Fast radiochemical extraction of carbon in photoactivation analysis of pure boron

Abstract

Special fast procedure for radiochemical extraction of carbon impurities from boron samples was developed. The procedure consists of alloying the sample in a mixture of KNO3 +KOH at 600 ~ dissolving of the cooled melt in water, and subsequent distillation of CO2 from the boiling acidic solution of HNO3. Time span of the whole procedure equals 25 min and provides more than one thousand-fold extraction of initial carbon impurity from the boron sample. Kinetics of the carbon extraction was measured with carbon-11 radiotracers which were induced in the investigated samples by the irradiation with 26 MeV bremsstrahlung. IntroductionBeginning with the pioneering works on the parity non-conservation in weak interactions, the problem of possible small violations of the fundamental physical principles has been constantly drawing much attention. Physicists have analyzed possible non-conservation of the electric charge, the CPT violation and Lorentz invariance. The problem under consideration was stimulated by the investigation of a possible violation of the Pauli exclusion principle [1].The exclusion principle declares that two or more fermions cannot exist in the same quantum state. In the simplest case, the violation of the Pauli principle in an atom leads to a transition of a valent electron to low-lying atomic shell that is favourable from the point of view of energy. The transition ofa valent electron from outer to inner shell means that such anomalous atom with atomic number Z will chemically behaves as an element with atomic number Z-1. This is a consequence of a general statement that elements with similar structures of outer electron shells have similar chemical properties. Therefore, if a violation of the Pauli exclusion principle does take place, an accumulation of anomalous atoms proceeds during the whole period of nucleosynthesis, and impurity of the anomalous atoms Z can be now found in nature in a chemical compounds of the element Z-1.The concentration of anomalous atoms in the host matter is maximized when the cosmic abundance of the mother element, Z+I, is large while that of element Z is small.On the basis of this arguments Novikov and Pomansky [2] pointed out that the most promising pair of atoms for such a type of an experiment is the pair carbon-boron because the carbon abundance in the Solar system is about six orders of magnitude higher than that of boron.