followed with a treatment on the analysis of X-ray, gamma-ray, Auger electron, and positron-emitters by LSC. A detailed discussion of the interferences encountered in LSC, including background, quench, radionuclide mixtures, luminescence, static, and wall effects, and methods for their correction is presented. The chapter continues with a treatment on the LSC of dual- and triple-radionuclide analysis techniques and the analysis of more complex mixtures by spectral fitting, unfolding and interpolation techniques. A detailed discussion of radionuclide standardization by the CIEMAT/NIST efficiency tracing and the triple-to-double coincidence ratio (TDCR) methods is provided. Neutron/gamma-ray measurement and discrimination by LSC is discussed. The use of LSC for the detection and measurement of double beta (ββ) decay is provided. A treatment of LSC schemes for the detection and measurement of neutrinos is provided. Other liquid scintillation methods, which are discussed are microplate scintillation and luminescence counting, PERALS and liquid scintillation α-spectrometry with LAAPD, and simultaneous α/β analysis. Other methods described are the use of plastic scintillators in LSC, scintillation counting in noble liquids, radionuclide identification by LSC, and air luminescence counting. The chapter concludes with a treatment about the assessment of liquid scintillation counter performance and optimization.