QUALITY FACTOR The linear-energy-transfer -dependent factor by which absorbed dose is multiplied to obtain dose equivalent . IUPAC82.
QUALITY OF RADIATION Penetration of radiation: frequently measured by its half-value layer, the thickness of some standard material which transmits 50% of the incident radiation. NM.
QUANTUM YIELD The number of moles transformed in a specified process, physically (e.g., by emission of photons) or chemically, per mole of photons absorbed by the system. C.
QUENCHING 1. The process of inhibiting continuous or multiple discharges following a single ionizing event in certain types of radiation detectors), particularly in (Geiger-Müller counter tubes . 2. The deactivation of an electronically excited state by non-radiative process, e.g., as a source of error when using liquid scintillation detectors . 3. The shortening of the lifetime of positronium by its interaction with other species. IUPAC94, partial.
QUENCHING CORRECTION Correction for errors due to different quenching for standards and test portions. When using liquid scintillation detectors , these corrections can be based on the standard addition or sample channels ratio method, or the use of automated external standardization. IUPAC94.
Q-VALUE In a nuclear transformation, the energy equivalent of the difference in atomic masses between the reactants and products, all in their nuclear ground states.
Qo-VALUE The ratio of resonance integral to thermal cross section in activation analysis .